US2136826A - Manufacture of molded binder-reinforced fiber articles of pliant character - Google Patents

Description

Nov. 15, 1938. M. o. SCHUR 2,136,325

" MANUFACTURE OF MOLDED 'BINDER REINFORCED FIBER ARTICLES OF PLIANT CHARACTER Filed Sept. 4, 1935 2 Sheets-Sheet 1 I Nov. 15, 1938. M. o. SCHUR 2 MANUFACTURE OF MOLDED BINDER-REINFORCED FIBER ARTICLE E. PLIANT CHARACTER Filed pt. 4, 1955 2 Sheets-Sheet 2 I|IIITIIT| Patented Nov. 15, 1938 MANUFACTURE OF MOLDED, BINDER-REIN- FORCED FIBER ARTICLES F PLIANT CHARACTER Milton 0. Schur, Berlin,

Company. Berlin, N.

Maine N.. H., assignor to Brown R, a corporation oi Application September 4, 1935, Serial No. 39,197

3 Claims.

This invention relatesto the manufacture of molded, binder-reinforced, fiber articles of a pliant character, for instance, articles of a pliancy comparable to that of suede or of the felt in a true .felt hat. It deals more especially with articles of the sort whose molded fibrous base is an interfelted, Waterlaid one in the sense that it is deposited by flowing an aqueous fiber suspension onto a foraminous or wire mold through which the free water of the suspension drains or is sucked while the fibers are being matted or laid down in inter-felted relationship as a layerconforming to the configuration of the mold.

In accordance with the present invention, various kinds of molded, binder-reinforced, fiber articles of a pliant character, for instance, hat shapes, are formed by depositing fibers of the appropriate character from aqueous suspension onto foraminous molds, the aqueous suspension carrying additionally, if desired, binder of suitable character so that the binder-reinforced articles maybe formed in a single operation; or,

shape and preferably both-its surfaces if desired, the molded articles may be formed substantially without binder as sufliciently porous and absorptive structures to undergo readily a subsequent impregnating operation with suitable binder, the articles preferably being compacted and dried prior to such impregnation. While not limited thereto, the principles of the present invention are applicable to especial advantage in the fabrication of seamless hats whose appearance, feel, pliancy, toughness and other qualities are imitative of those of genuine felt hats. In such case, after the binder-reinforced hat shape has been produced as hereinbefore in-' dicated, at least the external surface of the hat are 1111- ished with fiber 11001: to simulate in appearance and feel the surface of a genuine felt hat.

With the foregoing and other features and objects in view, I shall now describe my'invention as applied to hat-making with particular reference to the accompanying drawings, wherein Figure 1 is a section through one form of apparatus that may be employed for molding a hat shape, the apparatus including adjuncts for compacting and, if desired, drying the wet hat shape Figure 21s a section through somewhat modified molding apparatus during themolding oper-' ation, with which apparatus a different type of instrumentality for compacting the wet hat shape is designed. to be used. I

Figure 3 is a similar view of the apparatus of Figure 2 after the molding operation and with the compacting instrumentality in place.

Figure 4 is a similar view of the same apparatus while compacting of the layer constituting the hat shape is being eiiected.

Figure 5 is a side view of the molded hat shape. Before dealing with the particular fiber furnish, binders, and other materials employed'in fabricating the hats of the present invention, it is perhaps well to describe the particular molding apparatus shown in the accompanying drawings, which apparatus, it is to be understood, is subject to considerable variation. The apparatus of Figure 1 comprises a cylindrical vat l0 into which an aqueous fiber suspension of the appropriate consistency, namely, of a fiber content usually not exceeding about 2%, is delivered from a suitable source of supply (not shown) by a valved pipe I I. In order to realize uniform interfelting of the fibers as they are being deposited from aqueous suspensicmit is preferable to deliver very dilute fiber suspensions to the apparatus, for instance, suspensions of a fiber content of to or even lower. The apparatus as depicted in Figure 1 comprises only a single wire mold l2, but it is obvious that multiple-mold apparatus may be employed. The mold illustrated, which assumes the form of an inverted hat shape, may be constructed of wire cloth of a mesh and quality similar to that serving as the endless wire of a Fourdrinier papermaking machine or as the periphery of the cylinder mold of a so-called cylinder papermaking machine. Its marginal portion l3 may be fixed, as by welding, to the out-turned flanged upper end portion ll of a cylindrical supporting frame l5 movable vertically out of the vet along with the mold carried thereby while guided in such movement by a cylindrical outer shell IS with which it makes sliding contact. The lower end of the shell I may be fixed to the bottom ll of the vat and its upper end may serve as up the mold so as to deposit a substantially uniform layer of fibers It on the mol d as-the water of the suspension is draining through the mold into the compartment 2|! defined by the shell [6. A valved pipe 2| for withdrawing the white water from the compartment 20 is kept open during the molding operatiomwhich operation is preferably initiated with a supply of white water in the compartment 20 up to the very top of the mold, namely, to the level of its marginal portion [3, so as to avoid a "water-wing eifect, that is, an immediate sealing of the openings of the mold by the water of the pulp suspension that prevents osited on the mold is compacted the valve 22 in the pipe 2| is preferably a twoway one designed to permit downward flow of white water from the compartment through its branch 23 during a molding operation and upward fiow of white water through its branch 24 into the compartment before beginning a molding operation. Aqueous suspension of fiber in volume predetermined to deposit a layer of fibers IQ of the desired thickness on the mold is progressively delivered into the apparatus and the valved pipe-Ii then closed.

