JPS61282464A - Production of perforated nonwoven fabric - 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 Field of Application) The present invention relates to a method for continuously producing a perforated nonwoven fabric.

(Prior Art and its Problems) Conventionally, there is a known method of manufacturing a perforated nonwoven fabric by sandwiching a web containing hot gJi fibers between templates having predetermined uneven parts and subjecting the web to heating and pressure treatment. For example, it is disclosed in Japanese Patent Application Laid-Open No. 50-95566.

The perforated nonwoven fabric produced by this method is highly flexible because the holes are distributed over the entire surface of the fabric, allowing it to absorb the distortion that occurs in the fabric, and it is essentially film-like like a partially heat-sealed nonwoven fabric. Since there are no parts, the texture is soft.

Moreover, since the fibers around the holes are thermally fused, the strength of the cloth is maintained sufficiently, and the fibers do not come out from around the holes or cracks occur.

However, since the above method uses templates, it can only be produced intermittently, and the heat and pressure are applied for a long time, so the fibers that make up the nonwoven fabric are subject to repeated deterioration such as melting, deformation, and cutting. However, there were drawbacks such as a hard texture on the entire surface and a decrease in durability.

Therefore, the present inventor attempted to continuously produce a perforated nonwoven fabric by using an embossing roll instead of a plate, but the roll and web were formed near the tangent line between the rolls.
Since the contact was only for a very short time, the fibers could not be easily cut and holes could not be formed unless the Ai temperature and high pressure were applied. Therefore, the manufacturing disadvantage of deterioration of the fibers constituting the nonwoven fabric has not yet been resolved.

(Objective of the Invention) The present invention was made in order to eliminate the drawbacks of the prior art, and its purpose is to provide a method for continuously producing thermo-CV plastic fibers around the holes without deteriorating them. shall be.

(Structure of the Invention) The present invention heats and presses a web made of thermoplastic fibers with a single fiber strength of 1.0 to 4.0 g/d using a pair of rolls made of embossing roll/L/door roll.
This method of manufacturing a perforated nonwoven fabric is characterized by forming curved holes in the web and simultaneously heat-sealing fibers around the through holes to each other.

The heat=iT plastic fibers used in the present invention pass through polyester fibers, polyolefin fibers, polyamide fibers, polyacrylonitrile fibers, etc., and the single fiber strength must be in the range of 1.0 to 4, ON/d. Must be. This is because the normally used single fiber strength is 4. If the fiber exceeds OF/d, the fiber cannot be easily cut by the calyx cutting force that is applied during heating and pressure treatment using embossing rolls and flat rolls, and fibers other than those around the holes may deteriorate. This is because the pores cannot be formed properly unless the temperature and pressure are high.On the other hand, when the single fiber strength is 1. This is because, although pores can be easily formed using fibers with oy/d droplets, the strength of the resulting nonwoven fabric is low, resulting in fiber breakage and insufficient durability. Especially preferred single fiber strength is 2.0~
3. OAl/d.

A web is formed using the fibers described above by a known dry method or wet method. After this, the web is heated and pressurized using a pair of enphos rolls and flat rolls, Oa-71/.In order to make it easier to form through holes, the web is given viscous shielding properties when heated and pressurized. The resin or rubber shown may also be used. That is, if the above-mentioned resin or rubber is provided, the punched pieces can easily form a layer on the roll surface, thereby improving the punching performance. The above resin or rubber includes polyacrylic acid ester thread resin, ethylene-
C-vinyl resin, vinyl acetate thread resin, NBR, 8BR, etc. can be used, and those exhibiting tackiness depending on the heating and pressing conditions may be appropriately selected and used. However, the above-mentioned resin or rubber is not used for the main purpose of binding fibers, and if applied too much, the texture of the non-woven fabric will become hard and the flexibility will be inhibited. % or less (solid content is the coating amount).

The web obtained by the above procedure is heated and pressurized using a pair of rolls consisting of an embossing roll and a flat roll.

7111 The heat pressing conditions vary depending on the ui fiber used, but if the temperature is within the range of the softening point and melting point (or decomposition point) of the fiber used, and the linear pressure is within the range of 10 to 100 Kp/3, Holes can be easily formed without deteriorating fibers other than those around the holes.

Furthermore, if the temperature of the flat roll is set higher than the temperature of the embossing roll, the FJ scraps will adhere to the flat roll inadvertently. This is because if you don't clean it in this way, debris will accumulate on the Enphos Roll.
Its removal is so difficult that production is interrupted.''
This is because it is possible.

The uneven pattern of the embossed roll coating is not particularly limited, but it is preferable that the unevenness pattern of the embossing roll is uniformly distributed in a predetermined shape such as linear, dotted, circular, or quadrilateral. Immediately minimize the occurrence of temporary debris and nr
Direct flexibility I! μ-shaped protrusions may be used to obtain IE. Furthermore, when a single column in multiple directions is to be simulated, it is effective to use a pattern in which the linear convex portions are differentiated to cross each other, or a pattern in which the linear convex portions are distributed in a zigzag pattern.

