Fabric for Wetsuit and Wetsuit Employing Said Fabric

Abstract

A fabric for a wetsuit wherein weft knit textile cloth comprising bare jersey knit fabric at which polypropylene multifilament yarn and elastic yarn have been knit in plating fashion while said elastic yarn was stretched to an elongation of 1.5 times to 2.0 times, exclusive of 2.0 times, is laminated to either or both faces of a sponge sheet made of chloroprene foam rubber. Furthermore, the elastic yarn in this fabric is thermally fusible polyurethane elastic fiber, and the elastic yarns in the knit textile are thermally fused to each other. Moreover, the elastic yarns are thermally fused to each other by heat-setting at 100 C. to 140 C.

Claims

1. A fabric for a wetsuit wherein weft knit textile cloth comprising bare jersey knit fabric at which polypropylene multifilament yarn and elastic yarn have been knit in plating fashion while said elastic yarn was stretched to an elongation of 1.5 times to 2.0 times, exclusive of 2.0 times, is laminated to either or both faces of a sponge sheet made of chloroprene foam rubber.

2. The fabric for a wetsuit according to claim 1 characterized in that the elastic yarn is thermally fusible polyurethane elastic fiber, and the elastic yarns in the weft knit textile are thermally fused to each other.

3. The fabric for a wetsuit according to claim 1 characterized in that the elastic yarns are in a state of having been thermally fused to each other by heat-setting at 100 C. to 140 C.

4. The fabric for a wetsuit according to claim 1 characterized in that the polypropylene multifilament yarn comprises not greater than 30 filaments, thickness thereof being such as to correspond to 20 decitex to 56 decitex.

5. The fabric for a wetsuit according to claim 1 characterized in that the polypropylene multifilament yarn is such that thickness thereof corresponds to 20 decitex to 56 decitex, and thickness per filament therein corresponds to not less than 1 decitex.

6. A wetsuit employing the fabric for a wetsuit according to claim 1.

7. A fabric for a wetsuit wherein weft knit textile cloth comprising bare jersey knit fabric at which polypropylene multifilament yarn and elastic yarn have been knit in plating fashion while said elastic yarn was stretched to an elongation of 1.5 times to 2.0 times, exclusive of 2.0 times, is laminated to at least an outer layer face of a sponge sheet made of chloroprene foam rubber.

8. The fabric for a wetsuit according to claim 7 characterized in that the elastic yarn is thermally fusible polyurethane elastic fiber, and the elastic yarns in the weft knit textile are thermally fused to each other.

9. The fabric for a wetsuit according to claim 7 characterized in that the elastic yarns are in a state of having been thermally fused to each other by heat-setting at 100 C. to 140 C.

10. The fabric for a wetsuit according to claim 7 characterized in that the polypropylene multifilament yarn comprises not greater than 30 filaments, thickness thereof being such as to correspond to 20 decitex to 56 decitex.

11. The fabric for a wetsuit according to claim 7 characterized in that the polypropylene multifilament yarn is such that thickness thereof corresponds to 20 decitex to 56 decitex, and thickness per filament therein corresponds to not less than 1 decitex.

12. A wetsuit employing the fabric for a wetsuit according to claim 7.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0038] FIG. 1 (a) is a sectional view of a working example of the present invention in which bare jersey knit has been arranged at both faces; (b) is a sectional view of a working example of the present invention in which bare jersey knit has been arranged at the outer layer face.

[0039] FIG. 2 Schematic diagram showing the situation that exists at the knit pattern in a bare jersey knit fabric at which plating was carried out.

EMBODIMENTS FOR CARRYING OUT INVENTION

[0040] Below, embodiments of the present invention are described with reference as appropriate to tables and drawings.

