JP2865370B2 - Bulk recoverable nonwoven fabric, method for producing the same, and method for recovering the bulk - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a nonwoven fabric capable of recovering bulk, a method for producing the same, and a method for recovering bulk. More specifically, the present invention relates to a bulk-recoverable nonwoven fabric which can be suitably used as a cotton pad, a brassier cup material, a shoulder pad material, a filter, and the like, a method for producing the same, and a method for recovering the bulk.

[Prior Art] In general, bulky nonwoven fabrics containing a large amount of air are used for cotton filling, filters and the like used for sports clothing and the like. For this reason, transporting and storing such cotton fillings is like transporting and storing air, and transporting and storing large quantities at once is It required a fairly large space and was extremely disadvantageous in terms of cost. Further, such a bulky nonwoven fabric has a drawback that it is difficult to handle because it is bulky and soft when working at an actual sewing site.

In order to overcome the above disadvantages, Japanese Patent Publication No. Sho 60-5808
In No. 6, the bulky nonwoven fabric is wrapped in a film,
A method has been adopted in which the air inside is extracted under reduced pressure, transported and stored in a reduced volume, and restored to its original bulky state by blowing in hot air during use. However,
When this method is adopted, when the first internal air is removed, the arrangement of the constituent fibers of the bulky nonwoven fabric is affected, and wrinkles are generated or deformed. The recovery is extremely poor, and the two-stage operation of removing the internal air and restoring hot air is required, resulting in extremely poor work efficiency. Furthermore, in this method, since it is a bulky nonwoven fabric at the actual sewing site, it is difficult to handle,
The disadvantage of poor workability has not been solved at all.

Further, as another method, when producing a non-woven fabric having latently crimped fibers as a constituent fiber, the material is compressed and fixed using a low melting point powder resin, and the heat is applied at about 150 ° C. when actually used. There is known a method in which a low-melting-point powder resin is re-melted to restore its bulk and cooled, whereby the low-melting-point powder resin is re-solidified to maintain a new shape. However, when the inner cotton is manufactured by this method, when heat is applied in a later step of the manufacturing of the inner cotton, the melting of the low melting point powder resin occurs as in the case of bulk recovery, and the compressed state is obtained. In some cases, or in a deformed state. In addition, when dry cleaning is performed, not only in the post-process, but also because of poor resistance to solvents other than heat, there is also a disadvantage that the bonding by the low melting point powder resin is broken and durability is poor. Furthermore, since it is only fixed with low melting point powder resin,
The shape stability when reheated and melted is poor, and there is a problem in using it as a cotton wool. Moreover, since the bulk was recovered at a temperature of about 150 ° C., the effect on the constituent fibers of the nonwoven fabric could not be ignored.

[Problems to be Elucidated by the Invention] The present invention is excellent in durability and shape retention after bulk recovery, has good workability at the time of sewing, etc., and can significantly reduce bulk during transportation and storage. It is an object of the present invention to provide a nonwoven fabric, a method for producing the same, and a method for recovering the bulk thereof.

[Means for Solving the Problems] According to the present invention, a nonwoven fabric in which constituent fibers are bonded by a fiber bonding adhesive has a melting temperature lower than the melting temperature of any of the constituent fibers and the fiber bonding adhesive. A nonwoven fabric having a degree of expansion of 5 times or more, which is fixed in a compressed state by a temporary adhesive and capable of recovering a bulk, and a fibrous web in which constituent fibers and heat-meltable fibers are mixed are bonded with a fiber bonding adhesive. And then heat-compressing the non-woven fabric to a thickness of 1/5 to 1/30 of the original non-woven fabric to melt the hot-melt fibers, and fixing the non-woven fabric in a compressed state. A method for producing a bulk-recoverable non-woven fabric, a fiber web is bonded to the non-woven fabric with a fiber bonding adhesive, and then a low-melting resin powder is attached to the non-woven fabric, and 1/5 to 1/30 of the original non-woven fabric. Heat and compress to a thickness of 3 to melt the low melting point resin powder A method for producing a bulk-recoverable nonwoven fabric, characterized by fixing a woven fabric, and a method for preparing the bulk-recoverable nonwoven fabric, the melting temperature of a temporary adhesive or higher, and the melting temperature of any of constituent fibers and a fiber bonding adhesive. The present invention relates to a method for recovering the bulk of a nonwoven fabric, which comprises performing a heat treatment at a lower temperature to recover the bulk so that the thickness becomes 5 times or more the thickness at the time of compression.

[Functions and Examples] In the nonwoven fabric capable of recovering bulk according to the present invention, the nonwoven fabric in which the constituent fibers are bonded by the fiber bonding adhesive has a melting point lower than the melting temperature of any of the constituent fibers and the fiber bonding adhesive. It is fixed in a compressed state by a temporary adhesive having a temperature.

