US 3020169 A
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Description (OCR text may contain errors)
Feb. 6, 1962 F. N. PHILLIPS, JR., ETAL 3,020,169
SHOE LINING AND STIFFENING MATERIALS 2 Sheets-Sheet 1 Filed Dec. 6, 1956 [TI/venon's Ferdinand N P/u'/Zz)os,c
Thomas C Mor/ILS Adolph M Chap/Ck Feb. 6, 1962 F. N. PHILLIPS, JR., ETAL 3,020,169
SHOE LINING AND STIFFENING MATERIALS 2 Sheets-Sheet 2 Filed Deo. 6, 1956 Inventors Ferdzhand N PhlzpS/L' Thomas CMorrz's Adolph M. Cha/@Zick maan United States Patent O 3,020,169 SHE LlNiNG AND STFFENWG MATERiALS Ferdinand N. Philiips, Jr., Brookline, and rlllomas C. Morris, Lexington, Mass., and Adolph M. Chaplicir, Hudson, NH.; said Morris and Chaplick assignors to B. E. Chemical Co., Boston, Mass., a corporation of 'Massachusetts Filed Dec. 6, 1956, Ser. No., 626,624 6 Claims. (Cl. 117-33) This invention relates to a new stiifening and lining for portions of shoe uppers.
To preserve the shape of shoe uppers it is customary to provide a stiff sheet material as a layer in the toe or heel portions of shoes. These stiffeners have either been initially stiff, as for example the common fiber counter stiffener which is provided as a preshaped stiff element, or have been materials softenable by heat or solvent to a condition in which they can be incorporated in a shoe upper and given the desired shape by lasting. v
The performed fiber stiener must have at least approximatelythe shape required in the final shoe and therefore a large stock-of fiber stiifener shapes is required. On the other hand, the heat or solvent softenable stiffener requires treatment to bring it to condition inwhich it can be incorporated in a shoe and it remains in moldable condition for only a limited time which imposes a definite time schedule on shoemaking operations. Each of the conventional shoe stiffener materials is ordinarily inserted between the outer layer of the shoe and an inner lining of leather or fabric. This factor introduces assembly problems in certain types of shoes and provides a multiply construction which may have undesired bulkiness.
It is a feature of the present invention to provide va stiffener or liner material which is permanently dry, flexible and lastable at room temperature for easy assembly in a shoe upper and which under the action of heat combines with and stiflens the shoe. In a preferred form, one face of the material has a character suitable for exposure as the inner surface or lining of a shoe.
The shoe liner of the present invention includes a single base sheet of relatively open, matted, knitted or felted fibrous material capable of stretching sufficiently to conform to the contour of a last, and at least one face carries a substantially solid unbroken, resiliently flexible,
heat softenable resinous adhesive coating localized substantially at the surface.A When the material is -to be used as a liner, a decorative coating or finish is applied to one face and the adhesive coating is appliedv to the other face, but if the material is to be interposed between the upper and liner of a shoe to provide a stiffener to take the place of a conventional counter, then both faces are provided with a resinous coating of the aforementioned character. The resultant sheet retains much of the flexibility and lastibilityl of the fibrous sheet in uncoated condition since the adhesive coating is localized at the surface of the sheet and does not interfere with limited relative movement of the fibers in the interior of the sheet. The sheet is thus readily incorporated in a shoe upper, for example at the heel, vamp or toe, before the shoe is shaped on a form, e.g. lasted, and the shoe assembly containing the lining material may then be shaped byconventional means. After shaping of the shoe, heat is applied to the resinousadhesive layer to soften it. The relatively thick layer or layers of resinous adhesive, when in heat softened condition, is initially on the surface of the lining material and is available to bond rapidly and firmly to the interior of the shoe upper and/ or liner as the case may be. At the same time, ydue to the tension of the upper against the form or last, the adhesive may penetrate into the fibrous sheet and surround a substantial portion ICC of the bers of the sheet particularly at areas of greater pressure as at the toe or heel to hold the fibers more firmly. After cooling and hardening, the lining material cooperates with the upper to provide a resilient stiffening or shape retaining action and snap-back characteristics through holding the fibrous base and the shoe upper stock in non-shifting plied relation. Also the fibers of the base itself are held more rigidly in the adhesive layer to give added stiffness.