[0041] When closed-cell sponge-like foam sheeting comprising synthetic chloroprene rubber is used as a fabric for wetsuits, it preferred that it have high elongation, tensile strength, and tear strength, and that it not absorb water. For example, a representative example of a blend thereof might be one in which, in terms of mass %, chloroprene rubber (CR) is 45%, carbon black is 10%, filler is 10%, foaming agent is 10%, plasticizer is 15%, and there are small amounts of vulcanization accelerator, crosslinking agent, and so forth blended therein. Such materials are made to pass sequentially through operations that include kneading, extrusion molding, primary vulcanization, and secondary vulcanization, as well as slicing as necessary, to obtain sponge sheeting made of foam rubber.

[0042] In addition, adhesive may further be applied to one or both faces, jersey material may then be placed on such face(s), this being compression-bonded and laminated thereto by means of an upper roller or a set of upper and lower rollers to obtain suit material, and this then being cut and sewn into the desired shape to obtain a wetsuit fabric.

[0043] At FIG. 1, (a) is a sectional view showing the situation that exists when sponge sheeting (2) made of chloroprene foam rubber is arranged centrally, and bare jersey knit fabric (3) comprising polypropylene multifilament yarn and elastic yarn is respectively laminated to a wetsuit outer layer face (4) and a wetsuit inner layer face (5). At FIG. 1, (b) is a sectional view showing the situation that exists when bare jersey knit fabric (3) comprising polypropylene multifilament yarn and elastic yarn is laminated to outer layer face (4) at one side of sponge sheeting (2) made of chloroprene foam rubber.

[0044] With a density of 0.91 g/cm.sup.3, polypropylene is the lightest of the synthetic fibers, being a fiber that floats in water; and it is also highly wear-resistant. Because it is also nonhygroscopic, it is to be expected that when employed as the outer layer of a wetsuit it will dry quickly.

[0045] Where cloth is obtained through use of only polypropylene multifilament fibers and this is laminated to foam rubber sheeting, because it will of course be the case that the stretchability of this will be inadequate, use of this without modification as cloth will make it impossible to achieve adequate elongation of the sort that exists with Nylon materials such as will allow it to be worn while it is stretched.

[0046] In accordance with the present invention, so as to employ polypropylene and yet also ensure stretchability, knitting is therefore carried out with plating of elastic yarn and polypropylene multifilament yarn. That is, combination of polypropylene with an elastic yarn such as spandex results in a fabric that is both quick-drying and stretchable, with an elongation similar to that of Nylon.

[0047] As shown in FIG. 2, plating, also referred to as plated knitting, is a way of knitting in which two yarns are simultaneously knit in tandem such that one is in front and the other is behind. As shown in FIG. 2, polypropylene multifilament fiber (6) and elastic yarn (7) comprising thermally fusible polyurethane elastic fiber are knit together such that the two overlap after the fashion of plain knit. Hereinafter, knit fabric in which there is plating with elastic yarn is also referred to as bare jersey knit fabric.

[0048] Note that if the elastic knitting yarn is such that, at the back, polypropylene multifilament fiber is arranged in front (at the stitch), then because polypropylene fiber which has good endurance will be exposed at the outer surface, the elastic yarn will be less likely to break.

[0049] As polypropylene multifilament yarn, 33-decitex 24-filament twisted yarn or the like is, for example, preferred. Where this is on the order of 20 decitex to 56 decitex, because the multifilament yarn will not be too thick, by appropriately selecting an elastic yarn comprising thermally fusible polyurethane elastic fiber that is on the same order as this, i.e., 33 decitex or the like, because when plating is carried out to make these into a bare jersey knit fabric it will also be possible to use heat-setting to cause the elastic yarns to thermally fuse with each other, this is preferred. The polypropylene multifilament yarn is such that depending on the manner in which it is caused to be combined with the elastic yarn, it will be possible to achieve the desired stretchability. In addition, where the number of filaments is not greater than 30, because there will be a small number of filaments, there will be less tendency for the capillary effect to occur between filaments. Because it will make it possible to suppress the amount of water retained between filaments, it is preferred that the number of filaments not be made too large.

