CN1599814A

CN1599814A - Nonwoven fabric and method of manufacture

Info

Publication number: CN1599814A
Application number: CNA028221974A
Authority: CN
Inventors: K·特拉塔; Y·卡吉亚; Y·马基塔
Original assignee: Du Pont Toray Co Ltd; EI Du Pont de Nemours and Co
Current assignee: Du Pont Toray Co Ltd; EIDP Inc
Priority date: 2001-11-06
Filing date: 2002-11-05
Publication date: 2005-03-23
Anticipated expiration: 2022-11-05
Also published as: CN100445450C; JP3934916B2; DE60206957T2; JP2003147670A; WO2003040452A1; KR100894599B1; EP1448824B1; EP1448824A1; KR20050043743A; DE60206957D1; HK1076132A1

Abstract

The invention provides a nonwoven fabric having isotropic recovery from extension of at least about 55 % and comprising a binder, about 3 to 50 weight percent bare elastomeric staple fibers based on weight of the fabric, and crimped staple bicomponent fibers.

Description

Supatex fabric and manufacture method

Technical field

The present invention relates to stretch nonwoven fabrics, relate more specifically to comprise this kind fabric of elastomer, binding agent (particularly binder fiber) and crimped fibre.

Background technology

Disclosed supatex fabric comprises elastic polyurethane and polyether ester fibre, for example United States Patent (USP) 5238534 and disclosed Japanese patent application JP43-026578, JP03-019952 and JP10-025621.Yet this kind fabric may have inaesthetic sense of heaviness, and may have feel poor, that be clamminess.The supatex fabric that comprises crimped fibre is also disclosed, for example U.S. Pat 5102724 and disclosed Japanese patent application JP02-091217 and JP05-171555, but they may have poor and anisotropic stretching and recoverability.These deficiencies all may make the direct unsatisfactorily and contact skin of the supatex fabric of prior art, for example in the situation of diaper.

The carded web of intersection-laying has been used to make vertical and horizontal performance similar products like, for example be disclosed among International Patent Application WO 00/63478 and disclosed Japanese patent application JP08-260313 and the JP11-061617, but this generic operation increases cost, and described fabric may be thick and may have poor feel, low compliance and/or stretching and the recoverability that differs from.

The laminated product of nonwoven web and elastomeric material is also disclosed, for example disclosed Japanese patent application JP08-188950, but this kind fabric may be thick unevenly and have low compliance equally, makes their healths of can not fitting satisfactorily.

The supatex fabric that comprises binder fiber also is disclosed, for example U.S. Pat 5302443 and disclosed Japanese patent application JP2000-328416, but this kind fabric lack usually enough stretchings-and-recoverability.

Still exist to have good hand feeling and good stretching-and-needs of the thin supatex fabric of recoverability.

Summary of the invention

The invention provides supatex fabric, it has isotropic elongation recovery percentage of about at least 55%, and comprises binding agent, is the exposed elastic short fiber of about 3 to 50 percetages by weight and the short bicomponent fiber that curls based on the weight of described fabric.

The present invention also provides the method for making this class supatex fabric, and it may further comprise the steps: short Spandex (a) is provided, and short latent crimp fiber, it takes place to curl when being heated, and binder fiber; (b) suspended substance of preparation Spandex, latent crimp fiber and binder fiber; (c) by the method that is selected from air lay and wet-laying suspended substance is configured as fibre web; (d) heat this fibre web with the described binder fiber of fusion with in conjunction with described fiber; (e) the heating fibre web curls to form in latent crimp fiber under relaxed state.

Description of drawings

Fig. 1 is the perspective view (Figure 1A) and the sketch (Figure 1B) of one of embodiment of demonstration supatex fabric of the present invention.

Fig. 2 shows among Fig. 1 along the diagrammatic cross-sectional view of the amplification of line IIA-IIA (Fig. 2 A) and IIB-IIB (Fig. 2 B).

Fig. 3 is the sketch of supatex fabric process units.

The fibre web of (Fig. 4 B) after (Fig. 4 A) and the heating before Fig. 4 schematically is presented at and heats.