The constituent fibers used in the present invention are not particularly limited, but those which have a swelling degree of 5 times or more and largely recover the bulk when released from the compressed state by melting of the temporary adhesive are preferable. Examples of the constituent fibers for greatly recovering the bulk include crimped fibers such as high crimped fibers. Among the crimped fibers, the latently crimpable fibers have a large crimp when heated. Because it is expressed
Particularly preferred.

The crimped fiber, when reheated for bulk recovery, when the temporary adhesive that had been temporarily bonded was melted and the adhesive strength was weakened, the crimped fiber that had been distorted until then was the original. The repulsive force for returning to the state works as a driving force for bulk recovery. Therefore, in the present invention, it is preferable to use a fiber having a large crimp rate, residual crimp rate and crimp elastic modulus as these crimped fibers.

The fibers having a large crimp rate, residual crimp rate and crimp elastic modulus refer to fibers having a crimp rate of 12 to 70%, a residual crimp rate of 7 to 70%, and a crimp elastic modulus of 30 to 100%. . Among such fibers, those having a crimp rate of 20 to 70%, a residual crimp rate of 15 to 70%, and a crimp modulus of 60 to 100% are particularly preferable. The crimp rate, residual crimp rate and crimp elasticity are numerical values when the crimp is actualized, and when the crimp is latent, the numerical value when the crimp is actualized is Express.

Examples of such fibers include hollow fibers, thick fibers having a fineness of 6 denier or more, fibers having a large crimp radius,
Fibers which are shrunk by heating or humidification to form a three-dimensional spiral structure, which are generally called high crimped fibers, can be used. In addition to these, the number of crimps that are mechanically crimped is 4
Fibers of about 30/25 mm can also be used.

In the present invention, the crimp rate, residual crimp rate, and crimp elastic modulus are defined as follows.

That is, the length (a) when an initial load of 2 mgf per denier is applied to the sample, and the length (a)
Measure the length (b) when a load of 0 mg f is applied. Next, after removing all the loads, after standing for 1 minute, the length (c) when the initial load is applied is measured, and the crimp rate (%) and the residual crimp rate (%) are calculated by the following formulas. Note that the number of tests is 20 times, and the average value of each test is shown.

The crimp modulus (%) is calculated based on the following equation.

As described above, in addition to the hollow fiber, the fiber having a large fineness and the fiber having a large crimp radius, the fiber having a high crimp rate, a residual crimp rate and a high crimp elastic modulus has good recoverability, so that it is preferably used. Can be used.

In the present specification, the expression “highly crimped fiber” mainly means a fiber having a large crimp rate, a residual crimp rate, a large crimp modulus and a fiber having a three-dimensional spiral structure. The crimp in the fiber may be either actualized or latent.

Examples of the fiber that shrinks by heating in a dry heat or wet heat state to have a three-dimensional spiral structure include a fiber in which crimp is evident in composite fiber, a fiber in which crimp is latent in composite fiber, and a single fiber. Fibers and the like, in which the crimp is latent due to a specific heat history as a component, may be mentioned.

Examples of the composite fiber include side-by-side, core-sheath, and eccentric composite fibers composed of two components of a low-melting polyester component and a high-melting polyester component and two components of a low-melting polyamide component and a high-melting polyester component. can give.

The fiber that has a latent crimp with a specific heat history in the single component, the fiber is rubbed with a heated blade under tension, or by rubbing the fiber with the blade in a heated state, the fiber and the blade A fiber that has been given a thermal history so as to disturb the arrangement of molecules in contact with each other.

The fibers shrink by heating in a dry heat or wet heat state to produce crimps of a three-dimensional spiral structure,
In the present invention, the crimp may be latent or actual at the time of completion of the non-woven fabric capable of recovering bulk. In the present invention, the fiber in which the crimp of the fiber is latent, expresses a crimp by heating at the time of bulk recovery, and since this acts as a restoring force for recovering the bulk, a meaning of improving the bulk recovery rate. Is desirable. In addition, when the degree of crimping expression increases, the thickness in the bulk direction increases,
Shrinkage occurs in the width direction, and the area of the nonwoven fabric is reduced. Therefore, when dimensional stability is particularly required, it is desirable to use fibers whose crimps have become apparent at the time of completion of the nonwoven fabric.

In the case of using the fiber in which the crimp is latent in the conjugate fiber or the fiber in which the single component has the latent crimp with a specific heat history as the fiber in which the crimp has become apparent, the bulk can be recovered. When producing a nonwoven fabric, the fibers may be heated to a temperature at which crimps are developed.

