US3687752A - Method of anchoring hair-like synthetic filaments to a wig base - Google Patents

Abstract

A METHOD IS HEREIN DESCRIBED FOR LOCKING HAIR-LIKE SYNTHETIC FILAMENTS FORMED FROM SUCH MATERIALS AS ACRYLIC AND MODACRYLIC TO A WIG STRUCTURE BY CHEMICALLY UNITING THE FILAMENTS AT THEIR ATTACHED POSITION WHEREBY THE FILAMENTS ARE FIRMLY SECURED IN THAT THEY REMAIN ATTACHED AND DO NOT LOOSEN UPON BRUSHING AND COMBING THE WIG STRUCTURE.

Description

. 3,687,752 METHOD OF aucaonme HAIR-LIKE SYNTHETIC FILAMEN'I'S TO A W16 BASE Filed Sept. 4, 1970 Aug. 29, 1912 F. s. RIORDAN, JR

FILAMENTS ASSEMBLED IN PARALLEL ALIGNMENT SECURE FILAMENTS ALONG A STITCH LINE ATTACH STITCHED FILAMENTS' TO CONTOURED BASE COALESCE FILAMENTS ALONG STITCH LINE DRY United States Patent 3,687,752 Patented Aug. 29, 1972 3,687,752 METHOD OF AN CHORING HAIR-LIKE SYNTHETIC FILAMENTS TO A WIG BASE Frank S. Riordan, Jr., St. Louis, Mo., assignor to Monsanto Company, St. Louis, Mo. Filed Sept. 4, 1970, Ser. No. 69,892 Int. Cl. A41g 5/00; B32b 5/02 US. Cl. 156-72 2 Claims ABSTRACT OF THE DISCLOSURE A method is herein described for locking hair-like synthetic filaments formed from such materials as acrylic and modacrylic to a wig structure by chemically uniting the filaments at their attached position whereby the filaments are firmly secured in that they remain attached and do not loosen upon brushing and combing the wig structure.

BACKGROUND OF THE INVENTION (1) Field of the invention (2) Description of the prior art Contoured bases or foundations in the head covering art are known by various names as hairpieces, wigs and toupees. In this art, the expert must effect a simulated hair growth pattern of filamentary material by arranging such material on the exterior surface of various types of 'foundation pieces, such as bases, skull caps and the like, which are often of net or weblike material.

In the head cover art relating to wigs and hairpieces there are several conventional types of covers designated as stretch, hand-tied and semi hand-tied Wigs. In general, the stretch wigs are characterized by having their hair-like filaments sewn into a weft which consists of fiber groupings with thread lock stitches holding the groupings in place. A hand-tied wig is constructed by tying as through knotting a plurality of filaments to a netted wig substrate. The semi hand-tied wig is characterized by lateral wefting at and around the crown and none at the marginal edge of the foundation piece of the head cover.

In the production of wigs, it is common practice to employ hairlike filaments formed from synthetic polymers. As is often the case, such polymers have as an integral part of the polymer chain or intimate contact therewith a number of chemical modifying agents added to overcome for the most part certain inherently undesirable properties associated with a particular synthetic polymer. Thus, it is known in the art that polymers of polyacrylonitrile do not have good flame resistant properties. In order to overcome this difiiculty, a number of flame retarding substances are employed. Further, often there are numerous difliculties associated with obtaining a suitable dye receptiveness so as to produce the shades of color desired by the trade. As to polyacrylonitrile resort is often made to the use of various dye receptive monomers incorporated in the polymer chain. In addition, a variety of coatings may be selected in order to lubricate an advancing filament during a conventional stitching or needling operation. Suffice it to say that when filaments are finally implanted within a substrate after such treatments, there are often difficulties associated with firmly connecting it to substrate by conventional means. That is to say, as is often the case, the advantage rendered by chemical treatment carry some inherent disadvantages with respect to certain composite structures. One particular problem to which this invetnion is addressed is the objectionable behavior, especially after chemical treatment, for filaments which are more or less physically tied to a fabric substance to become easily loosened and detached from said substrate by gentle forces.

