JPS63315654A - Production of nonwoven sheet - Google Patents

Abstract

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

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to improvements in the manufacturing method of nonwoven sheets.

<Conventional technology> In recent years, with the development of various binder fibers, the drying process that was necessary when using a sizing agent has become unnecessary, reducing power costs, increasing production speed, and lowering manufacturing costs. As a result, nonwoven fabrics using binder fibers have come to be widely used. These manufacturing methods include a thermal calendaring method, a hot embossing method, and a method using a conveyor heating chamber.

<Problems to be Solved by the Invention> The thermal calendaring method described above generally has the disadvantage of producing 2 vapors, the thermal embossing method has a limit to the thickness that can be processed, and the method using a conveyor and heating chamber has poor heating efficiency. It also had the disadvantage of temperature unevenness and difficulty in controlling shrinkage. The purpose of the present invention is to solve the above-mentioned problems with the prior art, and to provide a method that is inexpensive, easy, and highly flexible, and can form metal fibers or metal-plated fibers into sheets without impairing their performance. It's about doing.

Means for Solving the Problems> The present invention provides a method for manufacturing a nonwoven sheet using a fiber aggregate containing low-melting point synthetic fibers, in which the fiber aggregate is held between a pair of endless belts and bonded under heat and pressure. This is a method for manufacturing a nonwoven sheet characterized by:

The low melting point synthetic fiber (binder fiber) used in the present invention is
Examples include polyolefin fibers such as polypropylene fibers and polyethylene fibers, composite spun fibers of polypropylene and polyethylene, and low-melting point polyester fibers. The weight ratio of binder fibers to be mixed depends on the strength design of the resulting nonwoven fabric sheet, but is generally 5 to 50% by weight. The endless belt is preferably made of thin stainless steel plate or made of heat-resistant fiber fabric such as Kepler coated with Teflon. The gist of the present invention is to heat and pressurize a fiber aggregate containing binder fibers while gripping them with the endless belt to obtain a nonwoven fabric sheet. First, since the fiber aggregate is heated while being closely held by the upper and lower endless belts, the heating efficiency for the fiber aggregate is extremely good. The general method of heating is to heat the upper and lower endless belts from inside each one using various electric heaters through each endless belt.

In addition, the gripping force is 10 to 100 P to grip and pull out a polyester film with a thickness of 0.1 rn.
/50 rtrx width. Furthermore, in the press-bonding method, a pressure roll may also serve as a drive roll on each inner side of the upper and lower endless belts.

In addition, the edge pressure for pressure bonding is one of the characteristics of the nonwoven sheet obtained by the method of the present invention.
Alternatively, since a fiber aggregate containing plated fibers can be made into a sheet without damaging the fibers, the ep pressure is substantially 0.5 to 0.5.
The assembly is thermocompressed at a pressure of 10 kg/cm.0.5
kl? If it is less than /cm2, the resulting nonwoven sheet will have poor shape retention due to insufficient pressure and is not practical. Also, 1o
If it exceeds kg/α2, the resulting nonwoven fabric sheet becomes paper-like and lacks flexibility, and furthermore, fibers with hard fiber surfaces such as metal-plated fibers are undesirably deformed.

The metal fibers and metal-plated fibers used in the present invention are not particularly limited, and metal fibers such as copper, brass, and stainless steel with a fiber length of 10 mm or more are preferred. The metal-plated fibers may be plated fibers obtained by a method generally called chemical plating, and the metal coating used is copper, nickel, silver, or the like. Metal fibers, metal plated fibers, and mixtures of metal fibers and metal plated fibers can be used. The metal or plated fiber is mainly used as a countermeasure against static electricity or electromagnetic waves. Therefore, the metal and/or plated fiber is 1
It is essential that the fiber aggregate contains ~95% by weight.

If it is less than 1%, the aforementioned measures will not be effective, and if it exceeds 95%, the binder fiber ratio will decrease and the strength of the resulting nonwoven sheet will decrease significantly, which is not preferable. It may be made of three materials: the metal fibers and/or plated fibers, other ordinary fibers, and binder fibers as long as the weight percentages are within the above-mentioned range.

Although both filaments and short fibers can be used as the fiber aggregate used in the present invention, it is preferable to mainly use a carded web of short fibers because binder fibers can be used widely and easily.

The present invention will be explained in more detail below using Examples.

<Example> Using a worsted roller card (not shown), the following fiber aggregate (11) was prepared, and the upper and lower endless belts (2),
(2'), heating section (3)l (3'), heating roller (4), (4') and drive roller (5)l (
A nonwoven sheet (8) was manufactured under the following conditions using the illustrated processing machine (7) consisting of (5'), (6), and (6'). Fiber aggregate (1) is 30% by weight of conductive acrylic fibers chemically plated with 20i% of copper on 2d×51m of acrylic fibers, and 50% by weight of regular acrylic fibers of 3d×51s+m.
, and composite low melting point fibers of polypropylene and polyethylene (melting point 130°) 3dX64mm 20% by weight, the whole is a parallel web, and 43 P/i (
design).

Further, the conditions of the processing machine (7) were as follows.

B) Endless belt (2), (2'): Material Kepler fabric/Teflon coat, thickness 0.5", 1000 beads during processing (1 opening, heating section (3) t (3'): Heat source rod-shaped electric heater Heating section width 1000 mm x length 500 mm Pressure roll (4), (4'): length 1200 mm
Processing method using mX roll diameter 100 + mφ heat-resistant synthetic rubber-wrapped roll (one-sided air cylinder) Processing speed: 20ff! /min (E) Pressure roll pressure = 2 Yu/d H → Endless belt surface temperature (before pressure section) = 180
Non-woven seam 8) manufactured under conditions of °±5°C or above has a basis weight of 40,5
, P/m' (actual measurement), specific volume 0.23/7cm
It was flexible and had good electromagnetic shielding effect with no damage to the plated fibers.

<Effects of the Invention> As described above, according to the method of the present invention, flexible sheets with few processing irregularities and sheets containing metal fibers that are easily deformed by pressure and plated fibers whose surfaces are easily damaged can be easily produced. It has a special effect in that it can be manufactured.

[Brief explanation of drawings]

The figure is a schematic diagram of an apparatus for carrying out the method of the invention. 1 Fiber aggregate 2.2' Endless belt 3.3' Heating part 4.4' Pressure roller 5, 5', 6. 6’ Drive roll 7 Processing machine 8 Non-woven sheet 9 Winder

Claims (3)

[Claims] (1) A method for producing a nonwoven sheet using a fiber aggregate containing low-melting point synthetic fibers, which is characterized in that the fiber aggregate is held between a pair of endless belts and bonded under heat and pressure. manufacturing method. (2) Ep pressure during pressure bonding is 0.5 to 10 kg/cm^
2. The method for manufacturing a nonwoven sheet according to claim (1). (3) The method for producing a nonwoven sheet according to claim 1, which uses a fiber aggregate containing 1 to 95% by weight of metal fibers and/or metal-plated fibers.