In the present invention, a fiber bonding adhesive is used to bond the constituent fibers, and the fiber bonding adhesive is roughly classified into a thermosetting resin binder and a thermoadhesive fiber.

The thermosetting resin binder and the thermoadhesive fiber,
When the bulk is recovered by reheating, it plays a role of maintaining the shape before heating, and in the present invention, the influence of the heating for melting the temporary adhesive and the reheating for bulk recovery is reduced. Those that do not receive are used.

Examples of the thermosetting resin binder include a self-crosslinking type acrylate emulsion, an ethylene-vinyl acetate copolymer latex, a polyvinyl acetate latex, a polyvinyl chloride latex, a synthetic rubber latex, and a polyurethane latex. Examples thereof include latexes and polyester latexes obtained by adding a crosslinking agent.

Of these, acrylate-based emulsions are particularly preferably used. The acrylic ester emulsion is preferably used because polyester fibers are generally used as a constituent fiber of the nonwoven fabric. In addition to the fact that the polyester fibers have good adhesion to a hydrophobic surface and good water resistance, This is because it is possible to freely design a film from a soft adhesive to a hard adhesive. In addition, even if it is not a thermosetting resin binder, any resin binder having a melting temperature higher than the temporary adhesive by 10 ° C. or more can be used because the influence of heating and reheating is small.

Examples of the heat-adhesive fibers include, for example, all-melted fibers made of resins such as uncentrifuged polyester, low-melting polyester, and low-melting polyamide, and composite fibers containing these resins as one component. However, it is desirable that the melting temperature of the heat-adhesive fiber is higher than the melting temperature of the temporary adhesive by 10 ° C. or more, preferably 20 ° C. or more, and usually the melting temperature is preferably 100 to 230 ° C.

In addition, when the constituent fibers are particularly composed of conjugate fibers, the low melting point component of the conjugate fibers can be used as a fiber bonding adhesive. In this case, a thermosetting resin binder or a thermoadhesive fiber may not be used. However,
Even in this case, the melting temperature of the low melting point component of the conjugate fiber used as the fiber bonding adhesive must be higher than the melting temperature of the temporary adhesive.

Here, the melting temperature indicates a temperature when a solid generally called a melting point is melted in a dry heat state and a solid phase and a liquid phase are in an equilibrium state. In the meantime, it indicates the temperature of a non-crystalline substance which softens in the presence of water and becomes a liquid phase when the solid phase and the liquid phase are in an equilibrium state in the presence of water.

In the present invention, the above-mentioned relationship must be satisfied when the temporary adhesive described later is in a dry heat state or a wet heat state.

Here, an example in which the melting temperatures in the dry heat state and the wet heat state are different will be described. One example is the case where the temporary adhesive is polyvinyl alcohol. Polyvinyl alcohol exhibits a melting temperature of about 120 to 150 ° C in a dry heat state, but swells and softens to a molten state in a water heat state of about 100 ° C, that is, in a wet heat state, and generates adhesive force. In the molten state, the temperature may be about 100 ° C. Therefore, the melting temperature of the temporary adhesive may differ depending on whether the temporary adhesive is in a dry heat state or a wet heat state.

The temporary adhesive used in the present invention is intended to make a bulky nonwoven fabric temporarily bulkless, that is, a nonwoven fabric having a high density to make it easy to handle. It has the function of reducing the adhesive force of the agent and recovering the bulk by the repulsive force of the crimped fibers. Therefore, a temporary adhesive having a melting temperature that does not affect the constituent fibers of the nonwoven fabric or the adhesive for bonding fibers is required, and the melting temperature of the temporary adhesive is determined by either the constituent fibers of the nonwoven fabric or the adhesive for bonding fibers. 10 ° C above melting temperature
The lower condition is an essential condition. Most preferably
20 ° C or lower.

Among the above-mentioned conditions, preferred is one in which the melting temperature of the temporary adhesive is 100 ° C. or less. The melting temperature is 100 ℃
The reason for being preferably the following is that at such a temperature, the constituent fibers of the nonwoven fabric are hardly adversely affected, and the bulk can be recovered by a simple heating means in the sewing process.

Specifically, the form of the temporary adhesive includes, for example, a fiber form, a powder form, and the like.

A typical example of the fiber-shaped temporary adhesive is a heat-meltable fiber. Such fiber forms include conjugate fibers and monocomponent fibers. When the composite fiber is used in the present invention, only the low-melting-point component is melted, so that it is not excessively melted and adhered, so that the feeling is not impaired and the handling is easier.