The invention will be described with the drawings, in which, l
FIG. l is a greatly enlarged section of one form of the lining and stiffener material of the present invention;
FIG. 2 is a plan view of a counter of the lining and stilfener material prior to incorporation in a shoe;
FIG. 3 is an angular view of a shoe upper with the counter of FIG. 2 stitched in place;
FIG. 4 is an angular view ofa lasted shoe upper including the counter and showing a heater disposed to heat the upper and the resinous adhesive layer of the counter; FIG. 5 is a greatly enlarged section taken on line V-V of FIG. 4 showing the counter after heating and cooling;
FIG. 6His a -greatly enlarged section of a second form of the lining and stiffener material of the present invention;
FIG. 7 is a plan view of an allover liner and stifener for a shoe;
' FIG. 8 is an angular view of a shoe upper with the allover liner of FlG. 7 stitched in place;
FIG. 9 is anV angular view of a completed shoe upper including the allover liner andstiffener of FIG. 7',
FIG. l0 is a greatly enlarged section of a third form of the stiffener material of the present invention;
FIG. 11 is an angular view of a shoe upper with the stiifener material of FIG. 10 secured in place; and
y FlGclZ is a greatly enlarged section of a further form ofthe lining and stiffener material of the present invention.
As shown in FIG. l,- the liner or stifener material -10 comprises a fibrous base sheet 12, a decorative .coating'1'4 on one face of the sheet and av relatively thick layer 16 of thermoplastic resinous adhesive on the other. The adhesive layer 16 is localized on the surface so that only the ends 18 of the fibers 20 of the base sheet are held in the resinous adhesive layer 16; andA since the resinous coating 16 does not penetrate the fibrous sheet 12 relative movement of the fibers 20 in the interior of the brous sheet can occur. Because of this freedom of the fibers 20 to move relative to each other, the stiffness of the coated sheet 10 is substantially the 'sum of the stiffness of the decorative and resinous coatings 14 and 16 and the fibrous base sheet `12 itself. The coated sheet 10 can therefore bend and conform to a desired shape in the process vof lasting without the necessity of heating it or treating it with solvent to soften it.
. Pibrous sheets 12 in which the fibers 20 are in relatively loose relationship are desirable. Non-Woven fibrous base sheets, particularly relatively free fiber sheets, offer advantages in two-dimensional stretchability to enable a lining using such base material to conform to the irregular shape at the heel, toe and other parts of the last. At the same time, the adhesive layer 16 holds the ends of the fibers of the base sheet against displacement to give a more easily handled material. A fibrous base sheet material comprising fibers held in loosely matted relationship by a binder such as a synthetic polymer resin or synthetic polymer rubber has been found very satisfactory. In one suitable sheet, nylon and rayon fibers of l" -to 1% in length and 11/2 to 3 denier Wih 50% to 100% by weight of a butadiene-acrylonitrile synthetic rubber binder, based on the Weight of the fibers, holding the fibers at their points of contact forms a resilient flexible sheet material capable of stretching sufficiently to conform to the confurther in connection tour of a last. This sheet material has been found to possess desirable lasting characteristics enabling it to be conformed without objectionable wrinkling when subjected to lasting stress, Various thicknesses of the nylon fibrous sheet may be used but in general about 0.02 to about 0.1 inch gauge are preferred.
