JPS6226783B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid absorbent pad manufacturing apparatus. More specifically, the present invention relates to a liquid absorbent pad for manufacturing a liquid absorbent pad in which a liquid absorbent material is wrapped in a leakage prevention material, surrounded by a surface material, and a fiber aggregate layer is formed between the surface material and the liquid absorbent material. In the pad manufacturing equipment, a long continuous crimped fiber bundle is opened to form a cotton-like fiber aggregate,
A means for transporting the fiber aggregate by overlapping the long strip-shaped surface material, and a means for transporting the sheet-like liquid-absorbing material intermittently overlapping the long strip-like leak-preventing material at regular intervals, and A means for folding both side edges toward the liquid-absorbent material side, a means for wrapping the liquid-absorbing material with the leak-proofing material, and a fiber aggregate layered on the surface material, and further stacking these on the surface material. means for bending both side edges of the surface material so as to be surrounded by the material;
Manufacture of a liquid-absorbing pad comprising a structure in which a fiber aggregate and a leak-proofing material are laminated together by heating and pressurizing, and a means for cutting at the laminated part is provided so that the liquid-absorbing pad can be manufactured continuously. Regarding equipment.

Recently, the development of liquid-absorbing pads such as sanitary napkins and disposable diapers has been active. For example, a sanitary napkin has a structure in which absorbent paper and waterproof paper are stacked and surrounded by a surface material (or outer paper), and an adsorption layer of short fibers is formed on the back surface of the surface material on the absorbent paper side. It has been proposed together with a device (see Japanese Patent Application Laid-open No. 70693/1983).

On the other hand, in order to increase the liquid absorption capacity and improve the feeling of use, a new sanitary product has been developed that uses a hydrophobic fiber aggregate array made of hydrophobic fiber filament tow instead of the adsorption layer of short fibers. Napkins are suggested.

The present invention provides an apparatus for manufacturing liquid absorbent pads, of which this novel sanitary napkin is a representative example.

The above-mentioned method of adsorbing short fibers to the back side of the front paper involves transporting the front paper between the short fiber supply port and suction port that are close to each other, and the short fibers are extremely small and difficult to handle. Therefore, the device is complicated and large, and the problem of pollution cannot be avoided.

This invention is a new liquid absorbent pad manufacturing apparatus that does not have these problems, and one of its main structural features is the combination of the surface material (or exterior paper) and the liquid absorbent material (or absorbent paper). In order to form a hydrophobic fiber aggregate array between them, a means for opening a long crimped fiber bundle and delivering it as a band-shaped fiber aggregate is combined with a means for delivering other leakproof materials, liquid absorbent materials, and surface materials. The key is to work together and prepare. As a result, the structure of the device is simple and compact, and the problem of pollution is avoided.Furthermore, the liquid-absorbing pad with excellent properties, which is made by laminating a uniform array of hydrophobic fiber aggregates, can be continuously produced by simply supplying each material. can get.

Other features of the invention and its advantages will become apparent from the following description.

In this invention, the means for opening a long continuous crimped fiber bundle to form a cotton-like band-like fiber body, superimposing the fiber aggregate on a long band-like surface material, and transporting the fiber aggregate is as follows:
A long crimped fiber bundle is mechanically opened (or unbundled) into a cotton-like shape, adjusted to a predetermined width as necessary to form a belt-like body, and the fiber aggregate is then stacked on a long belt-like surface material. It also means a means of transport. As shown in the examples, the specific means for forming a cotton-like fiber aggregate is to send out the crimped fiber bundle while holding it under pressure with a roller, and to hold the crimped fiber bundle under pressure with another roller. A more preferable example is one in which the material is pulled and loosened into a fluffy shape at a faster speed.
Another method is to inject an air jet directly onto the crimped fiber bundle (injected through a number of holes arranged in an inverted V-shape with respect to the traveling direction of the crimped fiber bundle. See Japanese Patent Publication No. 46-6534. ), or the crimped fiber bundles moving on the belt are scratched by a needle embedded in the belt and loosened into cotton-like form (see Japanese Patent Publication No. 16205-1971).
Alternatively, a combination of the above means (a combination of air jet flow and rollers, see Japanese Patent Publication No. 39-7256) can be cited.

