US 3348549 A
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1967 G. BRODMANN EI-AL 3,348,549
BRASSIERE PAD AND PROCESS Filed July 6, 1964 INVENTOR George, B odmann Albert sum: BY 7 Wm 77.
United States Patent 3,348,549 BRASSIERE PAD AND PROCESS George L. Brodmann and Albert Stewart, Wilmington,
Del., assiguors to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Filed July 6, 1964, Ser. No. 380,528 Claims. (Cl. 128-481) This invention is concerned with molded articles from synthetic fibers in loose, non-woven structures. More specifically, it is concerned with a novel process for producing bulky non-woven shaped articles from synthetic polyester fibers and with the article so produced.
The conventional technique for preparing three-dimensional textile articles such as brassiere c-ups involves the cutting of flat woven fabrics into appropriately shaped pieces and then sewing the pieces together to give the desired three-dimensional form. This procedure is tedius,
time consuming and costly. When the technique is applied to the preparation of brassiere cup pads, the difficulties and disadvantages are greatly magnified. As an alternative procedure, the art has investigated various ways of molding fibrous material. Unfortunately none of the previously known procedures has given a fully satisfactory molded padded brassiere cup offering the combined ad-v vantages of resiliency, shape retention, and laundera-bility.
Foam rubber pads have been used as a substitute for textile pads, but it is Well known that foam rubber rapidly turns yellow with age, is sensitive to elevated temperatures as encountered in mechanical dryers, and usually possesses the characteristic odor of rubber. Polyurethane foams are equally disadvantageous.
It is therefore an object of this invention to provide a three-dimensional textile article such as a brassiere cup which exhibits the combined advantages of resiliency, shape retention, launderability, and tactile aesthetics.
Another object is to provide such an article from low cost materials which are also amenable to economical fabrication processes.
Another object is a process which will provide an article exhibiting the desirable qualities noted above.
In accordance with the present invention, three-dimensional textile articles having outstanding performance features are provided by a process which comprises (1) shaping, while unrestrained, a resin-bonded fibrous batt of randomly intermingled, crimped, oriented polyester staple fibers around a mold at a temperature below about 100 C., (2) then heating the fiber batt on the mold to a temperature in the range 120 C.180 6., preferably l35l55 C., and (3) thereafter cooling the molded batt to a temperature below 100 C., and removing it from the mold.
By resin-bonded fibrous batt is meant -a nonwoven fluffy web of synthetic polyester fibers, such as an uncompressed carded fibrous structure or a fibrous mat in which the fibers or filaments are distributed in random array, which has been treated with a suitable resin for the purpose of binding fibers together at crossover points, thereby rendering the batt incapable of felting.
The nature of the invention will become more clearly apparent by reference to the following detailed description when taken in connection with the accompanying illustrations, in which:
FIGURE 1 is a side elevation partially in cross-section of the batt and a ring and plug type mold just prior to molding;
FIGURE 2 is a plan view of a molded article produced according to this invention;
FIGURE 3 is an elevational View in cross-section taken along line 33 of FIGURE 2;
FIGURE 4 is a perspective view of an article formed according to this invention.
Referring to FIGURE 1 of the drawing, a ring 1 and hemispherically-shaped or dome-shaped plug 2 with base portion 3 and concave portion 4 are shown vertically aligned above and below, respectively, a batt 5, which is made of non-compacted fibrous material. By sandwiching the batt between the ring and plug in the directions Example I Polyethylene terephthalate staple composed of 1 /2 inch (3.81- cm.) fibers of 4 denier per filament with a spiral crimp is processed .through a garnett to give a fluffy fibrous batt having a weight of 4.3 oz. per yard (45 inches wide) (117 g./m. and a thickness of approximately 1% inches (3.17 cm.). The batt is sprayed with a resin-forming dispersion made up as follows:
Parts Penta(methoxymethyl)melamine 50 Ammonium chloride 1 Dicyandiamide 0.25 Water 48.75
Each side of the batt is separately sprayed and dried for 3 minutes at 140 C. Examination of the batt indicates that the resin spray has penetrated to the center so that a' completely coherent structure is obtained. The structure is soft and resilient. Resin pickup is found to be approximately 20% by weight.
