JPS58109667A - Production of laminated nonwoven web - 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 The present invention relates to a method for manufacturing a laminated nonwoven web, and more specifically to a method for manufacturing a laminated nonwoven web in which nonwoven webs with no difference in melting point are laminated. To efficiently provide a laminated nonwoven web that has an extremely excellent feel like thin felt and has excellent elongation in the lateral direction.

Nonwoven webs obtained by various means, including nonwoven webs called spunpond or carded webs, have a high tensile strength in the machine direction, that is, a high tensile strength in one direction, but a high tensile strength in the other direction. The tensile strength in the direction was extremely weak. In addition, the thickness of the nonwoven web is not very thick, and therefore, the use of nonwoven fabrics is limited by these limitations.

In view of these points, the inventors of the present invention have found that it is not possible to significantly strengthen the tensile strength of a nonwoven web, especially the tensile strength in the direction where it is extremely weak, and to form a web with a desired thickness, and that the feel of the nonwoven web is similar to that of cotton flannel. By providing a manufacturing method that can easily produce a nonwoven web that is extremely similar to the above and almost unchanged, we have conducted extensive research and conducted various experiments and experiments in order to broaden the range of new uses for nonwoven webs. As a result of stacking the fibers, the fibers are softened by heat and exhibit bonding properties.The entire fiber or these fibers are composed of at least two or more layers, and are made of a plurality of longitudinally oriented webs obtained from card, garnet, etc. They are stacked to form a laminated nonwoven web, and after needle punching is performed from one side of the laminated nonwoven web to the extent that it almost penetrates, there is a temperature difference between the embossing roll and the lower roll. , the embossing gelol can best achieve its purpose by performing binpoint embossing on the needle-punched surface of the laminated nonwoven web at a temperature near the melting point of the fibers of the nonwoven web. This is the result of the present invention.

The nonwoven web used in the present invention is suitably a nonwoven web made of thermoplastic synthetic fibers such as polyester, nylon, polypropylene, polyethylene, etc. These nonwoven webs are nonwoven webs that are aggregates of short fibers. The web is a non-woven web made of long fibers.
A nonwoven web obtained by any manufacturing method is preferably used regardless of the manufacturing method.

In the present invention, the nonwoven web is laminated to form a laminated nonwoven web having a desired thickness, but the nonwoven web to be laminated is not limited to two layers, but may optionally have three or more layers. . Further, when laminated, one nonwoven web and another nonwoven web to be laminated thereon may be the same nonwoven web, or may be different nonwoven webs.
In other words, it is of course possible to laminate nonwoven webs made of the same material by the same manufacturing method, but it is also possible to laminate nonwoven webs made of different materials, such as polyester and nylon, together. Often, nonwoven webs that are completely different in terms of materials and other conditions may be laminated together; It is necessary that there be no difference in the melting points of the fibers constituting the nonwoven webs. The fact that there is no difference in the melting points of the fibers that make up this nonwoven web is natural if the melting points of the nonwoven webs to be laminated are the same, but there is a slight difference in the melting points between the nonwoven webs. There is no problem.

In the present invention, there is no problem even if there is a difference in the fineness of the fibers constituting the nonwoven webs between the laminated nonwoven webs, but a nonwoven web composed of fibers with a thicker fineness is rich in bulkiness. Although it has an advantage, it is difficult to perform Bin Point Heat Embossing, so needling is performed from the side of the thin nonwoven web of fibers, and Bin Point Heat Embossing is applied to this side, that is, the side of the thin nonwoven web of fibers. It is better to apply

In the present invention, the needle punching density applied to the laminated nonwoven web is 100/♂~2
It is desirable that the number is about 50 needles/♂, and when needle punching, it is necessary to punch the needles until they penetrate the lower end of the laminated nonwoven web. It strengthens the bond between each layer of the laminated nonwoven wave, improves the delamination strength, and also contributes to improving the horizontal tensile strength of the web, resulting in a favorable raised appearance on the lower end surface of the nonwoven web. It is something.

In the present invention, when laminating the nonwoven webs, a small amount of thermoplastic synthetic resin may be sprinkled on the surface of the nonwoven webs. Furthermore, for example, before stacking multiple layers of thin webs from cards to obtain a web of a desired thickness, there are cases where the thin webs from cards are wound as they are. The web may also be provided with a very small amount of adhesive to aid in holding it.

As the adhesive at this time, it is preferable to use, for example, a relatively hard thermoplastic synthetic resin.