Here, the crimped fiber bundle is a crimped synthetic fiber such as polypropylene fiber, polyester fiber, polyamide fiber, cellulose acetate fiber, polyacrylic fiber, polyvinyl alcohol fiber, polyvinyl chloride fiber, etc.
It is a continuous fiber bundle of approximately 10,000 to 150,000 total denier made of semi-synthetic fibers, and is also called "tow." The preferred crimped fiber bundle for the liquid-absorbing pad according to the present invention is a fine filament of about 4 deniers or less, which gives a suitable feel, and has a total denier of 10,000 to 50,000 TD in the case of sanitary napkins. For disposable diapers, 30,000 to 150,000 TD is appropriate. Preferred fiber materials are hydrophobic polyester fibers and cellulose acetate fibers. In the case of these hydrophobic fibers, the fiber aggregate obtained by opening the crimped fiber bundle using them quickly transfers liquid to the adjacent layer of liquid-absorbing material, and hardly retains liquid itself. Therefore, it can give a smooth feel.

The present invention will be described in detail below based on embodiments shown in the figures.

First, in FIG. 1, each process is as follows.

Step A (process of opening the crimped fiber bundle and overlapping it with the surface material) The long continuous crimped fiber bundle 3 is manually pulled up from the packaging 1, and the fibers are separated by the guide ring 2 and guide rod 4. While preventing the bundles from getting entangled, the simple tow-like guides 5, 6, guide rod 7,
8, fiber opening devices 13, 14, size regulation guide 15,
Through the drive roll 16 and guide 17, the surface material 71 is overlapped with the surface material 71 transferred from another roll suspension device 72, and transferred to the next process (C process). Note that the surface material also functions as a support for the cotton-like fiber aggregate obtained by opening, since it is soft (has low stiffness).

The opening devices 13 and 14 consist of two sets of two rolls, and the roll set 13 (feed roll) on the forward side holds the fiber bundle under pressure so that it does not slip. Driven in conjunction with a drive motor (not shown), the moving speed of other materials Vo
The fiber bundle is sent out at a speed V ₂ that is 1.1 to 1.3 times faster than the moving speed of the leakage preventive material (for example, 60 m/min, which will be described later).
Roll set 1 in the previous stage for the feed roll
4 (pretension roll) feeds out the fiber bundle at a speed V ₁ that is 0.5 to 1.0 times the speed V ₂ of the feed roll while holding the fiber bundle under pressure to prevent it from slipping. Under these conditions, the crimped fiber bundle (polypropylene fiber bundle with 20 crimps/25 mm) is continuously opened by the tension exerted by the difference in peripheral speed between roll sets 13 and 14, and becomes a flocculent fiber aggregate. be done. The spread fiber bundle is adjusted in a trumpet-shaped size regulation guide 15 into a belt shape with dimensions corresponding to the product size, and then sent directly to the next process via a drive roll and a guide. drive roll 16
is driven in conjunction with the main drive motor at a circumferential speed that is 1.0 to 1.2 times the flow speed of other materials. The reason why this circumferential velocity is slightly larger than the flow velocity is because it contracts in its natural state. The ring guide 17 is provided to adjust the width of the opened fiber bundle immediately before it is laminated with other materials. The fibers used here were polypropylene fibers with a filament fineness of 4.0 denier and a total denier of approximately 30,000 TD.

By the way, the roll set 13 includes a main rotating roll 13' having an elastic layer (rubber layer) formed on its surface, and a sub rotating roll 13'' having a hard layer (metal layer) formed on its surface.
and are supported in parallel and close together. The main rotating roll 13' is supported by a fixed rotating shaft 13a driven by a drive motor, and one of the subordinate rotating rolls 13'' is supported by a moving shaft 13b.The moving shaft adjusts the pressurized air. It can be pressed by a pressure means such as a diaphragm 12 supplied via the valve 9, whereby the secondary roll 13'' can be pressed so that the fiber bundles interposed on the main roll 13' do not slip.