A sample of the batt is slip-molded using a plug and ring molding assembly with the plug size equivalent to a size C brassiere cup. The batt is shaped, at room temperature, by pushing the plug completely into the ring Without restraining the edges of the batt, and then holding the edges of the sample in position While the plug is withdrawn a fraction of an inch to relieve excessive tension on the concave side of the molded portion of the batt. The mold assembly with batt in place is then heated quickly to 140 C., maintained at that temperature for 2 minutes, and then cooled to room temperature before removing .the shaped sample.
Examination of the molded sample reveals asoft,
-- highly resilient, stable structure having a thickness of approximately /2 inch (1.27 cm.). Excess material around the molded cup is cut away and then the cup is sewn into a brassiere with a plain weave fabric covering the shaped batt on the outer surface and a tricot fabric covering the inner surface. The completed brassiere is then subjected to a series of five wash/tumble-dry cycles roughly equivalent to a home laundry cycle. Examination of the cup structure after the wash-dry treatment reveals that no detectable change has occurred in the molded batt, either in softness, resiliency, or size.
Example II I The general procedure of Example I is repeated with the exception that the polyester batt used has a weight of 3.3 oz. per 45-inch wide running yard g./m. and a thickness in the range of 0.81.0 inch (22.5 cm.). The brassiere cup pad shaped from this batt is found to be substantially equivalent to that of Example I, but, because of the difference in weight, is a little less dense and not quite as lively as the pad formed from the heavier batt.
3 Example Ill The general procedure of Example I is repeated with the exception that the melamine-formaldehyde resin is replaced with a commercially available self-cross-linking Weight. A resin pickup of 1825% is preferred. Usually the resin is cured by heating, with the time required being dependent upon the temperature. Curing times may vary from /2 min. at 177 C. to 6 min. at 105 C.
For the preparation of brassiere cup pads it is pre- 1 l l l d th d k fi ate i S1011 ymer so er 6 Ha P ferred that the fiberfill batt, before resin treatment, have Rh9plex HA16 by Rohm & Haas The,res1n 1$ a weight in the range 2-5 oz. per 45-inch-wide running aPPhed to e batt an 1 aqueous dlspefslon "E yard 54442 g./rn. Batts of this weight will have an by Welght Oxahc f added as a canalyst- RFSIH uncompressed thickness in the range %1% in. (0.635- plckup onfhe cured batt found be by 4.44 cm.). Choice of initial batt thickness will obviously The brasslere cuP Pad produced equlvalent depend upon the degree of padding desired in the final fmllallce to that of Example product. A lofty, bulky, uncompressed batt is required.
Similar results are obtalned using batts having weights Usually Such batts have a density in the range 0 413 of 2.2 and 3.3 oz./yd. (.0060 and .0094 g./cm. lbs/cu, ft 0 03 3 3 In the fixamples Presented in Table I below, p 15 The initial step noted above in the description of the able brassiere c p pads are molded from po y(et y process of this invention is conventionallyknown as terephthalate) staple fibers, following the general proslip-molding. By slip-molding is meant a molding procedure of Example I. cedure in which the material undergoing deformation,
TABLE I Example Number 4 5 6 Fiber:
Cut length inches (cm) 1 (3.8) 2 (5.1) 3 (7.6).
Crimp type Zigwarz Sniral Spiral.
Filament denier 4 10 6.
Weight(oz ./45yd.),(g./m. 2.2, (60) 3.3, (90) 4.4, (120). Resiliulk density (lbJcu. tt.), (g./em. 0.6, (.0096) 0.4, (.0064) 0.5, (.0080).