The resinous adhesive layer 16 may be applied by melting the resinous adhesive composition and spreading it either by means of a heated applying roll or by a heated doctor bar spreading device on a surface of the fibrous sheet 12. The thermoplastic material is heated to a temperature at which it is in relatively viscous condition so that the spreading operation does not cause substantial penetration of the molten resinous material into the `fibrous sheet. A spreading viscosity of from 6,000 to 60,000 centipoises has been found to give a desirable type of rmly adherent but non-penetrating coating. After spreading the molten resinous composition on the fibrous sheet 12, the coated sheet is allowed to cool to solidify the coating to substantially solid unbroken, usually transparent condition. The term substantially solid unbroken is employed herein to refer to a glossy continuous layer and to distinguish from discontinuous resinous deposits obtainable by saturation of a base with latices or other liquid dispersions of resin in a vehicle and coagulation or other treatment, eg. mechanical working to give discontinuity to the deposits of resin. A wide variety of resinous adhesive compositions having desirable resilient stiffness may be prepared by chem ists familiar with the compounding of thermoplastic res inous and adhesive compositions by blending of resins, plasticizers and/or fillers. Compositions based on linear polymer resins such as poiystyrenes, polyamides, polyvinyl acetate and ethyl cellulose are readily compounded to have the necessary spreading viscosity in molten condition and the necessary stiffness and resilience at normal temperatures. The properties of compounded resins for this use include the characteristic that the material exhibits substantially no cold flow at temperatures of at least 120 F. and preferably at least 140 F. when subjected to minor stress such as would normally occur in the making, shipping or use of a shoe. Convenience in spreading calls for a melt viscosity in the desired range of 6,000 to 60,000 centipoises at a temperature of around 300 F. The adhesive resinous material should also be relatively nonbrittle at room temperature to facilitate handling prior to incorporation in a shoe and possess the ability to wet and hond to the leather or fabric of the interior of a shoe in which the liner is to be used.
The other face of the fibrous sheet may be provided with any suitable decorative coating 14 possessing the necessary resistance to temperature and moisture conditions encountered in the interior of a shoe in shoemaking and in being worn. In the material illustrated in FG. 1 the decorative coating is a layer of ock fibers 22 secured in upstanding relation to the sheet by a layer 24 of ocking adhesive. The ock fiber coating provides a non-slip action which may be desirable in certain types of shoes. Where the decorative coating 14 includes flock fibers 22 it preferably is applied to the fibrous base sheet 12 before coating with the thermoplastic resinous adhesive layer 16. Conventional flocking procedure is followed in which a layer 24 of solution type synthetic rubber base flocking adhesive is spread on a face of the brous sheet base 12 and flock ber 22 is spread on the adhesive surface while vibrating the brous sheet 12 as by means of Va rotating hexagonal beater bar on the opposite face of the fibrous sheet.
Other decorative coatings 14 `(see FIGS. 6 and 7) such as inks, e.g. printing inks and pigmented resinous or ce1- lulose derivative finishes may be used. The coatings may be printed on in various designs and colors suitable for their intended purpose. In the application of finishes other than the flocking type finish it is usually immaterial whether the nish be applied before or after spreading on the resinous adhesive coating.
As noted above the liner material 10 of the present invention may be employed in various parts of the interior of a shoe such as the toe, vamp and counter portions or indeed may form a complete lining for a shoe. For purposesof illustration the use of the material as a stifener in the counter portion of a shoe will be described rst. For stiffening the counter of a shoe, there is died out a counter stiffener blank '26 comprising a rear portion extending from the heel base substantially to the top line at the back seam of a shoe 2S and portions of decreasing height extending forward towards the shank portion 30 of the shoe 23, If desired, the side portions may extend forward to include portions of the Vamp. The lower edge 32 of the stiffener blank 28 is provided with notches 34 at suitable intervals to reduce or eliminate the bunching and wrinkling of the stiiener blank below the heel seat of the shoe 2S when the shoe containing the stiifener blank is formed over a last 36.