Attempts heretofore have been made to solve the above mentioned problem, but they have not proven satisfactory. For example, it has been proposed to apply a latex-like layer and to allow the same to dry so as to anchor the hair-like synthetic filaments to a woven fabric, or to use a solid thermoplastic material and thereafter subjecting the thermoplastic material to the action of heat to plasticize the same so that it anchors the filaments to the fabric, or to employ netting devices to firmly secure the filaments in place. These former methods are more or less objectionable for several reasons in that they all involve the application of a substantial layer to a composite fabric and involve adding a layer which is often times quite bulky and sticky.

The method of embodying the invention herein is an improvement in the above category of known methods with novel features being provided in the anchoring method to be more fully described hereafter.

SUMMARY OF THE INVENTION In production of wigs, it is conventional to secure a plurality of filaments to form a wetting and to secure this to a netted wig substrate. It is often the case that in the regular maintenance of a wig, a number of filaments become loosened and are pulled out from their base to give an unsightly appearance.

It is therefore an object of this invention to provide a novel method for anchoring synthetic hair filaments so that they remain attached to the wig substrate and do not become dislodged therefrom.

The attainment of this object is accomplished by partially dissolving by a suitable solvent a plurality of filaments in intimate association so as to coalesce and to unite them.

The accompanying drawing depicts the process of the invention. The sequence of assembling, securing, attaching, coalesing and drying acrylic fibers is shown therein.

DESCRIPTION OF THE PREFERRED EMBODIMENT In accordance with my method a plurality of synthetic hair-like filaments are first assembled in a side by side arrangement and stitched to secure them to form a wefting, the stitching transversing the wefting and locking the filaments into groupings and leaving the distal ends of the filaments projecting outwardly, securing said wefting to a contoured base to form a wig structure and thereafter partially dissolving the filaments at their attached portion whereby that portion of the filaments coalesce and flow into one another and finally drying the dissolved portions of said filaments to firmly bond them together.

In one embodiment of my invention, a plurality of acrylic filaments are placed in a side by side arrangement, the length of said filaments being substantially uniform, stitching the plurality of filaments transversely to secure them together, the filaments being so secured so as to allow the ends thereof to extend outwardly, partially dissolving that portion of the filament in contact with and in proximity to a stitch line so as to coalesce that portion of the filaments to one another, drying the dissolved portion to form a stable wefting and attaching the wefting to a contoured base to simulate a natural growth pattern. The prepared wefting is generally attached to the base by sewing it to form a wig structure. At any rate, it can be readily 3 appreciated that the partial dissolusion and drying of the filaments may be done before attaching the prepared wefting to the contoured base.

It is contemplated that after stitching a wefting along its length to secure the filaments, the wefting may be attached to a contoured base and thereafter anchored in position by partially dissolving that portion of the filaments in contact with the stitch line. For this embodi ment, an acrylic solvent is sprayed in the form of a fine mist onto the underside portion of the cap of a headpiece to apply the solvent near and along the stitch line. The solvent may preferably be applied in the form of an aerosol.

It will be evident from this invention that the binding method is far superior to the binding in use in numerous respects. The method of this invention serves to reinforce the stitched section of the strip so that the filaments do not pull out in the course of time. The filaments remain firmly in position over the areas of the strip and cannot be readily dislodged. Moreover, the new binding method does not add to the thickness of the wig base and generally gives an attractive appearance. Moreover, the use of my method effects a saving in manufacture in that no supplemental devices or fabric layers are required.

The plurality of filaments are arranged in substantially parallel alignment, the filaments being of a more or less uniform length. The filaments may be folded along their length to form a loop. The folded portions are secured in place by a line of stitching which passes through the body of the fabric. The stitching thread may be of various materials, but preferably should be of some staple material as nylon. The thread material may be inert to and non-soluble in the solvent employed to partially dissolve the hair-like filaments to be used, A soluble thread may also be employed to effect a *firm bond to the implanted hair-like filaments with no added disadvantage.

The solvents of this invention include ethylene carbonate, propylene carbonate and trimethylene carbonate in a diluent such as a lower aliphatic glycol as propylene and ethylene glycol. Of course, aqueous solutions of said carbonates may also be advantageously employed. Also, other solvents may be used, such as dimethyl sulfone, tetramethylene sulfone, and dimethyl formamide. These may be dissolved in water, or may be dissolved in alcohol, ethylene glycol, benzene or the like. Water and ethylene glycol are preferred diluents. The range of solvent concentration may be from as little as 0.5 percent to 50 percent by weight. Common solvents for modacrylics are the ketones such as acetone. The diluents serve as a liquid vehicle inert to the material acted upon by the aforedescribed solvents.