Inasmuch as the hat shape l9 as deposited on the mold is too wet and pulpy to be removed from the mold or handled without damage, provision is made to compact and dewater it to a self-sustaining condition. To this end, the molding apparatus of Figure 1 includes means for raising the mold-supporting frame l5 while guided by the shell I6 out of the vat so as to bring the wet hat shape carried by the mold into pressing contact with a compacting instrumentality 25 of a configuration mating with that of the mold, as illustrated in dotted outline. Thus, the lower walls of the mold-supporting frame l5 may be bridged by a transverse bar 26 fixed in turn to the upper end portion of a plunger or reciprocatable rod 21 passing through a suitable stufllng box 26 into the compartment 26. Movement of the plunger may be effected by suitable means (not shown) to raise the wet hat shape carried by the mold I9 into pressing contact with the compacting instrumentality 25 and then to lower the mold to its molding position in the vat. If desired, the instrumentality 25, which may! be constructed of suitable metal, such as steel, and be smoothly finished .on its exterior, may have a hollow interior 29 into which steam or other suitable heating medium may be introduced by a pipe 30 so that upon bringing the wet hat shape into the desired pressing contact therewith, not only may the free water be squeezed from the shape but the shape may be partially or completely dried. Once the hat shape has been compacted and dewatered to a self-sustaining condition, so that it may be removed from the mold and handled without injury, a partial downward movement of the plunger 21 may be effected to permit the hat shape to be removed for further treatment, whereupon the remaining downward travel of the plunger may be completed.

The hat-molding apparatus shown in Figure 2 is essentially similar to that of Figure 1 excepting that no provision is made for raising the moldsupport to bring the hat shape carried by the mold .into pressing contact with a compacting instrumentality. On the contrary, the mold 40 appearing in the apparatus shown in Figure 2 is removably supported at its marginal portion 4| on an annular ledge 42- projecting inwardly from the upper portion of a cylindrical wall 43 .upstanding from and fixed to the bottom of the vat and defining a compartment 44 into which white water drains from the mold during the delivery of aqueous fiber suspension thereon. Leading from the compartment 44 is a two-way valved pipe 2|. having the same connections and the same functions as the similarly numbered pipe and connections of the apparatus of Figure 1.

The essential distinguishing feature between the apparatus of Figure 2 and that of Figure 1 is the means by which the wet hat shape lsdeand dewatered to'self-sustaining condition. Thus, as shown in Figure 3, after a wet hat shape has been deposited as previously described on the mold 46, a membrane 45 of rubber or equivalent stretchable and gas-impermeable material cemented or other wise fixed to a rigid marginal retaining ring 46 is placed over the mold with the marginal portion of the membrane or the ring 46 making sealing contact with the marginal portion 4 of the mold. The membrane or diaphragm 45, which normally extends horizontally over the top of the mold so as to close off the top completely, is thus in a position to be sucked or stretched downwardly against the hat shape into the mold-conforming configuration shown in Figure 4, and, in so being stretched, to squeeze the free water from the wet hat shape and thus to compactv it to a self-sustaining condition. The membrane may be placed under the appropriate suction by creating suction in the compartment 44 by opening a valved suction pipe 41 leading from such compartment to a vacuum chamber or pump (not shown). The valve 48 in the pipe 41 is preferably a two-way one, one way opening to a branch 49 communicating with the vacuum chamber or pump and the other to a branch 50 communicating with the atmosphere. After the desired compacting and dewatering of the hat shape has been accomplished, the suction branch 49 is closed and the atmospheric pressure branch 50 is opened to permit restoration of the compartment 44 to atmospheric pressure. In order to permit air to pass in between the membrane and the hat shape so as to break the suction that tends to persist therebetween and thus cause the membrane to peel away gradually from the hat shape and resume its normal unstretched position shown in Figure 3, the membrane is preferably provided, as at its center, with a valved, open-ended nipple 5| projecting upwardly there- -fr0m, the membrane being cemented or otherwise sealed to a thin flange element 52 constituting the lower end of the nipple. The nipple is closed while suction is being applied to the membrane and is opened sufficiently when air is subsequently introduced into the compartment 44 to permit it to peel away gradually from the compacted and' dewatered hat shape and thus to resume its normal unstretched position. The membrane and its rigid retaining ring 46 may then be removed from the mold, the mold and the hat shape carried thereby raised from its support, and the hat shape dried preferably while stillv carried by the mold, as in a hot air chamber.

