JPH0726459A - Damping cushion material - Google Patents

Abstract

PURPOSE:To provide a cushion material having a damping effect and a flame- retardant effect in addition to characteristics light in the weight and low in the permanent fatigue set characteristic to fiber cushion materials and effective for sheets and beds used in cars, ships, etc. CONSTITUTION:A damping cushion material comprising a >=50mm thick short fiber collected product comprising the blend of (A) polyester short fibers with (B) sheath-core type conjugate short fibers using a sheath component having a low melting point lower by >=30 deg.C than that of a core component, the three- dimensionally successive interlaced parts of the fibers being fused by the melting of the sheath parts of the sheath-core type conjugate short fibers, is characterized in that the short fiber collected product comprises the laminate of a high density layer having an average density of 0.03-0.05g/cm<3> to a low density layer having an average density of 0.01-0.03g/cm<3> wherein the dispersion range of the densities of the respective layers is + or -5%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushion material using a composite fiber.

[0002]

2. Description of the Related Art Conventionally, as a cushioning material for beds and the like, urethane foam or a spring sheet has been generally used, but these have the drawbacks of large fatigue and heavy weight. On the other hand, in recent years, a material using a fiber material such as polyester has been developed as a material for the cushioning material, and for example, it is proposed by the applicant of the present invention.
In Japanese Patent No. 223357, etc., a fiber cushion material using a heat fusion composite fiber is described. The cushioning material disclosed in this publication is a fiber aggregate having a thickness of about 10 to 100 mm and has extremely low density variation in any portion of its cross section, and is excellent in uniformity. It was extremely effective, and it was possible to produce a bed without sagging by utilizing the characteristics of polyester fiber.

Further, while the present inventor has conducted extensive studies on such a fiber cushion material, by setting such a fiber cushion material to a specific density or the like,
I noticed the peculiar property of exerting the damping effect and the flame retarding effect in the low frequency range. Therefore, when such a fiber cushion material is used as a cushion material for a seat or bed of a transportation facility such as a car or a ship, it can be extremely effective in combination with characteristics such as less fatigue and light weight.

[0004]

However, since the density of the cushioning material which does not cause fatigue and is comfortable to sleep as the bed and the density at which the damping effect is effectively exerted are different, it is disclosed in, for example, JP-A-62-223357. It was not possible to obtain a high-quality cushioning material suitable for the above-mentioned purpose by simply using the prepared fiber cushioning material.

The present invention has been made to solve the above problems, and its purpose is to provide a car cushion, which has a vibration damping effect and a flame retarding effect in addition to the characteristic that the cushioning material made of fibers has little fatigue and is light. It is to provide an effective cushioning material for seats and beds of ships and the like.

[0006]

According to the present invention, a polyester short fiber (A) is mixed with a core-sheath type composite short fiber (B) in which a sheath has a low melting point component having a melting point lower than that of the core by 30 ° C. or more. The entangled portion of the three-dimensionally continuous fibers is fused by melting of the sheath portion of the core-sheath type composite short fiber having a thickness of 50 mm.
In the above short fiber aggregate, the short fiber aggregate has an average density of 0.03 g / cm ³ or more and 0.05 or less g / c.
high density layer of m ^3, 0.01g / cm ³ or more 0.03g
A low-density layer having a density of less than 1 cm ³ / cm ³ is laminated, and the variation range of the density in each layer is ± 5% or less.
Polyester short fibers (A) and sheath with melting point of 30 ° C from core
Core-sheath type composite staple fiber (B) using a low melting point component lower than the above
And a high density web (H) having a density of 0.018 to 0.03 g / cm ³ and a density of 0.0025 to 0.0074 g.
/ Cm ³ of low density web (L) is produced, and a plurality of high density webs composed of the plurality of high density webs (H) and a plurality of low density webs composed of the low density webs (L) are alternately formed. It can be manufactured by laminating once, steaming the laminate under heat to fuse the layers, and then slicing the laminate in the laminating direction.