The died out stiffener blank 26 is incorporated in the stitched together upper of a shoe in any convenient manner, suitably by sewing it in place in the stitching room. As shown in FIG. 3, the stiffener material is sufficiently exible to bend readily with the shoe upper making it easy both to stitch in place and to place the upper with the stiifener on a last (see PEG. 4). The shoe 28 is then lasted and the notched lower edge 32- of the stilfener blank 26 will be found to wipe readily around the bottom edge of the last 36.
At any point thereafter, whether immediately after lasting or up to completion of the shoe 28 but before removal of the last 36, the portion of the shoe 2S containing the stiffener blank 26 is subjected to heat. Heat may be applied either by means of an iron or steam or by high-frequency heating, or a radiant heat source such as the electrically heated rod 40 shown in FIG. 4. The electrically heated rod 40 is bent to conform roughly lto the shape of the back of the shoe at two levels and a reflector 41 is disposed behind the rod to insure that heat is radiated evenly over substantially the entire area `containing the stiifener blank 28. Heat may be applied yby means of an electrically or otherwise heatedband or strap (not shown) stretched around the outside of the shoe portion containing the stiffener blank, and Ithis procedure gives an additional -force to conform the shoe to the mold or form, e.g. the last 36. High-frequency electric or magnetic devices may Aalso be used to generate the desired heatwithin the resinous adhesive layer 16.
After the steps of heating and conforming the shoe to the las-t or other form the adhesive layer 16 is allowed to cool and harden while the shoe is held lin shape on the last or form by the tension of the shoe or by the pressure of the `band or strap. It is' found that substantial stiffening is obtained in the resulting shoe when sufficient heat has been applied in the heating stage to soften the resinous adhesive layer 16 to a degree at which it will establish a firm bond to the interior of the upper 28 (see FIG. 5). Improved stiffness is obtained where the heating is for a time or to a temperature which renders the resinous adhesive somewhat fluid and causes it to ow into the fibrous sheet and more fully into engagement with the interior of the shoe upper;V
The stiifening action of the material of the present invention is due at least in part to a laminating action `in which the fibrous sheet 12 is held firmly to `the interior of the shoe. Further resilient stiffness appears to be due to the fact that the ends 20 of the stifiy resilient individuall bers of the fibrous sheet are held against movement in the relatively thick resinous adhesive layer 16 and provide the equivalent of a truss or lattice resiliently bracing the heel portion of the shoe 28 against distortion. -Where the stilfened portion has been subjected to heat suicient to canse tiow of the resinous adhesive around the fibers of the sheet 12, there is an additional locking of the fibers against relative movement which increases the stiffness of the assembly.
Material according to the present invention may form a complete lining of a shoe. In this relation the material enables the use of a greater range of shoe upper materials without further backing and provides substantial advantages in the assembly and manufacture of the shoe. The stiffening effect of the material eliminates the need for a stiffening insert which would -be required between the upper and conventional lining materials. Likewise, provision of a complete lining of the material eliminates diiiiculties in assembly as may be encountered with conventional backed or combined upper materials.
For allover shoe linings it is ordinarly desirable that the decorative surface coating 14 (see FIGS. 6 and 7) on the exposed face of the material be relatively smooth, as for example a simple ink printing 42 as shown for example in FIGS. 6 and 7. An allover liner 43 is cut or died out of .this liner material as shown in FIG. 7. Assembly with the upper 44 may be achieved by stitching the material to the upper along the edges 46 to provide a unit (see FIGB) which can be handled easily in subsequent shoemaking steps. Alternatively, it is possible to join the liner Ito the upper in the flat by application of only suilicient heat and pressure to establish a relatively weak bond between the adhesive of theliner and the interior of the upper. This composite of liner and upper may be cut or died out and stitched, and assembled with other necessary shoe elements in the fitting room. The resin can also be used as a combining cement for cornbining in continuous length the upper to the lining in place of cutting the linings individually.
