JPS6385154A - non-woven fabric - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention is lightweight and has high tensile and tear strength.
Shining on non-woven fabric.

The present invention is a nonwoven fabric that prevents the significant decrease in strength and nonuniformity of thickness that occur when the basis weight of the nonwoven fabric is reduced.

The present invention achieves significant light weight loss and cost reduction in nonwoven fabrics containing scrims.

(b) Conventional technology There are many known methods for manufacturing nonwoven fabrics, but in order to improve the uniformity of the thickness, it is common to use as many fibers as possible to feed the fiber web. It is believed that there is no better solution than to supply the fiber in portions of 100 ml and to increase the number of times the fiber web is overlaid so as to average the thickness.

However, supplying fiber little by little and spreading it by one amount is
This is a difficult technology considering the cost. Feasible techniques include a method in which the sliver is stretched using a cloth roller, and a method in which the spun threads are stretched and spread by air currents without being substantially aligned, but these methods do not allow for overlapping. A piece of fiber in front of me
It is extremely difficult to make one layer uniform with a thickness of 10 gems or less.

The strength of non-woven fabrics is
Since there is no woven structure, it relies on adhesion and entanglement between fibers. In the case of a nonwoven fabric that has a strength of t1 by adhesion, if you try to reduce the basis weight, the IJ that can be bonded
Since the strength at t at the intersection of I iff is small, the effectiveness of ti= tends to decrease, and in general, it tends to be difficult to obtain strength unless a large amount of adhesive is used. Increasing the size requires the use of more types of adhesive, so such nonwoven fabrics generally have less elasticity and tend to have a stiff texture, which is an inherent characteristic of nonwoven fabrics with small dates. There is a problem that it becomes inflexible and loses its light appearance.

In addition, particularly in the case of nonwoven fabrics whose strength depends on entanglement between m-phases, the low density of fiber intersections is a major cause of low strength.

When the basis weight is decreased, it becomes difficult to increase the density of fiber intersections, so the strength tends to decrease.

For example, in a needle-punched nonwoven fabric for carpets, which is a typical nonwoven fabric that relies on intertwining between iams, the strength tends to decrease rapidly when the basis weight becomes 350 g/+s'' or less.

In the case of needle-punched nonwoven fabrics, when the needles used for intertwining are made thinner and the punch density is increased, the date at which the strength decreases tends to be slightly smaller, but it is not M7. This is because it is difficult to obtain high strength with a small basis weight unless the fibers are thinned, but thinning the fibers poses many problems in terms of production and processing into a web, and is therefore difficult to achieve.

To solve this problem, a woven fabric called a scrim is inserted into the nonwoven fabric. Although this method has the advantage of improving the Wj stability of the nonwoven fabric, it has the problem of significantly increasing the cost of the nonwoven fabric due to the high cost of the fabric.

In recent years, flat yarn fabrics made from films have come into widespread use as scrims, and the cost problem is seen to have been solved to a large extent. However, it is difficult to make flat yarn fabrics with small openings.
Adding a scrim to a nonwoven fabric with a small basis weight is not often done because it increases the cost.

(c) Problems to be Solved by the Invention The present invention solves the disadvantages of non-uniform thickness and low strength, which are generally recognized in nonwoven fabrics with a small date. It is a non-woven fabric.

(D) Means for Solving the Problems The present invention provides a yarn array consisting of a first polymer arranged substantially parallel to the longitudinal direction, and a yarn array consisting of a polymer having a lower melting point than the first polymer. It is formed by using a network-like structure consisting of one branch to be buried and a large number of other thread rows substantially orthogonal to this branch as a core, and fixing a nonwoven fiber layer to at least one side of the structure. It is a nonwoven fabric characterized by the fact that The lI40-like structure is obtained by extruding a filament array made of a first polymer that is preferably arranged substantially in the longitudinal direction and a film embedding the filament array made of a polymer having a lower melting point than the polymer. After the film is embossed to form lines that are substantially perpendicular to the extrusion direction, it is stretched on two wheels. 2 constituting the reticulated tllI structure
Although the seed threads may be monofilament-like, it is preferable that they are fibrillated into several fibrils, and preferably have irregular wavy lines or fluff.

It is preferable that the first polymer and the low melting point polymer are not miscible with each other during the manufacturing process of the network structure.It is preferable for the stability of two-wheel stretching that the two polymers have no adhesive property to each other. However, it is advantageous and desirable to have adhesive properties for strength, especially scratch strength.As the first polymer, polyethylene terephthalate,
Polybutylene terephthalate, polyhexamethylene adipamide, polyε-casuamide, polypropylene,
Poly4-methylpentene-1, high grade polyethylene, etc. are used. Examples of the low melting point polymer include a copolymer of the first polymer, polypropylene, polyethylene, polybutylene terephthalate, polyε-casuamide,
etc. are used.