Examples of the polyester short fibers (A) include ordinary polyethylene terephthalate, polyhexamethylene terephthalate, polytetramethylene terephthalate, poly 1,4-dimethylcyclohexane terephthalate, polyhydrolactone or their copolymerized esters or (conjugate). Any of composite fibers can be used. In particular, the side-by-side type composite fiber composed of two kinds of polymers having different heat shrinkages is preferable because it exhibits a spiral crimp and has a three-dimensional structure, and it is more preferable to use a hollow fiber of 5 to 30%. When manufacturing such a polyester fiber, it is general to combine two or more kinds of polyesters having different relative viscosities to form a composite. Moreover, the fineness of the polyester short fibers (A) is preferably 3 to 30 denier, and the fiber length thereof is preferably about 25 to 76 mm.

Next, as the core-sheath type composite staple fiber (B),
It is manufactured by using an ordinary polyester fiber component for the core and combining low melting point polyester, polyolefin, polyamide, etc. for the sheath so that the difference in melting point between the core component and the sheath component is 30 ° C or more. The melting point of the part is 110
Those in the range of 220 ° C. are used.

In the present invention, it is desirable to use a low melting point polyester as the sheath component. Examples of the polyester include aliphatic dicarboxylic acids such as adipic acid and sebacic acid, phthalic acid, isophthalic acid and naphthalene dicarboxylic acid. Contains a predetermined number of alicyclic dicarboxylic acids such as aromatic dicarboxylic acids and / or hexahydroisophthalic acid, and aliphatic or alicyclic diols such as diethylene glycol, polyethylene glycol, propylene glycol, paraxylylene glycol, etc. A copolymerized ester in which oxyacids such as parahydroxybenzoic acid are added according to the above, and examples thereof include polyesters obtained by copolymerizing terephthalic acid and ethylene glycol with isophthalic acid and 1,6-hexanediol. The core-sheath type composite short fibers (B) preferably have a fineness of 1.5 to 20 denier and a fiber length of about 25 to 76 mm.

The present invention is a short fiber aggregate in which the above two kinds of short fibers are mixed, and the weight ratio of the polyester short fibers (A) and the core-sheath type composite short fibers (B) is 95 to 50: 5. Fifty
Is preferred. Further, in the present invention, in addition to the short fibers, about 40% by weight of third component fibers such as easily slipping short fibers and antibacterial short fibers may be contained.

The cushion material of the present invention has a three-dimensional structure in which the entangled portions of the fibers are fusion-bonded by melting of the sheath portion of the core-sheath type composite short fibers (B). Further, the thickness of the cushion material is 50 mm or more, and a thickness of about 100 mm can be obtained by the method described later.

The most important point in the present invention is that the short fiber aggregate is formed by laminating a high density layer and a low density layer described below. Sunawachi, high density layer mean density 0.03 g / cm ³ or more 0.05 g / cm ³ or less, the low-density layer has an average density of 0.01 g / cm ³ or more 0.0
It is less than 3 g / cm ³ , and the average density of both layers is 0.01 to
It is preferable that the difference is about 0.04 g / cm ³ . Also,
The thickness of the high density layer of the cushion material is preferably 40 to 80 mm, the thickness of the low density layer is preferably 40 to 20 mm, and the thickness ratio of the high density layer and the low density layer is preferably about 1: 1 to 1: 4. .

In this cushioning material, a high-density layer is arranged on the use surface (surface in contact with the body), but a single high-density layer and a single low-density layer are simply laminated, It is also possible to adopt a sandwich structure in which the upper and lower sides of the low density layer are sandwiched by high density layers. Furthermore, the high-density layer and the low-density layer have a density variation range of each layer ± ± in any of the vertical, horizontal, and height directions.
It is uniform within 5%.

