GB2120294A

GB2120294A - Non-woven textile scrim

Info

Publication number: GB2120294A
Application number: GB08312340A
Authority: GB
Inventors: Gilbert Chomarat
Original assignee: Fils dAuguste Chomarat et Cie SA
Current assignee: Fils dAuguste Chomarat et Cie SA
Priority date: 1982-05-12
Filing date: 1983-05-05
Publication date: 1983-11-30
Also published as: FR2526818A1; GB8312340D0; DE8313733U1; CA1185885A; GB2120294B; FR2526818B1

Abstract

Improved non-woven textile scrim of the type constituted by a layer of parallel weft yarns 14, hemmed in between two layers of likewise parallel warp yarns 2, 3 and in which said warp yarns are superposed one on the other and on the weft yarns and the whole assembly is bonded together by way of an appropriate resin, wherein part at least of the warp yarns are very bulky elastic textured multifilament synthetic yarns. <IMAGE>

Description

SPECIFICATION Non-woven textile scrim The present invention relates to a new type of non-woven textile scrim.

It is well known that in textiles, a "scrim" is a woven or non-woven fabric which is very perforated. The currently used scrims are mostly non-woven ones and are obtained by superposing at least one layer of warp yarns over a layer of weft yarns. Preferably, a layer of warp yarns is placed on either side of the weft layer which is in the center. There are a number of well-known techniques for producing these screens. One of these techniques is described in Applicant's French Patent Application No. 77 22475 of July 13, 1977, published under No. 2 397 479 and will not therefore need to be described here in detail.

In practice, the scrim or lattice structure is consolidated by passing the whole textile assembly in the appropriate adhesive or coating so as to bond the yarns together at their points of intersection.

Briefly, there are at the moment essentially two types of non-woven scrims: - a first type in which the warp yarns are offset from one face to the other, with respect to the weft yarns; - a second type in which the warp yarns are superposed with respect to the weft yarns.

The first technique with the offset structure enables to produce lightweight scrims, the mechanical strength of which however is inadequate for certain applications due to the fact that there is cohesion only at the respective points of intersection.

The second technique with the superposed structure gives stronger products, because the warp yarns, which are superposed, are bonded together throughout their length whilst being also bonded to the weft yarns at their points of intersection. These products however, are heavier and more expensive, which makes them difficult if not impossible to use in some applications.

In the manufacture of insulating coverings, for the building industry, the aim is to combine lightness with strength, which is difficult to achieve with glass-fibers. But today the market is asking more and more for these products.

It is the object of the present invention to overcome these drawbacks by proposing a product of the aforesaid type which is altogether economical, light, strong and more readily shapable, i.e. more able to adopt different shapes.

The improved non-woven textile scrim according to the invention which is of the type constituted by a layer of parallel weft yarns hemmed in between two layers of likewise parallel warp yarns and in which said warp yarns are superposed one on the other and on the weft yarns and in which assembly cohesion is obtained by bonding with the appropriate resin, is characterized by the fact that at least part of the warp yarns are elastic, textured, multifilament synthetic yarns of great bulkiness.

In practice: one of the two layers of warp yarns is entirely produced from textured multifilament synthetic yarns; - the textured yarns are obtained by false twist, set or not.

The fact that the textured yarn is a multifilament yarn and is very bulky, helps the retention of the adhesive and the subsequent adhesion, hence the cohesion of the assembly.

And also, the fact that the textured yarn is elastic and that such yarns are all situated on the same side with respect to the warp yarns, makes the assembly more readily deformable and so enables it to more readily adopt other shapes.

The present invention will be more readily understood on reading the following description with reference to the accompanying drawings in which: - Figure 1 is a cross-sectional view along the longitudinal axis of the weft yarn of an improved scrim according to the invention; - Figure 2 is a cross-sectional view of said scrim along the axis of the superposed warp yarns; - Figure 3 illustrates another embodiment in which the textured yarns are placed alternately on one side and on the other of the central weft yarns; - Figure 4 is a diagrammatical view of an installation for producing an improved scrim according to Figures 1 and 2.

