US3809589A - Method for making pile fabric - Google Patents

Abstract

FLEXIBLE PILE FABRICS ARE MADE BY BENDING THE END PORTIONS OF THE FIBRES IN A SURFACE OF AN ARRAY OF ALIGNED FIBRES, SETTING THE FIBRES IN THE BENT STATE, AND SECURING THE BENT FIBRE ENDS IN A LAYER OF ADHESIVE. SUITABLY ALIGNED FIBRES ARRAYS MAY BE MADE BY SEVERING THE PROJECTING FIRES OF A FURRED ANIMAL SKIN, SUCH AS RAW OR PICKLED WOOLED SKINS, OR OF AN ARTIFICIAL FABRIC HAVING PROJECTING FIBRES OF NATURAL OR SYNTHETIC ORIGIN. A FABRIC BACKING MATERIAL MAY BE ADHERED TO THE FACE OF THE PILE FABRIC CARRYING THE ADHESIVE LAYER BEFORE OR AFTER THE SETTING OF THE ADHESIVE.

Description

v. A. KERSTETTER ET AL 3,809,589

METHOD FOR MAKING FILE FABRIC May 7, 1974 4 Sheets-Sheet 1 Original Filed Jan.

INVENTORS VIRGINIA AKERSTETTER LOUIS R. MIZELL ATTORNEYS May 7, 1974 v. A. KERS TETTER ET AL 3,309,539

METHOD FOR MAKING FILE FABRIC 4 Sheets-Sheet 2 Original Filed Jan. 6, 1970 I VIRGINIA A. KERSTETTER INVENTORS LOUIS RIVIIZELL ATTORNEYS y 7, 1974 v. A. KERSTETTER ETTAL 3,809,589

METHOD FOR MAKING FILE FABRIC 4 Sheets-Sheet Original Filed Jan.

INVENTORS VIRGINIA AKERSTETTER ou|s R. MIZELL ATTORNEYS y 7, 1974 v. A. KERSTETTER ET AL METHOD FOR MAKING FILE FABRIC Original Filed Jan. 6, 1970 4 Sheets-Sheet L INVENTORS VIRGINIA A KEIQSTETTER LOUIS R MIZELL I y/ww 5/ ATTORNEYS -United States Patent Office 3,809,589 Patented May 7, 1974 3,809,589 METHOD FOR MAKING PILE FABRIC Virginia Ann Kerstetter, Chelmsford, and Louis Richard Mizell, Andover, Mass., assignors to I.W.S. Nominee Company Limited, London, England Continuation of abandoned application Ser. No. 961, Jan.

6, 1970. This application Dec. 8, 1971, Ser. No. 206,150 Int. Cl. B32b 5/08 US. Cl. 156-68 6 Claims ABSTRACT OF THE DISCLOSURE Flexible pile fabrics are made by bending the end portions of the fibres in a surface of an array of aligned fibres, setting the fibres in the bent state, and securing the bent fibre ends in a layer of adhesive. Suitably aligned fibres arrays may be made by severing the projecting fires of a furred animal skin, such as raw or pickled wooled skins, or of an artificial fabric having projecting fibres of natural or synthetic origin. A fabric backing material may be adhered to the face of the pile fabric carrying the adhesive layer before or after the setting of the adhesive.

This is a continuation of application Ser. No. 961, filed Jan. 6-, 1970, now abandoned.

This invention relates to the production of pile fabrics comprising natural or synthetic fibres which are secured in a layer of adhesive. The invention is particularly concerned with the production of flexible pile fabrics having good handle and drape properties, e.g. as blanket material, apparel fabrics and filter fabrics.

The manufacture of pile fabrics by anchoring the fibre ends of a pile in a layer of adhesive is well known, and many carpets have been formed in this way. The layer of adhesive has to be of such a thickness to firmly retain the pile fibres and accordingly such pile fabrics tend to have poor handle and a board-like structure. Whilst this is not a disadvantage when the pile fabric is a carpet, it is an extreme disadvantage when pile fabrics of the blanket type are required where good handle and drape are essential. In order to avoid this board-like structure, attempts have been made to use very thin layers of adhesive, but it was found that these thin layers did not give rise to satisfactory pile fabrics in that there was not sufiicient lateral bonding between adjacent fibres and the resulting fabric was mechanically weak.

In many processes for the production of pile fabrics, pressure has to be applied to the pile fibres after the adhesive is applied in order to ensure that there is adequate bonding between the fibres and the adhesive and it has been found that it is the application of pressure to the pile fabric which causes a continuous adhesive layer so producing the board-like feel of the fabric.

We have now found a method which enables pile fabrics of good handle and good drape to be produced by a simple process in which the need to apply pressure to the adhesive-treated pile is reduced or even completely removed.

According to the invention, there is provided a method of making a pile which comprises:

(a) providing an array of aligned fibres;

(b) urging the end portions of the fibres in a surface layer of the array to bend so that the said end portions are bent at an angle to the normal fibre direction in the array;

(c) setting the fibres in the bent state; and

(d) securing the bent fibre ends in a layer of an adhesive.

