[0001] The invention relates to a method of manufacturing a container for storing and transporting
waste material by winding strips of cardboard containing material with partly overlapping
turns in order to obtain a conical body.
[0002] From Dutch Patent Application 8020245 a device is known for manufacturing conical
containers from strip-shaped rejected material, being cardboard, having a width of
40 to 60 mm, said strips being wound and glued to one another. In particular Dutch
Patent Application 8020245 is directed to a device for manufacturing conical containers.
German Patent Specification 256,937 also discloses a machine for manufacturing packing
material from strip-shaped paper by interconnecting the partly overlapping strips
by means of an adhesive.
[0003] Cardboard containers manufactured in accordance with the Patent Application 8020245
are not suitable for storing and transporting wet waste material because the cardboard
becomes soaked and the mechanical strength of the container gets lost. In particular
attempts have been made to construct a container for storing, transporting and finally
destroying hospital waste material. There is a great need for containers for storing
and transporting this kind of waste because there is a tendency to destroy this waste
as much as possible at one centre. This means a tendency to destroy the containers
together with the waste, particularly to burn it so that the container can be used
only once, which means in addition that the container must be cheap. On the other
hand, however, the container has to meet given requre- ments of rigidity and sealing
capacity because otherwise the risk of infection is too high.
[0004] The waste to be processed is especially concerned with anatomic waste, dead test
animals, any infected waste material,chemical waste from laboratories and pharmacies,
injection needles, bandages, tampons and other rubbish material resulting from chirurgical
operations and domestic rubbish material from hospitals and similar institutes. The
above enumeration will show that for these purposes no cardboard container can be
used. Cardboard has, however, the advantage that it can be readily burnt together
with the waste material and it is a cheap raw material. Tests have shown that cardboard
can be made water-tight, but the synthetic resins to be used thereto are often noxious
to the environment due to the solvent to be employed. It is also possible to provide
the cardboard on the inner side with a bag of a synthetic foil, but it has been found
that such bags are readily torn or perforated, particularly, when injection needles
and other similar instruments are thrown in such a bag. Moreover, the container or
the vessel has to be resistant to moisture on the outer side, which is not the case
for the containers disclosed in Patent Application 8020245.
[0005] The research made has shown that it is possible to produce a container for the above-mentioned
waste material in a comparatively cheap way and the method according to the invention
is characterized in that the strip consists of strips of plasticized sheet material
rejected from milk carton manufacture which are bonded to one another by heating.
It has been found that a large amount of material used for producing packing material
for milk, known by the term of "milk boxboard" is rejected for this purpose because,
for example, it is slightly damaged during transport, it has become moist or waste
cuttings or the like result from the manufacture of beakers or the like. Moreover
a large amount of this material is rejected because of any bacteriological impurity.
This rejected "milk boxboard" consists of cellulose provided on both sides with a
polyethylene film, which material has a satisfactory resistance to moisture. Destruction
of this rejected milk boxboard involved great problems, because it cannot be reused
as board material since the cellulose is provided with a synthetic resin layer, as
a result of which the material is watertight and not suitable for recycling. Dumping
this rejected material is also undesirable, because this material is very slowly disintegrated.
Therefore, burning of this material is one of the few satisfactory solutions. Besides
milk boxboard a packing material is used in a comparable manner in which an aluminium
layer is sandwiched between the cardboard and the synthetic resin layer. This packing
material is mainly used in the beverage industry and it supplies a raw material for
the container embodying the invention in the same manner as said milk boxboard.
[0006] According to the method of the invention this rejected material having a thickness
of 0.5-2 mm, is cut into strip-shaped material having a width of 5 to 12 cm, after
which this material is processed to obtain containers in which the aforesaid wet waste
can be collected, stored, transported and destroyed. The method according to the invention
for manufacturing a container of the kind set forth is carried out by winding the
strip-shaped material on a mandril, the strips overlapping one another partly, which
strips are firmly connected with one another by heating them.
[0007] By heating the strips of plasticized cardboard, i.e. polyethylene in the case of
milk boxboard, the synthetic resin, particularly the polyethylene is fused so that
the two contacting strips are unreleasably interconnected. In this way the conventional
gluing operation for cardboard containers is replaced by a welding process. The resultant
advantage is that it is not necessary to use glue containing mixtures which have subsequently
to be burnt during the destruction of the waste so that now smaller amounts of noxious
substances are set free. Moreover, the resultant container is more resistant to water
and can be made at lower cost. Since it is has now been found that a container made
by the method according to the invention from plasticized cardboard has such satisfactory
properties for storing and transporting wet waste, it will be obvious that the invention
is not limited to containers made from strip-shaped milk boxboard, since for this
purpose other plasticized kinds of cardboard may be used as well. If a container according
to the invention is to be used for storing liquid material or liquid containing mixtures,
it is preferred to make the container from double-wound strips so that the inner and
outer sides of the container consist of uncut or continuous strips of material. The
fluid can thus not moisten the head side of the strip or soften and/or attack it.
