JPH0431248B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for backing a carpet including a foamed PVC layer on the backside, and more specifically, to
This is a carpet back processing method using a transfer method using mechanically foamed PVC, and is particularly concerned with a back processing method suitable for tile carpets.

(Prior art) Conventionally, carpeting involves coating a layer of PVC resin on the surface of a release belt, adhering a carpet on top of the layer, allowing the resin to gel, and then peeling off this laminate from the release belt. The backing method (referred to as transfer method) is known.

In addition, a method of lining a carpet with PVC foam using the above transfer method is described in Japanese Patent Publication No.
It is known from No. 61-245383.

However, these foamed PVCs are heat-sensitive foams.
This was done by so-called chemical foaming, which involves mixing it with PVC sol and foaming it by heating.

(Problem to be Solved by the Invention) In the case of chemical foaming, the hot air temperature for foaming requires a high temperature of 200°C or higher, which will damage the pile threads of the carpet. The carpet had to be attached after foaming was completed, heat treatment for foaming and bonding had to be done separately, and adhesive was needed to bond the carpet after foaming the PVC and curing it. .

Furthermore, since the temperature of the hot air in the heat treatment furnace is high, differences in the temperature distribution of the hot air tend to be large, and since it is difficult to control the expansion ratio, there is also large variation in thickness. In addition, the inclusion of a foaming agent increases costs.

In order to solve these problems, there was a need for a so-called machine-foamed PVC transfer backing method, in which a PVC sol with air bubbles dispersed in advance is applied using an oak mixer or the like.

In the past, attempts have been made to back tile carpets using a mechanically foamed PVC transfer method, but these methods have had the following problems. That is, when the PVC sol is heat-treated, the viscosity of the sol decreases in the range of 50 to 60°C. For this reason, in the case of a foamed PVC sol obtained by mechanically dispersing gas, the strength of the resin film surrounding the cells decreases when the viscosity decreases, and some cells are destroyed.

During processing, these destroyed cells can be damaged at the interface between the carpet base material and the backing layer, or if the backing layer has a multilayer structure.
They aggregate between the layers, causing peeling between the carpet and the PVC layer, which significantly reduces the commercial value of the carpet.

(Means for solving the problems) The present invention solves the above-mentioned drawbacks,
In a carpet lining method in which one or more backing materials are coated and laminated on the surface of a releasable belt, a carpet is placed on top of the backing material and the pressure-bonded material is peeled off from the belt, the layer closest to the carpet as the backing material. A mechanically foamed PVC sol is applied to the surface of the releasable belt, and the heating method described above is such that after all the backing material has been applied and laminated on the surface of the releasable belt, the laminate is heated only from below the releasable belt. When the mechanically foamed PVC sol in the uppermost layer becomes a semi-gel state, a carpet is placed and pressed on top of these laminates, and the laminated body is further heated to cure the mechanically foamed PVC sol. This is a carpet back finishing method.

The present invention will be explained in detail based on the example shown in FIG.

The release belt 11 is moving at a constant speed in the direction of the arrow. Then, 1 to 3 mm of non-foamed PVC sol 6 is placed on the release belt 11, preferably 1 to 3 mm.
It is coated with a doctor knife 7 to a thickness of 1.5 mm, and then one or more layers of tensile base fabric 5 such as glass fiber or polyester coarse woven fabric or non-woven fabric is inserted, and then mechanically foamed to a size of 2 to 5 times. was done
Layer 2 to 10 mm of PVC sol 4.

At this time, if the thickness of the non-foamed layer 6 is less than 1 mm, the weight will be insufficient and the static stability as a tile carpet will be insufficient, and if it is more than 3 mm, the heat conduction by the bottom heater 8 described later will be poor, and the cells of the foam will be takes a long time to stabilize.

Further, if the foam layer 4 is less than 2 mm, the cushioning properties of the product will be poor, and if it is more than 10 mm, it will take time to stabilize the cells and the product will be of excessive quality.

The PVC sol is uniformly applied by the doctor blade 7.

After the above lamination, the laminated body 13 is heated by the preheater 8 from the lower surface of the releasable belt. In this case, heating is performed on the foamed PVC layer 4 and the non-foamed PVC layer 6.
The purpose is to stabilize the cell by turning it into a semi-gel state.

This "semi-gel state" is an incomplete gel state in which the PVC sol has lost its fluidity due to heating but remains sticky and plastic, allowing the PVC layer to adhere to a base material such as a carpet simply by pressure bonding. state the condition.

One of the features of the present invention is that the PVC sol before the carpet is bonded is heated only from the lower part of the laminate 13, so that the lower layer gels first than the upper layer. Relatively large bubbles aggregated by destruction are PVC
The upper part of the layer is not gelled, allowing upward movement of air bubbles and degassing upwards from the surface of the PVC layer.

