JPS62268861A - Production of 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 [Field of Industrial Application] The present invention relates to a method for producing a nonwoven fabric that is soft to the touch and useful as sanitary materials.

[Prior art]

In the past, spunbond materials such as polyester μ and polypropylene were often used for sanitary materials, especially cover stock materials such as disposable diapers and sanitary napkins, but in recent years short fiber nonwoven fabrics made from heat-fused fibers have become rapidly popular. There is.

On the other hand, cellulose-based spunpond has high water absorption and tends to become sticky, so it is not used as a cover stock material but is used as an internal absorbent material.

In addition, without being limited to the manufacturing method of such nonwoven fabrics, nonwoven fabrics using short fibers of about 1.5 denier are generally manufactured industrially, but they are hard to the touch and the denier is made as thin as possible. It was hoped that the material would be soft to the touch.

[Problem that the invention seeks to solve]

Therefore, attempts have been made to manufacture non-woven fabrics using ultra-fine short fibers such as CL5 denier fibers, but such f@fine denier short fibers are difficult to card and the speed of carding cannot be increased, resulting in low productivity. This has led to problems such as an increase in cost and an economic disadvantage.

The inventors of the present invention have completed the present invention as a result of intensive research aimed at solving the above-mentioned problems.

[Means for solving problems]

In the present invention, splittable conjugate short fibers made of components that are incompatible with each other are made into split fibrils in the step of mechanically crimped after being drawn, and at the same time an oil agent is applied to the resulting splittable conjugate short fibers. After forming the web into a web, a high-pressure liquid stream is sprayed to promote split fibrillation of the fibers and entangle them in an integrated structure.

The present invention will be explained in more detail below.

As a specific example of the cross section of the splittable conjugate fiber according to the present invention, for example, as shown in FIGS. 1(a) to (d), two or more types of incompatible thermal It refers to a cross-sectional shape in which plastic polymer components are arranged alternately, but it is not limited to this as long as it can be distributed into a plurality of fibrils.

In the present invention, the combination of two mutually incompatible thermoplastic polymer components includes, for example, polyester μ and polypropylene, polyester and nylon, and nylon and polypropylene.

The splittable composite fiber used in the present invention is
Undrawn yarn composite-spun by a method known in Japanese Patent Publication No. 36, Japanese Patent Application Laid-open No. 50-5650, etc. is bundled and drawn, and then an oil agent is applied while mechanically crimp is applied, and the yarn is cut into finite fiber lengths. It can be obtained by making short fibers.

In addition, in order to obtain the nonwoven fabric of the present invention, it is preferable to heat-treat the splittable conjugate fibers by an appropriate method such as wet heat or dry heat so that the boiling water surface crushing shrinkage rate is 20 inches or less. This causes distortion due to the difference in heat shrinkage on the contact surface of the seed components, which has the effect of promoting split fibrillation in post-processing.

The thickness of the splittable composite fibers used is approximately 1 to 5 denier, and the denier of the split fibrillated single fibers formed by split fibrillation, which consists of at least one component, is preferably α5 denier or less. more preferably [L3
If it exceeds 115 denier, it becomes hard to the touch and loses its suitability as a cover stock material for sanitary materials in particular.

Furthermore, it is preferable that 20% by weight or more and 80% by weight or less of single fibers or fibers of the splittable composite fibers are completely or partially split by crimping.

If split fibrillation of a single fiber remains in the middle and does not completely break apart, a plurality of different deniers are formed between the unsplit large denier single fiber and the fine denier fibrillar fiber formed by complete split fibrillation. However, this does not pose any problem in achieving the object of the present invention.

The number of segments of the splittable composite fiber in the present invention may be determined to satisfy the above-mentioned Deny/l/range, and the greater the number of segments of one component in the single fiber, the greater the advantage of fibrillation. However, it is actually difficult to increase the number of segments so much, and it is usually advantageous to have 4 to 8 segments from the viewpoint of ease of manufacturing the fiber.

Also, the Denny p of each segment need not be the same.

The number of crimps of the splittable composite short fibers is preferably in the range of 5 to 25 crimps/inch. If the number of crimps is less than 5 crimps/inch, the division will not be sufficient, and the compression recovery properties will also deteriorate due to the weak intertwining of the females. On the other hand, if it exceeds 25 strands/inch, the splitting will proceed, but the crimp will become too pongee, and at the same time it will be difficult to open, and the bulk when made into a web will be small. Furthermore, the contact surfaces of different polymers are exposed due to the division, and since no oil is attached to the contact surfaces, a large amount of static electricity is generated during the carding process, resulting in significant neps. However, in the crimp imparting process, the crimper-pre-dropping lubrication method shown in Figure 3(e), Figure 3(
The oil is deposited by the method of injecting the oil into the crimper box shown in f) or the method of spraying the oil after the crimper shown in FIG.

The oil component mainly consists of an antistatic component and a low-smoothing component added thereto exhibits good performance in carding.

The combination of such oil components, that is, the smoothing component improves fiber opening properties, and the antistatic component suppresses the generation of static electricity after splitting.

In addition, it should be noted that since split fibrillation is still in the middle at this point, unsplit thick denier fibers are effective in preventing top μ such as cotton sinking of split fibrillar fibers during carding. obtain.

The fiber length of the splittable composite short fibers is preferably in the range of 15 to 80 cm. If the fiber length is less than 15, it will be difficult to control the split fibrillation by carding, and the resulting web will break, making it difficult to handle. On the other hand, the fiber length is 80m
If the value exceeds 100%, the fibril fibers divided by carding may be cut or neps may occur, resulting in problems in the process.
This makes it difficult to obtain a uniform web.

