US2027968A - Stiffening material - Google Patents

Description

v Jan. '14, 1936; l ussg 2,2?,96

STIFFENINGUMATERIAL Filed Aug. 19 1953 High/(j Porous Dupes/l f Precrplvafed Collolclal Malena! 8. Cellulose Esfer v More Col/aid d and More Sch/em- Res/diam Colloidal Mafer/a/ 6. Cellulose Esfer ATTORNEY Patented Jan. 14, 1936 UNITED STATES PATENT OFFICE STIFFENING MATERIAL I I Joseph Fausse, Melrose Highlands, Mass., 115- I signer to The Celastic Corporation, Wilmington, DeL, a corporation of Delaware Application August 19, 1933, Serial No. 685,908

10 Claims. (01. 12-14 This invention relates to stiffening material and particularly to an improved material of the general type disclosed in U. S. Patent 1,256,240, Lovell, February 12, 1918. Although not restricted to such use, materialof thepresent type finds advantageous application as stiffening material for boots and shoes, such as fabric, patent leather, cut-out, or perforated boots and shoes, and therefore is described with more particular reference to the boot and shoe industry.

Material of the Lovell type comprises a base fabric such as a woven material, for example cotton-cloth, or a structureless material, for example felt or paper, with its interstices carry- 15 ing a precipitated colloidal material in a highly porous form termed powdered by Lovell, such as a cellulosic derivative, casein, albumin and various gums and resins. immersed in a solvent for the precipitated material, thereby to resolve the same into a coalescent flaccid condition, and when the material is in this condition the fabric is applied in the lasting operations, shaped, and allowed to harden, by evaporation of solvent, in its shaped condition.

While material of the Lovell type is highly satisfactory in use, it sometimes gives rise to the difficulty that the colloidal matter becomes so soft and mushy when the stiffener is dippedinto the solvent, that the colloidal matter can be forced through the upper of a shoe of fabric or similar material, during the lasting operations, thereby staining, disfiguring and ruining the upper; and similarly, the coating on a patent leather shoe upper will be affected and softened during the lasting operations so that the coating,

will be peeled from the leather, thereby damaging theupper; and, again, in lasting shoes having cut-outs or perforations in the upper, the

colloidal matter may be forced through the cutcuts or perforations.

I have now devised a stiffening material of the general Lovell type which in itself, and because of particular character of the stiffening deposit, overcomes the dilficulties mentioned, and

45. have also devised a method for the manufacture of such material.

In-the accompanying drawing, the figure is a highly conventional exaggerated cross sectional view of stiffening material made in accordance 50 with the present process and embodying the present invention.

One object of my invention is to provide a stiffening materialof the mentioned and other desirable characteristics. A further object is to 5 provide a method for the production of such In use, the fabric ismaterial. To these ends, and also to improve generally on materials and methods of the general character indicated, my invention consists in the various matters hereinafter described and claimed.

These objects are accomplished by treating one side of the stiffener material with a solvent for the colloid, and drying the material, before it is dipped for use as a stiffener. Proceeding in this way a firm fihn is created on the treated side. 10

This film is relatively continuous and the colloidal material therein, firmer, harder, more colloided and-more solvent-resistant as compared to the untreated colloidal precipitated material with which the fabric as a whole is filled. As a 5 result, when the stiffener is dipped in solvent for the purpose of preparing it for use in the lasting operation, while the untreated precipitated colloidal material is rendered flaccid and coalescent in accordance with Lovells general procedure, 20 the fihn formed by the described treatment, although it is softened sufflciently and rendered sufficiently flexible, to permit the proper use for shaping of the stiffener in lasting, doe s not become so soft and mushy that it will, in the last- 5 ing operations, penetrate the fabric, cut-outs or l,

perforations in the shoe upper, or give rise to the troubles with patent leather, above mentioned.

It will be understood, of course, that the treated side of the fabric is that side which, 30 ordinarily is, in the lasting, used as the top side and placed immediately next to the upper, the untreated side of the material being ordinarily the inner side in use. Further in respect to the. use of the material with patent leather, the ma- 35 terial will not hold such an excess of solvent that the coating of a patent leather upper will be affected and peel and rub off during the lasting operations. I

In greater detail, the invention maybe prac- 40 ticed, and an improved stiffener for boots and shoes, made as follows. Taking a finished sheet of the colloid-treated shoe stiffener material, containing the precipitated colloidal material in general accordance with Lovell, I apply to one side, by any suitable means, a solvent for treating the same. There are several ways of treating the one side; For example, a solvent for thecolloidal matter may be painted on with a brush, mop, or'cloth, or may be applied to the one side by passing the stiffener material between two rolls, one of which passes through a bath of solvent whereby some of the solvent' is carried on the surface of the roll and transferred to the surface of the stiffener material at the point of contact. Or the same effect may be obtained with an endless belt of fabric or other material suspended from one of the rolls, with the other end passing through a bath of solvent. Again the solvent may be applied by spraying thesame on the one side of the material.

The amount of solvent to be applied and the extent to which the material is treated there- I with will, of course, depend upon the amount and thickness of the deposit in and on the particular treated fabric being processed, the size of the beading roll, the height of the solvent in the tank, the speed of the fabric, and the particular type of stiffener material, etc., as will be understood by those skilled in the art, .who willvary the various factors to suit the particular conditions, having in mind the particular feature of the invention; that is, that colloidal material on but one face of the stiffener material is to be treated, and care taken that the alteration in the colloidal material to convert it into a firm and relatively solvent-resistant layer, is not to be allowed to proceed to the extent of penetrating entirely through the stifiener material. The material, having been thus treated is now dried of solvent in any suitable manner, e. g. air dried, thus giving the desired firm continuous deposit on the one side.

