US 3284872 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
A. W. CLOSSON, JR
Nov. 15, 1966 METHOD OF MAKING NEEDLED SHOE STIFFENING MATERIAL Filed Feb. 12, 1963 INVENTOR. ADDISON W. CLOSSON,JR.
ATTORNEYS United States Patent 3,284,872 METHOD OF MAKING NEEDLED SHOE STIFFENING MATERIAL Addison W. Closson, Jr., Cambridge, Mass, assignor to Beckwith-Arden Inc., Watertown, Mass, a corporation of New Hampshire Filed Feb. 12, 1963, Ser. No. 257,931 2 Claims. '(Cl. 28-722) This invention comprises a new and improved sheet material for stiffening box toes and counters and includes within its scope box toe or counter blanks manufactured therefrom as well as a novel process of making the same.
The invention is based on the discovery of the surprising and unexpected advantages realized from the employment for such uses of a resin-carrying textile fabric having on at least one surface a needled nap of synthetic resinous fiber of high tensile strength, such as rayon, acrylic or polyester fibers.
Heretofore box toe and counter stilfeners have included in their structure a woven or felted body impregnated or coated with a thermoplastic or solvent-softening compound. When severely indented or bent such stiffeners have very generally broken down and shown fiber fracture. For this reason they have been, of course, deficient in the desired spring back characteristic. On the contrary, the stiffener of this invention, comprising a fabric base combined with a needled nap of rayon or the like is found to be practically unbreakable under conditions that would completely ruin a stiffener of previously known structure.
From this discovery flow many advantages. In the first place the stiffener responds to deflection with a high degree of spring back and so relieves the dealer or manufacturer of replacing shoes with permanently damaged box toes.
In the second place satisfactory stiffeners of the needled type may be manufactured in substantially thinner gauge than those of former construction. The lasting operation is therefore facilitated and made easier and the style of the shoe correspondingly improved.
The cost of the needled type stiffener is substantially less than that of stiifeners which have heretofore required a heavier more closely woven base fabric. The napping operation to which it has been necessary heretofore to subject cotton fabric impairs the tensile strength of the cotton and this step is also obviated by the present invention.
Moreover the present invention opens to the manufacturer a wide range of possible material in that the base fabric may be of any material selected for its special field of use while the needled nap supplies the necessary bibulous component for the stiffening compound and high strength for the fabric. For example, the base fabric may be light weight cotton woven or unwoven, fiberglass, metallic screening, felt, osnaburg, synthetic woven cloth, plastic film, paper, etc., while the needled nap may be rayon or other synthetic or natural fiber.
Furthermore, the novel process which I employ in making my improved stiffening material may be advantageously carried out in continuous or intermittent fashion at very moderate cost with machinery already avail able.
Other features and characteristics of the invention will be best understood and appreciated from the following description of a preferred embodiment of the material, selected for purposes of illustration and shown, together with an outline of the process of manufacture, in the accompanying drawing, in which:
FIG. 1 is a diagrammatic view suggesting the process and its related steps,
3,284,872 Patented Nov. 15, 1966 FIG. 2 is a plan view of a box toe blank incorporating the invention, and
FIG. 3 is a sectional view on the line 3-3 of FIG. 2 and on an enlarged scale.
In further explanation of my invention it is noted that when a flannel carries a nap, which it must do to absorb box toe latex resins, this nap must be obtained from the flannel by a scratching or napping process which weakens the flannel sheet, which, if carried to extremes, can lead to the formation of spots of very low tensile strength; while on the other hand, on the needled fabric, the nap is laid on from a carded batt or web and then needled into a carrier sheet by a process that does not appreciably weaken the basic woven carrier. Therefore, much greater naps can be put on lighter pieces of woven carrier than in conventional flannels and the lighter woven base will still, in many cases, be as strong if not stronger than a scratch-napped flannel made from much heavier sheeting. In other words, this napping process does not Weaken the base carrier when the nap is applied by needling.
The web of napping which we apply to the woven base on the new needled fabric is normally made from a synthetic fiber such as rayon, nylon or Dacron (du Pont trademark for polyester fiber) or combinations of these synthetic fibers, which in themselves as individual fibers can be made much longer and possess much greater tensile strength as individual fibers than do the short cotton fibers which are napped at random up from the cotton sheeting currently used in industrial fiannels-the present standard carrier for box toe manufacture. These fibers scratched from the threads are apt to be of low grade cotton and have neither the length nor the tensile to compare with the fiber which we are using as the standard fill on the needled fabric.
Of course, the strength of the fibers which constitute the napping on the surface of a box toe base carrier has nothing to do with its tensile strength before the whole is saturated with resins but once this carrier has been saturated or impregnated with a resin, the fibers then tend to be locked together by the resin and they assume great importance in raising the tensile strength of the box toe material.
As shown in FIG. 1 the base fabric 10, which may be osnaburg or cotton scrim, is advanced as a continuous web through a conventional needling machine where it receives a carded batt 11 of staple nylon fibers upon its lower surface and a similar batt 12 upon its upper surface. The components thus assembled are passed beneath a bank of barbed needles 13 by which the nylon fibers are drawn partly through the fabric 10 and permanently united thereto.
The needled web is then advanced to a bath 14 of styrene latex and guided by a roll 15 beneath the surface thereof being thus completely saturated and coated. Upon leaving the bath 14 the saturated needled Web passes between squeeze rolls 16 by which excess latex is removed. In place of styrene latex I may employ other vinyl compounds, rubber latex, or solvent colloids or even thermosetting compounds in the form of hot melt resins. In this connection it is important to note that the needled Web will pick up a minimum of ten percent (10%) more saturant per square yard than does napped cotton flannel of the same weight. The ratio of base fabric to resin saturant in the needled web averages 20:80, the impregnant resin being as against about 70% which is about the best than can be achieved when a napped flannel base is employed.