In the present invention, a thread array made of a first polymer arranged substantially parallel to the longitudinal direction used in the core of a nonwoven fabric, and a thin thread array made of a polymer having a lower melting point than the polymer and embedded in the thread array are arranged substantially parallel to the longitudinal direction. There may be one or more mesh-like tRiit objects consisting of a branch and a large number of other thread rows substantially perpendicular to the branch.

In the present invention, the yarn rows made of the first polymer arranged substantially parallel to the longitudinal direction are preferably made of flat yarns when the basis weight of the network structure is small; It is preferable that the surfaces are arranged substantially parallel to the surface forming the network structure.

In the present invention, a thread row made of a first polymer arranged substantially parallel to the longitudinal direction, a thin branch made of a polymer having a lower melting point than the polymer and embedding the thread row, and a thread row made of a first polymer arranged substantially parallel to the longitudinal direction; The non-woven fiber layer, which has a mesh-like core consisting of a large number of different orthogonal thread rows, may be made of any fiber, including cotton, wool, etc. The fibers may be natural fibers such as rayon, acrylic, nylon, or chemical fibers such as polyester, pulp fibers, long fibers, or short fibers.

In the present invention, the methods for fixing the nonwoven fiber layer to the mesh structure include adhesion, fusion, entanglement, etc. , 1, etc., all of the m-male fixing methods used in the production of nonwoven fabrics can be used. When fixing by adhesion or Me, whether by supplying an adhesive from the outside or by mixing heat-adhesive fibers into the nonwoven fiber layer, local melting of the fibers may occur from the outside. In the #s case in which heating may be performed, it is possible to use needle punching, air current entanglement, water flow entanglement, etc. These methods are used to fix the nonwoven fiber layer.
The above can be used in combination. Due to the combination of fixing methods, it is solid! It can make or break the A stage, and has various advantages in processing nonwoven fabrics and performance engineering.

A string of threads made of a first polymer arranged substantially parallel to the longitudinal direction, used in the core of the nonwoven fabric of the present invention, and thin branches made of a polymer with a lower melting point than the polymer and embedding the strings of threads. , and a number of other thread rows that are almost orthogonal to this branch, the net-shaped #1 structure has a thickness of 0.001 (up to)
- to 2.5-m, preferably 0.01-1 to 1.0-m in thickness, yarn row pitch in longitudinal and width directions 0
．． 01m+* to 100m5, preferably 0.1
-Plow to 25-Plow, with a porosity of 10% to 90%. Most preferably, the thickness is 0.1 m to 0.5 mm, and the yarn row pitch is 0.5 to 10.0.
mm, and the opening rate is 25% to 75%. If the thickness is smaller than this range, the strength will be too low, which is undesirable. If the thickness is larger than this range, it is not preferable.

This is undesirable because the non-cotton fabric becomes too stiff.If the yarn row pitch is smaller than this range, the mesh structure will have poor elasticity due to its mesh form, which is undesirable because the fit will become paper-like. If the pitch of the yarn rows is larger than this range, the strength of the portions away from the yarn rows will be low, and the abrasion resistance and bending resistance of the nonwoven fabric will be extremely poor, which is not preferable.

The nonwoven fabric of the present invention preferably has a kissing ratio of 1.5. /-2 to 300g7m", thickness 0.02mm to 5■-
Nonwoven fabrics with a smaller opening than this have low strength and are practically difficult to use, even though they are the nonwoven fabrics of the present invention. Also, those with a larger kiss than this are R1 compared to conventional nonwoven fabrics made of flat yarn m th as scrim. : Thicknesses smaller than this are undesirable because they do not have the following advantages. Thicknesses smaller than this have the disadvantage of becoming paper-like unless they are reduced by compression processing, etc., and are of little value in use.

If the thickness is 5 mm or more, a non-metal structure with a width of less than 300 g/m'' is undesirable because it becomes too bulky and has poor abrasion resistance.

Example 1 About 15.00 molecules of nylon 6 as the first polymer
Polypropylene with an MFR of 4.5 was used as the low melting point polymer, and after extrusion through a linear gouer, the surface temperature [1] was used before the polypropylene solidified.
The material was sandwiched between a gear-like embossing roller and an anvil roller with a flat surface at 55°C to form streaks perpendicular to the direction of travel, and then biaxially stretched to obtain a mesh-like transverse material. This jR structure has a thread density of 8 g/II in the longitudinal direction and 135 threads in the longitudinal direction/too many threads in the width direction, and the thread rows in the width direction are slightly cracked and irregular. It had some fluff.