In the present invention, after forming a web using a card using such splittable conjugate short fibers using a conventional method, the splittable conjugate short fibers in the web on the card are further promoted to become split fibrils, thereby preventing their entanglement. To cause this, a high pressure liquid stream is impinged on the web surface.

The liquid used as the liquid stream is preferably water or hot water because of ease of handling.

In addition, the hole diameter of the liquid jet nozzle is cL05~1.0■
, preferably 11 to 11.4 cm, and the injection pressure is 20
~80 K/cm”, and the distance between the injection hole and the web is 1
~15611 is preferable, and the wider the interval, the more the jetted liquid flow and air will mix, and the splitting and entangling effect will become smaller. In this way, the date of the non-woven fabric is 10~100 i/rn”
Within this range, it is possible to produce a nonwoven fabric that is soft to the touch and useful as sanitary materials.

EXAMPLES The present invention will be explained in more detail with reference to Examples below.

〔Example〕

The first component is polyethylene terephthalate with an intrinsic viscosity of α63 (at 25°C in orthochlorophenol-ρ), and M115
Polypropylene (A8TM D-1238, 230°C) was used as the second component, and melt composite spinning was carried out at a ratio of 1:2 (volume ratio), and the yarn was wound up in 1.000.7 minutes to form a yarn in Figure 1 (a).
A split type composite undrawn yarn having a cross section similar to that of ) was obtained.

The undrawn yarns were drawn together and stretched by a roller 55 times at a drawing temperature of 80°C to make the single fiber magnetism λ0 denier, and then the crimper-pre-drip as shown in Figure 3(a) was applied using a push-crimping machine. While applying oil by adding oil, mechanical crimping was applied at a rate of 20 crimps/inch, and the material was temporarily delivered to a container as a tow. This tow was transferred to an autoclave, subjected to relaxation heat treatment at 130° C. for 10 minutes, and then cut into 32 strips. The short fibers were opened on a roller card at a speed of 60 minutes/minute to form a web having a width of 40 fl/m, and then rolled.

Next, the web (
9) is fed onto the net conveyor (a), and the web (9)
From @ to hole diameter α15■, distance between holes @1. Using two jet nozzles /1/(9) of O■, water jets are jetted at a pressure of 97 wound 2 to the front stage 20 and 9/α2 to the rear stage 60 to divide and entangle the web structure. went. Note that the water used for spraying was removed using a suction box (6). The distance between the injection nozzle/L' (b) and the net conveyor (a) is 30m.
The speed of net conveyor 00 was 8°m/min.

Subsequently, this split fibrillated web was shrunk in a boiling water bath, dried in a dryer α, and wound up in a winder α9 to obtain a nonwoven fabric with a date of 45 fJ/@”. Raw cotton, card When the upstream web and the obtained nonwoven fabric were observed under an optical microscope, it was found that split fibrillated composite staple fibers and undivided composite staple fibers were mixed together.
yK, striped t-z approximately 5 ott, approximately 70% by weight in the carded web, approximately 95% by weight in the nonwoven fabric, and the single fibers are completely or partially split and fibrillated, and the unsplit ms and split fibrils are ρ-fibers. , split fibrils and other fibers and split fibrils and other fibers were randomly intertwined with each other.

The physical properties of the obtained nonwoven fabric are shown below.

1) Genie/l/2.5 genie of undivided single fiber
2) Split fibrillated single fiber denier polyethylene terephtha sort 1.18 denier polypropylene
[122 denier 3) Percentage of undivided single fibers 5
% 4) Non-woven fabric & fabric weight 45 fi/z M5) Thickness of non-woven fabric α8 [Effects of the invention] According to the present invention, after efficiently forming a web using splittable composite short fibers, high-pressure liquid is injected. A non-woven fabric can be obtained by using the method, and the obtained non-woven fabric exhibits special effects such as excellent suitability for sanitary materials such as cover stock materials.

[Brief explanation of the drawing]

1a) to 1(d) are cross-sectional views of examples of splittable composite short fibers used in the present invention, FIG. 2 is a schematic diagram of an example of a drawing device, and FIGS. 3(e) to (g) are te) is a pre-crimper dripping oil addition method, (f) is a crimper box-inside oil injection method, @ is a schematic diagram of an oil spraying method after the crimper. FIG. 2 is a schematic side view of the high-pressure liquid injection device. 1.2... Mutually incompatible polymer components, S... A group of stretching rollers, 4... Dry heat heating mill, 5... A group of take-up rollers, 6... A crimper for mechanical compaction -Ro, 7.
... Crimper box for mechanical crimping, 8... Tow container, 9... Web, 10... Net conveyor,
11... High-pressure fluid injection nozzle, 12... Suction box, 13... Boiling water bath, 14... Dryer, 1
5... Winder/+-4 diagram

Claims (3)

[Claims] (1) Splitable conjugate fibers made of components that are incompatible with each other are made into split fibrils in the mechanical crimp process after drawing, and at the same time an oil agent is applied, and the resulting splittable conjugate fibers are made into cards. A method for producing a nonwoven fabric, which comprises: forming a web, and then spraying a high-pressure liquid stream to promote split fibrillation of the fibers and random entanglement to form an integral structure. (2) The method for producing a nonwoven fabric according to claim 1, wherein the splittable composite short fibers are composed of any combination of polyester and polypropylene, polyester and nylon, or nylon and polypropylene. (3) Claim 1, in which the denier of the split fibrillated single fibers made of at least one component that is split and fibrillated from the splittable composite short fibers is 0.5 denier or less.
Manufacturing method of non-woven fabric as described in section.