In partially dissolving portions of the filaments, it is important that the solvent be only applied to that portion of the filaments in contact with and in proximity to the stitch line.

The dissolution of the filaments may be accomplished by drawing the wefting along said stitch line through a trough containing a solvent with an appropriate diluent. Sponging, brushing, or padding the solvent directly onto the filaments may also be done when the wefting is attached to the hairpiece foundation or prior to being attached to the foundation. Spraying via nozzles or nozzle-like means may also be employed to evenly distribute the solvent. Spraying may also be used after the wefting is attached to the foundation. The spray pattern in this latter case should conform more or less to that of the contoured base to be treated. The spray pattern in issuing upward and falling downward assumes approximately a hemispherical projection. Thus, in order to spray effectively a hairpiece upon the underside portion thereof said underside portion is exposed so that it substantially overlaps with that of the projected spray pattern. For proper coverage for the head of a wearer, the filaments should freely separate one from the other except for the anchored portion along the stitch line. Thus,

4 when spraying from a nozzle the issuing solvent must play upon the underside of the wig and be applied to the aforementioned portion.

Although spraying the solvents herein described has been mentioned as the preferred method of applying the solvent, conventional padding procedures may also be employed.

A filler may be admixed with the solvent. A wide array of fillers may be employed in conjunction with the solvent. Fillers such as silica, silica aerogel or finely divided precipitated silicas may be employed as well as TiO alumina, diatomaceous earth, crushed quartz, ferric oxide and calcium carbonate. It is best that there be from 5 to 15 percent by weight of these fillers. Amounts above or below the above specified range either decrease the bonding of the filaments or provide no beneficial effect.

Partial dissolution of the hair-like filaments is accomplished by exposing portions of the filaments in contact along the stitch line for a time and at a temperature suflicient to solvate the external sections of said filaments so that upon drying the filaments so treated no longer assume their original shape. In effect, the hair-like filaments at their point of contact spread toward one another and unite to form substantially a unitary structure. Generally, the temperature of the solvent-diluent may range from about 50 C. to the boiling point at atmospheric pressure for at least one second until dissolution.

Drying may be accomplished by heating the treated structure in a conventional fabric drying apparatus to evaporate and to concentrate solvent and diluent. Upon drying, a durable bond between and among the filaments is formed. If an aqueous ethylene carbonate solution is used alone, the exact temperature of drying is immaterial as long as the filaments so treated are dried; however, the temperature of drying must not go into the degradation point of the acrylic or modacrylic fibers, viz., 350 F. Of course, the drying may be done at room temperature or at an elevated temperature, depending upon the solvent employed. A conventional fabric drying apparatus, such as a chain dryer may be used, to evaporate the solvent-diluent. It is necessary that the drying results in concentrating the solvent so as to bond the filaments at their lower portions in contact with the stitch line to form a durable bond between and among themselves.

The term modacrylic denotes a fiber-forming substance of any long chain synthetic polymer composed of less than 85% but at least 35% by weights of acrylonitrile units, (CH CHCN),,. Polyacrylonitrile copolymers, including binary and ternary polymers of at least percent by weight of acrylonitrile units denote the acrylic materials herein. While the preferred polymers employed in the instant invention are those containing at least 80 percent of acrylonitrile, generally recognized as the fiberforming acrylonitrile polymers, it will be understood that the invention is likewise applicable to polymers containing less than 80 percent acrylonitrile.