On the other hand, the roll set 14 includes a main rotating roll 14'
The configuration is almost the same except that it is not driven, so the explanation will be omitted. Here, the moving speed of the crimped fiber bundle can be adjusted by adjusting the pressure of the regulating valve 10. In addition,
For reference, the diameter of the main rotating roll 13' of the roll set 13: 10 cm, and the rotation speed: approx.
190 rpm, diameter of slave roll 13'': 10 cm, fiber bundle speed: 60 m/min, diameter of diaphragm 12:
15cm〓, internal pressure: 0.75Kg/cm ² (G), diameter of main rotating roll 14' of roll set 14: 5cm
〓, Diameter of slave rotating roll 14'': 5 cm〓, Fiber bundle speed: 55 m/min, Diameter of diaphragm 11: 15 cm
〓, Internal pressure: 0.6Kg/cm ² (G). On the other hand, the rolled surface material 71 is supported by a suspension device 72. The facing material pulled out from the roll is sent from a guide roll 73, through a gluing device 74, to a stacking process with other materials. The purpose of the gluing device is to adhere the overlapping parts of surface materials by applying adhesive, but depending on the type of product, adhesion may not be necessary.

B process (step of overlapping and rolling the leakage prevention material onto the liquid absorbent material) The band-shaped liquid absorbent material (cotton-like pulp paper) 55 is placed on the chain belt 54, and the cut rolls 20, 2
0', and the strip-shaped absorbent material 55 is cut into a desired size (usually 160 mm in the longitudinal direction). Then, the liquid absorbing material 55' is sequentially fed to the next belt conveyor 29 at predetermined intervals (usually 30 mm in the longitudinal direction). Note that since the conveyor belt 29 is set to run at a slightly higher speed than the conveyor belt 54, the above-mentioned predetermined interval can be provided. On the other hand, a leakproof material (usually polyethylene laminate paper) 61 is continuously drawn into the upper guide roll 63' by the drive of the guide belt 63, and the cut absorbent material 55' is inserted therein. And leak prevention material 6
1 travels on the guide belt, the guide grooves and guide pins (not shown) provided on the conveyor belt 29 wrap around the liquid-absorbing material 55' spaced at equal intervals in a square shape, and the guide belt 18 for the next process is wrapped. is continuously sent to. Note that 62 is a roll suspension device for the leakage prevention material 61.

Process C (process of surrounding the entire other overlapping materials with the surface material) Cotton-like fiber aggregate 3 and surface material 7 obtained in Process A
At the same time, the absorbent material 55' obtained in step B and the leakage preventive material 61 wrapped in the absorbent material 55' obtained in step B are stacked upward and downward. They are drawn in and transported so that they fit together. During this transfer, the surface material 71 is moved along its both side edges by L-shaped guides (not shown) provided correspondingly.
The sheet is folded into a letter shape, and all other materials are wound between the conveyor belt 22 and the guide belts 18 and 19 by a rod-shaped folding guide (not shown), and both ends are overlapped. Note that the line speed was approximately 60 m/min.

D process (adhesion, cutting, and packaging process) The continuous stack, in which all other materials are wrapped with the surface material and overlapped on both sides, is sent to the heat seal cutters 21, 21' and sealed and cut. , and transported as a product on the conveyor belt 26. In addition, since the flocculent fiber aggregate is thermoplastic, it is convenient because the sealing is sufficiently performed.

The sanitary napkin N thus obtained is
By placing a flocculent fiber aggregate, that is, a long continuous crimped fiber bundle 3 to be opened, between the surface material 71 and the liquid absorbent material 51 of the material configured as shown in Figure 3, the fiber It is now possible to impart the flexibility of the bundle and appropriate elasticity, and this type of sanitary napkin can achieve excellent skin-fitting properties and a soft feel that could not be achieved with conventional products. I can do it. In addition, 61 is a leakage prevention material, and 81
are both side edges of the surface material 71.

Furthermore, regarding liquid absorption performance, body fluids that flow in spots through the surface material are not directly absorbed into the liquid absorbent material (with this type of absorption, there is a risk that body fluids may partially overflow while remaining in spots). The crimped fiber bundle 3 once receives the body fluid and spreads it forward, backward, left and right, especially in the flow direction of the fibers, thereby avoiding local overflow and evenly absorbing the body fluid into the absorbent material. This makes it possible to minimize performance loss.

Furthermore, in the liquid-absorbing pad after body fluid has been absorbed, since a fibrous layer is present on the wet liquid-absorbing material, re-diffusion of the body fluid to the skin side is prevented, and a pleasant feeling of use can be obtained.