Representative examples of the composite fiber include, for example, a composite fiber composed of a combination of a low-melting polyester component-a high-melting polyester component, a low-melting polyamide component-a high-melting polyester component, and the form of the composite fiber is, for example, Examples include a side-by-side type, a core-sheath type, and a sea-island type. The low melting point component of these conjugate fibers is 80-
Since it has a melting temperature of about 100 ° C., it can be heated and reheated at a low temperature, so that it has no effect on other constituent fibers, is also useful for energy saving, and has an advantage of improving workability.

In addition, if the mixing ratio of the heat-fusible fiber to the other constituent fibers increases, the fiber becomes harder, the bulk recovery property becomes poor, and, in the case of dry cleaning after bulk recovery, adhesion in a deformed state may occur. It is not preferable because it may cause On the other hand, when the mixing ratio of the heat-fusible fibers is small, the dispersion state of the heat-fusible fibers becomes uneven, and at the same time, the strength of the temporary bonding becomes insufficient. Therefore, the content of the heat-fusible fiber in all the fibers in the nonwoven fabric is desirably 5 to 40% by weight, preferably 10 to 30% by weight.

On the other hand, as a typical example of the temporary adhesive in a powder state,
Low-melting powder resin and water-soluble powder resin are listed.

Examples of the low melting point powder resin include powder resins such as polyamide, polyethylene, and ethylene-vinyl acetate copolymer having a melting temperature of 100 ° C. or lower, especially about 80 to 100 ° C.

Examples of the water-soluble powder resin include powder resins such as polyvinyl alcohol having a melting temperature of about 80 to 110 ° C. in a wet heat state.

As described above, the nonwoven fabric in which the constituent fibers are bonded by the fiber bonding adhesive is heated and pressed at a temperature of 100 ° C. or lower, and then cooled in the pressurized state to maintain its compressed state by the temporary adhesive. Therefore, a nonwoven fabric having a thickness of about 1/5 to 1/30 times that of the first nonwoven fabric can be obtained.

After carrying, transporting, storing, sewing, etc., the nonwoven fabric has a bulk of 5 to 30 by applying the same degree of heating as described above.
It can be recovered twice.

The “thickness” stored throughout this specification means a thickness measured by applying a load of 0.01 g per 100 mm ² to a 250 mm × 250 mm specimen.

Next, a method for producing the nonwoven fabric capable of recovering bulk according to the present invention will be described.

The method for producing the bulk-recoverable nonwoven fabric is different depending on whether a thermosetting resin binder is used as a fiber bonding adhesive or whether a thermoadhesive fiber is used, or whether a fusible fiber is used as a temporary adhesive. Or it depends on whether a low melting point powder resin is used.

When using a thermo-adhesive fiber as the fiber bonding adhesive and using a hot-melt fiber as the temporary adhesive, the constituent fibers,
The heat-bondable fiber and the heat-meltable fiber are mixed to form a fibrous web by means such as carding. Next, the obtained fiber web is heated to melt the heat-adhesive fibers and bond the fiber web to form a nonwoven fabric.

When using a heat-adhesive fiber as an adhesive for fiber bonding and using a low-melting resin powder as a temporary adhesive, the constituent fibers and the heat-adhesive fiber are mixed, and a fiber web is formed by means such as carding. Heating the resulting fibrous web,
After melting the heat-adhesive fibers and bonding the fibrous web to a nonwoven fabric, a low-melting resin powder is attached to the obtained fibrous web.

When using a thermosetting resin binder as the fiber bonding adhesive and using a heat-meltable fiber as the temporary adhesive,
The constituent fibers and the heat-meltable fibers are mixed to form a fibrous web by means such as carding, and then a thermosetting resin binder is attached to the obtained fibrous web, and the fibrous web is bonded to form a nonwoven fabric.

When a thermosetting resin binder is used as the fiber bonding adhesive and a low-melting resin powder is used as the temporary adhesive, the constituent fibers are formed into a fibrous web by means such as carding, and then the thermosetting resin is used. After attaching a binder to the obtained fiber web and bonding the fiber web to form a nonwoven fabric, a low melting point resin powder is added to the obtained nonwoven fabric.

In any case, it is preferable to mix high crimped fibers in the constituent fibers, and the mixing ratio of such high crimped fibers depends on the use of the obtained bulk-recoverable nonwoven fabric, the method of use, and the like. Can be set appropriately.

As described above, when a low-melting resin powder is used as the temporary adhesive, it is difficult to mix the constituent fibers and the low-melting resin powder into a fibrous web by means such as carding. When the melting point resin powder is added, and then bonded to the fiber web with a thermosetting resin binder to form a nonwoven fabric, the binder also surrounds and adheres to the low melting point resin powder as a temporary adhesive, In some cases, the function as a temporary adhesive cannot be sufficiently exhibited. Therefore, in the present invention, the low melting point resin powder is added after forming the nonwoven fabric.

