Elastic woven or knitted fabric, and cushioning material and seat using the same

Abstract

The present invention relates to an elastic woven or knitted fabric that has an elastic yarn comprising an organic synthetic macromolecule disposed in at least part thereof, and has the following physical properties: (1) a stress at 10% elongation in a range of 100 to 600N per 5 cm width in at least one of a warp direction and a weft direction, and an elongation recovery factor at 15% elongation of at least 75% in the same direction; (2) a ratio ST1 / ST2 of not more than 5, wherein ST1 is the stress at 10% elongation in one of the warp and weft directions, and ST2 is the stress at 10% elongation in the other one of the warp and weft directions, with the proviso that ST1>=ST2; and (3) a dry heat shrinkage factor at 180° C. in a range of 1.0% to 15% in each of the warp direction and the weft direction.

Description

[0001] The present invention relates to a woven or knitted fabric having excellent strength and elastic recoverability or a pleasant air permeability, and to a cushioning material, a chair-covering fabric and various types of seat using the woven or knitted fabric.DESCRIPTION OF THE RELATED ART[0002] Urethane foam, polyester fiber wadding, resin cotton or solid cotton having polyester fibers bonded thereto, and so on have conventionally been used as cushioning materials for furniture such as chairs, beds, seats for transportation machinery such as automobiles and trains, and so on. To obtain pleasant properties as a cushion, many materials used are devised in various ways, for example by combining materials having different cushioning abilities to one another, or by adopting a duplex structure when forming the cushion. However, all of these cushioning materials have had problems such as being bulky or it being impossible to obtain a material having a good cushioning ability with a s...

AI Technical Summary

Benefits of technology

[0033] There are no particular limitations on the raw materials of the elastic yarn comprising an organic synthetic macromolecule used in the present invention; nevertheless, the raw materials can by selected, for example, from ester-based resins, urethane-based resins, olefin-based resins, styrene-based resins, amide-based resins and so on; to obtain the strength, ability to recover after elongation and so on required of a woven or knitted fabric for seats, an aromatic polyester, for which an aromatic carboxylic acid and a glycol can be used as principal raw materials, is preferable. Furthermore, a polyester elastic yarn obtained by copolymerizing polybutylene terephthalate and polytetramethylene glycol is more preferable, since the ability to recover after elongation is good.

[0035] It is advantageous to use an elastic yarn comprising at least two polyether-ester-based elastomers having different melting points to one another as the elastic yarn in the present invention, since in this case, through carrying out heat treatment, a polyether-ester-based elastomer having a low melting point melts and resolidifies, whereby it becomes possible to carry out yarn fixing at points of intersection in the woven or knitted fabric, with the elastic modulus of a polyether-ester-based elastomer having a high melting point being maintained as is. Moreover, when the heat treatment has been carried out on the elastic yarn comprising polyether-ester-based elastomers having different melting points to one another, because the low-melting-point polyether-ester-based elastomer, which is flexible and has excellent elastic recoverability, fuses and solidifies at points of intersection between the warp and the weft in the case of a woven fabric or points of intersection between the yarns constituting the fabric in the case of a knitted fabric, strong yarn fixing can be obtained without there being a deterioration of the strength, elastic recovery factor and so on of the woven or knitted fabric.

Problems solved by technology

However, all of these cushioning materials have had problems such as being bulky or it being impossible to obtain a material having a good cushioning ability with a small volume.

Moreover, the air permeability greatly influences the comfort when seated, but with conventional cushioning materials such as urethane foam, polyester fiber wadding, and resin cotton or hard cotton having polyester fibers bonded thereto, there has been a limit to how much the air permeability can be increased.

There will be no problems with the mechanical properties such as the ability to recover after elongation even if the elastic yarn is a multifilament yarn, but the durability may be poor due to the resistance to friction being low.

At below 100 dtex, the resistance to friction will be low and it may not being possible to obtain sufficient durability, whereas at above 6000 dtex, handling during manufacture of the woven or knitted fabric will become difficult.

If the sliding resistance is less than 2N, then yarn slippage and fraying will occur, which is undesirable.

If the breaking strength is less than 250N per 5 cm width, then the woven or knitted fabric may break through the load to which the surface is subjected during use as a cushioning material, which is undesirable.

At less than 100N per 5 cm width, the sinking amount during use as a cushioning material will be large, and during use as a seat in particular there will be discomfort when seated.

On the other hand, at above 600N per 5 cm width, the sinking amount when used as a seat will be too low, and hence aching will arise while seated, and thus it will not be possible to tolerate prolonged usage.

If the elongation recovery factor determined in this way is less than 75%, then wrinkles will arise during use as a cushioning material, which is unsuitable from the perspective of the external appearance and the feeling when seated.

Moreover, if the dry heat shrinkage factor is greater than 15%, then the dimensional stability will be poor, leading to problems in handling in subsequent manufacturing steps.

When used as a cushioning material, if the air permeability is less than 100 cc / cm.sup.2.multidot.sec, then a feeling of stickiness will be prone to arising upon sitting for a prolonged time, and moreover once the cushioning material has become damp it will not dry easily, and hence there will be a problem from the perspective of hygiene.

On the other hand, if the air permeability is greater than 700 cc / cm.sup.2.multidot.se-c, then the flow of air will be prone to becoming too great, and hence there will be a problem from the perspective of warmth retention.

This is because if ST1 / ST2 is greater than 5, then one of the warp yarn and the weft yarn will be subjected to an excessive load, and hence permanent set in fatigue will arise in the yarn subjected to the excessive load, and thus there will be a large drop in performance.