TECHNICAL FIELD
[0001] The invention provides a cleaning additive and a cleaning method using the same,
for cleaning glass bottles in a primary caustic tank and a secondary caustic tank,
which enables a stable and good cleaning effect at a relatively low temperature.
BACKGROUND ART
[0002] In cleaning technologies used for industrial purposes, the selection and treatment
processes of cleaning agents are varied respectively for different objects to be cleaned,
such as glass bottles, metal containers, plastic cans or rubbers, due to different
materials, shapes and different physical and chemical properties of the containers.
[0003] CIP (also known as Clean In Place) commonly used in the cleaning industry is a safe
and automatic cleaning system, and has been widely used in the advanced food, sanitary
and pharmaceutical industries. CIP is generally used in the cleaning of large equipment,
systems and devices, and is not suitable for the cleaning of small objects, such as
glass bottles.
[0004] Recycled glass bottles are usually cleaned by a bottle cleaning machine with an industrial
cleaning temperature generally set at 80°C-90°C and a cleaning rate of 24,000-40,000
bottles per hour. The selection of a cleaning agent has a relatively large influence
on the cleaning effect and the cleaning rate. There are a variety of cleaning agents
(mainly acids and alkalis) used in the food industry, among which sodium hydroxide
and nitric acid are most widely used. In the glass bottle cleaning industry, alkaline
cleaning in a caustic tank is generally adopted, with addition of a cleaning additive
during the alkaline cleaning process, so as to improve the cleaning effect.
[0005] Currently, glass bottle cleaning additives include chelating agents and surfactants.
The chelating agents mainly include ethylenediaminetetraacetic acid (EDTA), sodium
gluconate, gluconic acid, citric acid, lactic acid, sodium phosphate, sodium tripolyphosphate,
sodium pyrophosphate, organic phosphine, etc., which are generally used alone or in
combination. The surfactants usually are used as nonionic surfactants and antifoaming
agents, etc..
[0006] The key of glass bottle cleaning technologies lies in the thorough removal of labels
at the outside of a bottle and removing dirt inside and outside the bottle. The degree
of difficulty of the label removal depends largely on the types of glue used during
labeling and the degree of weathering of the label. The dirt of glass bottles mainly
includes two types of dirt, namely mildew stains, and mud and clay. The mildew stains,
mud and clay become very dry in the air, such that they are firmly adhered to the
glass bottle, and the mouth of a glass bottle is usually smaller than that of a common
container, so that the dirt inside the bottle is very difficult to be removed.
[0007] Generally, repeated cleaning by a cleaning equipment, or manually repeated rinsing,
or an elevated cleaning temperature, is required to realize a good cleaning effect.
Generally, when the cleaning temperature is increased by every 10°C, the chemical
reaction rate will be increased by 1.5-2.0 times, and the cleaning rate is also increased
correspondingly, with a good cleaning effect.
[0008] Although the increase of the cleaning temperature helps to shorten the cleaning time,
or reduce the concentration of a cleaning agent, the energy consumption will be increased
correspondingly. Although it is theoretically considered that mould is dried at 82°C,
resulting in more difficult removal of the dried dirt, it is actually found in practice
of cleaning that the cleaning effect will be better by increasing the temperature,
even at 90°C. Therefore, the temperature increase is generally adopted in the cleaning
industry to enhance the cleaning effect, and in order to remove carbohydrates, proteins,
hard dirt and other contaminants which are difficult to be removed, on a glass surface,
the cleaning temperature is generally set at 80°C-90°C, and not lower than 60°C even
in special circumstances. However, cleaning at a high temperature results in not only
high energy consumption and high cost, but also has many potential safety hazards,
increasing the operational risk for operators, and making the working environment
severe.
[0009] To overcome the above disadvantages in the prior art, the invention provides, specially
for the cleaning of glass bottles, a novel cleaning additive and a corresponding glass
bottle cleaning method, which are particularly suitably for an caustic solution cleaning
environment, and achieve the same or better cleaning effect at a relatively low temperature,
thus saving energy and reducing the production cost.
SUMMARY OF THE INVENTION
[0010] The present invention provides a glass bottle cleaning technology for use in a caustic
cleaning environment, and by using the novel cleaning additive and cleaning method
of the present invention, the glass bottle cleaning temperature can be reduced to
50°C-70°C, with the same or better cleaning effect, so as to improve the productivity
and save energy.
[0011] In one aspect, the present invention provides a glass bottle cleaning additive for
use in the treatment of cleaning glass bottles in a primary caustic tank and a secondary
caustic tank, said cleaning additive consisting of a component A, a component B and
a component C, wherein,
the component A contains an organic phosphine chelating agent,
the component B contains a peroxide, and
the component C contains an antifoaming agent,
the component A is added in the primary caustic tank, the component B is selectively
added in the primary caustic tank, the component A and the component B are added in
the secondary caustic tank, and the component C is selectively added in the primary
caustic tank or the secondary caustic tank.
[0012] The organic phosphine chelating agent includes, but not limited to, amino trimethylene
phosphonic acid (ATMP), 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP), ethylene
diamine tetra(methylene phosphonic acid) sodium (EDTMPS), ethylene diamine tetra(methylene
phosphonic acid) (EDTMPA), diethylene triamine penta(methylene phosphonic acid) (DTPMPA),
2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA), polyhydric alcohol phosphate ester
(PAPE), 2-hydroxy phosphonoacetic acid (HPAA), hexamethylene diamine tetra(methylene
phosphonic acid) (HDTMPA), polyamino polyether methylene phosphonate (PAPEMP), and
bis(hexamethylene triamine penta(methylene phosphonic acid)) (BHMTPMPA).
[0013] The organic phosphine chelating agent has the effect of peeling off viscous dirt,
and can highly intensively penetrate and disperse mould, mud and clay on glass bottles,
so as to effectively remove them. In addition, the organic phosphine chelating agent
contained in the cleaning additive of the present invention is non-toxic to human
body, promotes the dissolution of dirt, has low corrosion to equipment, and has good
dirt inhibition performance.
[0014] The component A may also comprise any one or a mixture of two or more of gluconate,
gluconic acid, lactic acid, and citric acid, preferably comprising sodium gluconate
or gluconic acid.
[0015] Generally, the organic phosphine chelating agent is used to dissolve and disperse
dirt on glass bottles, and has strong dispersion and dissolution effects to mould,
mud and clay on glass bottles in a caustic environment, but has weak complexing power
for metal ions, such as calcium, magnesium, iron ions etc.; however, gluconate, gluconic
acid, lactic acid, citric acid or a mixture thereof is per se a chelating agent, has
relatively strong complexing power for calcium, magnesium and iron salts, but has
low removing power for other dirt. After adding a component such as gluconate or gluconic
acid, the overall chelating effect of the component A is significantly enhanced. Therefore,
when treating severely polluted glass bottles, any one or a mixture of two or more
of gluconate, gluconic acid, lactic acid, and citric acid can be selectively added
in the component A.
[0016] The present invention also comprises a component B containing a peroxide, and said
peroxide comprises, but not limited to, one or any combination of hydrogen peroxide,
sodium peroxide, sodium percarbonate, sodium perborate, magnesium peroxide, calcium
peroxide, barium peroxide, potassium peroxide, chlorine dioxide, peracetic acid, peroctanoic
acid and ozone water. Said peroxide is preferably one or any combination of sodium
percarbonate, sodium perborate and hydrogen peroxide. Alternatively, said peroxide
is preferably one or any combination of magnesium peroxide, calcium peroxide and barium
peroxide.