The amount of the fiber bonding adhesive used in the constituent fibers varies depending on the type. For example, when the fiber bonding adhesive is a thermosetting resin binder, the used amount (solid content) of the thermosetting resin binder is usually 3 to 50% by weight of the usually formed nonwoven fabric, especially 5 to 30% by weight. It is adjusted so that When the amount of the thermosetting resin binder used is less than the above range, the durability and strength of the nonwoven fabric after the bulk is recovered become insufficient, and when the amount is more than the above range. Means that a bulky nonwoven fabric cannot be formed, and it is difficult to compress, so that only a nonwoven fabric having a small bulk recovery rate can be obtained,
Moreover, the texture of the nonwoven fabric after bulk recovery tends to be hard.

Further, when the fiber bonding adhesive is a heat bonding fiber, when the heat bonding fiber is a fully melted fiber, and when the low melting point component is a conjugate fiber used as a fiber bonding adhesive. And its usage varies.

When the heat-adhesive fibers are all molten fibers, the amount of the total molten fibers used is usually 30 to
It is adjusted to contain 55% by weight, preferably 35 to 50% by weight. When the usage amount of the total molten fiber is less than the above range, the durability of the nonwoven fabric after the bulk recovery becomes poor by dry cleaning and washing, and when the amount is more than the above range, the nonwoven fabric becomes relatively less. There is a tendency that the blending amount of the constituent fibers is reduced and a bulky nonwoven fabric is hardly obtained.

When the heat-adhesive fiber is a conjugate fiber, the amount of the conjugate fiber used is adjusted so as to be usually 30 to 95% by weight, preferably 40 to 90% by weight in a nonwoven fabric to be formed. You. When the amount of the composite fiber used is less than the above range, the durability of the nonwoven fabric after bulk recovery by dry cleaning and washing becomes poor, and when the amount is more than the above range, a sufficient amount of the nonwoven fabric is used. Temporary adhesives cannot be compounded, and the thickness after pressing tends to be too small.

If the amount of the temporary adhesive is too large, the bulk recovery property is impaired. If the amount is too small, a sufficient effect of the temporary adhesive tends not to be exhibited. Therefore, when the temporary adhesive is a heat-fusible fiber, the amount of the heat-fusible fiber used is 5 to 40% by weight of the nonwoven fabric to be formed, preferably 10 to 30% by weight.
It is preferable that When the temporary adhesive is a low-melting resin powder, the amount of the low-melting resin powder used is:
It is preferably 5 to 40% by weight, especially 10 to 30% by weight of the nonwoven fabric to be formed.

Also, the basis weight of the non-woven fabric of the present invention whose bulk can be recovered is different depending on the use of the non-woven fabric whose bulk can be recovered, and thus cannot be unconditionally determined. For example, the non-woven fabric whose bulk can be recovered is used for sports clothing and the like. It is preferably about 30 to 200 g / m ² when used as a cotton filling, and about 50 to 400 g / m ^{2 when} used as a filter.

Next, the obtained nonwoven fabric is heated and compressed at a temperature of at least 10 ° C. lower than the melting temperature of any of the constituent fibers and the fiber bonding adhesive to a thickness of about 1/5 to 1/30 of the original nonwoven fabric. I do. By this heating, a part of the hot-melt fiber is melted, and the non-woven fabric is fixed in a compressed state.

Examples of the heat compression method include a method using a roller press and a method using a flat press. The method using a roller press is a preferable method in terms of production because the nonwoven fabric can be continuously heated and compressed.

The non-woven fabric is heated and compressed by a roller press,
As the temporary adhesive solidifies due to the decrease in heat when leaving the flat press device or belt press device, it is fixed with the thickness in the compressed state, but more reliably fixed with the thickness in the compressed state For this purpose, it is desirable to maintain the compressed state, stop heating and allow the mixture to cool, or actively cool the nonwoven fabric. In the above-mentioned heating and compressing step, a step of compressing after heating may be adopted as long as the heated non-woven fabric can be compressed before the temperature of the non-woven fabric does not decrease.

Further, in any of the above-mentioned heating and compression methods, the nonwoven fabric can be compressed in the entire surface or in a dot-like manner. It is more preferable because the bulk can be easily recovered by heating.

The bulk-recoverable nonwoven fabric produced as described above is
The bulk is recovered by heat treatment at a temperature lower than the lower melting temperature of the constituent fibers and the fiber bonding adhesive. Actually, it is preferable to recover the bulk with steam because it is simple. When this bulk recovery is determined based on the restoration rate and the degree of expansion defined below, the restoration rate is 70% or more and the degree of expansion is 5 times or more. Further, the nonwoven fabric capable of recovering bulk according to the present invention has better physical properties such as washing resistance and dry cleaning resistance before and after compression than normal nonwoven fabric.