Various binders may be used to impart the desired toughness and leather-like qualities to the fibrous body of the hat, for instance, such binders as rubber, glue, viscose, etc. These binders may be added to the aqueous suspension of fibers delivered to the hat-molding apparatus, in which case the white water system of the apparatus should preferably be maintained reasonably closed so as to utilize the binder carried away by the white water in preparing fresh or new fiber suspensions. In the case of rubber, the rubber may be added to the aqueous fiber suspension as at 4 to 6% fiber content in the form of rubber latex or artificial aqueous rubber dispersions and the rubber precipitated or coagulated on the fibers beforebeing diluted with water for delivery to the molding apparatus; or a dilute aqueous suspension of flocculated or precipitated rubber may be separately prepared from rubber latex or other aqueous rubber dispersion and admixed with the dilute aqueous fiber suspension immediately before its delivery to the molding apparatus. It may, however, be prefer able to impregnate the premolded hat shape in partially or completely dried condition. Thus, the premolded hat shape may be sprayed on either or both faces with rubber latex or other suitable binder to effect a substantial impregnation of itsbody, or, if desired, a substantially complete impregnation thereof.

Irrespective of whether the hat shape is molded in the presence of binder or whether binder is subsequently infused thereinto, it is then-preferably surfaced with fiber flock so as to simulate true felt or suede in its appearance and feel. If the hat is-molded in the presence of binder and is then dried, it is necessary to apply suitable binder, such as rubber I latex, glue, nitrocellulose cement, etc., as by spraying, on the surface of the hat and then to shower fiber flock on the sticky hat surface as the hat is supported on a suitable form or block, with rotary or other appropriate movement of the form, if desired, to ensure substantially uniform flocking of the hat surface with fiber. At least the outer surface of the hat is preferably thus finished with fiber flock; and it is usually desirable to turn the, hat inside out on the supporting form after its outer surface has been finished and to finish the nowouter surface in the same way as the previously outer surface. In those instances when the molded hat shape undergoes an after-impregna tion with rubber latex or other suitable binder, as by spraying the binder on the shape while supported by a form or block, sufficient binder may be applied not only to effect impregnation of the body of the shape to the desired degree but to develop an adhesive coating on its surface which is showered with fiber fiock and then permitted to dry or set. Thereupon, if desired, the inside surface of the hat may'be treated with binder and also flocked, as hereinbefore described. Of course, fiber flock of any'suitable color or sheen may be employed; and, if desired, flock of one or more colors may be distributed locally on the hat surface to produce highly ornamental eifects, the binder for the flock and/or the flock being applied, for instance, through suitable stencils in producing such effects.

In some cases it is advantageous to form the hat into a shape which only roughly conforms to the final desired pattern, then re-wetting and stretching over a mold or form against which the material will shrink during re-drying. The hat may then be flocked in the usual way. According to this procedure the number of relatively expensive foraminous molds necessary for the deposition of the pulp may berconsiderably reduced,

and changes in final hat shapes may be efiected through the stretching process.

The flocked or finished hat may be given a final blocking or shaping as is customary in hat manufacture; and it may be provided with the usual accessory hat elements, such as a lining, sweat band, etc., and the usual hat ornaments, such as an outer band or ribbon, buttons, feathers, buckles, etc.

- An important factor in the realization of hats possessed of the. desired body, feel, pliancy, and other qualities is the character of the fiber furnish employed in molding the hat shape. Thus, unless the furnish is of the proper kind and is properly conditioned for the hat-molding operation, the resulting hat shape may be comparatively rigid or boardy, as is true of the usual molded pulp articles. In accordance withthe present invention, I supply to the 'moldin'gapparatus aqueous suspensions of cellulosefibers preferably in substantially unhydrated condition, for instance, suspensions of cellulose fibers of a dimcultly hydratable character in such condition,

typical of which fibers are wood pulps refined to high alpha cellulose content,-say,"an alpha oel- "lulose content of about 92% to 98%, virgin cotton,

mercerized wood pulps or cotton, and the like. In suspending such fibers in water to form the dilute suspension delivered to the molding apparatus, care should be takento avoid substantial beating or other intensive mechanical action such as is accompanied by a hydration or gelatinization of the fibers and consequent .stiifness or I boardiness in articles molded from the fiber susgreater degree than is otherwise permissible, asv

wool and/or hair are unhydratable and lend to the molded hat shape the desired pliancy and other qualities.