Referring first to Figures 1, 2 and 4, these show: -in (1) the weft yarn, - in (2) the warp yarns of the lower layer, - in (3) the warp yarns of the upper layer of reset or non-reset multifilament synthetic yarns textured by false twist.

These two superposed warps (2) and (3) are placed over the weft layer (1) by any known technique, such as for example by that described in Applicant's French Patent Application No.

2 397 479, mentioned hereinabove, and using the grooved bars (10).

The resulting lattice structure (4) is picked up continuously first on a forming cylinder (5), then on an adhesive-coating cylinder (6) wherefrom it is brought to a coating tub containing a suitable resin such as: PVC, vinyl acetate, polyvinyl alcohol.

The adhesive-coated scrim (8) is thereafter brought through a coating-pressing roller (9) and finally into a drum drying system (11) to obtain a finished scrim (12) i.e. a scrim coated not only at the points of intersection (see Figure 2) (13) and (14) respectively of the lower (2) and upper (3) warp yarns with the weft yarns (1), but also on the lapped portions (1 5) of the warp yarns (2) and (3) between two successive weft yarns (1).

According to the embodiment diagrammatically illustrated in Figure 3, the textured warp yarn (3) is superposed on another warp yarn (2), but positioned alternately with respect to the weft (1).

According to Figure 4, a scrim according to Figures 1 and 2 is produced with: - as weft (1) and lower warp (2), a glass yarn of continuous filament of 51 Tex, - as upper chain (3), a polyester yarn 110 dtex/32 filaments textured by false twist, - a texture of 4 warp yarns and 4 weft yarns per centimetre, - a vinyl acetate adhesive (7) in aqueous suspension.

The finished scrim thus obtained, is an adhesive bonded scrim weighing around 50 g/m2 in which the weight of the adhesive represents about 10g/m2.

Such a scrim is advantageously used in the building industry, especially as reinforcement for insulating coverings because of: its lightness, its high mechanical resistance, its reduced cost price, due to the fact that textured yarns of a secondary low quality can be used, its excellent resistance to sliding due to the superposed structure, i.e. the bonding in (15), its foldability and shapability, since in this kind of deformation, the elasticity of the textured yarn (3) permits to play with the length and to absorb the differences.

Up until now, it was not known whether such properties, could be obtained nor how to obtain them, some of them belonging either to the scrims of superposed structure, such as for example strength, or to the scrim with offset structures, such as lightness and low cost, but not to both, and the novel characteristic of the invention is that which enables to obtain new properties such as the ability to conform. And neither was it possible to obtain as light a scrim even with a very similar texture when a scrim entirely made of glass was used.

Therefore, the scrims according to the invention find a useful application in insulating buildings, and reinforcing films, papers, etc.

Claims

1. Improved non-woven textile scrim of the type constituted by a layer of parallel weft yarns, hemmed in between two layers of likewise parallel warp yarns and in which said warp yarns are superposed one on the other and on the weft yarns and the whole assembly is bonded together by way of an appropriate resin, wherein part at least of the warp yarns are very bulky elastic textured multifilament synthetic yarns.

2. Scrim as claimed in claim 1, wherein one of the two layers of warp yarns is entirely made up of textured multifilament synthetic yarns.

3. Scrim as claimed in claim 1, wherein the textured yarns are obtained by false twist.

4. Improved non-woven textile scrim wherein said scrim is constituted by: - a layer of parallel weft yarns, - a first layer of parallel warp yarns disposed perpendicularly under the layer of weft yarns, - a second layer of parallel warp yarns composed of very bulky elastic multifilament synthetic textured yarns, placed over the layer of weft yarns and superposed on the warp yarns of the first lower layer, - the assembly of the weft and warp yarns being adhesively bonded together at their respective points of intersection and meeting points, by way of a suitable resin.

5. Non-woven textile scrim substantially as hereinbefore described with reference to and as illustrated in Figures 1 and 2 or in Figure 3 of the accompanying drawings.