When the non-woven fabric of the present invention whose bulk can be recovered is used for clothes, for example, it is preferable from the viewpoint of workability and the like to recover the bulk at the stage where sewing is completed. However, when the heat treatment for bulk recovery of the nonwoven fabric affects the outer material and lining of clothes and the like and the bulk cannot be recovered after sewing, the bulk can be recovered after transportation, storage or cutting. The nonwoven fabric may be used after recovering its bulk.

As described above, since the non-woven fabric capable of recovering the bulk of the present invention can reduce the bulk before its use, it improves the handling properties such as transportation and storage, and reduces transportation costs and storage costs. It has the advantage that it can be.

Next, the nonwoven fabric capable of recovering bulk of the present invention will be described in more detail based on examples, but the present invention is not limited to only these examples.

Example 1 Highly crimped polyester fiber (melting point: 256
90 ℃, 90% by weight of low-melting core-sheath type composite polyester fiber (core: polyester (melting point: 256 ° C), sheath: low-melting polyester (melting point: 87 ° C), fineness: 3 denier , Fiber length 51mm) 10% by weight
Was made into a fibrous web having a basis weight of 55 g / m ² by carding. Thereafter, the fibrous web was bonded using a self-crosslinking type acrylic ester emulsion as a binder to obtain a nonwoven fabric having a basis weight of 60 g / m ² . This non-woven fabric was compression-pressed in a dot shape with a heat roll at a temperature of 100 ° C. under a gauge pressure of 2 kg / cm ² . After 30 days, steam at 100 ° C was applied to recover the bulk. At this time, the restoration rate was 85%, and the degree of expansion was 11 times.

Next, the mixing ratio of the low melting point core-sheath type composite polyester fiber to the high crimped polyester fiber was 3, 5, 15, 20,
A fiber web having a basis weight of 55 g / m ² was obtained by changing the weight to 30, 35, 40, and 45% by weight. The fibrous web was bonded by a self-crosslinking acrylic ester emulsion to obtain a nonwoven fabric having a basis weight of 60 g / m ² . After heating and compressing this non-woven fabric in the form of dots under the same conditions, 30 days later, 100 ° C. steam is applied to recover the bulk,
The restoration rate and the degree of swelling were examined. Table 1 shows the results. As is clear from Table 1, in the present invention, it is found that mixing 5 to 40% by weight of the low-melting-point core-sheath type composite polyester fiber gives preferable results.

Next, after 30 days, the nonwoven fabric containing 15% by weight of the low-melting core-sheath type composite polyester fiber in Example 1 was recovered with steam at 100 ° C. Washing resistance and dry cleaning resistance of this nonwoven fabric and a normal nonwoven fabric which does not contain a low melting point component and which is not subjected to compression bonding were examined.

The washing resistance was grade 3 and the dry cleaning resistance was grade 5, and there was no change in the physical properties due to compression bonding. In addition, the test method and evaluation method of washing resistance and dry cleaning resistance are as follows.

(Washing resistance) Collect a 250mm x 250mm specimen, wrap it in nylon taffeta, use an automatic reversing washing machine, water temperature 40 ± 3 ° C, use 0.2% phosphorus-free synthetic detergent solution 32, water and specimen The load cloth was added under the condition of a bath ratio of 50: 1 (weight ratio) with the load cloth, washed for 90 minutes in a strong water flow, washed with water, dehydrated and air-dried, and the surface condition was observed. The rating is expressed in the following grade.

Grade 5: No change in appearance. Grade 4: Those with slight cottoniness. Grade 3: Medium with cottoniness and unevenness. Class 2: Those with large cottonyness and unevenness. (Dry cleaning resistance) Wrap a 250 mm x 250 mm specimen in nylon taffeta and use a commercial barclean dry cleaner to weigh 500 g of laundry.
Then, a load cloth was added thereto, the laundry was washed at a washing temperature of 25 ° C. for 8 minutes, and the steps of draining for 1 minute, draining for 4 minutes, drying for 5 minutes (60 ° C.), and deodorizing for 2 minutes were repeated three times. Thereafter, the surface condition is observed and the rating is expressed in the same grade as the washing resistance described above.

Example 2 Highly crimped polyester fiber (melting point: 256
C., a denier of 3 denier and a fiber length of 51 mm) were made into a fibrous web having a basis weight of 55 g / m ² by carding. The fibrous web was bonded using a self-crosslinking type acrylate ester emulsion as a binder to obtain a nonwoven fabric having a basis weight of 60 g / m ² . Then, sprayed polyvinyl alcohol resin powder 10 g / m ^2,
The nonwoven fabric had a basis weight of 70 g / m ² . And this non-woven fabric temperature
A point-shaped compression press was performed with a heat roll at 120 ° C. under the condition of a gauge pressure of 3 kg / cm ² . After 30 days, steam at 100 ° C was applied to recover the bulk. At this time, the restoration rate was 80%, and the degree of expansion was 7 times.