[0017] In the food industry, peroxides are usually used for food sterilization and disinfection,
but have never been used as a cleaning additive for glass bottles. The present inventor
found that, in a glass bottle cleaning process, the use of peroxides as part of a
cleaning additive formulation in combination with other formulations can synergistically
achieve a good cleaning effect.
[0018] Generally, the mouth of a glass bottle is relatively small, so it is difficult to
obtain a mechanical force for effective stirring inside the bottle to remove dirt,
and there is a need for manual rinsing or repeated flushing by equipment, which results
in a reduction in productivity. Since the cleaning additive of the present invention
is used in combination with the caustic solution in a caustic tank, the peroxide will
release oxygen gas when encountering the caustic solution, to generate bubbles in
the cleaning solution, and the bubbles continuously generated in the solution will
promote the stirring in the solution, resulting in a larger mechanical force in the
glass bottle to break dirt and reduce the adsorption force between the dirt and the
glass bottle, so as to make it easier to flush away and peel off the dirt. At the
same time, the peroxide has the effects of oxidizing and decomposing organic dirt,
to make it easier to clean away dirt inside and outside the glass bottle. After adding
the component B containing the peroxide, the cleaning additive of the present invention
has a better cleaning effect as compared to an ordinary glass bottle cleaning additive,
and hence can achieve a cleaning effect that is the same as or better than the prior
art at a relatively low temperature.
[0019] In addition, these peroxides used in the present invention are relatively stable
and low in cost, and generate substances after decomposition which have no toxicity
and side effects, achieving high safety and practical value when used in the glass
bottle cleaning technology of the present application in the food industry. The component
B is generally added in the secondary caustic tank, to save cost, and can be added
in the primary caustic tank when treating severely polluted glass bottles.
[0020] The cleaning additive of the present invention also comprises a component C, and
the component C contains an antifoaming agent, to provide an antifoaming effect in
the cleaning process. The antifoaming agents include, but not limited to, silicone
polyether, fatty alcohol polyether, ethylenediamine polyether antifoaming agents or
any combination thereof. Other antifoaming agents commonly used in the art may also
be selected.
[0021] In the glass bottle cleaning, the bubble release of the component B containing the
peroxide in the solution may enhance the generation of foams in a bottle cleaning
machine, and dirt carried by the glass bottle may also generate foams; in the production,
the generated bubbles help enhance the mechanical force for cleaning, whereas at the
same time, the generation of excessive foams should be controlled, because
- 1. excessive foams may lead to insufficient contact between the glass bottle and the
cleaning solution, to reduce the cleaning efficiency;
- 2. excessive foams may increase the difficulty in cleaning, lead to the prolonging
of the subsequent spray cleaning procedure, and impose the risk of residue of the
cleaning solution;
- 3. excessive foams will overflow from the bottle cleaning machine, to influence the
sanitary condition of the site of production.
[0022] Therefore, after applying the component B of the present invention, if there is the
phenomenon of excessive foams, the component C containing the antifoaming agent can
be added to the secondary caustic tank to inhibit the occurrence of the above harmful
phenomenon. If there is no generation of excessive foams, the component C needs not
to be added. Technicists can determine to add a proper amount of the component C according
to the condition at the site.
[0023] Because the cleaning additive of the present invention takes into account and utilizes
the synergistic action of the peroxide and the antifoaming agent, the same or better
cleaning effect as compared with the prior art is realized at a relatively low temperature
(50-70°C) while greatly increasing the glass bottle cleaning effect (oxidation and
enhanced mechanical force), and simultaneously the negative effect caused by excessive
foams can be eliminated.
[0024] The antifoaming agent of the present invention is preferably a mixture of a polyether-siloxane
polymer, polyoxypropylene polyoxyethylene fatty alcohol ether and polyoxypropylene
polyoxyethylene ethylenediamine ether at a ratio of 1-3:6:9, preferably 1:2:3. Alternatively,
the antifoaming agent of the present invention is a mixture of a non-alkyl terminated
fatty alcohol alkoxyl polymer, an alkyl terminated fatty alcohol alkoxyl polymer and
polyoxypropylene polyoxyethylene ethylenediamine ether at a ratio of 3-5:6:9, preferably
1:2:3. The non-alkyl terminated fatty alcohol alkoxyl polymer, and the alkyl terminated
fatty alcohol alkoxyl polymer are generally methyl terminated C4-C18 fatty alcohol
polyalkoxyl compounds.
[0025] The silicone antifoaming agent can form a low surface energy film in a medium, allowing
air bubbles to be continuously broken and move to form larger bubbles, so as to realize
antifoaming, and the silicone antifoaming agent also has a significant foam inhibition
effect, and can prevent the generation of foams while breaking foams. However, the
silicone antifoaming agents have poor compatibility and are difficult to be emulsified.
A polyoxyethylene fatty alcohol ether is an effective polymer antifoaming agent, and
can enter the foam bimolecular film, to lead to local reduction of the surface tension
in the film while keeping a relative large surface tension at the rest part of the
film, so as to break foams; however, as an antifoaming agent, the emulsified particles
thereof must be greater than 50 µm, otherwise it can only accelerate the generation
of foams or have a stabilization effect on foams and thus have certain disadvantages
in its particular production and application. The preferable antifoaming agent of
the present invention combines the silicone and the polyoxyethylene fatty alcohol
ether, to eliminate their respective disadvantages through the synergistic action,
and achieve a good antifoaming effect by using the two at the same time.
[0026] Each component of the cleaning additive of the present invention can be added in
different caustic tanks separately, and based on the weight of the caustic solution
added in the primary caustic tank or secondary caustic tank, the addition amount of
the component A is 0.05%-0.5%, the addition amount of the component B is 0.1%-0.5%,
and the addition amount of the component C is 0%-0.5%. The caustic solution in the
primary caustic tank and the secondary caustic tank is generally a 1.5%-3% sodium
hydroxide solution.
[0027] The component A containing the organic phosphine chelating agent can highly intensively
penetrate and disperse mould, mud and clay on glass bottles, to effectively peel off
viscous dirt; after the dirt is dispersed, the component B containing the peroxide
can perform oxidation more effectively, to decompose organic dirt that is difficult
to be removed, and on the other hand facilitate the component A containing the organic
phosphine chelating agent in further peeling off the dirt, so as to make the glass
bottle cleaning in the subsequent procedure easier. Meanwhile, since the peroxide
contained in the cleaning additive of the present invention releases oxygen gas under
the action of the caustic solution in the caustic tank, to generate bubbles in the
cleaning solution, the bubbles continuously generated in the solution increase the
stirring in the solution, resulting in a larger mechanical force to break dirt and
reduce the adhesion force between the dirt and the glass bottle, so as to make it
easier to flush away the dirt. With the synergistic action of the peroxide and the
antifoaming agent, the present invention realizes the same or better cleaning effect
as compared with the prior art at a relatively low temperature while greatly increasing
the glass bottle cleaning effect (oxidation and enhanced mechanical force), and eliminates
the negative effect caused by excessive foams simultaneously.