[0050] Thus, the multifilament yarn that is 20 decitex to 56 decitex, i.e., 18 denier to 50 denier, inasmuch as it is polypropylene fiber, will be such that there will be no absorption of water by the filament fibers themselves. Of course, because it is multifilament, there will be retention of water in the gaps between filaments due to the capillary effect and so forth. It is therefore effective to also reduce the number of filaments. Furthermore, if filament thickness is increased, because what would otherwise be fine gaps are made large, this reduces the capillary force and also reduces surface area, permitting decrease in the amount of water adhering thereto.

[0051] Thickness is therefore additionally made such that this is not less than 1 decitex per filament, it being more preferred that thickness thereof be such that this is not less than 1.2 decitex. For example, for 30-decitex 24-filament yarn, this would be 1.25 decitex per filament; and for 50-decitex 40-filament yarn, this would also be 1.25 decitex per filament. Furthermore, for 56-decitex 30-filament yarn, this would be 1.87 decitex per filament. By adjusting the number and thickness of filaments in this fashion, it will be possible to reduce the amount of water that is retained, and to make it less likely to get heavy, and also faster to dry, when wet.

[0052] As thermally fusible polyurethane elastic fiber in accordance with the present invention, Mobilon (registered trademark) R, R-L, K-L, R-LL, and so forth manufactured by Nisshin Spinning Co., Ltd., may be cited as examples. This thermally fusible polyurethane elastic fiber is one of the types of fiber that are generally referred to as spandex, such fibers being capable of use in which following plated knitting therewith they are subjected to heat-set treatment in which saturated steam at, e.g., 120 C. is directed thereat to cause the elastic fibers to thermally fuse together.

[0053] Note that while the polypropylene cannot be said to be highly heat-resistant as it exists after it has been made into bare jersey knit fabric as a result of plating of polypropylene and polyurethane elastic yarn, it is preferred that heat-set treatment be carried out for dimensional stability due to the tendency for wrinkles to form. It is generally the case when carrying out heat-set treatment that, where possible to employ a temperature as high as 150 C. to 200 C., doing so will make for good ease of operations and make it possible to reliably obtain heat-set effect. However, with the polypropylene of the present invention, even at on the order of 140 C. to 160 C., heat resistance cannot be described as good, as there is liable to be impairment of texture and so forth.

[0054] Therefore, in accordance with the present invention, as elastic yarn which is combined with polypropylene multifilament, particularly preferred among thermally fusible polyurethane elastic fibers are yarns capable of being thermally fused at low temperature, low-temperature-compatible thermally fusible polyurethane elastic fibers capable of being thermally fused in saturated steam at 130 C. or less being preferred. As fibers that soften and are capable of being thermally fused at 120 C. or less, Mobilon R-L, K-L, R-LL, and so forth may be cited as favorable examples.

[0055] The heat-set method employs a heat-set treatment apparatus, the knit textile being subjected to saturated steam while it is inserted within a mold, this being carried out by causing heat-setting to occur in such fashion as to be accompanied by thermal fusion. With regard to the temperature of the saturated steam in such case, because the relationship governing the dependence on the pressure of the steam being supplied thereto is known, saturated steam of desired temperature may, for example, be obtained by adjusting the pressure of a boiler. When carrying out heat-setting, employment, for example, of saturated steam at 100 C. to 130 C.saturated steam at 105 C. to 125 C. being particularly preferredwill make it possible to achieve the desired knit width, without formation of wrinkles, and without impairment of texture, and to obtain knit textile of prescribed shape. Treatment time during such heat-setting is 2 to 120 seconds, 5 to 60 seconds being preferred. At the working examples, this was carried out for 20 seconds.

[0056] Of course, besides employment of saturated steam, it is also possible to carry out heat-set treatment by causing dry heat within a range such as will not cause texture to be sacrificed, e.g., heat at 130 C. or 140 C., to be directed thereat.