Detailed Description Of The Invention

Unexpectedly find now, the supatex fabric that comprises binding agent, crimped staple and exposed elastic short fiber, even under low elasticity fiber content and low basis weight and thickness situation, have unusual good hand feeling (illustrated) as there not being viscosity, good elongation recovery percentage after repeated stretching.They are still flexible and have isotropic mechanical performance.This fabric is very suitable for having the goods of tensile property, for example clothing sandwich, diaper, be used for base material, cloth for wiping or dusting and packaging material that external drug is handled.

Refer to (unlapped) staple fibre of exposing at this " elastomer ", it does not contain diluent, have and any irrelevant elongation at break of 100% that surpasses that curls, and be stretched to the twice of its length, when keeping discharging then in one minute, it is being loosened its initial length that is withdrawn in back a minute less than 1.5 times.This fibrid includes but are not limited to, IR fiber, Spandex, polyether ester fibre, biconstitutent fibre and elastic polyester (elastoester)." Spandex " refers to a kind of fiber of manufacturing, the long-chain synthetic polymer that wherein becomes fine material to be made up of the block polyurethane of at least 85% weight." isotropic mechanical performance " refers to performance, for example TENSILE STRENGTH and elongation recovery percentage, fabric laterally in be fabric at least 80% in vertically." biconstitutent fibre " refers to the fiber made, its polymer with first general category is a kind of component of thermoplastic elastomer (TPE) for example, with the polymer of second general category second component of thermoplasticity inelastic body for example, two kinds of components are continuous along the length of fiber basically; This fiber can have concentric or eccentric skin-core formula or block form structure." bicomponent fiber " refers to a kind of fiber, and two kinds of polymer of wherein identical general category are in block form or eccentric skin-core formula relation, and comprise crimped fibre and have fiber potential crimping property, that do not curl as yet.

At first, a kind of embodiment of non-woven elastic fabric 10 of the present invention has been described schematically wherein with reference to Figure 1A.Details in Figure 1B has shown that this fabric comprises elastomer 12, crimped fibre 14 and binding agent 16, this binding agent is bonded to crimped fibre 14 with elastomer 12, for example the contact point between them 18 makes the stretching of elastomer and crimped fibre and recoverability not be compromised.

With reference now to Fig. 2 A and 2B,, wherein schematically shown the cross section of a kind of embodiment of non-woven elastic fabric of the present invention, comprise elastomer 12, crimped fibre 14 and binding agent 16.Crimped fibre 14 is shown as the block form bicomponent fiber, and it comprises component 14x and 14y.Binding agent 16 is shown as skin-core formula binder fiber, and it comprises skin 16x and core 16y.

It is about 3 to 50 percetages by weight, the exposed elastic short fiber of 5 to 30 percetages by weight preferably approximately that supatex fabric of the present invention comprises based on fabric weight.When the amount of elastomer during less than about 3 percetages by weight, the elongation recovery capacity of fabric may not be satisfactory, and when the amount of elastomer surpasses about 50 percetages by weight, feel unacceptable, viscosity that elastic nonwovens may have.

It is about 40 to 80 percetages by weight, the more preferably crimped staple of about 50 to 70 percetages by weight that fabric preferably further comprises based on fabric weight.Under the amount less than about 40 percetages by weight, supatex fabric may have the tensile property of reduction, the compliance of difference and hard feel.Under amount greater than about 80 percetages by weight, the elongation recovery capacity when repeated stretching that fabric may have poor mechanical strength and therefore reduce.

It is about 10 to 50 percetages by weight, the more preferably binding agent of about 20 to 40 percetages by weight that fabric preferably also comprises based on fabric weight.Under the amount less than about 10 percetages by weight, fabric may have poor mechanical strength, and is being higher than under about 50 percetages by weight, and tensile property may be compromised, and fabric may have too hard feel.

Fabric of the present invention has about at least 55% elongation recovery percentage, and can have about at least 50 microns and less than 135 microns thickness.

The example of useful elastomer comprises Spandex, polyester ether elastic fiber and polyetheramides elastomer.Can also use natural rubber, synthetic rubber and semi-synthetic rubber, and biconstitutent fibre.Spandex is preferred, and the Spandex that comprises polyurethane-urea is preferred.Polyurethane-urea usually can be by polymer diol, vulcabond and diamines or alcoholamine chain extender preparation.