The polymer may be a copolymer of from 80 to 98 percent acrylonitrile and from 2 to 20 percent of another monomer containing the c=c linkage and copolymerizable with acrylonitrile. Suitable mono-olefinic monomers include acrylic, alpha-chloroacrylic and methacrylic acids; the acrylates, such as methylmethacrylate, ethylmethacrylate, butylmethacrylate, methoxymethyl methacrylate, beta-chloroethyl methacrylate and the corresponding esters of acrylic and alpha-chloro acrylic acids; vinyl chloride, vinyl fluoride, vinyl bromide, vinylidene chloride, 1 chloro-bromo ethylene; methacrylonitrile, acrylamide and methacrylamide; alpha-chloroacrylamide; or monoalkyl substitution products thereof; methylvinyl ketone carboxylates, such as vinyl acetate, vinyl chloroacetate, vinyl propionate, and vinyl stearate; N-vinylimides, such as N-vinylsuccinimide methylene malonic esters; itaconic acid and itaconic esters; N-vinylcarbazole; vinylfurane; alkyl vinyl esters; vinyl sulfonic acid, ethylene alpha, beta-dicarboxylic acids or their anhydrides or derivatives, such as diethylcitraconate, diethylmesaconate, styrene, vinyl naphthalene; vinyl-substituted tertiary heterocyclic amines, such as the vinylpyridenes and alkylsubstituted vinylpyridines, for example, 2-vinylpyridine, 4-vinylpyridine, 2-methyl-5-vinylpyridine, etc., l-vinylimidazole and alkyl-substituted l-vinylimidazoles, such as 2-, 4-, or 5-methyl-l-vinylimidazole, and other c-c containing polymerizable materials.

The polymer may be a ternary or higher interpolymer, for example, products obtained by the interpolymerization of acrylonitrile and two or more of any of the monomers, other than acrylonitrile, enumerated above. More specifically, and preferably the ternary polymer comprises acrylonitrile, methacrylonitrile, and 2-vinylpyridine. The ternary polymers preferably containing from 80 to 98 percent of acrylonitrile, from 1 to percent of a vinylpyn'dine or a l-vinylimidazole, and from 1 to 18 percent of another substance such as methacrylonitrile or vinyl chloride.

The polymer may also be a blend of a polyacrylonitrile or of a binary interpolymer of from 80 to 99 percent acrylonitrile and from 1 to 20 percent of at least one other c=c containing substance with from 2 to 50 percent of the weight of the blend of a copolyrner of from 10 to 70 percent of acrylonitrile and from to 90 percent of at least one other c=c containing polymerizable monomer. Preferably, when the polymeric material comprises a blend, it will be a blend of a copolymer of 90 to 98 percent acrylonitrile and from 2 to 10 percent of another mono-olefinic monomer, such as vinyl acetate, which is not receptive to dyestulf, with a sufiicient amount of a copolymer of from 10 to 70 percent of acrylonitrile and from 30 to 90 percent of a vinylsubstituted tertiary heterocyclic amine, such as vinylpyridine or l-vinylimidazole, to give a dyeable blend having an overall vinyl-substituted tertiary heterocyclic amine content of from 2 to 10 percent, based on the weight of the blend. It will be apparent that different embodiments of this invention may be made without departing therefrom.

Having thus described my invention, what I desire to claim and secure by Letters Patent is:

1. A method of anchoring synthetic hair-like filaments to a wig structure, comprising the steps of:

assembling a plurality of filaments in a side by side arrangement, the individual filaments being of substantially uniform length and in substantially parallel alignment, said filaments being polymers of the group consisting of acrylic and modacrylic;

stitching the plurality of filaments transversely of their length to secure the filaments together into groupings of filaments leaving the distal ends of said filaments extend outwardly of a stitch line;

attaching the stitched plurality of filaments to the exterior section of a contoured base to simulate a natural growth pattern;

partially dissolving by exposing the underside partions of the contoured base and thus the filaments in contact with and in proximity to the stitch line whereby those portions of said filaments coalesce and flow into one another, the partial dissolution being effected by a solvent comprising from about 0.5 to about weight percent of compounds selected from the group consisting of ethylene carbonate, propylene carbonate, trimethylene carbonate, dimethyl sulfone, tetramethylene sulfone, dimethyl formamide, acetone, and mixtures thereof, and from about 50 to about 95.5 weight percent of a liquid vehicle; and

drying the dissolved portions of said filaments to firmly bond them together.

2. The method of claim 1 wherein the solvent contains colloidal silica.

References Cited UNITED STATES PATENTS 3,307,562 3/1967 Corbett et a1. l3255 3,357,878 12/1 967 Newman 15 6-296 3,530,862 9/1970 Hudson 13253 BE'NJAMIN A. BORCHELT, Primary Examiner I. V. DORAMUS, Assistant Examiner US. Cl. X.R. 1325 6

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