The bending of the fibre ends in the surface of the array is an important step in the process, and by setting them in this bent state it enables a small amount of adhesive to achieve a larger bonding effect than if the fibres were in an unbent state. The bent fibres overlap and cross one another, leaving a portion of the length of the fibres exposed in the surface, and ready to receive adhesive; the major proportion of the length of each fibre is below the surface plane and is protected from adhesive by neighboring or overlapping fibres. Thus the adhesive layer is, in effect, reinforced by the ends of the fibres which have been bent and form part of that layer. In this way maximum use is made of the minimum amount of adhesive. Particularly flexible fabrics are obtained when a discontinuous layer of adhesive is applied to the bent fibres, and in these circumstances the spots or regions of adhesive can be regarded as spot-welding a large number of pile fibres together. By the use of such small amounts of adhesive, very flexible pile fabrics are produced, and these fabrics have good drape and handle properties. Of course it will be understood that the degree of flexibility will depend on the thickness of the adhesive layer and that maximum flexibility will be obtained where the layer is discontinuous.

Suitably aligned fibre arrays may be made by severing the projecting fibres from an existing pile fabric, e.g. a furred animal skin or an artificial piled fabric having projecting fibres of natural or synthetic fibres. Particularly suitable for use in the method of the invention are raw or pickled wooled sheepskins; sliver-knit pile fabrics may also be used.

Pile fabrics useful in the method of the invention include sliver-knit and other piled fabrics having uniform or tufted piles or naps of natural or synthetic fibres including wool and wool-like fibres, cellulose and cellulosebased fibres and artificial or synthetic fibres of all types. When using such piled fabrics the adhesive may be applied to the outer ends of the fibres before or after the fibres are severed from the fabric or to the cut ends of the fibres after severance. It is preferred, however, to apply the adhesive to the cut ends of the fibres.

The end portions of the fibres in the surface of the array may be bent by applying pressure to the fibres in a direction substantially parallel to the normal fibre direction, i.e. at right angles to the surface formed by the fibre tips and this may be conveniently achieved by means of a flat bed press or a pair of calendering rolls. In the case of protein fibres it is also convenient to apply heat to the fibres in the presence of water in order to set the fibres in the bent state. However, as most protein fibres normally have sufiicient moisture absorbed thereon it is usually unnecessary to add additional water; if it is necessary, steam may be applied during the pressure step or, alternatively, the fibres may be wetted before the pressure step. In the case of artificial fibres setting of the fibres may be achieved by the usual methods, e.g. by the application of heat or pressure or both.

As mentioned in the preceding paragraph bending and setting of the fibres in the bent state may be carried out in one operation and this is usually the most convenient way in which to operate the process according to the invention. However the two operations may be carried out sequentially, that is to say bending followed by setting, provided that the fibres retain their bent position long enough for them to be set in that position.

As mentioned above, the fibres may be secured in a discontinuous layer of adhesive and this method of bonding leads to exceptionally flexible pile fabrics. Such discontinuous layers of adhesive also make the pile fabric porous, and thus particularly suitable for use as blanket material and for applications in filtering and humidfying applications. Whilst the adhesive may be applied to the bent fibre ends by any of the known methods, for example, by knife coating techniques, the preferred discontinuous layer may be obtained by depositing the adhesive 3 in the form of discrete droplets onto the bent ends of the fibres.

A wide range of adhesives may be utilized for forming the adhesive layer of the pile fabrics of the invention, including polyacrylics, polyurethanes, epoxies, Neoprenes, butadiene-styrene copolymers, polyesters, polyamides, phenolics and animal and vegetable glues. Typically useful are the commercially available polyacrylic latex adhesives, such as Rhoplex E-30 and Rhoplex E-32 of Rohm & Haas Co., applied, for example, at a rate to deposit about 4 ounces of solids per square yard of fabric when dried. Adhesives which set under conditions in which the fibres do not melt or otherwise undergo degradation are, of course, desirable.

The adhesive may be allowed to dry or cure itself at ambient temperatures, but it is usually preferable to include a heating step, e.g. to a temperature in the range 30 to 150 C., to speed up the process. If desired, a reinforcing backing fabric may be applied to the layer of adhesive at the base of the pile fabric and may be applied before or after the adhesive is dry. Backing fabrics may be woven, knitted, felted or otherwise consolidated porous web structures of natural or synthetic fibrous materials.

As an alternative method of securing the bent fibre ends in a layer of adhesive there may be used as the adhesive a heat-softened thermoplastic or hot-melt adhesive. The bent ends of the fibres may be secured by applying the softened thermoplastic to them, for example by means of a curtain coater. The thermoplastic material selected should have a melting point below the melting point, if any, of the fibres with which it is to be used. The film-backed fabric so produced may be.

laminated to a further fabric-backing material, such as cotton flannel or cheesecloth, before, at or subsequent to the embedding of the array of fibres in the thermoplastic material.