[0057] Where heat-set temperature was as high as 150 C., wrinkles became prominent and there was impairment of texture. On the other hand, when heat-setting was carried out at 130 C. or lower, wrinkles tended not to be prominent, form stability and dimensional stability were within acceptable tolerances, and texture tended not to be impaired. When the polypropylene multifilament yarn exceeds 56 decitex, because wrinkles tend to become prominent, particular ingenuity is required with regard to heat-set temperature and the temperature characteristics of the elastic yarn.

[0058] Plating is carried out while the elastic yarn is stretched to an elongation of 1.5 times to 2.3 times, this being such that the degree of stretching is less than the stretching to 2.5 times to 3.3 times that would normally be employed at the procedure where these are knitted together. Stretching to 1.5 times to 2.1 times is more preferred, and stretching to 1.5 times to 2.0 times is still more preferred. At the working examples, DR was 1.75.

[0059] By thus keeping draft ratio (DR) low, the pre-lamination fabric will tend not to be wrinkled and will tend to exhibit dimensional stability. Because polypropylene has low heat resistance, making it impossible to employ a high heat-set temperature, it would be difficult to attempt to achieve further dimensional stability through heat-set treatment, so the draft value is made low in advance so as to prevent the elastic yarn from being overstretched. By so doing, because upon being stretched the fabric will gently recover, it will be less likely to produce a tight feeling when worn but will make it possible when worn to produce a natural feeling that allows it to be worn without discomfort.

Drying Characteristics

[0060] Observations were made regarding the change in weight following washing in water of wetsuit fabric comprising sponge sheeting made of foam rubber of thickness 2 mm to which polypropylene bare jersey knit fabric (p.p. jersey) was laminated, this constituting a working model of the present invention; and a full wetsuit employing wetsuit fabric at which Nylon jersey knit was laminated to sponge sheeting made of foam rubber of thickness 2 mm. Results are shown in TABLE 1.

TABLE-US-00001 TABLE 1 Item name PP Jersey Nylon Jersey Weight when dry (g) 978 978 Elapsed time PP Jersey Nylon Jersey After 30 minutes Weight (g) 1440 1764 % 147% 181% Increase in weight (g) 462 792 After 60 minutes Weight (g) 1380 1692 (after 1 hour) % 141% 174% Decrease in weight (g) 60 72 After 120 minutes Weight (g) 1308 1608 (after 2 hours) % 134% 165% Decrease in weight (g) 72 84 After 180 minutes Weight (g) 1272 1536 (after 3 hours) % 130% 158% Decrease in weight (g) 36 72 After 300 minutes Weight (g) 1200 1428 (after 5 hours) % 123% 147% Decrease in weight (g) 72 108

[0061] Despite the fact that the dry weight of each was more or less equivalent, increase in weight after 30 minutes had elapsed following washing in water was such that increase in weight of the p.p. jersey was 462 g while the increase for the Nylon jersey which served as comparative example was 792 g, the difference due to the increase in weight as a result of absorption of water by Nylon being striking. These values may be considered to be the weights during use when in a wet state. Those difference in increased weight Because when is such state there is a large change to what would otherwise be a lightweight wetsuit, a difference in weight of 300 g will from the perspective of the wearer constitute a large difference in terms of ease of movement.

[0062] It was only after drying for 5 hours that the weight of the Nylon jersey finally was on the same order as that of the p.p. jersey immediately following its becoming wet. On the other hand, as drying of the p.p. jersey had progressed to the point where this was 1200 g, because the water content was half that of the Nylon jersey or less, it is clear that the p.p. jersey wetsuit was the faster-drying of the two.

[0063] Note that the p.p. jersey of the working example required 1185 minutes (approximately 20 hours) to completely dry. On the other hand, because the Nylon jersey was still not dry even after 24 hours had elapsed, it was confirmed that this would present an obstacle to use, since it would have to be used while still wet when used every day for a continuous period.