v The shoe upper 44, whether assembled by stitching together or lightly bonding together the upper material and the liner stiffener material, may be placed on `a last and shaped thereon with no difficulty. Heating to effect a more permanent union of the liner stiener and the upper may be carried out before or after shaping the assembled shoe upper to the last. lt has been found that after cooling, a shoe upper (FIG. 9) provided with an allover lining of the stiffener liner material assumes and retains a shape more closely following the last than has heretofore been obtained in shoemaking Where the shoe is removed from the last within a short time after the lasting or shaping operation. This treatment gives the shoe the property known to the Shoemaker Ias character, i.e., the exact reproduction in the shoe of the lines of the last. It Will be understood that for use as an allover lining the liner stiffener material will ordinarily be chosen of a grade somewhat less firm than the materials which may be more desirable for use only in stiffening the counter or toe portions of a shoe. Nevertheless, the liner stilener does provide resilient snap back type shape retention throughout the shoe.
In a further modification of the invention (see FIG.
10) resinous adhesive layers 16 may be applied to both surfaces of the fibrous base sheet l2 in a manner to insure that the molten resinous adhesive composition vremains substantially on the surface of the fibrous sheet 12 and does not penetrate substantially into the sheet. Double-surface adhesive coated sheet material 48 may be used in counters or toe portions to provide even greater stiffness. It will be understood that these materials will be used in shoes 50 having a lining or counter pocket 52 ,(see FIG. ll) and will be disposed between the upper 50 and the lining or counter pocket S2. On heating a bond will be created between the upper S0 and the adhesive coated sheet 48 and between the adhesive coated` sheet 48 and the lining or counter pocket 52. ParticularlyK with this double-surface coatedmaterial 48 which `provides somewhat greater stiifness than the single adhesive coated material, it may be desirable to extend the stiffener material the full length of the quarter and down under the arch to give improved arch supporting action. l
Many other variations are possible in materials and structures including the fibrous base sheet andthe surface coating or coatings of thermoplastic resinous adhesive, for example a relatively thick coating of vinyl or other comparable resinous coating finish (not shown) ernbossed to resemble a leather lining, may be provided on the surface of the fibrous sheet opposite the resinous 'adhesive layer. Again, thin suede leather skivers 54 (see FIG. l2) may be adhered to one side of the tibrous sheet 12 to provide a material useful as a combination counter land non-slip, where service conditions or other factors render a flocked surface not acceptable. Accordingly, it is to be understood that the invention is not restricted to the particular materials and procedures shown except as defined in the claims.
The following examples are given to illustrate the material of the present invention more fully:
Example I A 0.027 thick, 6 oz. per square yard, non-woven sheet of blended l1/2 to 3 denier nylon and rayon iibers averaging about 1l long and containing about 75% by weight of the sheet of a synthetic polymer rubber binding the fibers at their points of contact was flocked by conventional flocking procedure involving the steps of spreading on an 0.020" wet thickness coating of a conventional neoprene flocking cement, depositing 0.5 mm. long rayon flock fibers on the adhesive coatingand vibrating the sheet by bringing the uncoated side inrcontact with a rapidly rotating hexagonal beater bar. The flocked fabric was ldried and the flocking cement cured by passing the fabric through an oven in accordance lwith conventional procedure for making iiocked products.
After hardening of the iiocking cement the uncoated side of the nylon vfiber base' sheet was coated with an 0.01 thick coating of a thermoplastic resinous adhesive. The coating operation involved blending 5 parts by weight of mixed ortho and para-Ntoluene sulfonamides with parts by weight of a polyamide formed by the reaction o-f dimerized soybean oil fatty acid With ethylene diamine and having an amine value of 1.9 milligrams of *NH2 per gram of resin,v an acid number of about 7, an ash content of 0.10 maximum, a specific gravity of .917, an average molecular weight of 3000 to 6500, and aball and ring softening point (ASTM) of to C.
The molten resin mixture was brought to a temperature of about C. and spread on the base sheet using a knife spreader of which the knife` temperature was C. The applied resin hardened promptly after application to a transparent, brownish,-stiiiiy flexible lrn.