As a result of the above, the PVC sol becomes a semi-gel state,
Fluidity is lost and the bubbles stop consolidating. In addition, if something that prevents the passage of air bubbles, such as a carpet or base fabric, is attached to the foamed PVC layer 4 before it becomes a semi-gel state, the air bubbles may form air pockets and form a bond between the carpet base material and the foamed PVC layer. A peeling phenomenon occurs at that portion. Also, if the gelation of the upper layer of foamed PVC occurs earlier than the lower layer, air bubbles will not be able to escape upward from the surface of the upper layer, resulting in air pockets.

Furthermore, in this heating step, by heating only from the bottom surface, gelation of the adhesive surface on the surface of the foamed PVC is delayed the most, and sufficient adhesive strength can be maintained. If the foamed PVC layer is heated from the top, the surface will gel, a film will be formed, and the adhesive force will become weak, which is not preferable.

Moreover, the heating method at this time is to heat the laminated body 13 from the lower part by bringing the iron plate 8 heated by an electric heater under the releasing belt into contact with the belt.

The heating conditions at this time are the above iron plate temperature of 10℃.
Above, preferably 20 to 60 seconds at 130 to 160°C, preferably 20 to 30 seconds is suitable. The heating method may be other methods such as hot air or infrared rays.

The heating conditions at this time are the release belt and PVC.
It is necessary to adjust the thickness and material of the layer and intermediate base fabric layer. Therefore, the heating conditions here require heating until the foamed PVC layer 4 becomes semi-gelled. At this time, the temperature of the heating heater is controlled to be constant using a remote thermometer or the like.

After the foamed PVC layer 4 is in a semi-gel state by the above method, a carpet base material is placed on the foamed PVC layer with the back side as the adhesive surface, and a press roller 9 is used to bond the carpet base material and the foamed PVC layer. Press and bond without using any adhesive.

To prevent the pile from falling out, it is recommended that the carpet base material be coated with a primer and dried beforehand.
The primer is EVA, so that it has good adhesion to the foamed PVC.
Emulsion types such as PVC are suitable.

Thereafter, the releasable belt 11 and the laminate 13 are introduced into the heat treatment furnace 10 and heated from the releasable belt side with hot air at a temperature of 150 to 170°C to completely cure the PVC layers 4 and 6. Thereafter, the laminate is peeled off from the release belt.

In addition, when making a tile carpet, the laminate is cooled and then cut into a predetermined size to make a tile carpet.

In the above, the butting material is unfoamed in order from the bottom.
In this example, PVC, tensile base fabric, and foamed PVC are used, but there are other methods such as using only one layer of the above-mentioned foamed PVC without layering non-foamed PVC or tensile base fabric, and using foamed PVC instead of the non-foamed PVC in this example. All methods of laminating mechanically foamed PVC layers to are included in the present invention.

(Effects) The present invention enables mechanical foaming, which was previously difficult.
It has become possible to line carpets with PVC using a transfer method. That is, in the present invention, by heating the foamed PVC layer from the bottom surface to promote gelation from the bottom surface and bringing it into a semi-gel state before bonding the carpet base material, air pockets due to cell destruction are avoided. Stabilize cells and foam
Because the PVC surface has appropriate plasticity and adhesive strength,
PVC gets into the unevenness of the back side of the carpet, and due to the synergistic effect with the anchoring effect, PVC foams without adhesive.
and carpet base materials can be strongly bonded,
The thickness of the foam layer was also more uniform compared to chemical foaming.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the lining method of the present invention.
FIG. 2 is a cross-sectional view of one embodiment of a tile carpet manufactured according to the present invention. 1... Pile, 2... Primary base fabric, 3... Sealing layer, 4... Mechanically foamed PVC, 5... Glass base fabric,
6...Non-foamed PVC, 7...Doctor knife, 8
...Preheater, 9...Press roller, 10
... Heat treatment furnace, 11 ... Release belt, 12 ...
Hot air device, 13... laminate.

Claims (1)

[Scope of Claims] 1. A carpet lining method in which one or more backing materials are coated and laminated on the surface of a releasable belt, and then a carpet is placed thereon and pressure-bonded and then peeled off from the belt, comprising: A mechanically foamed PVC sol is applied to the layer closest to the carpet as a material, and the heating method described above is such that after all the backing materials have been applied and laminated on the surface of the release belt, the heating of these laminates is released. The molding process is carried out only from below the molding belt, and when the top layer of the mechanically foamed PVC sol is in a semi-gel state, a carpet is placed and pressed on top of these laminates, and the laminate is further heated to form the mechanically foamed PVC sol. A carpet back processing method characterized by curing sol.