The linear density of short elastomer can be about 0.5 to 40 dtex, common about 1 to 30 dtex.Under less than about 0.5 dtex, this fiber may have too low mechanical strength, and is being higher than under about 40 dtexs, and the number that constitutes the elastomer of fibre web per unit surface area is reduced; Outside this scope, fabric may have the elongation recovery percentage of reduction.Short elastomer can have about 3 and arrive 50mm, common about 5 to 30mm length.Less than under the about 3mm, fabric may have low mechanical strength in length, and in length greater than under the about 50mm, may be difficult to obtain the even distribution of fiber in fabric web.Shape of cross section to elastomer does not have special qualification, and it can have circular cross section, as shown in Figure 2, and the perhaps cross section of Gai Bianing, the cross section of for example leg-of-mutton or graduation.

Useful crimped staple can be polyester fiber, polyamide fiber, acrylic fibers and polyamide fiber.In this fibrid, can be after elastomer, latent crimp fiber and binding agent be mixed and preferably after forming fibre web by it, form curling by heat treatment under relaxation condition by corresponding latent crimp fiber.Latent crimp fiber and corresponding crimped fibre have bicomponent structure, and wherein useful polymer is to comprising polyethylene terephthalate and poly-(ethylene glycol terephthalate-copolymerization-ethylene isophthalate); Poly-(ethylene glycol terephthalate) and poly-(terephthalic acid (TPA) 1, ammediol ester); Poly-(ethylene glycol terephthalate-copolymerization-ethylene isophthalate) and poly-(terephthalic acid (TPA) 1, ammediol ester); Poly-(ethylene glycol terephthalate) and poly-(terephthalic acid (TPA) 1,4-butanediol ester); Poly-(hexamethylene adipamide) and poly-(hexamethylene adipamide-copolymerization-adipyl 2-methyl isophthalic acid, 5-pentanediamine); Or the like.

Latent crimp fiber can have the curling temperature that represents of the softening temperature that is lower than elastomer.If latent crimp fiber curling represents the softening temperature that temperature is higher than elastomer, then the elongation recovery capacity of elastomer may be compromised during representing curling.

Crimped fibre can have the linear density of about 0.2 to 20 every long filament of dtex, usually the every long filament of about 0.5 to 10 dtex.If crimped fibre has the linear density less than the every long filament of about 0.2 dtex, the tensile property of fabric can be inadequate.Under the linear density that is higher than the every long filament of about 20 dtexs, fabric may be hard and have poor feel.As the situation of elastomer, crimped fibre can have about 3 and arrive 50mm, common about 5 to 30mm length.Shape of cross section to crimped fibre does not have special qualification and them can have circular cross section, as shown in Figure 2, perhaps triangle, graduation or " snowman " cross section.

Binding agent can be for example polyester, polyolefin, acrylic compounds or a polyamide of thermoplastic resin.When being heated and fusion, cool off then and when solidifying, its fiber with fibre web (predecessor of fabric of the present invention) bonds together.The melt temperature of binding agent can be lower than the softening temperature of elastomer, makes the elongation recovery capacity of elastomer not be compromised when precursor web is heated with the bond vitrified agent.Form to binding agent does not have special restriction, and it can be liquid, powder or fiber, as illustrated in fig. 1 and 2.Fibre morphology is preferred, for example has concentric or eccentric skin-core formula structure, wherein thermoplasticity skin fusion under the low temperature of comparing with core.The example of this fibrid comprises that wherein skin is that poly-(ethylene glycol terephthalate-copolymerization-isophthalic acid glycol ester) and core are those of poly-(ethylene glycol terephthalate).As the situation of elastomer, binder fiber can have about 3 and arrive 50mm, common about 5 to 30mm length.

The polymer that constitutes fiber can be a copolymer, it comprises the monomer of its preparation of other improvement, function or processing, for example be used for improving stainability (for example 5-of polyester sodium-sulfoisophthalic acid salt), optimize crimpness, melt viscosity, cohesiveness, anti-environment degradable or the like, as long as benefit of the present invention is without prejudice.Similarly, fiber can comprise additive, for example titanium dioxide, zinc oxide, carbon black or the like, the antimicrobial that comprises silver, zinc or its compound, deodorant, spices and antistatic additive for example poly-(oxirane) of ultra-violet absorber, antioxidant, antitack agent, lubricant, hindered phenolic stabilizing agent, sterically hindered amine stabilizer, inorganic pigment for example be not as long as benefit of the present invention affects adversely.

