|Title of Invention||
NEW POLYMER SHEET,METHOD THEREOF AND METHOD OF BACKING CARPET OR SUCH THICK FABRIC MATERIAL WITH THE SAME.
|Abstract||A NEW POLYMER SHEET AND METHOD OF BACKING A CARPET OR SUCH THICK MATERIAL WITH THE SAID POLYMER SHEET WHEREIN THE POLYMER SHEET COMPRISES ETHYL VINYL ACETATE (EVA) OR POLYMER CHOLRIDE (PVC)OR BLEND OF EVA AND PVC TOGETHER WITH A FILER MATERIAL. THE POLYMER SHEET IS BACKED ON THE CARPET OR SUCH THICK MATERIAL BY HOT PRESSING THE POLYMER SHEET IN A HEATING CHAMBER ON A HEATING PLATE.|
|Full Text||The present invention relates to a new polymer sheet,
method thereof and a method of backing carpet or such thick
fabric materials with the said polymer sheet.
More particularly the invention relates to a new polymer
sheet and to a method for improved backing of carpet or such
thick fabric materials with the new polymer sheet thereby
improving the durability and aesthetic aspect of the carpet.
According to the prior practice, backing of carpet or such
thick fabric materials is done by bonding multiple backing
textile fabrics with chemical coating such as latext which is a
rubber compound comprising ingredients like adhesive, fillers(
which includes zinc oxide, chalk powder, sulpher powder,
titanium dioxide, sodium hexametaphospate, etc.), preservative(
zinc, pentaclorophenol or such compounds) and other chemicals.
However the formulation of latex and its manual application for
bonding multiple backing textile fabrics is hazardous, toxic
and the process is time consuming and drudgery.
The tufts of carpet or such type of thick fabric project
upward on the face of fabric and provide comfort to foot and or
aesthetic look. Such tufts are formed over a yarn or group of
yarns of a warp beam or over a yarn or group of yarn of a
Primary fabric of desired material and construction. Commonly
used materials are cotton yarn/silk yarn/blended yarn and
fabrics of cotton & jute. The tufts formed over yarn or fabric
results formation of a thick fabric known as Carpet. Such
carpets/thick fabrics, irrespective of manufacturing method,
are used for
purposes like floor covering, wall hanging, upholsteries,
furnishings, etc., after the backing process which in many cases
like tufting, involves secondary backing followed by third
backing using different type of fabrics and chemicals as per the
requirement to enhance the tuft withdrawl force cum durability
and also enhances the aesthetic appeal of the carpet.
Presently used technique for backing involves using of two
series of backing fabrics (net fabric and dosuti/Matt or Hessian)
which are fixed by chemicals, such as Latex, for both the backing
surfaces, followed by stretching and drying of the backing
surfaces. All the operations are either carried out mechanically
or manually (fully or partially). The feed back reveals that the
receipe and or operation as mentioned above does not meet the
requirement in many cases. The backing techniques in practice are
not user friendly.
The drawbacks of the presently used methods are:
(i) Chemicals used for the backing, requires in heavy quantity
and poses problem for material handling.
(ii) Use of such chemicals in higher does is hazardous either
from the process and or product point of view.
(iii) Most chemical formulation demands addition of
preservative/pesticide which is another problem with respect to
(iv) Poor availability of net fabric and problem in handling.
One aspect of the present invention is to produce a new polymer
sheet which is used for backing carpet or such thick fabric
Another aspect of the present invention is a method for backing carpet or such thick fabric
material with the said new polymer sheet.
According to the present invention there is provided:
New polymer sheet comprising Ethyl Vinyl Acetate(EVA) or Polyvinyl
Chloride(PVC) or blend of Ethyl Vinyl Acetate and Polyvinyl Chloride and filler materials.
The invention is now described in details with reference to the
Fig. 1 shows a heating chamber for heating the new polymer sheet
and backing the carpet or such thick fabric with said sheet.