In the present invention, since pinpoint heat embossing, which will be described later, must be performed on the needle-punched surface of the laminated nonwoven web, the needle-punched surface of the laminated nonwoven web must be Since the surface effect produced by point heat embossing appears, and the other side exhibits an extremely favorable raised effect by needle punching, which side of the finally obtained laminated nonwoven web should be used? Accordingly, various conditions must be set, including the selection of the material of the nonwoven web of each layer to be laminated.

Pinpoint heat embossing in the present invention is performed only on one side of the laminated nonwoven web, but this pinpoint heat embossing must be performed in a state where there is a temperature difference between the upper and lower surfaces of the laminated nonwoven web. .

This is usually done by heating one side of the roll, in which case the pinpoint heat embossing roll is heated while the lower roll is cooled or
It is necessary to maintain a temperature difference between both rolls, either at room temperature or controlled to maintain a constant temperature. In these cases, the temperature of the bin point heat embossing roll needs to be around the melting point of the live fibers, more specifically, the melting point is equal to or higher than 95°C.

Note that the lower roll used in the present invention may be any roll such as a flat roll or an uneven roll.According to the method of the present invention, by laminating the desired number of manufactured nonwoven webs, a single sheet suitable for various uses can be obtained. Not only can it be easily made into a laminated nonwoven web, but the laminated nonwoven web can be firmly bonded to such an extent that there is no concern about delamination, and the tensile strength in the horizontal direction can be strengthened to an extent that can withstand practical use. In addition, an extremely favorable raised effect appears on the penetrating surface due to needling, and combined with the surface effect due to pinpoint heat embossing on the surface, the overall result is a laminated nonwoven web with an extremely soft feel of cotton nelp. For example, it is easily obtained as a base fabric for poultices, and it is also an extremely preferable material for synthetic leather, leather base fabrics, and industrial materials for interior decoration. .

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 A web with a web weight of 18.9/m2 was made of 70 inches of rayon with a single yarn fineness of 3d and a fiber length of 51cm and 30 inches of 6-nylon with a single yarn fineness of 3d and a fiber length of 51cm using recycled garnet. 7 sheets were laminated. This laminated nonwoven web was punched at a density of 1 with #40 regular barb needles.
Needle punching was performed at a rate of 20 punches/cm'', then the upper roll had a bin point of 10 points/inch both vertically and horizontally, and the surface temperature was 205°C, and the lower roll was a flat roll with a surface temperature of 55°C, and the roll gap was Pinpoint heat embossing was performed by passing it through a pinpoint embossing roll whose temperature was set to 0.05.

The web obtained in this way can laminate a desired number of extremely thin webs made of garnet without any delamination, and the web as a whole does not stretch in the vertical direction but stretches in the horizontal direction with pinpoint engraving. The surface effect due to botting was also good and the product had an extremely soft feel.

Example 2 A 60-inch piece of rayon with a single yarn fineness of 3 d and a fiber length of 51 mm and a 40-inch polyester fiber with a single yarn fineness of 3 d and a fiber length of 51 mm were combined using an isomizer (manufactured by Brocter & Schwartz).
A web with a web volume of 7 m2 was prepared using the same method, and the web was impregnated with the acrylic acid ester resin dispersion of Koga and dried. Tsutsuisha set the solid content to 5 parts by weight per 100 parts by weight of fiber. Two sheets of this web were laminated, and this laminated nonwoven web was subjected to needle punching in the same manner as in Example 1. The bottom roll is a flat roll with a surface temperature of 55°C, and is passed through a bin point embossing roll with a roll gap of 0.058 for pinpoint heat engraving. Botching was applied. The web thus obtained was substantially similar to the web obtained in Example 1.

In Examples 1 and 2, a plurality of thin sheets are combined to form the desired thickness, and the overall result is a sheet that does not stretch in the vertical direction, but stretches in the horizontal direction, and has an extremely soft feel. A certain web could be produced industrially and efficiently.

Patent applicant: Dynic Co., Ltd.

Claims (1)

[Claims] It consists of all or at least 20 fibers that soften by heat and exhibit bonding properties, and is a card,
A plurality of longitudinally oriented webs made of garnet or the like are laminated in the longitudinal direction to form a laminated nonwoven web, which is needle punched from one side of the laminated nonwoven web to the extent that it almost penetrates, and then embossing gel roll is formed. and the lower roll, and the embossing roll is applied at a temperature approximately near the melting point of the fibers of the nonwoven web to the needle-punched surface of the laminated nonwoven web. A method for producing a laminated nonwoven web characterized by subjecting it to heat embossing