[0001] This invention relates to a sunshade and a method of preparing a canopy, more particularly
to a sunshade with a canopy which includes a light-transmissible fabric sheet of undyed
yarns and an opaque enamel coating.
[0002] A conventional method for preparing a canopy of a sunshade with waterproof and sunshade
functions includes a step of coating a waterproof coating material on a fabric sheet
of dyed yarns.
[0003] Formation of the dyed yarns involves immersing undyed yarns into a dyeing bath. During
the dyeing process, dye enters an interior of each fiber of the undyed yarns so as
to impart an opaque property to the dyed yarns. The preparation of the canopy requires
the dyeing of the undyed yarns and the coating of the waterproof coating material
to be processed separately, which complicates the process of preparing the canopy.
Moreover, the dyeing process results in generation of a considerable amount of dyeing
waste water, which is difficult to be disposed of.
[0004] Therefore, an object of the present invention is to provide a sunshade that can overcome
the aforesaid drawbacks associated with the prior art.
[0005] Another object of the present invention is to provide a method of preparing a canopy
of the sunshade.
[0006] According to one aspect of the present invention, there is provided a sunshade comprising:
a support frame and a canopy. The canopy is connected to the support frame and includes
a light-transmissible fabric sheet of undyed yarns and an opaque enamel coating coated
on at least one side of the light-transmissible fabric sheet. The undyed yarns are
woven and cross one another to form fabric pores thereamong. The opaque enamel coating
fills the fabric pores.
[0007] According to another aspect of this invention, there is provided a method of preparing
a canopy. The method comprises: providing a light-transmissible fabric sheet of undyed
yarns; coating an enamel composition on at least one side of the light-transmissible
fabric sheet to form an opaque enamel coating on the light-transmissible fabric sheet;
and drying the opaque enamel coating.
[0008] In drawings which illustrate embodiments of the invention,
Fig. 1 is a partly sectional view of the first preferred embodiment of a sunshade
according to the present invention;
Fig. 2 is a sectional view of a canopy of the sunshade of the first preferred embodiment;
Fig. 3 is an enlarged schematic view of a light-transmissible fabric sheet of the
canopy of the first preferred embodiment;
Fig. 4 is a sectional view of the second preferred embodiment of the canopy of the
sunshade according to the present invention;
Fig. 5 is a sectional view of the third preferred embodiment of the canopy of the
sunshade according to the present invention;
Fig. 6 is a flow chart of a method of preparing the canopy of the present invention;
and
Fig. 7 is a schematic view of a processing system that can be used in the method of
preparing the canopy of the present invention.
[0009] Before the present invention is described in greater detail with reference to the
accompanying preferred embodiments, it should be noted herein that like elements are
denoted by the same reference numerals throughout the disclosure.
[0010] Figs. 1, 2 and 3 illustrate the first preferred embodiment of a sunshade according
to the present invention. The sunshade includes a support frame 1 and a canopy 2 connected
to the support frame 1. The structure and shape of the support frame 1 are not limited.
The sunshade may be portable, such as an umbrella, or fixed, such as a garden sunshade.
[0011] The canopy 2 includes a light-transmissible fabric sheet 21 of undyed yarns and an
opaque enamel coating 22 coated on one side of the light-transmissible fabric sheet
21.
[0012] Preferably, the light-transmissible fabric sheet 21 is a woven fabric. The undyed
yarns are woven and cross one another to form fabric pores 211 thereamong. The opaque
enamel coating 22 fills the fabric pores 211, and covers sealingly the undyed yarns
at said one side of the light-transmissible fabric sheet 21, so that said one side
of the light-transmissible fabric sheet 21 is waterproof and opaque.
[0013] Preferably, the opaque enamel coating 22 includes a pigment and polyurethane-acrylic
polymer. More preferably, the opaque enamel coating 22 includes hexamethylene diisocyanate
(HDI).
[0014] The undyed yarns are preferably made from a material selected from the group consisting
of polyvinyl chloride, polyurethane, aliphatic diisocyanate, and combinations thereof.
Aliphatic diisocyanate may be hexamethylene diisocyanate (HDI). More preferably, the
undyed yarns are made from HDI.
[0015] Fig. 4 illustrates the second preferred embodiment of the sunshade according to the
present invention. The second preferred embodiment differs from the first preferred
embodiment in that said one side of the light-transmissible fabric sheet 21 is coated
with two different opaque enamel coatings 22, 23 at two different regions, respectively.
Compositions of the opaque enamel coatings 22, 23 are different, so that the two different
regions of the light-transmissible fabric sheet 1 have different colors and/or properties.
[0016] Fig. 5 illustrates the third preferred embodiment of the sunshade according to the
present invention. The third preferred embodiment differs from the second preferred
embodiment in that the two opaque enamel coatings 22, 23 are coated on two opposite
sides of the light-transmissible fabric sheet 21, respectively.
[0017] Fig. 6 illustrates consecutive steps of a method for preparing the canopy 2 of the
sunshade of the first preferred embodiment according to the present invention.
[0018] The method includes the steps of: providing a light-transmissible fabric sheet 21
of undyed yarns (step 71) ; coating an enamel composition 20 on at least one side
of the light-transmissible fabric sheet 21 to form an opaque enamel coating 22 on
the light-transmissible fabric sheet 21 (step 72); and drying the opaque enamel coating
22 (step 73).