[0008] The bottom of the container according to the invention is preferably also made from
the same material as the body, whereas the cover is an injection moulded product,
preferably, of polyethylene.
[0009] The invention will be further explained with reference to the accompanying drawing,
in which
Fig. 1 is a front view of a device in accordance with the invention at the beginning
of the manufacturing method,
Fig. 2 is a plan view of the device embodying the invention in which strip-shaped
material is wound,
Fig. 3 shows a container according to the invention,
Fig. 4 shows a detail of the bottom of the container and
Fig. 5 shows a detail of the cover.
[0010] Fig. 1 shows by way of example a device suitable for manufacturing the containers
according to the invention. For this purpose a conical body or mandril 2 is rotatable
around its axis and arranged in a machine part 1 fastened to a frame 4. On the side
of the large diameter of the mandril a sliding ring 3 is arranged for removing the
container from the device whilst co-operating with the displaceable supporting part
8. On the side of the small diameter of the mandril, said mandril 2 is supported by
a disc 7, which urges the bottom part 6 centrally against the mandril 2. For rotating
the mandril 2 the disc 7 is journalled in a supporting part 8 shown schematically,
which is movable in the direction of length on the frame 4 in the direction indicated
by the arrow 5 so that after being wound up to the desired height the container can
be removed from the device shown in Fig. 1. As soon as the container has been wound
up to the desired height, the underside and the top side of the container are cut
by means of the knives 11 and 12 so that a container of the correct dimensions and
with a smooth top side and underside is obtained. At the beginning of the operation
the bottom part 6 is first formed by sealing a few layers of milk boxboard to one
another so that a cup-shaped model as shown in Fig. 4 is obtained. This bottom 6 is
disposed in the device of Fig. 1 on the rotatable disc 7, after which the first path
of strip-shaped milk boxboard is placed at the level of the bottom and connected herewith
by spraying a hot melt glue to the bottom 6 so that a firm connection is established
between the first strip and the bottom. The hot melt serves, in addition, to seal
the underside 15 of the bottom so that the various layers of board are satisfactorily
interconnected. After the application of the first turn, a heating member 25 as shown
in Fig. 2 is used instead of the glue head 10.
[0011] The heating member 25 may be a burner by which a flame is held at a given distance
from the plasticized board material, which is thus heated so that the synthetic resin
melts and a satisfactory adhesion is obtained between the partly overlapping turns.
The required temperature depends on the melting point of the synthetic resin to be
used on the board material. Because a burner has certain disadvantages with respect
to safety, this burner can be replaced by infrared radiators, hot air blowers and
the like. of a kind known to an expert in this field. The heating member 25 is fastened
to a slide 9 shown in figs. 1 and 2 so that the heating member 25 moves synchronously
with the supplied strips of board material designated by 22 and 23. Fig. 2 shows two
strips 22 and 23, although it is also possible to supply only one strip or more than
two strips in accordance with the deesired rate of production. By supplying two or
more strips the rate of production is raised. Instead of using two strips the same
rate of production could also be obtained by a single strip of twice the thickness,
but for aesthetical reasons the off-set of the strips of the container, which is visible
on the outer side of the container, should not be too large. An off-set of 1 to 2
cm has been found to be most suitable. Since rejected milk boxboard is usually available
in a thickness of 0.5 mm it is advisable to supply simultaneously two or more strips
as illustrated in Fig. 2. The mandril 2 is cooled in order to prevent the inner side
of the container from becoming sticky and from adhering to the mandril 2. The strips
22 and 23 pass from the supply point not shown in the drawing through a member ensuring
a constant tension on the strips to the slide 9, the strips being fastened via the
rollers 21 in the part 20, where they are turned through about 90° and set at.the
desired angle depending on the speed of rotation of the mandril 2, the speed of displacement
of the slide 9, the number of strips supplied and the thickness of the material and
after being turned they are guided towards the mandril 2 below the heating member
25. Thus a container according to the invention is obtained in which the turns partly
overlap one another and the overlapping layers are welded to one another.
[0012] The heating member 25 may be a member moving together with the supply of material,
for which purpose the width of the heating member and the speed of displacement are
variables determinable by one skilled in the art. As an alternative the material can
be fed to a totally heated environment, in which case no displaceable heating members
are used, the local temperature being automatically controlled in dependence on the
place of supply of the material. After the last turn has been disposed and the container
has obtained the desired height, the top and bottom edges are cut clean by means of
a knife and the container is taken off from the mandril. Then a container as shown
in Fig. 3 is obtained, in which the offset wall 30 is unreleasably connected to the
bottom 6. The cover 31 is shown in detail in Fig. 5.