The tensile strength has a great deal to do with the breaking strength, or impact strength, of a box toe; as, for instance, after a polystyrene impregnation of this new needled fabric and the subsequent activation and fusion of polystyrene resin by solvent, the polystyrene resin locks in place the fibers in the needled fill as Well as those of its base carrier and I have obtained a much greater impact strength than comparable box toe material made from regular cotton flannel would give. After activation, the same or higher impact strength is obtained, for instance, in a given weight polystyrene box toe, even when using a light cotton tobacco cloth carrier with a nap of these long, strong nylon fibers, as we get from the use of a very heavy cotton flannel which costs far more and which has much greater tensile strength in the raw unimpregnated state.
Of course, this greater impact strength may be increased even more by employing a base carrier for the needled fill which has greater tensile in the raw state than the previously mentioned standard flannel. This stronger base for the fill, such as nylon, Dacron or glass-woven base or even a very heavy cotton-woven base, on which to needle these long staple artificial fibers, can give a much stronger tensile to the box toe carrier in the unimpregnated state.
After leaving the squeeze rolls 16 the saturated web is dried by being passed about heated drying cans 17-18. These may be located and spaced as desired and are merely conventionally represented in FIG. 1. The dried web may now be immediately advanced to calender rolls 19-20 or it may be coiled and calendered at any convenient later date. As a result of the calendering operation the web is substantially compacted, hardened and reduced in thickness, to the desired gauge. Most mens shoe manufacturers employ box toe blanks within a range of .045 to .056" in thickness. The dried needled web may readily be reduced to such thicknesses by calendering rolls 19-20. Where it is needed a heavier gauge box toe material acn be made with given weight of needled fabric than with the same weight of cotton flannel. Conversely, the needled fabric may be held down to a lower gauge during manufacturing, if need be.
Box toes made from this needled fabric are as easy, if not easier, to skive than conventional flannel base materials. The light and extensible nature of the cotton scrim used as a carrier for the needled fabric in a cured rubber box toe allows for much easier bedlasting, which is a very great advantage never before achieved with a cured rubber toe.
From the calendered sheet stock the required box toe blanks and counter linings may be cut out. The box toe blank of FIGS. 2 and 3 is of conventional shape, being .045 to .056" in thickness and having a wide scarf formed by skiving along its rear edge. The sectional view of FIG. 3 is enlarged about six diameters.
The following table indicates the superiority of box toes of needled material above described compared with other box toes commercially available in the market at the present time.
AVERAGE RESULTS OF IMPACT TESTS Only experiments labeled l, 2 and 3 were conducted with box toes of needled material and in respect to them there was no actual cracking, only a slight hair-line checking. These three samples could not be broken down and after the-tests recovery was excellent.
Tests marked Beckwith 47D and Beckwith 55D were conducted with box toes drawn at random from the corn-v mercial stock of BeckWith-Arden Inc. Tests marked BX No. 40 Special, BX No. 37 and BX No. 50 Special were conducted with box toes drawn at random from the commercial stock of Bixby Box Toe Co. Inc. All of these box toes were subjected to destructive testing while the box toes of experiments 1, 2 and 3 successfully withstood the same testing treatment.
The fibers which are used for the napping, namely rayon or combination of artificial fibers, are not only stronger in tensile, as I mentioned, but also have more elasticity and resiliency, which is a very important point and therefore, when they are locked together by the styrene resin forming a hard shell, for instance, they are doubly protected against a hard blow or impact since they will not sever when extreme stress is applied since they will give and return in a resilient and elastic manner.
Since the manner in which the napping is applied to the needled fabric is not directionally warp and woof oriented but rather a mat where fibers at random can absorb a load or stress which is applied and distribute this load in all directions, I feel that this has an advantage over the straight woven and conventionally-mapped flannel which is two directional only.
My invention may be embodied to good advantage in needled material wherein the impregnate is a colloid soluble in a non-aqueous solution. Nitrocellulose, cellulose acetate or other cellulose derivatives or combinations thereof may be employed and are readily absorbed by the composite Web as suggested in FIG. 1.
Having thus disclosed my invention and described in detail an illustrative embodiment thereof, I claim as new and desire to secure by Letters Patent:
1. The process of making stiffening material for box toes and counters, comprising the steps of needling a batt of staple rayon fibers to a sheet of loosely woven osnaburg to form a bibulous ply of high tensile strength, saturating the needled composite sheet in a bath of polystyrene latex, drying the saturated sheet, and thereby bonding the rayon fibers together, and then compacting and severely compressing the dried sheet, thus forming a thin dry product carrying a charge of polystyrene amounting in weight to about of the weight of the woven fabric base.
2. The process of making stiffening material of high tensile strength for shoe parts, comprising the steps of needling a batt of synthetic resin fiber to a thin textile sheet thereby forming a bibulous ply of high strength, saturating the needled sheet in a bath of resinous latex, drying the saturated sheet thereby bonding the resin fibers together, and then calendering the dry sheet to a uniform thickness of 0.045 to 0.056 inch carrying resinous latex amounting by weight to 80% of the weight of the textile sheet.
References Cited by the Examiner UNITED STATES PATENTS 1,825,827 10/ 1931 Smith 16l64 1,991,464 2/ 1935 Mellerio 161-85 2,059,132 10/1936 McDermott 161-81 2,543,101 2/1951 Francis l6185 2,959,509 11/1960 Marshall 161-81 X 2,970,365 2/1961 Morgenstern l56l48 X FOREIGN PATENTS 888,146 l/ 1962 Great Britain.
EARL M. BERGERT, Primary Examiner.
L. T. PIRKEY, P. DIER, Assistant Examiners.