In the methods of the invention, the suspended substance that has prepared short elastomer (preferred Spandex), short latent crimp fiber and binding agent (preferred binder fiber).Randomly, dispersant and/or thickener can be added this suspended substance.By wet-laying method or air lay method suspended substance is shaped to fibre web, and with fibre web heating so that binding agent fusion and make latent crimp fiber curling.Heating steps makes that preferably at very little pressure or tension force or there be not under pressure or the tension force (that is, fibre web is under the relaxed state) to carry out curling of latent crimp fiber do not hindered, and carries out being lower than under the softening temperature of elastomer.Heating steps can be divided into for two steps to carry out, and step is used to make the fiber bonding, and another step is used for curling in the latent crimp fiber development, perhaps its can finish bonding and both one step of curling in carry out.

A kind of embodiment of using the inventive method of the device that schematically illustrates among Fig. 3 has below been described.In this specific embodiment, latent crimp fiber and fiber binding agent have been used.

At first, in the fiber suspension preparation process (" A " among Fig. 3), elastomer, latent crimp fiber and binder fiber can be added to the water, with for example mix in the beater at whirligig 20, so that fiber disaggregation and the suspended substance of formation fiber in water make described suspended substance have about 0.1 to 3wt% fibre concentration.This suspended substance can be transported to mixing channel 22 by pump (" P "), arrives machine jar 24 then.Randomly, in order to help in the suspended substance preparation process with fiber dispersion, can be for example based on total fiber weight to be the amount adding dispersant of 0.01 to 10% weight, for example non-ionic dispersant, weak cation polyester and polyether dispersant or the like based on polyethers.Randomly, can also add water miscible thickener, for example be 5 to 50ppm (based on the thickener solid) amount adding with the weight based on water.

Then, in fibre web-formation step (" B " among Fig. 3), can will be fed to the silk screen conveyer belt 26a of weak point-net paper machine 26 by pump (" P ") from the suspended substance of machine jar 24, and on silk screen conveyer belt 26a, dewater, on conveyer belt, to form fibre web.In this step, Fig. 4 A has schematically illustrated a kind of embodiment of fibre web, and it comprises elastomer 12, latent crimp fiber 14 and binder fiber 16.Then, the fibre web on silk screen conveyer belt 26a can be transferred on the felt 28, and it can have the more level and smooth surface than silk screen conveyer belt 26a.

Then, in adhesion step (" C " among Fig. 3), fibre web on the felt 28 can be transferred on the cylinder type drying machine 30, and it can have the surface more level and smooth than felt 28, and fibre web can be heated to the predetermined temperature of the skin 16x fusion of the binder fiber 16 that is enough to make in the fibre web therein.Then, fibre web can be drawn back and cools off from cylinder type drying machine 30, make the adhesive cures of fusion, make

fiber

12 and 14 be bonded in together,, thereby form supatex fabric for example at point 18 (referring to Figure 1B).

Represent (" D " among Fig. 3) in the step curling, can fabric be fed to heated oven 32 by feed roller 31, it is the mode heat supply of infrared ray or far-infrared radiation for example.Temperature in the heated oven 32 can be lower than the softening temperature of elastomer 12, but is enough to make fiber 14 to curl.In order to curl, preferably the fabric in the heated oven 32 is in relaxed state.Therefore, the peripheral speed that can regulate feed roller 31 and take out roller 34 is not so that apply tension force on fabric.Fig. 4 B has schematically illustrated a kind of embodiment at the fabric of this step, and wherein fiber is represented according to the numbering system that is used for Fig. 4 A.

At last, fabric can be wrapped on the winder 36 (" E " among Fig. 3).