Type Melamine-formaldehyde Acrylic Acrylic.
Trade name Aerotex Resin M-B E-255 Rhoplex HA-lfi.
Manufacturer American Gyanamide--- Rohm & Haas" Rohm & Haas.
Percent pickup (dry) 14. 0 24.
Curing temp., 0.. 13R 17 150.
Curing time, min 4. 1 2.
Molding temp, C 60 45.
Heat setting temp, O H0 170 145.
Heat setting time, min 4 1. 2.
Release temp., 0.- 60 30- 50.
The fibrous batt is preferably prepared from drawn and crimped poly(ethylene terephthalate) staple fibers of the type described generally in U.S. Patent No. 2,465,319. The fiber crimp may be of the type introduced mechanically by a stufiing box crimper as described in U.S. Patent No. 2,311,174, or the spirally crimped type prepared by asymmetric quenching during melt spinning by the process of Kilian described in U.S. Patent No. 3,050,821. The staple fibers may be formed into a carded web by a garnett or card or the batt may be prepared by other methods such as that disclosed in U.S. Patent No. 3,019,151. Optionally, the batt may be put through a needling type felting machine having barbed needles ,which push individual fibers through the batt from one face to the other, thereby imparting greater coherency.
It is essential for the process of this invention that the batt be treated with a suitable bonding resin before the molding operation. A suitable resin is one which is thermosetting and which provides a batt stable to washing without imparting stiffness or tackiness. It is preferred that the resin be non-flammable and non-yellowing. The batt should be treated with sufficient resin to give good structure and prevent fiber leakage and surface pilling, but not enough to materially change the inherent resilience and softness of the initial batt. Suitable resins may be chosen, for example, from the acrylics, the vinyls, the melamine-formaldehyde resins, and the ureaformaldehyde resins. Suitable resins are described in U.S. Patents Nos. 2,915,418, 3,101,292, 3,074,834, 3,012,911, 2,982,682 and 3,081,197.
Unbonded batts do not have suificient integrity of structure to permit molding in the manner described here. Preferably the bonding resin is applied to the fiber batt by spraying the batt with a water emulsion containing about 12-25% resin by weight. Both sides of the batt are sprayed to give a total resin solids content, after curing, in the range of 1240%, based on initial fiber i.e., the fibrous batt, is in an unrestrained condition in at least the initial part of the forming process. Equipment used for slip-molding may be of the conventional plug and ring type, or of matching male and female forms, but arranged so that no pins or clamps hold the fiber batt around the edge of the mold during initial deformation. In the molding operation, the fiber batt is formed into the desired three-dimensional shape of the mold utilizing the inherent conformability of the noncompacted fibrous batt structure. In contrast to this procedure, the molding of batts by the procedure of Hardy described in U.S. Patent No. 2,285,967, in which a textile material is clamped around the edges and then drawn into shape by a cold drawing process, gives excessive leaning out of material and severe loss of bulk with the result that the pads produced are completely unsatisfactory for the purposes described here.
The initial molding step is conveniently carried out at room temperature, but in any case it should not be carried out at a temperature higher than about C. Cold shaping is necessary to prevent the setting of one surface of the batt before the internal stresses developed during shaping have been equalized throughout the structure.
Following the shaping step the batt and contacting mold parts must be heated to a temperature in the range -180 C., preferably 155 C., to set the structure in its molded shape. Lower temperatures do not give sufficient setting, while higher temperatures may cause yellowing of the resin. Time of exposure to the heat source need be only long enough to heat the fibrous material to the desired temperature, i.e., no dwell time at the peak temperature is necessary. On the other hand, longer dwell times are not harmful as long as resin bonding agent is not discolored. Dwell times up to twenty minutes have been successfully used.
After setting, the batt must be cooled to a temperature below 100 C. before being released from the mold.
Release of the molded batt at a higher temperature results in spontaneous fiber retraction and an appreciable size change in the formed article.