[0019] Fig. 7 illustrates a processing system that can be used in the method of the present
invention shown in Fig. 6. As shown in Figs. 6 and 7, in step 71, a supply reel 41
is provided for supplying the light-transmissible fabric sheet 21 to undergo subsequent
coating and drying operations. The enamel composition 20 is stored in a tank 24. When
conducting coating of step 72, the enamel composition 20 is guided to one side of
the light-transmissible fabric sheet 21 using a die head 25, followed by spreading
the enamel composition 20 using a scraper 26 so that the opaque enamel coating 22
is uniformly coated on the light-transmissible fabric sheet 21. In step 73, a dryer
3 is provided for drying the opaque enamel coating 22 on the continuous light-transmissible
fabric sheet 21 processed by the scraper 26 so as to obtain the canopy 2. A pickup
reel 42 is provided for collecting the canopy 2 thus obtained.
[0020] Preferably, the enamel composition 20 includes a pigment, polyurethane-acrylic polymer,
and a solvent. Based on the total weight of the enamel composition 20, the pigment
is in an amount ranging from 12 to 17 wt%, the polyurethane-acrylic polymer is in
an amount ranging from 40 to 60 wt%, and the solvent is in an amount ranging from
20 to 40 wt %. More preferably, the amount of the pigment is 15 wt%, the amount of
the polyurethane-acrylic polymer is 50 wt%, and the amount of the solvent is 35 wt%.
[0021] Examples of the solvent are dimethylformamide (DMF) and toluene.
[0022] Preferably, the enamel composition 20 further includes a cross-linking agent. The
cross-linking agent is in an amount ranging from 1 to 4 wt% of the total weight of
the enamel composition 20.
[0023] Preferably, the method of preparing the canopy 2 further includes dipping the light-transmissible
fabric sheet 21 coated with the opaque enamel coating 22 into a hot water bath (not
shown) to wash away excess opaque enamel coating 22 before drying the opaque enamel
coating 22, followed by dipping the light-transmissible fabric sheet 21 coated with
the opaque enamel coating 22 into a cold water bath (not shown) to cool and solidify
the opaque enamel coating 22. The temperature of the hot water bath ranges from 100
to 120°C, and the temperature of the cold water bath ranges from 30 to 50°C.
[0024] Preferably, drying of the opaque enamel coating 22 is conducted by subjecting the
opaque enamel coating 22 on the continuous light-transmissible fabric sheet 21 to
a hot air blowing treatment.
[0025] The advantages of the present inventions can be summarized as follows. As compared
to the method of preparing the conventional canopy, both the opaque and waterproof
properties are imparted to the light-transmissible fabric sheet 21 in only one single
step, i.e., the step of coating the opaque enamel coating 22 on the light-transmissible
fabric sheet 21, and undyed yarns of the light-transmissible fabric sheet 21 are not
required to undergo the dyeing process in advance, thereby eliminating the aforesaid
problem of generation of dyeing waste water. In addition, the method of the present
invention allows coating of the light-transmissible fabric sheet 21 at different regions
thereof with different colors of the opaque enamel coatings 22 so as to permit formation
of various designs and features on the light-transmissible fabric sheet 1.
1. A sunshade comprising:
a support frame (1); and
a canopy (2) connected to said support frame (1);
characterized by said canopy (2) including a light-transmissible fabric sheet (21) of undyed yarns
and an opaque enamel coating (22) coated on at least one side of said light-transmissible
fabric sheet (212), said undyed yarns being woven and cross one another to form fabric
pores (211) thereamong, said opaque enamel coating (22) filling said fabric pores
(211).
2. The sunshade as claimed in Claim 1, characterized in that said opaque enamel coating (22) includes a pigment and polyurethane-acrylic polymer.
3. The sunshade as claimed in Claim 1, characterized in that said undyed yarns are made from a material selected from the group consisting of
polyvinyl chloride, polyurethane, aliphatic diisocyanates, and combinations thereof.
4. A method of preparing a canopy,
characterized by:
providing a light-transmissible fabric sheet (21) of undyed yarns;
coating an enamel composition (20) on at least one side of the light-transmissible
fabric sheet (21) to form an opaque enamel coating (22) on the light-transmissible
fabric sheet (21); and
drying the opaque enamel coating (22).
5. The method of claim 4, characterized in that the enamel composition (20) includes a pigment, polyurethane-acrylic polymer, and
a solvent, and, based on the total weight of the enamel composition (20), the pigment
is in an amount ranging from 12 to 17 wt%, the polyurethane-acrylic polymer is in
an amount ranging from 40 to 60 wt%, and the solvent is in an amount ranging from
20 to 40 wt%.
6. The method of claim 4, further characterized by dipping the light-transmissible fabric sheet (21) coated with the opaque enamel coating
(22) into a hot water bath before drying the opaque enamel coating (22), followed
by dipping the light-transmissible fabric sheet (21) coated with the opaque enamel
coating (22) into a cold water bath, wherein the temperature of the hot water bath
ranges from 100 to 120°C, and the temperature of the cold water bath ranges from 30
to 50°C.
7. The method of claim 6, characterized in that drying of the opaque enamel coating (22) is conducted by subjecting the opaque enamel
coating (22) to a hot air blowing treatment.