Used above-mentioned steps and device in an embodiment, but they only illustrate a kind of embodiment of the present invention, and can change in many aspects.For example, keep the jar (mixing channel 22 and machine jar 24) of suspended substance to form by one or three or above jar.In fibre web-formation step, replace weak point-net paper machine, can use other type paper machine, for example fourdrinier machine or cylinder mould machine.In fiber suspension preparation process and fibre web-formation step, replace water can use other liquid for example ethanol as medium.In addition, the length and the number of the felt of carrying fibre web can change, and perhaps can use one or more rollers to replace felt.In addition, can provide pressing step independently between fibre web-formation step and adhesion step, wherein fibre web pushes under impressed pressure.In adhesion step, can use other type heater (for example dried-air drier, air through-circulation drying machine, infrared drier, suction dried machine) to replace the cylinder type drying machine.Adhesion step represents step and can carry out in time of separating or position with curling, and perhaps these steps can be integrated so that realize bonding and curling representing in the identical time.

Can provide between step and the winding step by means of with the fabric feel by regulating non-woven elastic fabric or step of surface nature between calender roll (randomly having embossed surfaces) (not shown) curling to represent.In fiber suspension preparation process and fibre web-formation step, can use the air lay step to replace the wet-laying step.In air-laid process, in the fiber suspension preparation process, can use the opener (not shown) with fiber disaggregate and dispersion, and the mix suspending body of fiber can use the fiber mixer (not shown) to prepare.In fibre web-formation step, can use random carding machine to improve the degree of randomness of fiber orientation.

In an embodiment, fabric property is measured by the following method.Basis weight and thickness measure according to the test number JISL-1096 of Japanese Industrial Standards and TENSILE STRENGTH is measured according to JISP-8113.Elongation recovery percentage is by measuring the test length (L of specimen before _o), with sample on the Instron test instrument, carry out five times 15% elongations-and-recovery cycles, be determined at the 5th time when elongation sample length (L _e) and after replying for the 5th time the length (L of sample _f) measure.Percentage (R is replied in elongation _e) calculate by following formula:

R _e(％)＝100×(L _e-L _f)/(L _e-L _o)

In table 1, " contrast " refers to Comparative Examples, and TENSILE STRENGTH is reported with thousand Newton/meter.

Embodiment 1

The elastomer that uses is Spandex (Lycra  T-127C, DuPont-TorayCo., the registration mark of Ltd.), and it has the linear density of the every long filament of 7 dtexs, 6 millimeters fibre length and about 180 ℃ softening temperature.Latent crimp fiber is poly-(ethylene glycol terephthalate)+poly-(ethylene glycol terephthalate) copolymer bicomponent fiber (T81, by UnitikaFiber Co., Ltd. make), it has the linear density of the every long filament of 1.7 dtexs, 5 millimeters fibre length and about at least 140 ℃ curling temperature that represents.Binding agent is skin-core formula binder fiber (" Melty " 4080 of poly-(ethylene glycol terephthalate) and poly-(ethylene glycol terephthalate-copolymerization-isophthalic acid glycol ester) (30% isophthalate), by Unitika FiberCo., Ltd. make), it has the linear density of the every long filament of 1.1 dtexs, 3 millimeters fibre length and about 110 ℃ skin melt temperature.

Use beater that the Spandex of 5 percetages by weight, the latent crimp polyester fiber of 65 weight % and polyester skin-core formula binder fiber of 30 weight % are dispersed in the water.Then, add 10ppm (thickener solid, weight based on water) polyacrylamide thickener (" MyResin " R10L, by Mitsui-Cytec, Ltd. make, 40% emulsion) and the nonionic polyoxyalkylene ester dispersant of the modification of 1 weight % (based on total fiber weight) (MDP-002, by Takemoto Yushi KK make), provide suspended substance with about 0.5 weight % fibre concentration.

Use the weak point-net paper machine with the suspended substance wet-laying that obtains, make that fiber is a random orientation basically, in having 120 ℃ the cylinder type drying machine of surface temperature, heat then, provide and have 22g/m ²The fibre web of basis weight.Fibre web with relaxed state curls with development in latent crimp fiber by fixed infrared heater to 160 ℃ then.Then, use cylindrical roll to suppress fibre web under 10kgf/cm pressure, obtain supatex fabric, its performance is shown in table 1.