The new polymer sheet is prepared, from Ethyl vinyl Acetate (EVA)
or Polyvinyl Chloride (PVC) Or blends of both EVA and PVC are
mixed with filler materials to form the new polymer sheet. The
filler material used is one or more of the materials selected
from chalk powder, zinc powder or talc. The filler material
content in the polymer sheet is 18 ± 12 % of the final
composition. The content of EVA or PVC or blend of both in the
polymer sheet is 70 to 80 % of the final composition. The EVA or
PVC granuales or blends of both are mixed with filler materials
in a homogeniser at a temperature between 70 deg. C to 120 deg. C
until the mixture is mixed homogeniously and forms a viscous
pasty material. This pasty material is extruded and hot pressed
and subsequently cooled in atmosphere or by a blower to form the
new polmer sheet. The new polymer sheet so formed have the
following physical characteristics :
Specific Gravity : 1.3 ± 0.2
Ash content(in %) for EVA : 23 ± 4
PVC : 0.03 ± 0.01
Acetone Extract(in %) for EVA : 23 ± 4
PVC : 35 ± 10
Melting Point : 75 ± 10 deg.C
The carpet 1 or such thick fabric material is layed upside down
on a platform 5, such that the top surface of the carpet rests on
the platform and back surface is on the top. On the back surface
of the carpet , the new polymer sheet 2 is layed. On top of the
polymer sheet, if necessary , textile backing(TB) 3 is also layed
in a single or multiple layer depending upon the requirement for
forming the backing sheet. The platform alongwith carpet, new
polymer sheet and textile backing is inserted into the heating
chamber 6. The heat plate 4 of the heat chamber, is heated by an
electrical heating coil( 240 V, 500W ) until the temperature of
the heat plate rises to 130 to 280 deg. C. The heated heat plate
is brought in contact with the polymer sheet until it initiates
melting of the polymer sheet. The temperature of the plate is
monitored by a digital thermocouple. The heated heat plate, which
xs in contact with polymer sheet, presses the polymer sheet by a
pneumatic system or a counter load system at an average pressure
of 2 to 8 kg/sq.cm for a period of open time 30-120 sec. for
backing the carpet or such thick fabric material with the new
polymer sheet. The composite material of new polymer sheet and
carpet or such thick fabric material is passed through a pair of
rollers, which may be manually driven or self driven, to ensure
uniform bondage of the new polymer sheet and textile backing
tnaterxal on to the carpet or such thick fabric material and also
ensuring that the bonded carpet is properly selvedged. The carpet
backed with the new polymer sheet is removed from the heat
chamber and kept in open air and allowed to be cooled for atleast
an hour. The carpet or such thick fabric material is finally
backed with the new polymer sheet.
It is evident that the steps of the method of backing the carpet
may be modified in order to obtain the same result without
departing from the scope of the invention.
1. New polymer sheet comprising Ethyl Vinyl Acetate(EVA) or Polyvinyl Chloride(PVC)
or blend of Ethyl Vinyl Acetate and Polyvinyl Chloride and filler materials.
2. New polymer sheet as claimed in claim 1 wherein filler materials is one or more
selected from chalk powder, zinc oxide or talc.
3. New polymer sheet as claimed in claim 1 wherein Ethyl vinyl acetate is 70 to 80
weight% of the final composition of polymer sheet.
4. New polymer sheet as claimed in claim 1 wherein polyvinyl chloride is 70 to 80
weight% of the final composition of polymer sheet.
5. New polymer sheet as claimed in claim 1 wherein the filler materials content is 18 ± 12
weight% of the final composition.
6. Method of preparing the new polymer sheet as claimed in claim 1 comprising the steps
of mixing the granules of EVA and/or granules of PVC together with the filler materials in a
homogeniser at a temperature between 70 to 120 deg. C to form a viscous liquid which is
subsequently extruded, hot pressed and cooled in atmosphere.
7. A method of backing carpet or such thick fabric material with the new polymer sheet as
claimed in claim 1, comprises the steps of:
(a) laying the carpet or such thick fabric material, upside down, on a platform of a heating
(b) laying the new polymer sheet on the back side of the carpet or such thick fabric
(c) inserting the platform along with the carpet and polymer sheet inside the heating
(d) pressing the new polymer sheet with the heard plate at an average pressure of 2 to 8
kg/sq.cm for a period of 30 tol20 Sec. until the new polymer sheet initiates melting and
bonded to the backside of the carpet.
(e) passing the composite material of new polymer sheet and carpet or such thick fabric
material through a pair of rollers for uniform bondage.
(f) cooling the composite material of new polymer sheet and carpet or such thick fabric
8. A method of backing carpet as claimed in claim 6 wherein the plate is heated to 130 to
280 deg. C by an electrical heating coil.
9. A method of backing carpet as claimed in claim 6 wherein the pressure on the polymer
sheet is applied by pneumatic system.
10. A method of backing carpet as claimed in claim 6 wherein the composite material is
cooled in the open air or by a blower for at least one hour.
11. A method of backing carpet as claimed in claim 6 wherein at least a layer of textile
backing is layed over the new polymer sheet for backing carpet or such thick fabric material.
12. New polymer sheet substantially as herein before described.
Dated this 10th day of June 2004.
A new polymer sheet and method of backing a carpet or such thick material
with the said polymer sheet wherein the polymer sheet comprises Ethyl Vinyl
Acetate(EVA) or Polyvenyl Cholride(PVC) or blend of EVA and PVC together with a
filler material. The polymer sheet is backed on the carpet or such thick material by
hot pressing the polymer sheet in a heating chamber on a heating plate.
|Indian Patent Application Number||311/KOL/2004|
|PG Journal Number||43/2007|
|Date of Filing||10-Jun-2004|
|Name of Patentee||DR. KAMAL KANTI GOSWAMI|
|Applicant Address||C/O. S. N. DATTA & ASSOCIATES, 7B, KIRAN SHANKAR RAY ROAD, 4TH FLOOR, KOLKATA 700 001.|
|PCT International Classification Number||D06N 7/00|
|PCT International Application Number||N/A|
|PCT International Filing date|