Blanks of suitable shape may now be cut from the treatedmaterial. In use these are dipped into a suitable solvent, e. g. diacetone alcohol and ethyl alcohol which will render the blank soft enough to conform to the desired shape. A treatment sufficient to render thedeposit on the untreated side of the stiffener material, and therein, sufiiciently coalescent and flaccid to be utilized in accordance with the Lovell invention will not render the deposit on the treated side soft and mushy or cause it to hold such an excess of solvent that it can be forced through fabric or perforated shoe uppers, or cause patent leather shoe uppers to peel during the lasting operations. softness and flexibility to the treated side.

While the stiifener is in this condition it is cable may be, as above indicated of many general types. Whenpf cellulosic derivative, it may be of cellulose ester, e. g. cellulose nitrate or cellulose acetate, or cellulose ether, e. g. ethyl cellulose or benzyl cellulose. The solvent for treatment in accordance with the present in-' vention will, as will be understood by those skilled in the art, be a solvent compatible with the particular colloidal substance in the stiffen- .ing material, e. g. acetone for cellulose esters and ethers and certain gums, e. g. gum copal. Generally speaking, for Lovell material having a fabric e. g. flannel for a base and carrying about six ounces of precipitated cellulose nitrate per square yard, I find that ten seconds treatment with twenty percent ethyl acetate is adequate for the purposes of the invention in the treatment of the stiffening material.

While boots and shoes have been more particularly referred to, it will be understood that stiifeners of the present type may be used in any article of footwear where their use recommends itself, and furthermore, may be used at It will, however, impart sufilcient its treatment in accordance with the present invention may be carried on as a single continuous process.

It will be particularly noted that in the present stiffening material the protective advantages are attained by the stiffening deposit itself. Thus, the entire colloid content is capable of being softened by a single solvent. That is, the protective harder and firmer portion of the colloid is softenable sufficiently for lasting purposes by the solvent used for treating the stiffener, and particularly the unaltered precipitated portion, with the result that the protective portion functions in the stiffener as does the precipitated portion so far as being a stiffening factor is concerned. The entire colloid content is preferably water-insoluble.

I claim:

1. Method of treating a stiffening material for shoes and the like, of the type comprising fabric carrying a cellulosic derivative precipitated in the interstices thereof which method comprises applying a solvent to said material to dissolve only part of the cellulosic derivative without removing it from said fabric, drying the material to convert the dissolved cellulosic derivative into a colloided solvent resistant form while leaving the remaining cellulosic derivative in its original precipitated form, and thereafter treating said material with a cellulosic derivative solvent to soften it, shaping it, and allowing it to dry in the desired final form.

2. Method of treating stiffening material for shoes and the like, of the type comprising fabric carrying cellulose nitrate precipitated in the interstices thereof which method comprises applying a solvent to said material to dissolve only part of the cellulose nitrate without removing it from said fabric, drying the material to convert the dissolved cellulose nitrate into a colloided solvent resistant form while leaving the remaining cellulose nitrate in its original precipitated form, and thereafter treating said material with a cellulose nitrate solvent to soften it, shaping it,

and allowing it to dry in the desired final form.

side of the material without removing it from said fabric, drying the material to convert the dissolved cellulosic derivative into a colloidal solvent resistant form while leaving the cel1u- -losic derivative in its original precipitated form on the other side, and thereafter treating said material with a cellulosic derivative solvent to soften it, shaping it, and allowing it to dry in the desired final form.

4. Method of treating stiffening material for shoes and the like, of the type comprising fabric carrying cellulose nitrate precipitated in the interstices thereof which method comprises applying to one side only of said material a solvent to dissolve the cellulose nitrate on said side of the material without removing it from the material, drying said material to convert the dissolved cellulose nitrate into a colloided solvent resistant form while leaving the cellulose nitrate in its original" precipitated form on the other side, 76

to be treated with a cellulosic derivative solvent to soften same, and then shaped and dried'in the desired final form. 1

6. A stiffening blank comprising a fabric having cellulose nitrate disposed in the interstices thereof, part of said cellulose nitrate being in precipitated form readily subject to the action of solvent and part being in a colloided solvent resistant form, said blank being adapted to be treated with a cellulose nitrate solvent to soften same, and then shaped and dried in the desired final form.

7. A stiffening blank comprising a fabric having a cellulosic derivative in precipitated form in the interstices thereof on one side and having said cellulosic derivative in a colloided solvent resistant form on the other side, said blank being adapted to be treated with a cellulosic derivative solvent to soften same, and then shaped and dried in the desired final form.

8. A stiffening blank comprising a fabric havingcellulose nitrate in precipitated form in the interstices thereof on one side and having cellulose nitrate in a colloided solvent resistant form on the other side, said blank .being adapted to be treated with a cellulose nitrate solvent to soften same, and then shaped and dried in the desired final form.

9. A stiffening blank comprising a'fabric having cellulose acetate in precipitated form in the interstices thereof on one side and having cellulose acetate in a colloided solvent resistant form on the other side, said blank being adapted to be treated with a cellulose acetate solvent to soften same, and then shaped and dried in the desired final form.

10. A stiffening blank comprising a fabric having a cellulose ether in precipitated form in the interstices thereof on one side and having said cellulose ether in a colloided solvent resistant form on the other side, said blankbeing adapted. to be treated with a cellul ose ether solvent to soften same, and then shaped and dried in the desired final form.

JOSEPH FAUSSE.

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