Washing resistance and cleaning resistance are each 3
And non-compressed non-woven fabrics.

Comparative Example 1 Highly crimped polyester fiber (melting point: 256
80% by weight of low-melting core-sheath type composite polyester fiber (core: polyester (melting point: 256 ° C), sheath: low-melting polyester (melting point: 87 ° C), fineness: 4 denier, fiber length: 51mm) ) fibers consisting of 20 wt% was carded to give a basis weight 60 g / m ² nonwoven fabric. This nonwoven fabric was compression-pressed in a point-like manner with a heat roll at a temperature of 100 ° C. under a gauge pressure of 2 kg / cm ² . After 30 days, steam at 100 ° C was applied to recover the bulk. The restoration rate at this time is 40%,
The degree of expansion was 6.5 times.

Next, when the nonwoven fabric was examined for its washing resistance and cleaning resistance, it was classified into first and second grades, respectively, and there was a problem with the durability.

Comparative Example 2 Highly crimped polyester fiber (melting point: 256
A fiber web having a basis weight of 49.5 g / m ² was obtained by carding. This fibrous web by adding a low-melting polyamide resin powder 10.5 g / m ² basis weight 60
g / m ² non-woven fabric was obtained. Thereafter, the nonwoven fabric was compression-pressed by a heat roll at 100 ° C. in the form of dots at a gauge pressure of 2 kg / cm ² . Thirty days later, the bulk was recovered by applying steam at 100 ° C. At this time, the restoration rate was 40%, and the degree of expansion was 4.5 times.

Next, when the dry cleaning resistance of this nonwoven fabric was examined, it was grade 2 or 3, which was inferior to the case where a resin binder was used. Before washing, the nonwoven fabric had poor shape retention, so that the washing resistance could not be examined.

Example 3 As a constituent fiber, a high crimped polyester fiber (melting point: 256
° C, fineness 3 denier, fiber length 51 mm) 60% by weight, low melting point core-sheath type composite polyester fiber (core: polyester (melting point 25
6 ° C), sheath: low melting point polyester (110 ° C melting point), fineness 4
30% by weight of denier, fiber length 51mm) and low melting point core-sheath composite polyester fiber (core: polyester (melting point 256 ° C)
Sheath: A fiber web having a basis weight of 60 g / m ² was formed by carding a fiber composed of 10% by weight of a low-melting polyester (melting point: 87 ° C., fineness: 3 denier, fiber length: 51 mm). Then 150
C. to apply heat to the fibrous web to bond the fibrous web;
I got a non-woven fabric.

Next, the obtained nonwoven fabric was compression-pressed by a heat roll at a temperature of 100 ° C. in a point-like manner at a gauge pressure of 2 kg / cm ² . 30
One day later, steam at 100 ° C. was applied to recover the bulk. At this time, the restoration rate was 45%, and the degree of expansion was 8 times.

Further, the washing resistance and the dry cleaning property were tertiary and tertiary, respectively, and showed good resistance as well as non-compressed non-woven fabric.

Example 4 90% by weight of a low-melting core-sheath composite fiber (core: polypropylene, sheath: polyethylene (melting point: 130 ° C.), fineness: 14 denier, fiber length: 76 mm) as a constituent fiber, and a low-melting core-sheath composite polyester fiber as a temporary adhesive (Core: polyester (melting point
Fiber composed of 10% by weight of a low melting polyester (melting point: 87 ° C.), fineness: 3 denier, fiber length: 51 mm) was formed into a fiber web having a basis weight of 300 g / m ² by carding. Thereafter, the fiber web was bonded by applying heat at 150 ° C., and the thickness was adjusted with a heat roll to obtain a nonwoven fabric having a thickness of 20 mm.

The obtained nonwoven fabric was compression-pressed by a heat roll at a temperature of 110 ° C. in a point-like manner at a gauge pressure of 4 kg / cm ² . 3 days later, 100
C. steam was applied to recover the bulk. At this time, the restoration rate was 105%, and the expansion rate was 11 times.

Next, this nonwoven fabric was measured for the initial pressure loss and the collection efficiency as an air filter. 2.5m wind speed
/ Sec, the initial pressure loss in the conditions of dust concentration 22.3 mg / m ³ 10
mmAq, and the average trapping efficiency until the pressure loss reached 20 mmAq was 80%, which sufficiently satisfied the properties as an air filter.