Although the examples illustrate the invention with specific reference to fibers of poly(ethylene terephthalate), it is to be understood that other synthetic linear condensation polyester fibers may be substituted with substantially equivalent results. Suitable polyesters are described, for example, in U.S. Patents Nos. 2,465,319, 2,658,055, 2,676,945, and 2,901,466.
In a preferred embodiment of the invention, the polyester polymer is a synthetic linear condensation polyester of bifunctional ester-forming compounds wherein at least about 85% of the repeating glycol-dicarboxylate structural units of the polymer chain include a dicarboxylate radical derived from terephthalic acid, 2,6-naphthalene dicarboxylic acid, or 2,7-naphthalene dicarboxylic acid. 'Up to about of the recurring structural units may contain other dicarboxylate radicals such as the adipate, sebacate, isophthalate, bibenzoate, hexahydroterephthalate, and 4,4'-sulfonyldibenzoate radicals. In a preferred polyester, 0.5% to 4% of the repeating units contain dicarboxylate radicals derived from S-sodium sulfoisophthalic acid as described in US. Patent No. 3,018,272.
The glycol portion of the glycol-dicarboxylate structural unit may be derived from any suitable dihydroxy compound. Preferred dihydroxy compounds include the aliphatic glycols of the series HO(CH OH, where n is 2 to 10. Other suitable dihydroxy compounds include diethylene glycol, quinitol, cisor trans-hexahydro-pxylylene glycol, neopentylene glycol, 1,4-bis (hydroxyethyl)benzene, 1,4-bis(hydroxyethoxy)benzene, and 1,4- bis (,B-hydroxyethyl) bi phenyl.
Although the invention has been discussed with respect to the preparation of a brassiere pad, it is to be understood that other shaped articles may be preparedin accordance with the principles of the invention. The present invention provides a practical and economical procedure for preparing three-dimensional shaped fibrous pads, such as brassiere pads, which are soft and highly resilient, dimensionally stable, aesthetically appealing, and which possess the wash-wear launderability and other ease-of-care properties of conventional synthetic polyester fiber garments.
As many widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that this invention is not limited to the specific embodiments there-of except as defined in the appended claims.
What is claimed is:
1.. A process for preparing molded, three-dimensional textile articles which comprises (1) shaping, while unrestrained, a resin-bonded fibrous batt of randomly intermingled, crimped, linear polyester staple fibers around a hemispherically-shaped mold at a temperature below about C., (2) then heating the fiber batt on the mold to a temperature in the range 180 C., and (3) thereafter cooling the molded batt to a temperature below 100 C. before removing the batt from the mold.
2. The process of claim 1 wherein the said textile article is further cut to trim away excess material and then sewn into a brassiere.
3. The process of claim 1 wherein the said polyester is polyethylene terephthalate.
4. A process for preparing molded, three-dimensional textile articles which'comprises (1) shaping, while unrestrained, a resin-bonded fibrous batt of randomly intermingled, crimped, oriented linear polyester staple fibers around a mold at a temperature below about 100 C., (2) then heating the fiber batt on the mold to a temperature in the range -155 C., and (3) thereafter cooling the molded batt to a temperature below 100 C. before removing the batt from the mold.
5. A shaped article produced by the process of claim 1 having a substantially flat peripheral lip portion and a substantially hemispherically-shaped cup portion corresponding approximately to the shape of said mold.
References Cited UNITED STATES PATENTS 2,378,642 5/1945 Kopplin 264-292 2,401,180 5/1946 Parmelee 264137 2,875,474 3/1959 Lauterbach 264-137 2,963,744 12/1960 Cooper 264292 3,067,482 12/1962 Hollowell 264-136 3,070,870 1/ 1963 Alexander 264324 ADELE M. EAGER, Primary Examiner.
ROBERT E. WHITE, Examiner.
R. B. MOFFITT, Assistant Examiner.