[0028] The selection of the components of the cleaning additive of the present invention
is obtained by the present inventor through many experiments, which components act
in a synergistic and stable way, to effectively clean glass bottles at a relatively
low temperature (generally, 50°C-70°C), effectively remove labels on recycled glass
bottles, and achieve a significant cleaning effect (even better than that achieved
by a conventional method at 80°C) on glass bottles containing severe mildew stains,
mud or clay dirt. Generally, an caustic solution at a high temperature has stronger
corrosivity, and in the cleaning process, it may easily cause labels to be broken
in the caustic tank, leading to difficult removal of the labels, and a stronger corrosion
to glass bottles. Therefore, with the cleaning additive of the present invention,
low-temperature cleaning can be realized, which facilitates the complete peeling off
of labels, facilitates the cleaning and maintenance of the caustic tank, and reduces
the corrosion to glass bottles.
[0029] In another aspect, the present invention provides a glass bottle cleaning method
by using the cleaning additive of the present invention to clean glass bottles, comprising
the steps of:
- (i) adding the component A containing an organic phosphine chelating agent to an caustic
solution of a primary caustic tank, selectively adding the component B to the primary
caustic tank, and mixing them thoroughly; adding the component A containing the organic
phosphine chelating agent and the component B containing a peroxide to an caustic
solution of a downstream secondary caustic tank, and mixing them thoroughly;
- (ii) immersing glass bottles in the primary caustic tank, to sufficiently contact
with the mixed solution in the primary caustic tank;
- (iii) transferring and immersing the glass bottles into the downstream secondary caustic
tank after they have left the primary caustic cleaning tank, to sufficiently contact
with the mixed solution in the secondary caustic tank, and selectively adding the
component C containing an antifoaming agent; and
- (iv) moving the glass bottles out of the secondary caustic tank, and subjecting them
to spray cleaning.
[0030] In cleaning steps (i)-(iii), the temperatures in the primary caustic tank and the
secondary caustic tank can be set and maintained in a range of 50°C-80°C, or in a
range of 50°C-70°C.
[0031] The cleaning method of the present invention comprises, before step (i), pre-spraying,
pre-soaking and pre-heating the glass bottles, to remove surface dirt that is easy
to be removed and facilitate the subsequent cleaning steps.
[0032] In the cleaning process, technicists can determine whether there is a need for adding
an effective amount of the component C containing the antifoaming agent, to perform
antifoaming treatment, according to whether there is generation of foams. The component
B is generally added in the secondary caustic tank, but may also be added in the primary
caustic tank when treating severely contaminated glass bottles, to enhance the cleaning
effect.
[0033] Generally, when cleaning the glass bottles in the primary caustic tank, foams may
be generated due to the dissolution and dispersion of dirt, and technicists can determine
whether there is a need for adding the component C containing the antifoaming agent
to the primary caustic tank, to perform antifoaming treatment, according to the condition
of foams.
[0034] When performing a spraying treatment to the glass bottles, there is usually a need
for gradually reducing the temperature for spray cleaning of the glass bottles, in
order to prevent breakage of the glass bottles due to non-uniform heating.
[0035] In the cleaning process, a step for removing the peeled off labels from the primary
caustic tank and the secondary caustic tank may be also included. Therefore, with
a low-temperature treatment, the cleaning method of the present invention is advantageous
in keeping the integrity of labels, so as to facilitate the removal of the peeled
off labels by label removing equipment, such as a label remover, and consequently,
facilitates the cleaning and maintenance of a caustic tank.
[0036] Meanwhile, the caustic solution and the components A, B and C are consumed in a certain
amount after cleaning for a certain time, and a corresponding concentration monitoring
is performed to help the technicists to determine whether there is a need for feed
supplementation, to keep an proper concentration of the cleaning solution, as so to
realize continuous cleaning and achieve a stable cleaning effect.
[0037] In another aspect, the present invention also provides a glass bottle cleaning system
using the glass bottle cleaning additive of the present invention to clean glass bottles,
said cleaning system comprising:
a primary caustic tank;
a secondary caustic tank located downstream;
a spray cleaning device located downstream of the secondary caustic tank;
a glass bottle conveying device for conveying glass bottles among the parts of the
glass bottle cleaning system.
[0038] The caustic solution in the primary caustic tank and the secondary caustic tank is
generally a 1.5%-3% sodium hydroxide solution, and the temperatures in the primary
caustic tank and the secondary caustic tank are set at 50°C-80°C, or at 50°C-70°C.
[0039] The cleaning system of the present invention also comprises a pretreatment device
located upstream of the primary caustic tank for pre-spraying, pre-soaking and pre-heating;
a concentration monitoring system for monitoring the concentrations of the caustic
solution and the components A, B and C; and corresponding feeding devices. The cleaning
system of the present invention also comprises a label remover connected to the primary
caustic tank and the secondary caustic tank respectively, for removing the peeled
off labels in time.
[0040] The terms "primary caustic tank" and "secondary caustic tank" used in the present
invention both refer to a container for accommodating a caustic solution, and the
differences between the "primary caustic tank" and the "secondary caustic tank" are
that the secondary caustic tank is located downstream of the primary caustic tank,
and the secondary caustic tank can comprise one or more independent caustic tanks.
[0041] The advantages of the present invention are that, through using the glass bottle
cleaning additive and cleaning method of the present invention, the operating temperature
of the cleaning equipment is reduced, thereby making the operation safer and more
comfortable, the equipment wear and tear is reduced at low temperature, with the consumption
of cooling water and energy consumption being reduced, and the low-temperature treatment
is advantageous in prolonging the service life of recycled glass bottles and in the
cleaning and maintenance of the equipment.
- 1. A glass bottle cleaning additive for use in treatment by cleaning glass bottles
in a primary caustic tank and a secondary caustic tank, said cleaning additive consisting
of a component A, a component B and a component C, wherein
the component A contains an organic phosphine chelating agent,
the component B contains a peroxide, and
the component C contains an antifoaming agent,
the component A is added in the primary caustic tank, the component B is selectively
added in the primary caustic tank, the component A and the component B are added in
the secondary caustic tank, and the component C is selectively added in the primary
caustic tank or the secondary caustic tank.
- 2. The cleaning additive according to 1, characterized in that said organic phosphine
chelating agent is selected from one of amino trimethylene phosphonic acid, 1-hydroxy
ethylidene-1,1-diphosphonic acid, ethylene diamine tetra(methylene phosphonic acid)
sodium, ethylene diamine tetra(methylene phosphonic acid), diethylene triamine penta(methylene
phosphonic acid), 2-phosphonobutane-1,2,4-tricarboxylic acid, polyhydric alcohol phosphate
ester, 2-hydroxy phosphonoacetic acid, hexamethylene diamine tetra(methylene phosphonic
acid), polyamino polyether methylene phosphonate and bis(hexamethylene triamine penta(methylene
phosphonic acid)), or any combination thereof.
- 3. The cleaning additive according to 1 or 2, characterized in that said component
A further contains gluconate, gluconic acid, lactic acid, citric acid or a mixture
thereof.
- 4. The cleaning additive according to 1 or 2, characterized in that said peroxide
is selected from one of hydrogen peroxide, sodium peroxide, sodium percarbonate, sodium
perborate, magnesium peroxide, calcium peroxide, barium peroxide, potassium peroxide,
chlorine dioxide, peracetic acid, peroctanoic acid and ozone water, or any combination
thereof.
- 5. The cleaning additive according to 4, characterized in that said peroxide is selected
from one of sodium percarbonate, sodium perborate and hydrogen peroxide, or any combination
thereof.
- 6. The cleaning additive according to 4, characterized in that said peroxide is selected
from one of magnesium peroxide, calcium peroxide and barium peroxide, or any combination
thereof.
- 7. The cleaning additive according to 1 or 2, characterized in that said antifoaming
agent is selected from silicone polyethers, fatty alcohol polyethers, ethylenediamine
polyethers or any combination thereof.