Example 5 Low-melting core-sheath composite polyester fiber (core: polyester (melting point: 256 ° C.), sheath: low-melting polyester (melting point: 87 ° C.), fineness: 3 denier, fiber length: 51 mm) as a temporary adhesive 10
Low melting point core-sheath composite polyester fiber (core: polyester (melting point 130 ° C), sheath: low melting point polyester (melting point 125 ° C), fineness 2 denier, fiber length 5
1 mm) A fiber consisting of 90% by weight was adjusted to a basis weight of 50 g / m ² by carding. Thereafter, the fibrous web was bonded by applying heat at 150 ° C., and then compression-pressed in a point-shape with a heat roll at a temperature of 100 ° C. under a gauge pressure of 2 kg / cm ² .

Three days later, steam at 100 ° C was applied to recover the bulk. The restoration rate at this time was 90%, and the degree of expansion was 12 times.

The non-woven fabric whose bulk has been recovered and polyester fiber (melting point
Nonwoven fabric made of 256 ° C) and not subjected to compression bonding (having a basis weight of 50g / cm ² and bonded by applying heat at 150 ° C)
As a result, the washing resistance and dry cleaning resistance were examined. As a result, the washing resistance was grade 4 and the dry knelling resistance was grade 4, and there was no change in the physical properties due to compression bonding.

[Effect of the Invention] Since the non-woven fabric which can recover the bulk of the present invention uses a temporary adhesive having a lower melting point than the constituent fibers and the adhesive for bonding the fibers, it is necessary to reduce the heating and the adhesive force when the temporary bonding is performed. Has no effect on the constituent fibers and the fiber bonding adhesive upon reheating, and the physical properties do not change before and after the temporary bonding. For this reason, the bulky nonwoven fabric can be made thinner with a sense of security, which contributes to reduction in transportation and storage costs, and because of the high density, operations such as cutting and sewing can be performed effectively.

In addition, since the nonwoven fabric capable of recovering bulk of the present invention uses not only a low adhesive but also a fiber bonding adhesive in advance, the adhesive strength between constituent fibers was reduced by reheating. Sometimes, the shape easily recovers to the shape before heating, and after the recovery, the dry cleaning resistance, the washing resistance, and the like are superior to those of a normal nonwoven fabric.

Therefore, the non-woven fabric capable of recovering bulk of the present invention can reduce the thickness of the non-woven fabric without affecting the physical properties of the non-woven fabric,
Because it can be made thicker, it is useful as a filling material, as well as bra cup material, shoulder pad, filter, etc. is there.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-89604 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) D04H 1/00-18/00

Claims (9)

(57) [Claims] 1. A non-woven fabric in which constituent fibers are bonded by a fiber bonding adhesive is fixed in a compressed state by a temporary adhesive having a melting temperature lower than that of any of the constituent fibers and the fiber bonding adhesive. A nonwoven fabric having a degree of swelling of 5 times or more and capable of recovering bulk, which is characterized in that: 2. The non-woven fabric according to claim 1, wherein the fiber bonding adhesive is a thermosetting resin binder. 3. The non-woven fabric according to claim 1, wherein the fiber bonding adhesive is a heat-adhesive fiber. 4. The non-woven fabric according to claim 1, wherein the constituent fibers are conjugate fibers, and the adhesive for bonding fibers is a low melting point component of the conjugate fibers. 5. The method according to claim 1, wherein the temporary adhesive is a heat-fusible fiber.
5. The nonwoven fabric capable of recovering bulk according to 2, 3 or 4. 6. The non-woven fabric of claim 1, wherein the temporary adhesive is a low melting point resin powder. 7. A nonwoven fabric obtained by bonding a fiber web in which constituent fibers and heat-meltable fibers are mixed with a fiber bonding adhesive, and then forming the nonwoven fabric to a thickness of 1/5 to 1/30 of the original nonwoven fabric. A method for producing a non-woven fabric capable of recovering bulk, characterized in that the non-woven fabric is heated and compressed to melt the heat-fusible fiber and the non-woven fabric is fixed in a compressed state. 8. After bonding the fiber web with a fiber bonding adhesive to form a nonwoven fabric, a low melting point resin powder is attached to the nonwoven fabric and heated to a thickness of 1/5 to 1/30 of the original nonwoven fabric. A method for producing a bulk-recoverable nonwoven fabric, which comprises compressing to melt a low-melting resin powder and fixing the nonwoven fabric in a compressed state. 9. The nonwoven fabric capable of recovering bulk according to claim 1 is subjected to a heat treatment at a temperature higher than the melting temperature of the temporary adhesive and lower than the melting temperature of any of the constituent fibers and the fiber bonding adhesive. A method for recovering the bulk of a nonwoven fabric, wherein the bulk is recovered so as to have a thickness of at least five times the thickness at the time.