When using arrays of severed fibres, the fibres may be urged into closer juxtaposition in the array before applying the adhesive to the bent end portion of the fibres. When using fibre arrays cut from wooled skins the arrays of severed fibres from a plurality of skins may be urged into close association at the edges of the arrays to form consolidated array before applying the adhesive particles or a plurality of skins may be adhered together in edge to edge relation to form an extended structure, for example, by adhering the flesh side of the skins or the free tip ends of the fibres to a temporary tacky support of paper, fabric or the like and thereafter severing the fibres. Likewise, a temporary support may be applied to the outer ends of the projecting fibres of pile fabrics before the fibres are severed from the fabric.

In general, the length of the fibres in the pile of the fabrics of the invention will be in the range from about A to 1% inch although piles of longer or shorter lengths can be made by the method of the invention. The pile starting material can have fibre lengths up to 4 inches or more.

The invention will be more fully described and various embodiments thereof illustrated with reference to the accompanying drawings in which like elements are identified by the same reference numerals.

In the drawings:

FIG. 1 is a longitudinal section through apparatus for cutting an array of fibres from a piled article, forming a discontinuous adhesive layer on one face of the array of fibres and applying a fabric backing to the adhesive layer;

FIG. 2 is an enlarged fragmentary perspective showing of a portion of an array of fibres to which a layer of discontinuously contiguous adhesive droplets have been applied;

' FIG. 3 is an enlarged fragmentary longitudinal section 'showing diagrammatically the structure of the porous piled fabric produced by the method illustrated in FIG. 1;

FIG. 4 is a further enlargement of the piled fabric of FIG. 3;

FIG. 5 is a section on line 55 of FIG. 4;

FIG. 6 is a longitudinal section through apparatus generally similar to FIG. 1 but including means for applying a temporary supporting web to one face of the array of fibres; and

FIG. 7 is a longitudinal section through apparatus generally similar to that of FIG. 1.

In FIG. 1, 1 are Wool skins which are passed by conveyor belt 2, which may be of glass ,bre coated with Teflon or silicone, and suction roll 3 into cutter block 4- of a band knife machine. The arrays 5 of wool fibres cut from the skins are bent over at their cut ends by heated roll 6, which may be heated up to 400 F. and maintained at a pressure against roll 6 of from about 50 to about 500 p.s.i. After passing rolls 6, 6' a spray of adhesive particles is projected on the bent upper ends of the fibres by spray nozzles 7 in spray hood 8, forming a layer 9 (FIG. 2) of discontinuously contiguous particles.

A backing layer 10, for example, of woven woolen goods from supply roll 11, is applied to the adhesive layer 9 by rolls 12, 12' which exert just enough pressure to cause the backing fabric to make uniform contact with the adhesive throughout the fabric surface. The adhesive is dried and indurated by passing the ensemble under bank 13 of infra red lamps.

FIGS. 3, 4 and 5 show more clearly the porous and flexible structure of the pile fabric produced by the method illustrated in FIG. 1, including the array 5, the discontinuous layer 9 of adhesive and the fibrous backing layer 10.

In the apparatus of 'FIG. 6, a temporary support layer of gummed paper 14 from supply roll 15 is moistened by roll 16 and applied by rolls 17, 17' to the outer ends of the pile of sliver-knit pile fabric 18, which is then fed by roll 19 into cutter blade 4 of a band knife machine. Fibre array 5 is then flattened by roll 6, discontinuously coated with a spray of adhesive by nozzles 7 and after applying a fabric backing 10, the adhesive is cured by heater 13. The temporary support 14 is then removed at 20 and the resulting pile constituted by the fibre array 5 is brushed up by steam brush 21.

In the apparatus of FIG. 7, the fibre array 5, cut from pile fabric 14- by knife 4, is carried through the fibre: bending rolls 6, 6', adhesive spray 7, backing applier rolls 12, 12., and curing lamps 13 on conveyor belt 2.

In addition to producing very flexible pile fabrics, which also may be rendered highly porous if the layer of adhesive is discontinuous, the method of the invention is a faster process than those used hitherto for the production of pile fabrics. In these known processes the pile fibre ends are pressed into a layer of adhesive and held there for 2 to 3 minutes, whereas the only pressure step in the method of the invention is the pressing and setting of the fibre ends, which step takes 15 seconds or less in a flat bed press or can be made continuous when a heated pressure nip or similar pair of surfaces is used. It is to be noted that the prior art processes do not lead to the production of flexible pile fabrics having good handle and good drape.

What is claimed is:

1. A method of making a pile fabric consisting of the steps of providing an array of aligned fibres, urging the end portions of the fibres in a surface layer of the array to bend so that said portions are bent at an angle to the normal directions of the fibres in the array, setting said bent portions of the fibres in the bent state, and thereafter solely securing the set bent portions of the fibres into a continuous flexible layer by depositing adhesive on the bent and set portions of the fibres in the form of discontinuous and discrete droplets of the adhesive.

2. A method as claimed in claim 1 wherein said array of aligned fibres is obtained by severing the projecting May 7, 1974 R. s. FANTINI ETTAL 3,809,590

JET ENGINE STARTER HOSE AND METHOD OF MAKIG IT 7 Filed Feb. 14, 1972

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