[0013] Because the vessel or container has to be firmly closed during and after use, a cover
is designed of the kind shown in Fig. 5. It has a U-shaped end 29 fitting to the top
edge of the outer wall 30 of the container. Owing to the U-shaped profile a satisfactory
closure is ensured as long as the container can be filled up so that undesirable odours
will not escape from the container. As soon as no further material need be stored
in the container, the cover can be struck to the edge of the container so that the
extension 35 clamps tight around the rim 33, from which it can only be loosened with
the aid of tools. The rim 33 may be made from metal or a synthetic resin. In this
way a safe closure of the container with its contents is obtained. The rim 33 may
be applied as a sleeve 33 to the top edge of the wall 30 or in the U-profile of the
cover 31.
[0014] The extension 35 serves to lock the cover around the hook 34. A simpler embodiment
of the cover 31 can be obtained by causing the extension 35 to co-operate with a notch
in the wall 30 at the level of the extension 35. In order to hold the extension 35
firmly in the notch, a compressible synthetic resin plug is provided in the U-profile
29, said plug being slightly compressed on the top edge of the wall 30 when the cover
31 is disposed on the container and the extension 35 snaps into the notch. In this
embodiment the rim 33 can be dispensed with.
[0015] Furthermore the cover preferably made from polyethylene is provided with an upwardly
extending extension 32, which is arranged on the cover at a place such that a vessel
disposed on the cover of the first vessel fits within the dimensions of the extension
32. In this way a safe stack of filled containers is obtained. The containers not
yet used and without cover have such a conical shape that they are readily nestable
so that within a given space a maximum number of containers can be stored.
[0016] It is preferred to make a container of a height of 68 cm and a bottom diameter of
30 cm, the cover having a diameter of 34 cm. For the manufacture thereof it is preferred
to use milk boxboard having a thickness of 0.5 mm, whilstthe successive strips overlap
one another over a distance of 17 mm. With a strip width of 7 cm the wall thickness
of the container will then be 70/17 times the thickness of the material, which comes
down to a wall thickness of about 2 cm. When two strips are supplied, the thickness
will be 1 mm and the overlap 34 cm so that the wall thickness is also about 2 cm.
[0017] When the container is being used, it is preferably standing in a frame of a pedal
pail construction. By foot pressure the filling opening is set free. The cover will
not move up and down, but it will move in a substantially horizontal plane so that
air displacement is minimized and the risk of infection of the ambient air is also
minimized. The cover can be fastened in this frame by clamping it to the extensions
32.
1. A method of manufacturing a container for storing and transporting waste material
by winding strips of cardboard-containing material with partly overlapping turns in
order to obtain a conical body, characterised in that the strip consists of strips
of plasticised sheet material rejected from milk carton manufacture which are bonded
to one another by heating.
2. The method as claimed in claim 1, characterised in that the strips have a width
of 5-12 cm and a thickness of 0.5-2 mm.
3. The method as claimed in claims 1-2, characterised in that the plasticised sheet
material from milk carbon is.-further provided with an aluminum layer.
1. Verfahren zur Herstellung eines Behälters zur Aufnahme und zum Transport von Abfallmaterial
durch Wickeln von Streifen aus Karton enthaltendem Material mit sich teilweise überlappenden
Windungen zur Erzielung eines konischen Wickelkörpers, dadurch gekennzeichnet, dass
der Streifen aus Streifen aus plasticifiziertem Blattmaterial besteht, das bei der
Herstellung von Milch-Kartonbehältern abfällt und die durch Erhitzen miteinander verbunden
werden.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass die Streifen eine Breite
von 5-12 cm und eine Stärke von 0,5-2 mm haben.
3. Verfahren nach Anspruch 1-2, dadurch gekennzeichnet, dass das plastifizierte Blattmaterial
aus Milchkarton zusätzlich mit einer Aluminiumschicht versehen wird.
1. Procédé de fabrication d'un conteneur pour recueillir et transporter des matières
à jeter, par enroulement de bandes de matière contenant du carton, en spires se recouvrant
partiellement, en vue d'obtenir un corps conique, caractérisé en ce que la bande se
compose de des bandes de matière en feuille plastifièe rejetée au cours de la fabrication
de carton pour le lait, qui sont liées les unes aux autres par chauffage.
2. Procédé selon la revendication 1 caractérisé en ce que les bandes ont une largeur
de 5-12 cm et une épaisseur de 0,5-2 mm.
3. Procédé selon les revendications 1-2, caractérisé en ce que la matière en feuille
plastifiée de carton pour le lait est pourvue en plus d'une couche d'aluminium.