Embodiment 2

Under the condition identical, produce supatex fabric, except the ratio of Spandex is that the ratio of 10 weight % and latent crimp polyester fiber is 60 weight % with embodiment 1.The performance of the fabric that obtains is shown in table 1.

Embodiment 3

Under the condition identical, produce supatex fabric, except the ratio of Spandex is that the ratio of 20 weight % and latent crimp polyester fiber is 50 weight % with embodiment 1.The performance of the fabric that obtains is shown in table 1.

The comparative example 1

With preparing supatex fabric, except not using Spandex with embodiment 1 the same method.The performance of the fabric that obtains is shown in table 1.

Table 1

Embodiment 1 embodiment 2 embodiment 3 contrasts 1

Proportion of fibers (wt%)

Spandex 5 10 20 0

Crimping polyester bicomponent fiber 65 60 50 70

Polyester binding fiber 30 30 30 30

Fabric property

Basis weight (g/m ²) 42 40 38 44

Thickness (micron) 119 132 124 137

TENSILE STRENGTH, MD (kN/m) 1.1 1.0 0.9 1.1

TENSILE STRENGTH, CD (kN/m) 1.0 0.9 0.8 1.0

Elongation recovery percentage, MD (%) 69 73 86 50

Elongation recovery percentage, CD (%) 63 67 79 46

Data in the table 1 show, compare with the fabric of preparation among the comparative example 1 who is not suitable as stockinette, and the non-woven elastic fabric of preparation has isotropic elongation recovery percentage in embodiment 1,2 and 3, and it also is very high.Fabric of the present invention also has good hand feeling (low viscosity) and good compliance.

Claims

1. supatex fabric, it has isotropic elongation recovery percentage of about at least 55%, and comprises binding agent, is the exposed elastic short fiber of about 3 to 50 percetages by weight and the short bicomponent fiber that curls based on the weight of described fabric.

2. the fabric of claim 1, it comprises based on fabric weight is the exposed elastomers of about 5 to 30 percetages by weight.

3. the fabric of claim 1, wherein crimped fibre comprises that to be selected from following polymer right:

Poly-(ethylene glycol terephthalate) and gather (terephthalic acid (TPA) 1, ammediol ester) and

Poly-(ethylene glycol terephthalate) and poly-(ethylene glycol terephthalate-copolymerization-isophthalic acid glycol ester),

It has and is selected from following cross section: block form and eccentric skin-core formula, and binding agent is binder fiber, it is that the amount of about 10 to 50 percetages by weight exists with the weight based on fabric, and has the melt temperature of the softening temperature that is lower than elastomer.

4. the fabric of claim 1, wherein elastomer is Spandex and crimped fibre being that the amount of about 40 to 80 percetages by weight exists based on fabric weight.

5. the fabric of claim 1, wherein Luo Lu elastomer is that polyurethane-urea Spandex and fabric have about at least 50 microns and less than 135 microns thickness.

6. the fabric of claim 1, wherein elastomer has the linear density of 0.5 to the 40 every long filament of dtex, and binding agent is that fiber and elastomer, crimped fibre and binder fiber have 3 to 50 millimeters length.

7. make the method for the supatex fabric of claim 1, it may further comprise the steps:

(a) provide short Spandex, short latent crimp fiber, it takes place to curl when being heated, and binder fiber;

(b) suspended substance of preparation Spandex, latent crimp fiber and binder fiber;

(c) by the method that is selected from air lay and wet-laying suspended substance is configured as fibre web;

(d) heat this fibre web with the described binder fiber of fusion with in conjunction with described fiber; With

(e) the heating fibre web curls to form in latent crimp fiber under relaxed state.

8. the method for claim 7 is wherein carried out suspended substance preparation process (b), makes latent crimp fiber being that the level that is equivalent to 40 to 80 percetages by weight exists based on fabric weight, and heating steps (d) and (e) carry out as one step.

9. the method for claim 7, wherein heating steps (d) and (e) under the temperature of the softening temperature that is lower than Spandex, carry out.

10. goods, it comprises the fabric of claim 1, and it is by the method manufacturing of claim 7 and be selected from base material, cloth for wiping or dusting and the packaging material that clothing sandwich, diaper, external drug are handled.