For your reference, we have listed the material and dimensional specifications of sanitary napkin N.

Sanitary napkin N length: 17cm, width: 6.5cm,
Free height: 1cm, surface material 71: Japanese paper, fiber bundle 3:
Polypropylene fiber, leak-proofing material 61: polyethylene laminate paper, liquid-absorbing material 51: laminated 11 sheets of pulp paper. In addition, as a means of supplying the liquid-absorbing material in the B process, as shown in Fig. 4, the width is A liquid-absorbent material made by laminating a plurality of wide paper sheets 51' and processed into a strip shape can be used. 52 is a slicer type cutter, and 53 is a guillotine type cutter, which are used for cutting in the vertical and horizontal directions, respectively. Of course, when operating a guillotine type cutter, it is necessary to stop the material from absorbing liquid. The liquid-absorbing material cut into desired dimensions is dropped piece by piece 55 onto a table below by an arm 57 that is linked with a deformation cam 56, and placed at a required interval (usually 10 to 40 mm) with a convex adapter. It is transported intermittently using a chain belt 54.

Furthermore, as a means for supplying the absorbent material, there is also a method in which pulverized pulp is placed on a belt using a stacking device, cut vertically and/or horizontally with a suitable cutter, and then transported as described above.

The conditions for performing the bonding in step D in Figure 1 by the hot melting method are the type of fiber bundle, the amount of fiber,
It also varies depending on the type and thickness of the leakage preventive material or the type and thickness of the surface material, etc., but the conditions for common-sense materials are usually at a temperature of 150 to 300 degrees Celsius, for a time of about 0.01 to 0.05 seconds, and as a fiber bundle made of polypropylene fibers. 4 denier, 25000 total denier,
When polyethylene laminate paper is used as the leak-proof material and Japanese paper is used as the surface material, the bonding conditions are a temperature of 160°C.
Approximately ±20°C and 0.05 seconds are appropriate.

[Brief explanation of the drawing]

Fig. 1 is a functional explanatory diagram of the liquid absorbent pad manufacturing apparatus according to the present invention, Fig. 2 is a cross-sectional view of the completed liquid absorbent pad, Fig. 3 is a perspective view of the completed liquid absorbent pad, and Fig. 4 is a liquid absorbent pad manufacturing device. FIG. 6 is a perspective view showing another embodiment of the material transfer means. 1...Continuous crimped fiber bundle packing, 5, 6...Trough-shaped guide, 11, 12...Diaphragm, 13...
...Feed Roll, 14...Pretension
Roll, 15...Trumpet type guide, 16...
...Drive roll, 17...Ring guide,
18, 19, 63...Guide belt, 20, 2
0'... cutlet roll, 21, 21'... heat seal cutter, 22, 26, 29... conveyor belt, 52... slice type cutter, 53...
Guillotine type cutter, 54... Chain belt with convex adapter, 62, 72... Roll suspension device,
74... Gluing device.

Claims (1)

[Scope of Claims] 1. A liquid absorbent pad for producing a liquid absorbent pad in which a liquid absorbent material is wrapped in a leakage prevention material and surrounded by a surface material, and a fiber aggregate layer is formed between the surface material and the liquid absorbent material. In the pad manufacturing apparatus, (A) a means for opening a long continuous crimped fiber bundle to form a cotton-like fiber aggregate, superimposing the fiber aggregate on a long strip-like surface material and transferring the fiber aggregate; B) means for transporting the sheet-like liquid-absorbing material intermittently overlapping the long strip-like leak-preventing material at regular intervals, and folding both side edges of the leak-preventing material toward the liquid-absorbing material; (C) Layer the liquid-absorbing material wrapped in the leakage prevention material and the fiber aggregate layered on the surface material, and bend both edges of the surface material so that they are further surrounded by the surface material. (D) The surface material, the fiber aggregate, and the leakage preventive material are stacked together by heating and pressurizing so that each liquid-absorbing material is in the center of the obtained strip-shaped stack, and cutting is performed at the stacked part. A liquid absorbent pad manufacturing apparatus comprising a means for manufacturing liquid absorbent pads in cooperation with each other and configured to continuously manufacture liquid absorbent pads.