- 8. The cleaning additive according to 7, characterized in that said antifoaming agent
is a mixture of a polyether-siloxane polymer, polyoxypropylene polyoxyethylene fatty
alcohol ether and polyoxypropylene polyoxyethylene ethylenediamine ether.
- 9. The cleaning additive according to 8, characterized in that the ratio of polyether-siloxane
polymer to polyoxypropylene polyoxyethylene fatty alcohol ether to polyoxypropylene
polyoxyethylene ethylenediamine ether in said antifoaming agent is 1-3:6:9.
- 10. The cleaning additive according to 8, characterized in that the ratio of polyether-siloxane
polymer to polyoxypropylene polyoxyethylene fatty alcohol ether to polyoxypropylene
polyoxyethylene ethylenediamine ether in said antifoaming agent is 1:2:3.
- 11. The cleaning additive according to 7, characterized in that said antifoaming agent
is a mixture of a non-alkyl terminated fatty alcohol alkoxyl polymer, an alkyl terminated
fatty alcohol alkoxyl polymer and polyoxypropylene polyoxyethylene ethylenediamine
ether.
- 12. The cleaning additive according to 11, characterized in that the ratio of non-alkyl
terminated fatty alcohol alkoxylate polymer to alkyl terminated fatty alcohol alkoxylate
polymer to polyoxypropylene polyoxyethylene ethylenediamine ether in said antifoaming
agent is 3-5:6:9.
- 13. The cleaning additive according to 11, characterized in that the ratio of non-alkyl
terminated fatty alcohol alkoxylate polymer to alkyl terminated fatty alcohol alkoxylate
polymer to polyoxypropylene polyoxyethylene ethylenediamine ether in said antifoaming
agent is 1:2:3.
- 14. The cleaning additive according to any one of 1-13, characterized in that the
addition amount of the component A is 0.05%-0.5%, the addition amount of the component
B is 0.1%-0.5%, and the addition amount of the component C is 0-0.5%, based on the
weight of an caustic solution added in the primary caustic tank or the secondary caustic
tank.
- 15. The cleaning additive according to 14, characterized in that the caustic solution
in said primary caustic tank and said secondary caustic tank is a 1.5%-3% sodium hydroxide
solution.
- 16. A cleaning method for glass bottles, by using a cleaning additive of any one of
1-15 to clean glass bottles, comprises the following steps:
- (i) adding the component A containing an organic phosphine chelating agent to an caustic
solution of a primary caustic tank, selectively adding therein the component B, and
mixing them thoroughly; adding the component A containing an organic phosphine chelating
agent and the component B containing a peroxide to the caustic solution of a downstream
secondary caustic tank, and mixing them thoroughly;
- (ii) immersing glass bottles in the primary caustic tank, to sufficiently contact
with a mixed solution in the primary caustic tank;
- (iii) transferring and immersing the glass bottles into the downstream secondary caustic
tank after they have left the primary caustic tank, to sufficiently contact with a
mixed solution in the secondary caustic tank, and selectively adding the component
C containing an antifoaming agent; and
- (iv) moving the glass bottles out of the secondary caustic tank, and subjecting them
to spray cleaning.
- 17. The cleaning method according to 16, characterized in that in said steps (i)-(iii),
the temperatures in the primary caustic tank and the secondary caustic tank are 50°C-80°C.
- 18. The cleaning method according to 17, characterized in that in said steps (i)-(iii),
the temperatures in the primary caustic tank and the secondary caustic tank are 50°C-70°C.
- 19. The cleaning method according to 16 or 17, characterized in that said method comprises
treatments of pre-spraying, pre-soaking and pre-heating the glass bottles before step
(i).
- 20. The cleaning method according to 16 or 17, characterized in that said method comprises
selectively adding the component C containing an antifoaming agent to the primary
caustic tank to carry out an antifoaming treatment during step (ii).
- 21. The cleaning method according to 16 or 17, characterized in that in step (iv),
the temperature for spray cleaning of the glass bottles is reduced gradually.
- 22. The cleaning method according to 16 or 17, characterized in that said method further
comprises a step of removing peeled off labels from the primary caustic tank and the
secondary caustic tank, a step of monitoring the concentrations of the components
A, B and C and the caustic solution, and a feeding step for supplementing the components
A, B and C and the caustic solution.
- 23. A cleaning system for glass bottles which employs a glass bottle cleaning additive
of any one of 1-15 to clean glass bottles, said cleaning system comprising:
a primary caustic tank;
a secondary caustic tank located downstream;
a spray cleaning device located downstream of the secondary caustic tank; and
a glass bottle conveying device for conveying glass bottles among the parts of the
cleaning system for glass bottles.
- 24. The cleaning system according to 23, characterized in that the temperatures in
the primary caustic tank and the secondary caustic tank are set at 50°C-80°C.
- 25. The cleaning system according to 24, characterized in that the temperatures in
the primary caustic tank and the secondary caustic tank are set at 50°C-70°C.
- 26. The cleaning system according to 23, characterized in that the caustic solution
in said primary caustic tank and said secondary caustic tank is a 1.5%-3% sodium hydroxide
solution.
- 27. The cleaning system according to 23, characterized in that said cleaning system
comprises a pretreatment device for pre-spraying, pre-soaking and pre-heating, located
upstream of the primary caustic tank.
- 28. The cleaning system according to 23, characterized in that said cleaning system
comprises feeding devices and concentration monitoring devices for the caustic solution
and the components A, B and C, and further comprises a label remover connected to
the primary caustic tank and the secondary caustic tank respectively for removing
the peeled off glass bottle labels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042]
Figure 1 is a schematic flow chart illustrating the cleaning glass bottles procedure
according to one embodiment of the present invention.
Figure 2 is a schematic diagram of comparison of the average mildew stain removal
rate achieved by cleaning at 60°C according to one embodiment of the present invention
with those achieved by cleaning at 60°C and 80°C according to prior art.
Figure 3 is a schematic diagram of comparison of the average mud and clay removal
rate achieved by cleaning at 60°C according to one embodiment of the present invention
with those achieved by cleaning at 60°C and 80°C according to prior art.
Figure 4 is a schematic diagram of comparison of the average label removal time achieved
by cleaning at 60°C according to one embodiment of the present invention with those
achieved by cleaning at 60°C and 80°C according to prior art.
DETAILED DESCRIPTION
[0043] In general, the cleaning effect is influenced by the following four factors:
Cleaning agent and concentration thereof
[0044] The selection of a cleaning agent relates to the type of dirt and the material of
a surface to be cleaned. For different materials, it is required to select a suitable
cleaning agent which not only improves the cleaning effect but also prevents an object
being cleaned from corrosion. In the meantime, an increase in the concentration of
a cleaning agent can shorten cleaning time properly or compensate for the insufficiency
of a cleaning temperature. However, the increase in the concentration of a cleaning
agent leads to an increase in cleaning cost; moreover, the increase in concentration
may not necessarily improve the cleaning effect effectively, and sometimes may even
lead to the prolongation of cleaning time.
Cleaning time
[0045] The longer the cleaning time with a cleaning agent is, the better the cleaning effect
is. However, the prolongation of cleaning time means a reduction of productivity and
an increase of production cost. If the cleaning time is shortened blindly, it will
be possible that a desired cleaning effect cannot be achieved. Therefore, it is required
to determine a proper cleaning time according to actual conditions in industrial applications.