Next, a method for producing the above-described fiber cushion material will be described. First, the polyester short fibers (A) and the core-sheath composite short fibers (B) are mixed and
High density card web (H) and low density card web (L)
Are manufactured respectively. Generally, when used as a cushion material for beds or chairs, the density of the high density card web (H) is 0.018 to 0.03 g / cm ³ , and the density of the low density card web (L) is 0.0025 to 0. .0074 g / cm ³
And specifically, a basis weight of 360 to 600 g / c
High density card web (H) with a thickness of about 20 mm in m ²
Another example is a low density card web (L) having a basis weight of 200 to 590 g / cm ² and a thickness of about 80 mm. Further, it is preferable that the surface of the card web is temporarily fused with a far infrared ray or a hot air heater because the subsequent handling becomes easy.

Then, the card webs are laminated according to the standard of the intended cushion material. That is, when low-density webs and high-density webs are alternately laminated and subjected to the heat treatment described later, the high-density webs expand, and the low-density webs change in the direction of compression and There is a tendency to reduce the density difference. Therefore, the number of stacked card webs for the low density layer and the number of stacked card webs for the high density layer are set in consideration of the amount of change. For example, when laminating card webs having the above-mentioned density, the number of low density card webs (L) forming the low density layer is 1 to 4, and the high density card webs (H) forming the high density layer. The number of laminated sheets is preferably about 5 to 15.

In addition, each of the layers may be laminated by laminating a single high-density layer and a single low-density layer to manufacture one cushion material. However, the lamination is repeated a plurality of times. It is preferable that a plurality of main cushioning materials are manufactured by slicing the heat-treated material after the heat treatment, which will be described later, to obtain a high production efficiency.

The card webs laminated as described above are compressed and held between plates such as metal plates having good thermal conductivity,
Set in a steam pot and perform steam heat treatment. For steam heat treatment, depressurize the inside of the steam pot to 750 mmHg or more, then 1 kg /
It is preferable to carry out by introducing vapor of cm ² or more, and the plate is preferably a perforated plate.

[0018]

EXAMPLES In this example, each value was measured by the following method. Apparent density, compression hardness JIS K6767 Test size 100 × 100 × 100 mm Compressive residual strain JIS K6401 Test size 100 × 90 × 90 mm Repeated compressive residual strain JIS K6401 Test size 100 × 150 × 150 mm Resonance frequency, damping ratio (1) test Place the body on the vibration table and place the equivalent mass on it. (2) The vibration table is vibrated with a vibration frequency range of 5 to 20 Hz, a sweep time of 5 to 20 Hz / 90 minutes, and a double amplitude of 1 mmpp. (3) The acceleration of the vibration table and the acceleration of the equivalent weight are measured by the acceleration sensor (made by VP4200IMV), and the frequency response function is obtained by the FFT analyzer (made by Ono Sokki CF910). (4) From the measured frequency response function, find the resonance frequency and damping ratio by curve-fitting with one degree of freedom.

(Example 1) Polyethylene terephthalate having a relative viscosity of 1.37 and polyethylene terephthalate having a relative viscosity of 1.22 were mixed in a side-by-side type at a ratio of 1: 1 to obtain a hollow ratio of 16.1%, a fineness of 13 denier, and a cut. Long 5
1 mm hollow conjugated polyester fiber (A) 8
A core-sheath composite with a fineness of 4 denier and a cut length of 51 mm, containing 0% by weight, a copolyester having a melting point of 110 ° C. (terephthalic acid / isophthalic acid = 60/40) as a sheath component, and polyethylene terephthalate having a melting point of 257 ° C. as a core component. 20% by weight of the fiber (B) is mixed with an opening machine and carded, and then two kinds of webs are manufactured with a cross layer,
Continuously pass through a far infrared heat treatment machine at 130 ° C. for temporary fusion to give a basis weight of 500 g / m ² , a thickness of 80 mm and a density of 0.
00625g / cm ³ (L) and basis weight 400 g / m ^2, to obtain a thickness 20 mm, density 0.02 g / cm ³ the web (H).