A carded web (width: 12 g/m') consisting of staples of 15 denier x 38 mm of polypropylene fibers was layered on this mesh structure and entangled with water flow. Water pressure 50kg/am”, nozzle (orifice) diameter 0
．． 15mm, nozzle spacing 2.35-ring, number of nozzle rows 5,
The expansion angle of the water flow was 3°, and the wire mesh that retained the l'II structure during entanglement had a wire diameter of 0.3@m and a wire pitch of 21-.

This treatment was carried out on both sides of the ■■-shaped structure, and the obtained nonwoven fabric had a basis weight of 32 g/m', a thickness of 1°2 crush-1 strength of 6.4 kg (measured at a C1 cm width), and the nonwoven fabric was It had no pores and had a fluffy, uniform appearance. The polypropylene fibers derived from the carded web were well entangled, and both abrasion resistance and washing resistance were good. When this nonwoven horizontal relic was cut into 2.5 cm squares, the weight variation rate was 13.4%.

Comparative Example 1 Three card webs of Example 1 were stacked to form a Kawaguchi-shaped rA.
Entanglement between fibers was carried out using a water stream in the same manner as in Example 1 without using any structure. The obtained nonwoven fabric has a basis weight of 30g
/i', thickness 1.2 m, and strength 2.4 kg (measured by lea width).The basis weight and thickness were not much different from Example 1, but the strength was considerably inferior. This non-woven fabric is 2.5c
The change in weight of the material cut into ++ angles was 25.5%.

Example 2 A polyester fiber web (basis weight: 9 g/m') containing 15z of polyester binder fibers (unstretched type) was layered on both sides of the mesh-like tl ornament of Example 1, and 13
A nonwoven fabric was produced by adhering with hot air at 0''C.The obtained nonwoven fabric had a basis weight of 26 g/+s2, a thickness of 0.9-1, and a strength of 5.4 kg (measured in lc-width).

This nonwoven fabric was less likely to peel off at intervals of m and exhibited excellent performance as a wiping cloth.

Example 3 Polyethylene terephthalate with an intrinsic viscosity of 0.75 was used as the first polymer, and 52 was used as the low melting point polymer.
The surface temperature was 125° before extruding from a straight goo and solidifying.
The lines extending in the width direction are sandwiched between an embossing roller with a gear-like shape and an anvil roller with a flat surface.
Obtained 1 creation. This t,'! Structure weight is 10g/
m'', the density of the yarn in the long hair direction was 220 yarns/cm, and the density of the yarn in the width direction was 1 to 800 yarns/-.

Into this mesh structure, polyethylene synthetic pulp (manufactured by Mikata Petrochemical) was mixed with 10% paper-making vinylon and 1% 15% acrylic binder, layered to a basis weight of 12 g/s', and dried. I then glued it.

The obtained nonwoven fabric had a basis weight of 22 g/a+2, a thickness of 0°8-1, and a strength of 5-5 kg (measured in lc-width).
This relic had an appearance similar to Japanese paper.

Example 4 As the first polymer, nylon 66 with a molecular size of about 15°Ooo is used as a low melting polymer.
A mixture of nylon 6 and low-density polyethylene MFRll, 0 (30% by weight) was extruded through a linear die, solidified, and then flattened with an embossing roller with a gear-like shape at a surface temperature of 205°C. The film was sandwiched between anvil rollers having a uniform surface to form streaks extending in the width direction, and then biaxially stretched. The obtained mesh structure had a mesh size of 25 g/m'', a thread density in the longitudinal direction of 180 threads/11, and a thread density in the width direction of 90,000 mm.

This mesh structure is made of nylon 2 denier x 441
Web consisting of staples (1 piece with opening 28g/+a 2
) were stacked on both sides, and the fibers were entangled by the needle punch method. The obtained nonwoven fabric has a high strength of about tt ml, and has excellent properties such as abrasion resistance and texture. It had 8.

(e) Effects of the Invention The nonwoven fabric of the present invention can be used as a protective sheet for painting, as an outstanding sheet for agriculture, as a light-shielding sheet, especially as a sheet for hanging, disposable wipers, and fresh food. It shows excellent performance when used for packaging single items, etc.

The nonwoven fabric of the present invention can be used as a water-absorbing layer for diapers, sanitary napkins, etc., especially when exposed to extremely harsh 3F coatings, and has excellent strength, abrasion resistance, and bending resistance, and is lightweight and soft. and exhibits excellent quality.

The nonwoven fabric of the present invention exhibits excellent performance as a heat insulating material by stacking a large number of layers.

that's all

Claims (1)

[Claims] A thread row made of a first polymer arranged substantially parallel to the longitudinal direction, a thin branch made of a polymer having a lower melting point than the polymer and embedding the thread row, and a large number of branches substantially perpendicular to the thread row. A nonwoven fabric characterized in that it is formed by having a core body consisting of a mesh-like structure consisting of yarn rows, and a nonwoven fiber layer fixed to at least one side of the structure.