Cleaning temperature
[0046] The cleaning temperature refers to a temperature at which a cleaning agent is kept
during a cleaning cycle, which temperature should be kept constant during the cleaning
process. If sodium hydroxide is used, the temperature is generally 80°C-90°C; if nitric
acid is used, the temperature is generally 60°C-80°C. The increase of the cleaning
temperature can help to shorten the cleaning time or reduce the concentration of a
cleaning agent, but corresponding energy consumption will be increased.
Mechanical cleaning force
[0047] Generally, a certain flow rate of a cleaning agent is ensured during cleaning to
improve the turbulence of the fluid, so as to enhance an impact force of the cleaning
agent, such that a certain mechanical action may be generated in the cleaning process,
thus resulting in a good cleaning effect.
[0048] By means of the synergistic action of its components, the cleaning additive of the
present invention enhances the mechanical cleaning force and the cleaning effect over
the same cleaning time without increasing the concentration, and can achieve the same
or better cleaning effect at a relatively low temperature.
[0049] The cleaning additive and cleaning method of the present invention also take full
account of the following factors, that is, it needs to remove a label wholly to prevent
the label from becoming pulp, to prevent ink and colors on the label from being dissolved,
to reduce the possibility of foaming in the cleaning process and to avoid a harmful
sticking reaction.
[0050] Particular embodiments mentioned and described below in the present invention are
only used for illustration and detailed description of technical solutions of the
present invention, but not intended to limit the scope of protection of the present
invention.
[0051] The cleaning additive of the present invention can be used with existing bottle cleaning
machine equipment, such as a single-end bottle cleaning machine system or a double-end
bottle cleaning machine system, without the need for a specific cleaning equipment,
and thus has a wide extent of application.
[0052] Figure 1 illustrates a schematic flow chart of low-temperature cleaning carried out
by using the cleaning additive of the present invention in an existing bottle cleaning
machine system. During cleaning, glass bottles are fed in from an inlet of the bottle
cleaning machine system, wherein each of the bottles is loaded into a corresponding
bottle box or other similar conveyors, wetted by way of pre-spraying, pre-soaking,
pre-heating, etc., by a pretreatment device, with part of loose dirt flushed away,
and then enters a primary caustic tank. A caustic solution is added into the primary
caustic tank in advance, which caustic solution is usually a sodium hydroxide solution
at a concentration of 1.5%-3%. To the primary caustic tank is added a component A
containing an organic phosphine chelating agent (such as HEDP) at a concentration
of 0.05%-0.5%, based on the weight of the caustic solution in the primary caustic
tank. In case that the contamination of glass bottles is very severe, 0.1%-0.5% of
a component B containing a peroxide (such as sodium percarbonate) can also be added
to the primary caustic tank. The cleaning temperature of the primary caustic tank
is set and kept in a range of 50°C-70°C during the cleaning process. In the primary
caustic tank, the glass bottles contact with the caustic solution and the cleaning
additive sufficiently, so that most of labels are peeled off there, and are carried
away by a label removing device (such as a label removing chain belt). Dirt, such
as mould, mud and clay and so on, is also dispersed and dissolved under the action
of the cleaning solution in the primary caustic tank.
0.05%-0.5% of a component A containing an organic phosphine chelating agent (such
as ATMP) and 0.1%-0.5% of a component B containing a peroxide (such as hydrogen peroxide)
are added to a downstream secondary caustic tank, said concentrations being based
on the weight of the caustic solution in the secondary caustic tank. The glass bottles
enter the secondary caustic tank along the conveyor. In the secondary caustic tank,
the labels, which have not been peeled off completely, are further peeled off here
and then are carried away from the bottle cleaning machine system. The dirt on the
glass bottles is completely dispersed and dissolved in the secondary caustic tank
under the action of the cleaning solution.
[0053] Due to the addition of the component B containing peroxide and the action of the
caustic solution in the secondary csustic tank, bubbles are generated, which enhance
the mechanical force for cleaning glass bottles. During the cleaning process, technicists
can adjust the addition amount of a component C according to an on-site foam condition
in the bottle cleaning machine system, and the addition concentration may be 0-0.5%,
based on the weight of the caustic solution in the caustic tank.
[0054] Subsequently, the bottles enter a spraying zone after they have left the secondary
caustic tank. After spraying hot water, spraying warm water and spraying cold water,
the temperature of the glass bottles per se is reduced gradually, and the dirt inside
and outside the bottles and the cleaning solution adhered on the bottles are flushed
away. Finally, the cleaned bottles exit from an outlet of the bottle cleaning machine.
They can be fed to a filling zone for packing of beer or other drinks.
[0055] In addition, it is usually required to detect the cleanness of cleaned glass bottles
between the bottle cleaning machine and the filling zone. Empty bottle inspection
rate (EBIR) is an important index for evaluating the cleaning effect and quality of
recycled bottles. An empty bottle inspector (EBI) uses a technique of detecting the
bottle body, the bottle bottom and the bottle mouth via a high-resolution camera over
360 degrees, and compares them with a standard bottle, so as to screen out unqualified
bottles. High empty bottle inspection rate will influence the working efficiency of
subsequent procedures, such as a procedure of filling beer or a beverage, etc. Therefore,
the productivity can be improved effectively by improving the cleaning efficiency
of recycled bottles and reducing the empty bottle inspection rate (EBIR).
[0056] With the component A containing an organic phosphine chelating agent, which can highly
intensively penetrate and disperse mould, mud and clay on glass bottles, being added
in the primary caustic tank, viscous dirt can be peeled off effectively; after the
dirt is dispersed, with the component B containing a peroxide being added to the secondary
caustic tank, oxidation can be carried out more effectively, to decompose organic
dirt that is difficult to be removed, and on the other hand to help the component
A containing an organic phosphine chelating agent in the caustic tank further peel
off dirt, so that it is easier to clean the glass bottles in subsequent procedures.
In the meantime, since the peroxide component B contained in the cleaning additive
of the present invention releases oxygen gas under the action of the caustic solution
in the caustic tank, bubbles are generated in the cleaning solution, and the bubbles
continuously generated in the solution increase the stirring in the solution, resulting
in a larger mechanical force, thereby breaking the dirt, reducing the adsorption force
between the dirt and the glass bottle, so as to make it easier to flush away the dirt.
Meanwhile, the prevent invention employs the synergistic action between the peroxide
component B and the antifoaming agent component C, which achieves the same or better
cleaning effect at a relatively low temperature (50°C-70°C) while remarkably increasing
the cleaning effect of glass bottles (oxidation and enhanced mechanical force), and
at the same time, also takes account of the potential negative influence that the
peroxide possibly results in excessive foams.
[0057] In addition, those skilled in the art can determine the addition amount of each components
of the cleaning additive according to factors such as the degree of contamination
of glass bottles, the nature of contaminants, cleaning process, etc., and a generally
desired cleaning effect can be achieved with an addition amount within a concentration
range defined in the present invention, whereas there is no need to use too much cleaning
additive, which leads to the increase of cleaning cost.
[0058] During the cleaning process, the concentration of caustic solution and the concentration
of cleaning additive in the caustic tank reduce continually, so there is a need for
technicists to detect the concentrations periodically and supplement them in time,
or to supplement the alkali and additive by a specific adding equipment, in order
to hold a certain concentration for ensuring the cleaning effect.