Hygroscopicity

[0064] Hygroscopicity of the working example being 15% while hygroscopicity of the Nylon jersey of the comparative example being 28%, it was confirmed that the p.p. jersey was the more nonhygroscopic of the two.

Antibacterial Characteristics

[0065] As shown in TABLE 2, investigation was carried out with respect to the antibacterial characteristics of the p.p. jersey which was a working model of the present invention, and the W/N (woolly nylon) jersey of the comparative example. The antibacterial characteristics of the p.p. jersey were superior to those of the Nylon jersey.

[0066] Note that as the values shown at TABLE 2 are logarithmic, the value of 1.30 at the working example indicates that this had more or less reached the minimum value. Note that whereas for comparison purposes it is indicated that the Nylon jersey when new had somewhat fair antibacterial characteristics, this being 2.67, but that after 100 wash cycles the antibacterial characteristics of the Nylon jersey had deteriorated to 4.11 due to loss of the water repellant coating at the surface as a result of use. Thus, the antibacterial characteristics of the Nylon jersey deteriorated as a result of use. For reasons such as the fact that urination is sometimes performed while wearing the wetsuit, and because the environment in which it is used is not necessarily clean, differences in antibacterial characteristics will over a long period of time be accompanied by differences in smell and so forth, which will result in a different feeling when worn.

TABLE-US-00002 TABLE 2 Antibacterial Characteristics (Test Results) Common logarithm of live bacteria count (difference between largest and smallest) Immediately following After culturing Antibacterial No. Sample inoculation for 18 hours activity value (1) PP jersey Original item 4.49 (0.0) 1.30 (0.0) 5.7 (2) W/N jersey Original item 4.53 (0.1) 2.67 (1.8) 4.3 Control sample/standard fabric 4.58 (0.0) 6.96 (0.0) Growth value (100% cotton; white fabric) F: 2.4 Note: Test bacteria suspension to which surfactant (Tween 80) had been added was used. Test procedure: JIS L1902: 2015; bacterial solution absorption method Bacterial variety used for testing: Golden Staphylococcus/Staphylococcus aureus NBRC12732 Washing method: In accordance with washing method (standard washing procedure) for SEK Mark textile products; Japan Textile Evaluation Technology Council (a general incorporated association).

Water Repellant Properties

[0067] Investigation was carried out with respect to the situation in terms of change in water repellant properties following abrasion testing in accordance with JIS L 1092 of the p.p. jersey of the working example and the W/N jersey (jersey made of woolly nylon; water-repellant coating applied to surface) of the comparative example.

[0068] Following 10 cycles, 50 cycles, 100 cycles, or 500 cycles of abrasion treatment, spray testing was carried out in which water droplets were sprayed on the fabric, the degree to which water was repelled being evaluated by ranking this between 1 and 3 (testing was performed three times). A ranking of 3 indicated that water was repelled to a high degree, while a ranking of 1 indicated that there was no repelling of water.

[0069] 1: The entire surface became moist.

[0070] 2: Half of the surface became moist, and small individual spots of moisture were observed to penetrate the cloth.

[0071] 3: The surface was moistened by small individual droplets of water.

[0072] Abrasion treatment was carried out using a uniform abrasion tester, 0.1 ml of water being sprayed onto the surface to be abraded, following which a prescribed number of cycles of abrasion treatment was performed on a common bolt of cloth by applying a compressive load of 4.45 N thereto. Results for 500 cycles are shown in TABLE 3, while results for 10, 50, and 100 cycles of abrasion treatment are shown in TABLE 4.

[0073] For the Nylon jersey, ability to repel water was somewhat inferior after a mere 10 cycles of abrasion treatment, and by 100 cycles the ability to repel water had almost completely disappeared. Similar results were observed after 500 cycles. While this Nylon jersey was such that the surface thereof had been coated as a result of having been subjected to a water repellant treatment, because the water repellant properties of the Nylon jersey were rapidly lost as a result of abrasion and/or deterioration, it was confirmed that it had a greater tendency to absorb water and dry slowly.