The ratio of the convex area to the surface area of the roll (or the ratio of the hole area to the nonwoven fabric area) is 3 to 50%.
Good. This is because if the thickness is reduced by 50%, the number of holes and the number of thermal shields will decrease, resulting in a decrease in both flexibility and strength.

The ratio of the convex area to the roll surface deviation that is immediately preferable is 5.
~30%.

The above-mentioned manufacturing method yields a perforated nonwoven fabric in which the fibers in areas other than those around the holes are not substantially degraded, but in order to perform continuous production over a long period of time, it is necessary to add a step to remove punched pieces generated during manufacturing. Good. To remove the punched pieces, the temperature of the flat roll is made higher than the temperature of the embossing roll, and the punched pieces are preferentially removed by 1 inch r from the flat roll.
A better method is to let it dry and then peel it off from the flat roll. In order to remove the punching pieces pickled in vinegar from the flat roll, it is easy to contact the roll with a cleaning member such as a blade. Since it is conceivable that the blanks may not be easily accommodated, it is preferable to transfer the punched pieces from a flat roll to a flat roll or belt and then clean the roll or belt with a cleaning member.

(Examples and Comparative Examples) Example 1 Polyester fibers with a single fiber strength of 2.6 II/d were made into a web with a basis weight of 30 g1/d by the carding method, and this was made into a web with a basis weight of 30 g1/d.
I-shaped convex area 1 having a uniformly distributed pattern
2% embossing roll.

Emboss roll with a flat roll or a pair of rolls/M! 198 °C1 flat roll lhI
,! A perforated nonwoven fabric was obtained by heat and pressure treatment under the conditions of X200'c and -pressure of 60 to 1.

The resulting perforated nonwoven fabric had a soft feel and good flexibility, and had sufficient strength and bendability, with fibers outside the pores showing no signs of deterioration.

Comparative Example The procedure was the same as in Example 1 except that polyester fibers with a single fiber strength of 4.8 Jl/d were used. However, the holes were not formed well and the portions that were supposed to be holes were made into a film. I stayed.

Implementation I! AJ2 Single fiber @ 3.2jl/d of polyester fiber is made into a web with a basis weight of 30g/d by the carding method, and then an acrylic emulsion containing butyl polyacrylate as a soil component is produced.
The web is impregnated with a solid mass (3 N/~) and dried at 110°C so that the resin is in an uncured state, and then this web is formed into a convex inner bond having a pattern in which rectangles are distributed like 1,000 J4 tops. A pair of rolls consisting of a 20% embossing roll and a 7 rat roll, ntArK 190°C, linear pressure 25
A perforated non-woven fabric 1 was obtained by heat and pressure treatment under conditions of Kp/.

At this time, although the temperature and pressure conditions were lower than in Example 1, the punched piece was easily removed and a clean spherical hole was formed. The resulting perforated non-woven fabric was slightly soft in texture and malleability.
fi, was inferior to that of Example 1, but superior in strength and rigidity.

In addition, since the punched pieces that were forged on the flat roll were transferred to the transfer roll and then cleaned up with a blade, there was no problem such as the punched pieces piled up on the flat roll or embossing roll and production could not be performed. , stable continuous production was possible.

(Effect of the invention) Hereinafter, as shown in H, in the present invention, the single fiber strength is 1.0 to 4.
．． Since the web made of 0g1/d heat-resistant fiber is heated and pressure treated with a pair of rolls consisting of an embossing roll and a flat roll, it can be easily processed under heat and pressure conditions that do not deteriorate fibers other than those around the holes. can be completely formed.

Therefore, according to the present invention, the fibers around the holes are heat-shielded and have strength, and the perforated nonwoven fabric is soft in one heat exchange. It is the ability of rTf to continue producing iI.

2. The perforated nonwoven fabric manufactured by the present invention has strength,
It is durable and has a soft texture, so it can be used for many purposes, but it is particularly flexible, so it is printed on 15C interlining.

Claims (1)

[Scope of Claims] 1. A web made of thermoplastic fibers having a single fiber strength of 1.0 to 4.0 g/d is subjected to heating and pressure treatment using a pair of rolls consisting of an embossing roll and a flat roll, so that the web is A method for producing a perforated nonwoven fabric, which comprises forming through holes and simultaneously thermally fusing fibers around the through holes to each other. 2. The method for producing a perforated nonwoven fabric according to claim 1, wherein the web is coated with a resin or rubber that exhibits tackiness during heating and pressure treatment, and then subjected to heating and pressure treatment using the pair of rolls. 3. The method for producing a perforated nonwoven fabric according to claim 1, wherein the temperature of the flat roll is higher than the temperature of the embossing roll.