Indeed, when, say, 5% to 65% of wool and/or hair, based on the dry weight of the entire fibrous furnish constitutes, along with cellulose fiber, the fibrous furnish, it may be desirable to effect some degree of hydration or gelatinization of the cellulosic fibrous portion of the furnish in order to effect a binding or cementing together of the fibers of the hat base by the cellulose hydrate or gelatinized cellulose. Part of the fibrous furnish may be long-fibered pulps, such as chemically pulped manila, sisal, ramie, etc., 5% to 50%, based on dry weight of the furnish, of such long-fibered pulp improving notably the results secured from furnishes containing a substantial proportion of mercerized cellulose fiber and/or wool.

Various proportions of binder may serve as the reinforcing impregnant in the hat shape. Thus, the hat-shape may contain from about 5 to 100% of rubber, or from about 8 to 40% of glue, or from about to 5% of cellulose regenerated from viscose, based on the dry weight of fiber in the hat shape. In the case of all of these binders and especially in the case of glue and viscose, it is desirable to introduce a suitable softening or plasticizing agent into the hat shape in order to neutralize or offset such undesirable stifiening action of the shape as may come from the binder.

, Thus, hat shapes impregnated with dry rubber latex solids may to advantage contain about 5 to 25%of glycerine, based on latex solids; those impregnated with glue, about '75 to 200% of glycerin-e, based on glue solids; and those impregnated with about V to 5% cellulose regenerated from viscose, about 5 to 30% of glycerine, based on the dry weight of fiber. Other softening )agents, such as ethylene glycol or other homologues of glycerine, glucose or, other invert sugars, Nulmoline, and the like might be employed in lieu of glycerine. The glycerine or other softening agent may be introduced directly into such impregnants as rubber latex, glue solution, and'visdose, with which they may be applied to the binder-impregnated hat shape either generally or locally, as in the form of aqueous solutions. So, too, such stiffening agents as waterglass, starch paste, etc., maybe added to'the hat shape along with the binder. In some instances, binders such as rubber latex are "compatible; or they I and glue, rubber latex and viscose, and rubber latex, glue and viscose may be admixed to develop the proper degree of stifiness in the hat. In this connection, it might be noted that the addition of glue and/or viscose to a rubber latex binder has the effect of increasing the stiffness of the hat shape impregnated with the binder. As in the case of the softening agent, the stifiening agent maybe infused into the binderirnpregnated hat shape, as in the form of an aqueous solution; and such infusion may be had generally or locally, for instance, only at'the brim portion of the hat, whereat greater stiffness is generally desired than at the crown portion.

While the thickness of the hat body or structure prior to surfacing it with fiber flock is sub- Ject to variation, it is generallythe case that the thickness desired ranges from about 20 to 60 mils, as at such thickness it can be finished with fiber flock to produce a final hat structure or body whose'thickness is comparable to that of suede or felt in a-true felt hat.

I claim:-

1. A method of making a seamless, molded, binder-reinforced, waterlaid fiber article which comprises depositing fiber and an elastic binder' from aqueous suspension into approximate article shape on a porous mold, compacting the article to remove free water therefrom and dewatering it to self-sustaining condition on said mold,

so removing the dried article from said mold, re-

wetting and stretching the article in rewetted condition to its final shape on another mold, and redrying the article on said other mold, thereby causing it to shrink against said other mold.

2. A method of making a seamless, molded, rubber-reinforced, waterlaid fiber article which comprises depositing fiber and fiocculated rubber from aqueous suspension into approximate article shape on a porous mold, compacting the article to remove free water therefrom and dewatering it to self-sustaining condition on said mold, removing the dried article from said mold, rewetting and stretching the article in rewetted condition -t.o-its final shape on another mold, and redrying the article on said other .mold, thereby causing it toshrink against said other mold.

3; A method of making a seamless, molded, waterlaid fiber article which comprises depositing 'fiber from aqueous suspension into approximate article shape on a porous mold, compacting the article to remove free water therefrom and dewatering it to-self-sustaining condition on said mold, removing the article from said mold,

stretching the article, in whose body an elastic binder is incorporated as an impregnant, in the presence of moisture to its final shape on another mold, and drying the article on said other mold,

thereby causing it to shrink against said other mold.

MILTON O. SCHUR.

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