US1544813A - Box toe - Google Patents

Description

Patented July 7, 1 925.

UNITED'STATES PATENT OFFICE.

ALBERT L. cLArP, or DAN-VEBS, MAssAcHusETTs, ASSIGNOR To BEGKWI'IE MANU- FAGTURING coMrANY, or BOSTON, MASSACHUSETTS, A conroaATrou or MAINE.

BOX TOE.

No Drawing.

To all whom it may concern.

Be it known that I, ALBERT L. CLAPP, a citizen of the United States, residin at Danvers, in the county of Essex and tate 5 of Massachusetts, have invented new and useful Improvements in Box Toes (Case A), of which the following is a specification.

This invention has for its object to produce a shoe stiffener or sheet material from which I such stiffeners may be produced. 7

Heretofore it has been customary in the manufacture ofshoe stifi'eners such as box toes to form a sheet of fibrous material, usually cotton and wool felt or like open porous material, and then to saturate or impregnate the sheet with a molten mass of a stiffening agent in the nature of hydrocarbons, which when cold is hard and friable but which when softened by a. relatively moderate degree of heat permits .the sheet or blank cut therefrom to become limp and flexible, so that the box-toe blank may be molded about the end of the last in pull ing over or lasting the shoe. Various stiffening agents have been employed for this purpose, suoh as resins, gums, asphalts and hydrocarbons vof the nature of Montan wax.

More particularly, the object of the present invention is to produce box toes or the sheets from which the box-toe blanks may be cut, by incorporating the stiffening agent with the pulp during the manufacture of the sheet in a paper machine so as to render unnecessary the step, of separately impregnating the already formed sheet of fibrous material. It is necessary that the stiffening agent or agents should be throughly distributed throughout the sheet, that they should be of such nature that the box toe -when molded is resilient and stiff, that they I may be softened so as to render the sheet limp and flexible when heated to a relatively low temperature, and that they will set quickly when permitted to cooL- One of the prime requisites of the sheet is that it must not part or tear easily when the stiffening agent is in a soft plastic condition, and that it may be stretched to some extent and pulled about the toe end of the last without being weakened or torn so as to conform to the shape of the last without inju The presentinvention consists o a boxtoe blank, the sheet from which it is cut and- Application filed October 31, 1922. Serial No. 598,214.

a method of producing the same which will provide a box toe having the optimum characteristics which I have hereinbefore referred to.

In initially preparing the sheet, I employa furnish, including long fibers such .as cattle hair, long rope fibers or flax fibers, and even in some cases may utilize long cotton quantity of'stifi'ening agent in the sheet, it

fibers. In addition to these fibers, however, I also employ short fibers, perferably of the is necessary that the fibrous body of which the sheet is formed should be of such charactor. that it will form properly in a web and yet be sufficiently open to permit the proper discharge of the water from the cylmder in the paper machine. An even web formation is secured by employing both the long fibers of the nature of cattle hair and short fibers such as obtained in the production of chemical wood pulp or suchas obtained from waste kraft paper or the like. Of course, in lieu of wood pulp, one might employ}- rags or other raw material which provides relatively'short fibers, which, when mixed with long fibers, will furnish a sheet having the desired characteristics.

As the stiffening agent I may utilize any provided they be in the form of an aqueous emulsion, sothat they may be diluted with water and be throughly incorporated with the other elements or ingredients of the furnish in the beater stock.

As an exam 1e, one may proceed as folmay likewise be lows: 8 parts y weight of cattle hair or 7 other long fibers and 8 parts by wei ht of sulphate pulp or equivalent short brous material may be placed in the beater with a lar e amount of water, much more than is ordinarily necessary for beating the stock. The beating'engine is started 1n operation but the kmves are carefully adjusted so as not to cut the fibers but merely to brush them and secure a thorough, physically homogeneous mixture. The stock should be thin with water as this permits the rapid admixture of the ingredients. Of course, by

taking a longer time, one might secure the same results with a thicker stock or one having less water. By having a very thin stock, it is possible to secure the desired physical homogeneity in the course of 15 to minutes. After the beater contents have been brushed as described, the thermo-plastic stiffening agents may now be added. In the example herein given, I employ parts by weight of rosin, 25 parts by weight of gilsonite and 5 parts by weight of Montan wax, all pulverized to about mesh. These ingredients are introduced into the beater, together with about 30 parts of asphalt emulsified or dispersed in water. This emulsion or dispersion preferably consists of normally adhesive asphalt emulsified or dispersed in -Water with a colloidal clay emulsifying agent, the asphalt constituting the dispersephase of the emulsion. The amount of the emulsion added to the heaters is figured asthe asphalt on a dry basis.