[0074] On the other hand, for the p.p. jersey of the present invention, ability to repel water was unchanged, continuing to be ranked as a 3 even after 500 test cycles, water repellant properties being maintained in the same state as they were at the beginning.

TABLE-US-00003 TABLE 3 Test Results (1) PP (2) W/N Test Test Item jersey jersey Procedure Degree to which water 3, 3, 3 1, 1, 1 JIS L 1092 repelled (ranking) Spray testing
Abrasion treatment: Uniform abrasion tester was used
0.1 ml of water sprayed onto surface to be abraded, following which 500 cycles of abrasion performed on common bolt of cloth by applying 4.45 N compressive load thereto

TABLE-US-00004 TABLE 4 Test Results (1) PP (2) W/N Test Test Item jersey jersey Procedure Degree to which After 10 cycles of 3, 3, 3 2, 2, 2 JIS L 1092 water repelled abrasion treatment Spray testing (ranking) After 50 cycles of 3, 3, 3 2, 1, 1 abrasion treatment After 100 cycles of 3, 3, 3 1, 1, 1 abrasion treatment
Abrasion treatment: Uniform abrasion tester was used
0.1 ml of water sprayed onto surface to be abraded, following which 10, 50, or 100 cycles of abrasion performed on common bolt of cloth by applying 4.45 N compressive load thereto

Thermal Retention Properties

[0075] Investigation was carried out with respect to the situation in terms of retention of body temperature with the p.p. jersey wetsuit working model versus the Nylon jersey comparative model when each was used to engage in surfing in seawater for 50 minutes while wearing the wetsuit.

[0076] Body surface temperature directly beneath the wetsuit which had fallen to 26 C. due to seawater upon entering the water increased to 32 C. over the course of 4 minutes. Thereafter, while the working model was able to maintain a temperature of 31.5 C., temperature dropped to 30.5 C. with the Nylon jersey. Thus, occurrence of a difference in the body surface temperature when the wetsuit was worn was due to the fact that, because the outer layer of the Nylon jersey became wet, there was a greater tendency for it to become cool due to the heat of vaporization.

Stretchability

[0077] At the polypropylene jersey of the working model of the present invention, where elastic yarn comprising thermally fusible polyurethane elastic fiber was further knitted together therewith in such fashion that the degree of stretching thereof was 2 times or less and this was heat-set to cause the elastic yarns to thermally fuse with each other, it was possible during stretching to cause this to be stretched out without needing to apply much force.

[0078] For example, with a wetsuit fabric in which there was lamination of bare jersey knit fabric comprising 33-decitex 24-filament polypropylene multifilament yarn and 33-decitex thermally fusible polyurethane elastic fiber, the force necessary to stretch this by 50% was 0.8 N in the wale direction (longitudinal stretching) of the knit fabric, and was 0.2 N in the course direction (transverse stretching). (In accordance with the method of JIS 1096 B, the force required to cause an elongation of 50% relative to the unelongated length of a test piece of width 5 cm (stretching force at low elongation) was measured. Elongation rate: 20 cm/min; chuck separation: 20 cm.) It was confirmed that stretching of this was extremely good, elongation on the same order as that of Nylon being adequately achievable.

[0079] Furthermore, with a wetsuit fabric in which there was lamination of bare jersey knit fabric comprising 56-decitex 48-filament polypropylene multifilament yarn, when the knit fabric was stretched to an elongation of 2.9 times, stretching was accomplished by 1.8 N in the wale direction, and 0.8 N in the course direction.

EXPLANATION OF REFERENCE NUMERALS

[0080] 1 Wetsuit fabric [0081] 2 Sponge sheeting made of chloroprene foam rubber [0082] 3 Bare jersey knit fabric [0083] 4 Outer layer face [0084] 5 Inner layer face [0085] 6 Polypropylene multifilament yarn [0086] 7 Thermally fusible polyurethane elastic fiber