[0059] The glass bottle cleaning additive and cleaning method of the present invention can
realize effective cleaning of recycled bottles at a relatively low temperature. The
reduction of cleaning temperature can save energy without doubt, improve the operational
environment, and also further promote the cleaning effect substantially. Apparently,
a caustic solution at a high temperature has a stronger negative influence on the
breaking of the labels per se or the dissolution of ink on the labels, whereas the
cleaning technology at a low temperature overcomes this shortcoming. Thus, it is more
advantageous for cleaning and maintenance of the cleaning equipment itself. Moreover,
data from experiments showed that the glass bottle cleaning additive of the present
invention has an obvious effect on cleaning glass bottles severely contaminated by
mildew stains, mud or clay, even exceeding the cleaning effect of prior art at 80°C.
[0060] In order to further describe the advantageous effects of the cleaning additive and
the low-temperature cleaning technology of the present invention, the following comparison
tests were carried out by the applicant by simulating on-site cleaning conditions
in the laboratory.
Experiment 1: mildew stain removal test
[0061] All tests employed recycled glass bottles of the same type from the same factory
at the same time and with similar degrees of mildew stain contamination. Each set
of tests employed 8 samples of recycled bottles of the type, and the mildew stain
level for each glass bottle was observed and recorded. The situation with severest
mildew stains was defined as level 5, whereas the situation without mildew stains
was defined as level 0. The mildew stain levels of each glass bottle before and after
cleaning were recorded. Specific processes of the tests were as follows:
Control test I for mildew stain cleaning
[0062]
- 1) Selecting recycled glass bottles with similar mildew stain degrees, recording the
initial states of mildew stains and evaluating the mildew stain level of each glass
bottle;
- 2) Preparing two cleaning solutions with tap water, each of which cleaning solutions
contained a 2% sodium hydroxide solution and 0.2% of a cleaning additive Stabilon
BPU, a bottle cleaning additive product with a relatively good mould removal performance
from Ecolab Company;
- 3) Heating the two cleaning solutions and holding them at a temperature of 60°C, taking
two glass bottles and soaking them in the first cleaning solution firstly, taking
out the bottles after they had been soaked for 7 minutes, and then pouring out the
solution from the bottles completely;
- 4) Placing the glass bottles in the second cleaning solution, then taking out the
bottles after they had been soaked for 3 minutes, and pouring out the solution from
the bottles completely;
- 5) Flushing the interior and the exterior of the bottles with warm water and cold
water in sequence; and
- 6) Staining the bottles with methylene blue, then observing and recording the mildew
stain levels after cleaning.
Table 1: Mildew stain levels of glass bottles after cleaning at 60°C by prior art
Glass bottle number |
Mildew stain level before cleaning |
Mildew stain level after cleaning |
1a |
5 |
5 |
1b |
5 |
5 |
1c |
5 |
3 |
1d |
5 |
5 |
1e |
4 |
4 |
1f |
4 |
4 |
1g |
4 |
2 |
1h |
4 |
4 |
Control test II for mildew stain cleaning
[0063] Said control test I was repeated except that the cleaning temperature was set at
80°C, giving the following data:
Table 2: Mildew stain levels of glass bottles after cleaning at 80°C by prior art
Glass bottle number |
Mildew stain level before cleaning |
Mildew stain level after cleaning |
2a |
5 |
4 |
2b |
5 |
2 |
2c |
5 |
5 |
2d |
5 |
2 |
2e |
5 |
2 |
2f |
5 |
3 |
2g |
5 |
1 |
2h |
5 |
1 |
Control test III for mildew stain cleaning
[0064] Said control test I was repeated except that a formulation A of the cleaning additive
of the present invention without a peroxide was used to replace the cleaning additive
Stabilon BPU in the above test, wherein the formulation A was a mixture of 15% sodium
gluconate, 15% amino trimethylene phosphonic acid and 70% water, and the following
data was obtained :
Table 3. Mildew stain levels after cleaning at 60°C by using the formulation A of
the cleaning additive of the present invention without adding peroxide
Glass bottle number |
Mildew stain level before cleaning |
Mildew stain level after cleaning |
3a |
4 |
3 |
3b |
5 |
3 |
3c |
5 |
2 |
3d |
5 |
3 |
3e |
5 |
2 |
3f |
5 |
5 |
3g |
5 |
3 |
3h |
5 |
3 |
Mildew stain cleaning test IV using the cleaning additive of the present invention
[0065]
- 1) Selecting recycled glass bottles with similar mildew stain degrees, recording the
initial states of mildew stains and evaluating the mildew stain level of each glass
bottle;
- 2) Preparing two cleaning solutions with tap water, the first cleaning solution of
which contained a 2% sodium hydroxide solution and 0.2% of the formulation A; and
the second cleaning solution contained a 2% sodium hydroxide solution and a total
concentration of 0.2% of the formulation A and a formulation B;
wherein the formulation A was a mixture of 15% sodium gluconate, 15% amino trimethylene
phosphonic acid and 70% water, and the formulation B was a 50% hydrogen peroxide solution;
- 3) Heating the two cleaning solutions and holding them at a temperature of 60°C, taking
two glass bottles and soaking them in the first cleaning solution, taking out the
bottles after 7 minutes, and then pouring out the solution from the bottles completely;
- 4) Placing the glass bottles in the second cleaning solution, then taking out the
bottles after they had been soaked for 3 minutes, and pouring out the solution from
the bottles completely;
- 5) Flushing the interior and the exterior of the bottles with warm water and cold
water in sequence; and
- 6) Staining the bottles with methylene blue, and then observing and recording the
mildew stain levels after cleaning.
Table 4. Mildew stain levels after cleaning at 60°C by using the cleaning additive
(formulation A + formulation B) of the present invention
Glass bottle number |
Mildew stain level before cleaning |
Mildew stain level after cleaning |
4a |
4 |
0 |
4b |
5 |
2 |
4c |
5 |
0 |
4d |
4 |
0 |
4e |
5 |
1 |
4f |
5 |
1 |
4g |
4 |
0 |
4h |
4 |
0 |
[0066] After completion of the experiments, mildew stain removal rates were obtained from
the data obtained in tables 1-4 above according to a computing equation for mildew
stain removal rate, and mean values of the 8 bottles were plotted to obtain figure
2.

[0067] As shown in tables 1-4 or figure 2, it is evident that the mildew stain removal rate
for cleaning at 80°C by a conventional method is higher than that at 60°C under identical
conditions, indicating that the increase of temperature improves the cleaning effect
significantly. It is evident that the mildew stain removal effect by using a single
component of the cleaning additive of the present invention (without adding a peroxide)
is not as good as that by using the cleaning additive of the present invention under
the synergistic action of its components. Lastly, the mildew stain removal rate obtained
by cleaning at 60°C using the cleaning additive of the present invention is still
higher than that obtained by the conventional method at 80°C. Therefore, the cleaning
additive of the present invention can achieve a better cleaning effect at a relatively
low temperature.
Experiment 2: Mud and clay removal test
[0068] All tests employed recycled glass bottles of the same type from the same factory
at the same time and with severe mud and clay contamination. Each set of tests employed
8 samples of recycled bottles of the type. During the experiments, the situation with
severest mud and clay was defined as level 5, whereas the situation without mud and
clay was defined as level 0, and the mud and clay levels of each glass bottle before
and after cleaning were recorded.