The obtained web is cut into a width of 1 m and a length of 2 m, a web of H and a web of L are piled up as shown in Table 1, and the upper and lower sides thereof are sandwiched by a porous stainless steel plate and set in a steam pot.
After reducing the pressure to 0 mmHg, 3 kg / cm ² of steam was blown in, and heat treatment was performed at 130 ° C. for 10 minutes. Next, the steam inside the steam pot is extracted again with a vacuum pump, and the entangled portions of the fibers are fused and integrally molded into 100 cm × 200 cm ×
An 8 cm cushion material was obtained. Table 1 shows the vibration characteristics of the obtained cushion material and the conventional urethane foam cushion material and the compression characteristics of the mattress.

[0021]

[Table 1]

As can be seen from Table 1, the cushioning material of the present invention is excellent in the damping effect especially in the low frequency vibration region and the compression characteristic as the mattress. Also,
The cushioning material of the present invention showed flame retardancy equivalent to the performance test standard of flameproof products.

(Example 2) A hollow conjugate polyester fiber (A) and a core-sheath type composite fiber (B) which are the same as in Example 1 except that the fineness is 20 denier are obtained in the same manner as in Example 1 and have a basis weight of 500 g. A web having a thickness of 80 mm / m ² , a thickness of 80 mm (L), a basis weight of 480 g / m ² , and a thickness of 20 mm (H) was obtained.

The obtained web is cut into a width of 1 m and a length of 2 m, and 10 H webs (I
I), 2 L webs (III), 10 H webs (IV), and 1 L web (V) are successively stacked on top of each other, and the upper and lower parts are sandwiched by porous stainless steel plates and shown in Table 2. The heat treatment was performed with the set values set as targets. That is, set the laminated web in a steam pot, reduce the pressure to 750 mmHg, and then
A steam of g / cm ² was blown in and heat treatment was performed at 130 ° C. for 10 minutes. Then, the steam inside the steam pot is extracted again by the vacuum pump, and the entangled portions of the fibers are fused and integrally molded.
A fiber assembly having a size of 00 cm × 200 cm × 32 cm was obtained.
Then, the fiber assembly was horizontally sliced at the central positions of the II, III, and IV webs to obtain four cushion materials (1 to 4) having a thickness of 8 cm. Table 2 shows the physical properties of the obtained cushion material. Further, the resonance vibration characteristics of the obtained cushion material were 7.38 Hz and the damping ratio was 3.64, which showed the flame retardancy corresponding to the flammability standard of the material for railway vehicles.

[0025]

[Table 2]

As is clear from Table 2, all of the four obtained cushion materials satisfy the physical properties of this cushion material.

[0027]

EFFECT OF THE INVENTION The cushioning material of the present invention has little settling, uniform density and hardness, and is excellent in damping effect in the low frequency vibration region. Therefore, it is extremely useful to use the cushion material for seats and beds of cars and ships. Further, according to the method of the present invention, the cushion material can be efficiently manufactured.

Claims (2)

[Claims] 1. A polyester-short fiber (A) and a core-sheath type composite short fiber (B) in which a sheath has a low melting point component having a melting point lower than that of the core by 30 ° C. or more (B) and are three-dimensionally continuous. In a short fiber aggregate having a thickness of 50 mm or more in which the entangled portion of fibers is fused by melting of the sheath portion of the core-sheath type composite short fiber, the short fiber aggregate has an average density of 0.03 g / c.
a high density layer of m ³ or more and 0.05 or less g / cm ³ , and 0.0
A low-density layer of 1 g / cm ³ or more and less than 0.03 g / cm ³ is laminated, and the density variation range of each layer is ± 5.
% Or less, a vibration damping cushion material. 2. A polyester sheath short fiber (A) and a core-sheath type composite short fiber (B) in which a sheath has a low melting point component having a melting point lower than that of the core by 30 ° C. or more are mixed to obtain a density of 0.018 to 0. 03
High density web (H) of g / cm ³ and density 0.0025 ~
A low density web (L) of 0.0074 g / cm ³ is produced, and a high density layer web composed of a plurality of the high density webs (H) and a low density layer web composed of the low density webs (L) are prepared. A method for producing a vibration-damping cushioning material, which comprises alternately laminating a plurality of times, subjecting the laminate to steam heat treatment under compression to fuse the layers, and then slicing the laminate in the laminating direction.