An emulsion, such as herein described, is not per so my invention, and can be obtained on open market under the trade name of K-B emulsion.

With these hydrocarbon resinous ingredients, which constitute the thermo-plastic stifi'ening agent, I preferably add a small amount of casein dissolved in an alkaline solution. Instead of casein, I may use any other ingredient, which when precipitated by a precipitating agent carries down with it the stiffening materials in a more or less conglomerate mass. Thus, in lieu of casein, I may use .rosin size, viscous animal size, or other equivalent material.' In some cases, however, I do not utilize either casein or the sizing material last referred to, but ordinarily I find that it may be used with advantage. .After these ingredients have been thoroughly intermixed with the fibrous material in the beater by continued rotation of the beater roll adjusted somewhat away from the bed plate, I then add 10 parts by weight of alum as a precipitating agent.

. The fibrous stock with the stiffening agent thoroughly incorporated therein is now formed into a sheet by a cylinder paper machine, and, when the sheet is of the desired thickness, it is cut and removed from the make-up roll. The sheet is then dried for the removal of water, and, when dry, is relatively open, free and p'orous with free rosin, gilsonite, Montan wax and asphalt distributed as discrete particles throughout the sheet and, when magnified, are visible as such. While still warm from the drier, the sheet is now preferably passed through calender rolls heated to a sufficient temperature to flux the hydrocarbon stiffening agents so that they will coalesce throughout the sheet. The effect of the ealendering is further to condense and compact the sheet, so that, when the sheet cools, it is relatively hard, compact or dense, stiff and resilient; and it is not affected by body temperature or materially affected by solar heat, but may be rendered limp and flexible at a temperature of 140 to 150 F.

It is quite evident that the particular ingredients, which I have mentioned in the foregoing example, may be changed or added to, although the furnish as described gives excellent results. For example, I may change the fibrous ingredients by utilizing 5 parts by weight of long fibers such as cattle hair, 5 parts by-weight of sulphate pulp, and 5 parts by weight of the waste of the final sheet 01' waste which is produced from box-toe material as ordinarily made. In such case, the box-toe waste, which is the residue after cutting out the box toes or other shoe stifi'eners, must be disintegrated before being added to the beater. I find that this disintegration may be accomplished by subjecting the material to the action of an Abbe rotary cutter or grinder. Such machines are on the market and are easily procurable. Since there is some tendency of the stiffening agents in the waste to gum the knives, I employ as a preventative a small amount of talc which may be thrown into the grinder from time to time by the handful. For example, I find that in any given amount of the disintegrated waste fiber, there need not be over "a of talc to insure the successful operation of the grinder. The disintegrated Waste material consists of the usual fibers of which the felt was formed together with the gums or solid hydrocarbons with which it was impregnated. It is possible to reduce the proportion of the asphalt emulsion from 30 parts by weight to, say, 20 parts by weight, and to increase the percentage of the casein or other size which is employed.

By long continued experiment, I have found that ash'eet, having onlythe asphalt emulsion asthe stiffening agent, does not produce satisfactory box toes. for the reason that the sheet is too soft and does not possess the requisite rigidity and resiliency when a certain desirable toughness to the Sheet when it is warm, and contributes towards.