Control test I for mud and clay cleaning
[0069]
- 1) Selecting recycled glass bottles with similar mud and clay degrees, recording the
initial states of mud and clay and evaluating the mud and clay levels of each glass
bottle;
- 2) Preparing two cleaning solutions with tap water, each of which cleaning solutions
contained a 2% sodium hydroxide solution and 0.2% of a cleaning additive Stabilon
HP, a bottle cleaning additive product with a relatively good mud and clay removal
performance from Ecolab Company;
- 3) Heating the two cleaning solutions and holding them at a temperature of 60°C, taking
two glass bottles and soaking them in the first cleaning solution firstly, taking
out the bottles after they had been soaked for 7 minutes, and then pouring out the
solution from the bottles completely;
- 4) Placing the glass bottles in the second cleaning solution, then taking out the
bottles after they had been soaked for 3 minutes, and pouring out the solution from
the bottles completely;
- 5) Flushing the interior and the exterior of the bottles with warm water and cold
water in sequence;
- 6) Observing and recording the mud and clay levels after cleaning.
Table 5: Mud and clay levels of glass bottles after cleaning at 60°C by prior art
Glass bottle number |
Mud and clay level before cleaning |
Mud and clay level after cleaning |
5a |
4 |
2 |
5b |
5 |
4 |
5c |
5 |
5 |
5d |
5 |
2 |
5e |
5 |
2 |
5f |
4 |
4 |
5g |
4 |
3 |
5h |
4 |
2 |
Control test II for mud and clay cleaning
[0070] The above mud and clay cleaning test was repeated except that the cleaning temperature
was set at 80°C, and the following data in table 6 was obtained:
Table 6: Mud and clay levels of glass bottles after cleaning at 80°C by prior art
Glass bottle number |
Mud and clay level before cleaning |
Mud and clay level after cleaning |
6a |
5 |
3 |
6b |
5 |
4 |
6c |
5 |
1 |
6d |
5 |
2 |
6e |
5 |
2 |
6f |
5 |
1 |
6g |
5 |
0 |
6h |
5 |
0 |
Control test III for mud and clay cleaning
[0071] The above mud and clay cleaning test I was repeated except that a formulation C of
the cleaning additive of the present invention without a peroxide was used to replace
the cleaning additive Stabilon HP in the above test, wherein the formulation C was
a mixture of 20% lactic acid, 10% 2-phosphonobutane-1,2,4-tricarboxylic acid and 70%
water, and the following data was obtained:
Table 7: Mud and clay levels after cleaning at 60°C by using the formulation C of
the cleaning additive of the present invention without adding peroxide
Glass bottle number |
Sand level before cleaning |
Sand level after cleaning |
7a |
5 |
3 |
7b |
5 |
4 |
7c |
5 |
2 |
7d |
5 |
3 |
7e |
5 |
2 |
7f |
5 |
3 |
7g |
3 |
1 |
7h |
3 |
2 |
Mud and clay cleaning test IV using the cleaning additive (formulation C + formulation
D) of the present invention:
[0072]
- 1) Selecting recycled glass bottles with similar mud and clay degrees, recording the
initial states of mud and clay and evaluating the mud and clay levels of the bottles;
- 2) Preparing two cleaning solutions with tap water, the first cleaning solution of
which contained a 2% sodium hydroxide solution and 0.2% of the formulation C; and
the second cleaning solution contained a 2% sodium hydroxide solution and a total
concentration of 0.2% of the formulation C and a formulation D; wherein
the formulation C was a mixture of 20% of lactic acid, 10% of 2-phosphonobutane-1,2,4-tricarboxylic
acid and 70% of water, and the formulation D was 50% sodium percarbonate;
- 3) Heating the two cleaning solutions and holding them at a temperature of 60°C, taking
two glass bottles and soaking them in the first cleaning solution, taking out the
bottles after 7 minutes, and then pouring out the solution from the bottles completely;
- 4) Placing the glass bottles in the second cleaning solution, then taking out the
bottles after they had been soaked for 3 minutes, and pouring out the solution from
the bottles completely;
- 5) Flushing the interior and the exterior of the bottles with warm water and cold
water in sequence;
- 6) Observing and recording the mud and clay levels after cleaning.
Table 8. Mud and clay levels after cleaning at 60°C by using the cleaning additive
of the present invention
Glass bottle number |
Mud and clay level before cleaning |
Mud and clay level after cleaning |
8a |
3 |
0 |
8b |
3 |
0 |
8c |
5 |
0 |
8d |
5 |
1 |
8e |
5 |
2 |
8f |
5 |
0 |
8g |
5 |
0 |
8h |
5 |
1 |
[0073] After completion of the experiments, mud and clay removal rates were obtained from
the data obtained in tables 5-8 above according to a computing equation for mud and
clay removal rate, and mean values of the 8 bottles were plotted to obtain figure
3.

[0074] As shown in tables 5-8 or figure 3, it is evident that the mud and clay removal rate
for cleaning at 80°C by a conventional method is higher than that at 60°C under identical
conditions, indicating that the increase of temperature improves the cleaning effect
significantly. It is evident that the mud and clay removal effect by using a single
component of the cleaning additive of the present invention (without adding a peroxide)
is not as good as that by using the cleaning additive of the present invention under
the synergistic action of its components. Lastly, the mud and clay removal rate obtained
by cleaning at 60°C using the cleaning additive of the present invention is still
higher than that obtained by the conventional method at 80°C. Therefore, the cleaning
additive of the present invention can achieve a better cleaning effect at a relatively
low temperature.
Experiment 3: Label removal test
[0075] All tests employed recycled glass bottles from the same factory at the same time
and with an identical wear degree of labels. Each set of tests employed 8 samples
of recycled bottles of the type, and the label removal time of each glass bottle was
observed and recorded.
Control test I for label removal
[0076]
- 1) Selecting recycled bottles with intact neck labels, front labels and back labels,
and recording the initial states of the labels;
- 2) Preparing two cleaning solutions with tap water, each of which cleaning solutions
contained a 2% sodium hydroxide solution and 0.2% of a cleaning additive Stabilon
BPU, which commercially available bottle cleaning additive is regarded as a bottle
cleaning additive with a relatively good mould removal, label removal and mud and
clay removal performance in the market; if the label removal time for the present
low-temperature cleaning technology in the laboratory is equivalent to or shorter
than that at 80°C by using the Stabilon BPU, the low-temperature cleaning method can
satisfy the requirements for label removal in industrial production;
- 3) Heating the two cleaning solutions and holding them at a temperature of 60°C, taking
two glass bottles and soaking them in the first cleaning solution, and starting the
timing;
- 4) Taking out the bottles after they had been soaked for 7 minutes, and then pouring
out the solution from the bottles completely; placing the glass bottles in the second
cleaning solution, and soaking them until all labels had been peeled off; and
- 5) Recording the time when the neck labels, the front labels and the back labels were
peeled off, respectively.