A counter stiifener blank was cut from the coated base .sheet material in an outline as shown in FIG. 2 including notches along the lower edge. The counter stiffener was stitched into a shoe upper by a row of stitches extending along the curved upper edge of the blank and the assembly was then placed on a last.
The shoe upper assembly including the stitfener blank was pulled over and lasted without heating. No diiliculty was encountered in this operation. The heel end of the lasted shoe was then heated to a temperature of about 100 C. by disposing it approximately one inch from a shaped electrical heating unit and the upper was held at this temperature for about 30 seconds.
The upper cooled in about 3 to 4 minutes. Further shoemaking operations including sole attaching, heeling, etc. were carried out on the shoe and the shoe was rcymoved from the last. The portion of the shoe containing `the stiffener was Aresiliently iiexible but sufficiently stit. to retain in large measure the shape imparted to the shoe by the last. The shoe was cut open and it was observed that the resin coating had flowed into intimate adhesive contact with the interior of the shoe upper and formed a strong bond to it. This action appears to be aided by the pressure of the upper against the last due to tension re- ',sulting from the lasting operation. It is also considered that the leather-upper may have shrunk to a limited exacadien tent during the application of heat and created additional pressure squeezing the counter stiffener between the shoe upper and the last. The fibers of the nylon fiber base sheet had penetrated somewhat further into the resin coating and it appeared also that the resin had flowed somewhat into the interior of the base sheet. The fiock bers remained in upstanding relationship in the fiocking adhesive.
Other shoes prepared in the same manner were Worn and it was found that the upstanding flock fibers provided the desirable non-slip action on the heel of the foot to hold the shoe against undesired motion relative to the heel.
Example II Flocked and resin coated counter stiffener blanks were incorporated in a shoe upper and the upper disposed on a last and lasted as in Example I. Thereafter air from a hot air gun at a temperature of about 190 C. was directed against the portions of the shoe underlying the stiffener blank. The air blowing was continued until the temperature of the leather reached about 100 C. and was then discontinued. It was found that a satisfactory union of the counter stiffener and shoe 'upper was obtained.
Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:
1. A normally exible, lastable sheet material comprising a relatively open two-dimensionally stretchable non-woven fibrous sheet base from 0.02 to 0.1 inch in thiol-:ness of which the individual bers are held in loosely matted relationship and a substantially solid continuous layer of heat softenable, stiff, resilient thermoplastic adhesive localized substantially at a surface of said base, proiecting ends of fibers of said fibrous sheet being embedded in and held against displacement by said layer of adhesive and portions of the fibers in the interior of said fibrous sheet being capable of limited movement relative to each other, said layer of adhesive having a substantial thickness relative to the thickness of said base sufficient to penetrate said base and surround substantial portions of the fibers of said base when said adhesive is softened by heat and an assembled shoe including the sheet material is stretched against a form in the shaping of the shoe.
2. A normally flexible, lastable shoe liner comprising a relatively open two-dimensionally stretchable nonwoven fibrous sheet base from 0.02 to 0.1 inch in thickness of which the individual fibers are held in loosely matted relationship, a decorative surface on one face of said bas-e and a substantially solid continuous layer of heat softenable, stiff, resilient thermoplastic adhesive localized substantially at the surface on the other face of said base, projecting ends of fibers of said fibrous sheet being embedded in and held against displacement by said layer of adhesive and portions of the fibers in the interior of said fibrous sheet being capable of limited movement relative to each other, said layer of adhesive having a substantial thickness relative to the thickness of said base sufficient to penetrate said base and surround substantial portions of the fibers of said base when said adhesive is softened by heat and an assembled shoe and lixer are stretched against a form in the shaping of the s oe.