permittin the.box-toe blanks to be folded and stretc ed about the last when the shoe is being pulled over or lasted. Since the, asphaltic emulsion is insufficient to produce a sheet of the necessary resilienc rigidity and stiffness, I employ rosin, gi sonite or the equivalent which is distributed'in the pulp in fine particles. In fact, instead of utihzing both rosin and gilsonite, I may employ rosin alone, although I do, not regard the final product as desirable as one in which these two ingredients are employed. Gilsonite, having a high melting point, adds stiffness and rigidity to the molded box toe when subjected to body or solar heat. Inasmuch as the hydrocarbons must coalesce and become more or less amalgamated in the sheet, I use a certain pro ortion of Montan wax, which, because of its 'gh degree of penetrablity when molten, acts as a fluxing agent for the other hydrocarbons in the sheet. The addition of Montan wax or like hydrocarbon of high penetrability and relatively low melting point is particularly desirable when a tempering agent such as gilsonite is employed, as otherwise it would be necessary to heat the calendering rolls to such a hig temperature to flux or coalesce the other hydrocarbon ingredients as might or would tend to burn the hair or other long fibers employed in making the sheet. An advantageun employing casein rather than other size is that when precipitated with alum it is not affected 'by dry heat but will soften when moist. Ordinarily, in the pulling over or lasting of' shoes, in which stiffened box-toe blanks are employed, it is customary to subject the blank to moist heat, and therefore it is desirable to use some agent which when precipitated is not affected by dry heat but which will soften when subjected to heat and moisture.

After the sheet is finished, the blanks. are cut and skived to serve as shoe stifi'eners, such as box toes or counters.

The stiffening agents may be referred to as thermo-plastic material, meaning to include by that term those compounds or mixtures which function as herein set forth, namely those which may be incorporated in the wet mass of fibrous material while in a finely divided condition, which softens on the application of heat not injurious to the shoe, which set rapidly when cooled, which give rigidity, stiffness and resiliency to the molded box toe, and which will permit the heated and limp box-toe blank to be stretched about the toe end of the last, in the pullingover and end-lasting operations.

What I claim is:-

1. A process of making box-toe material, which comprises intimately commingling and pulpinglong fibers of the character of cattle hair and short fibers of the character of chemical wood pulp, incorporating and disfibers by precipitation, and forming the mass into a sheet.

2. A process of making box-toe material, which comprises intimately commingling and pulping long fibers of the character of cattle hair and short fibers of the character of chemical wood pulp, incorporating and distributing a finely divided therm-plastic compound in and throughout the mass, fixing the particles of said compound on the fibers by precipitation, forming the mass into a sheet, and compactin sald sheet by the application of heat and pressure.

3. A process of making box-toe. material which comprises intimately commingling and pulping long fibers of the character of cattle hair and short fibers of the character of chemical wood pulp, incorporating and distributin finely divided thermo-plastic material, inc uding an aueous emulsion of asphalt, in and-throug out the mass, coagulating and precipitating said thermo-plastic.

material on the fibers, and forming the pulpy mass into a sheet.

4. A process of making box-toe material;

' on the fibers, and forming the mass into a sheet.

5. A process of makin 'comprismg. pulping a 7 water, incorporating in the pulpy mass an aqueous emulsion of asphalt and Montan wax, forming the mass intoa sheet and d ing the same, and cutting box-toe bl therefrom.

6. A- process'of makin box-toe material, comprising pulping a rous material "in water, incorporating and distributing a finely divided thermo-plastic material in and throughout the mass, precipitating such thermo-plastic material on the fibers, and sheeting the pulpy mass on a paper machine.

7 A process of making box-toe material, comprising pulping a rous material in water, incorporating and distributing a finely divided thermo-plastic material in and throughout the mass precipitating such thermo-plastic material on the fibers, sheeting the pulp mass on the paper machine and then byh the thermo-plastic material in said sheet.

box-toe material,

rous material in eat causing the coalescence o comprising pulping a" fibrous material in escencerof said finely divided thermo-p'lastic Water, incorporating and distbributingaafimiy material and condensing and compacting divided thawing-plastic material in and the sheet. I 3

throughout the mass, precipitating; such In testimony whereof I have afix my 5 theme-plastic material on the fibers, sheet-r, signature. 7

ing the puipy mass on the paper 1znasi1ixie,-

and by heat and. pressure-.musmg the cqgl- [ALBERT L. 'CLAPF.