Table 9: Label removal time (second) of glass bottles during cleaning at 60°C by prior
art
Glass bottle number |
Neck label removal time (second) |
Front label removal time (second) |
Back label removal time (second) |
9a |
1320 |
260 |
600 |
9b |
683 |
264 |
600 |
9c |
890 |
247 |
600 |
9d |
720 |
1074 |
720 |
9e |
905 |
287 |
600 |
9f |
932 |
500 |
720 |
9g |
887 |
461 |
720 |
9h |
895 |
300 |
600 |
Control test II for label removal
[0077] The above test was repeated except that the cleaning temperature was set at 80°C,
and the following data in table 10 was obtained:
Table 10: Label removal time of glass bottles during cleaning at 80°C by prior art
Glass bottle number |
Neck label removal time (second) |
Front label removal time (second) |
Back label removal time (second) |
10a |
430 |
300 |
1800 |
10b |
405 |
290 |
365 |
10c |
358 |
205 |
255 |
10d |
264 |
197 |
243 |
10e |
345 |
200 |
590 |
10f |
335 |
278 |
298 |
10g |
315 |
190 |
245 |
10h |
379 |
176 |
521 |
Control test III for label removal
[0078] The above control test I for label removal was repeated except that a formulation
E of the cleaning additive of the present invention without a peroxide was used to
replace the cleaning additive Stabilon BPU in said test, wherein the formulation E
was a mixture of 25% citric acid, 5% 1-hydroxy ethylidene-1,1-diphosphonic acid and
70% water, and the following data was obtained:
Table 11: Label removal time of glass bottles during cleaning at 60°C by using the
formulation E of the cleaning additive of the present invention without adding a peroxide
Glass bottle number |
Neck label removal time (second) |
Front label removal time (second) |
Back label removal time (second) |
11a |
315 |
438 |
488 |
11b |
278 |
281 |
720 |
11c |
433 |
150 |
325 |
11d |
400 |
253 |
778 |
11e |
379 |
429 |
720 |
11f |
446 |
293 |
720 |
11g |
510 |
369 |
307 |
11h |
516 |
302 |
720 |
Label removal test IV using the cleaning additive of the present invention:
[0079]
- 1) Selecting recycled bottles with intact neck labels, front labels and back labels,
and recording the initial states of the labels;
- 2) Preparing two cleaning solutions with tap water, the first cleaning solution of
which contained a 2% sodium hydroxide solution and 0.2% of the formulation E; and
the second cleaning solution contained a 2% sodium hydroxide solution and a total
concentration of 0.2% of the formulation E and a formulation F; wherein
the formulation E was a mixture of 25% citric acid, 5% hydroxy ethylidene diphosphonic
acid and 70% water, and the formulation F was 50% sodium perborate;
- 3) Heating the two cleaning solutions and holding them at a temperature of 60°C, taking
two glass bottles and soaking them in the first cleaning solution, and starting the
timing;
- 4) Taking out the bottles after they had been soaked for 7 minutes, and then pouring
out the solution from the bottles completely; placing the glass bottles in the second
cleaning solution, and soaking them until all labels had been peeled off; and
- 5) Recording the time when the neck labels, the front labels and the back labels are
peeled off, respectively.
Table 12: Label removal time of glass bottles during cleaning at 60°C by using the
cleaning additive (formulation E + formulation F) of the present invention
Glass bottle number |
Neck label removal time (second) |
Front label removal time (second) |
Back label removal time (second) |
12a |
600 |
445 |
445 |
12b |
600 |
411 |
451 |
12c |
423 |
423 |
600 |
12d |
410 |
410 |
570 |
12e |
600 |
454 |
328 |
12f |
439 |
308 |
600 |
12g |
294 |
294 |
350 |
12h |
519 |
280 |
335 |
[0080] After completion of the experiments, mean values of removal time for the neck labels,
the front labels and the back labels were respectively calculated according to the
data obtained in tables 9-12 above, and a maximum value of the mean values was taken
as the time required for all the three labels to be peeled off totally, with results
being shown in figure 4.
[0081] As shown in tables 9-12 or figure 4, it is evident that the label removal time when
cleaning at 80°C by a conventional method is shortened obviously, compared to that
at 60°C under identical conditions, indicating that the increase of temperature improves
the cleaning effect significantly. It is evident that the label removal time when
cleaning by using a single component of the cleaning additive of the present invention
(without adding a peroxide) is obviously longer than that by using the cleaning additive
of the present invention under the synergistic action of its components. Lastly, the
label removal time when cleaning at 60°C using the cleaning additive of the present
invention is shorter than that performed at 80°C by the conventional method. Therefore,
the cleaning additive of the present invention can achieve a better cleaning effect
at a relatively low temperature.
1. A cleaning method for glass bottles, by using a cleaning additive,
said cleaning additive consisting of a component A, a component B and a component
C, wherein
the component A contains an organic phosphine chelating agent,
the component B contains a peroxide, and
the component C contains an antifoaming agent,
to clean glass bottles, comprises the following steps:
(i) adding the component A containing an organic phosphine chelating agent to an caustic
solution of a primary caustic tank, selectively adding therein the component B, and
mixing them thoroughly; adding the component A containing an organic phosphine chelating
agent and the component B containing a peroxide to the caustic solution of a downstream
secondary caustic tank, and mixing them thoroughly;
(ii) immersing glass bottles in the primary caustic tank, to sufficiently contact
with a mixed solution in the primary caustic tank;
(iii) transferring and immersing the glass bottles into the downstream secondary caustic
tank after they have left the primary caustic tank, to sufficiently contact with a
mixed solution in the secondary caustic tank, and selectively adding the component
C containing an antifoaming agent; and
(iv) moving the glass bottles out of the secondary caustic tank, and subjecting them
to spray cleaning.
2. The cleaning method according to claim 1, characterized in that in said steps (i)-(iii), the temperatures in the primary caustic tank and the secondary
caustic tank are 50°C-80°C.
3. The cleaning method according to claim 2, characterized in that in said steps (i)-(iii), the temperatures in the primary caustic tank and the secondary
caustic tank are 50°C-70°C.
4. The cleaning method according to claim 1 or 2, characterized in that said method comprises treatments of pre-spraying, pre-soaking and pre-heating the
glass bottles before step (i).
5. The cleaning method according to claim 1 or 2, characterized in that said method comprises selectively adding the component C containing an antifoaming
agent to the primary caustic tank to carry out an antifoaming treatment during step
(ii).
6. The cleaning method according to claim 1 or 2, characterized in that in step (iv), the temperature for spray cleaning of the glass bottles is reduced
gradually.
7. The cleaning method according to claim 1 or 2, characterized in that said method further comprises a step of removing peeled off labels from the primary
caustic tank and the secondary caustic tank, a step of monitoring the concentrations
of the components A, B and C and the caustic solution, and a feeding step for supplementing
the components A, B and C and the caustic solution.
8. A cleaning system for glass bottles which employs a glass bottle cleaning additive,
said cleaning additive consisting of a component A, a component B and a component
C, wherein
the component A contains an organic phosphine chelating agent,
the component B contains a peroxide, and
the component C contains an antifoaming agent, to clean glass bottles, said cleaning
system comprising:
a primary caustic tank;
a secondary caustic tank located downstream;
a spray cleaning device located downstream of the secondary caustic tank; and
a glass bottle conveying device for conveying glass bottles among the parts of the
cleaning system for glass bottles.
9. The cleaning system according to claim 8, characterized in that the temperatures in the primary caustic tank and the secondary caustic tank are set
at 50°C-80°C.
10. The cleaning system according to claim 8, characterized in that the temperatures in the primary caustic tank and the secondary caustic tank are set
at 50°C-70°C.
11. The cleaning system according to claim 8, characterized in that the caustic solution in said primary caustic tank and said secondary caustic tank
is a 1.5%-3% sodium hydroxide solution.
12. The cleaning system according to claim 8, characterized in that said cleaning system comprises a pretreatment device for pre-spraying, pre-soaking
and pre-heating, located upstream of the primary caustic tank.
13. The cleaning system according to claim 8, characterized in that said cleaning system comprises feeding devices and concentration monitoring devices
for the caustic solution and the components A, B and C, and further comprises a label
remover connected to the primary caustic tank and the secondary caustic tank respectively
for removing the peeled off glass bottle labels.