3. A normally flexible, lastable shoe liner comprising a non-woven, two-dimensionally stretchable, brous sheet base from 0.02 to 0.1 inch in thickness, a decorative surface coating on one face of said base and a substantially solid continuous layer of heat-softenable, stiff, resilient thermoplastic adhesive localized substantially at the surface on the other face of said base, said fibrous sheet base including a binder holding the individual fibers in relatively open, loosely matted relationship substantially only at their points of contact, projecting ends of fibers of said fibrous sheet being embedded in and held against displacement by said layer of adhesive and portions of the i fibers in the interior of said fibrous sheet being capable of limited movement relative to each other, said layer of adhesive having a thickness relative to the thickness of said base of the order of 0.01:0.027 whereby said adhesive will penetrate said base and surround substantial portions of the fibers of said base when said adhesive is softened by heat and an assembled shoe and liner are stretched against a form in the shaping of a shoe.
4. A normally flexible, lastable shoe stiffener comprising a two-dimensionally stretchable, non-woven fibrous sheet base from 0.02 to 0.1 inch in thickness and substantially solid continuous layers of heat-softenable, stiff, resilient thermoplstic adhesive localized substantially at the surfaces on the faces of said base, said fibrous sheet base including a binder holding the individual fibers in relatively open, loosely matted relationship substantially only at their points of contact, projecting ends of fibers of said fibrous sheet being embedded in and held against displacement by said layers of adhesive and portions of the fibers in the interior of said fibrous sheet being capable of limited movement relative to each other, said layers of adhesive having a thickness relative to the thickness of said base of the order of 0.01:0.027 whereby said adhesive will penetrate said base and surround substantial portions off the fibers of said base when said adhesive is softened by heat and an assembled shoe and stiffener are stretched against a form in the shaping of a shoe.
5. A normally flexible, lastable shoe liner comprising a relatively open non-woven, two dimensionally stretchable, fibrous sheet base from 0.02 to 0.01 inch in thickness, a coating of fiocking cement on one face of said base, flock fibers held in upstanding relation to said sheet by said coating of cement, and a substantially solid continuous layer of heat softenable, stiff, resilient, thermoplastic adhesive localized substantially at the surface on the other face of said base, said fibrous-sheet base including a binder holding the fibers in 'relatively open, loosely matted relationship substantially only at their points of contact, projectingA ends of fibers of said fibrous sheet being embedded in and held against displacement by said layer of adhesive and portions of the fibers in the interior of said fibrous sheet being capable of limited movement relative to each other, said layer of adhesive having a thickness relative to the thickness of said base of the order of 0.01:0.027 whereby said adhesive will penetrate said base and surround substantial portions of the fibers of said base when said adhesive is softened by heat and an assembled shoe and liner are stretched against a form in the shaping of a shoe.
6. A normally flexible, lastable shoe liner comprising a relatively open two-dimensionally stretchable nonwoven fibrous sheet base from 0.02 to 0.1 inch in thick- I ness of which the individual fibers are held in loosely matted relationship, a layer of fiexible, lastable sheet material adhered to one face of said base, and a substantially solid unbroken coating of heat softenable, stiff, resilient thermoplastic adhesive localized substantially at the surface on the other face of said base, projecting ends of fibers of said fibrous sheet being embedded in and held against displacement by said coating of adhesive and portions of the fibers in the interior of said fibrous sheet being capable of limited movement relative to leach other, said layer of adhesive having a thickness relative to the thickness of said base of the order of 0.01:0.027 whereby said adhesive will penetrate said base and surround substantial portions of the bers of said base when said adhesive is softened by heat and an assembled shoe and liner are strecthed against a form in the shaping of a shoe.
References Cited in the file of this patent UNITED STATES PATENTS Beckwith et al Sept. 27, 1921 @ther references en foiiowina page *KJ i 11 9 UNITED STATES PATENTS 10 Ernst May 13, 1952 Brophy Nov. 25, 1952 Levy Nov. 25, 1952 Horwich Feb. 16, 1954 Maisel Mar. 5, 1957 Emerson June 24, 1958 FOREIGN PATENTS Great Britain Oct. 19, 1955