JPS61189921A - Manufacture of flexible resin foam and its device - Google Patents

Abstract

PURPOSE:To produce continuously resin foam which is excellent in flexibility and has a smooth surface without wrinkles at high efficiency by orientating the resin foam, while heating and plasticizing said resin foam with far infrared rays. CONSTITUTION:The orientation in the direction of longitudinal axis is carried out, while causing the pinch roll on an exit side to have larger peripheral speed than that of the pinch roll on an inlet side. Stock resin foam F is nipped into by the pinch roll stand 1 on the inlet side and then is heated and plasticized by a far infrared heater 2. Said foam is nipped into by the pinch roll stand 4 on the exit side and is wound up on a winding roller 10 by way of a tenter 5. The tenter 5 orientates in a transverse direction the stock resin foam F having been orientated longitudinally. The lugs on both sides of the stock resin foam F are gripped with a gripping tool according to the rotation of driving gears 6, 6', and in this state, the gripping tool is moved along the width expanding rail 13 diverging in a rear direction, thereby carrying out its orientation in the direction of a transverse axis. A far infrared heater 7 for plasticizing the foam is provided at the front step position of the tenter 5 only on its upper part.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention uses a continuous thermoplastic resin primary foam (closed foam) product as a material, plasticizes it, and stretches it to create a smooth, wrinkle-free surface. This relates to a method and apparatus for manufacturing relatively thin resin foam, and uses a far-infrared heater that can instantaneously heat up to the core of the foam as a heat source for plasticization without using an eave closure device or a decompression/vacuum device. By using OT, it is possible to obtain a wrinkle-free and flexible resin foam with a relatively low temperature and simple equipment. Many methods and devices for continuously manufacturing flexible resin foams have been proposed.

For example, Japanese Patent Publication No. 46-43319 relates to a device for preventing damage to a linear or strip-shaped foam to be treated at the sealing portion of a continuous closed treatment device. Therefore, it is not related to the present invention, which does not perform sealing treatment.

Furthermore, the method described in Japanese Patent Publication No. 47-42626 uses a closed-cell foam as a material, plasticizes it by treatment with a swelling agent or heat treatment, expands it under reduced pressure, and then returns it to normal pressure. In a way that shrinks it.

A crushed resin foam with many wrinkles is obtained. Such a resin foam with many wrinkles and crushed cells is different from the wrinkle-free and flexible resin foam that is the object of the present invention, and since the present invention does not perform vacuum treatment, this point will be ignored. But they are different.

Next, what is published in Utility Model Publication No. 48-14675.

This is a device for producing the same wrinkled resin foam as above, and is equipped with a vacuum treatment chamber, a sealing mechanism at the inlet and outlet 6, and an infrared heater and a heating device using a heat medium as a heat source inside. A cooling device is also provided for imparting strength by cooling the softened surface of the foam to be treated due to the heat source of the brackets. Therefore, there is no need to use a vacuum treatment chamber, and the heating device is an infrared heater or heat medium, which is a heat source that does not soften the core because only the surface of this foam, which has extremely low thermal conductivity, becomes soft. The present invention does not use for softening,
There's nothing related to it.

Furthermore, as one of the prior art techniques, there is also a method in which the foamed material is passed through hot water at 100° C. and stretched between rolls. Naturally, with this method, the foamed material tends to tear easily when it comes into contact with hot water, making it impossible to stretch it to a large extent. In addition to the need to control the temperature of the hot water and take safety measures for the pot, if the hot water becomes dirty, the resin foam will become discolored. Furthermore, the surface of the foam that comes into contact with the guide rolls and stretching rolls (in hot water) collapses and collapses, resulting in a product with many wrinkles.

[Problem that the invention seeks to solve]

In this way, the continuous foam material is plasticized.

It has been difficult with conventional techniques to produce a continuous, wrinkle-free, flexible, and relatively thin resin foam with high efficiency by stretching.

The reason for this is that the thermoplastic resin foam used as the material has excellent heat insulation properties.
This is because even if this material foam is heated externally to plasticize it, uneven temperature distribution will always occur in the thickness direction.To prevent this, long-term heating is unavoidable, and the heating time is sufficient. Otherwise, depending on the thickness of the foam material, the core will not be heated sufficiently, and even if the area near the surface is softened, the core will be stretched without being softened enough. Therefore, there is a difference in shrinkage after stretching between the part near the top surface where the degree of softening is large and the part of the core where softening is insufficient, resulting in unnecessary wrinkles on the surface, making it difficult to obtain a smooth surface and good flexibility. .

This phenomenon is the same regardless of whether the conventional heat source is hot water, steam, or infrared rays; in each case, a difference in heating occurs between the surface and the core of the foam to be treated. Therefore, with the conventional technology, it has been difficult to produce a wrinkle-free, smooth-surfaced, yet flexible resin foam on a high-speed continuous line.

[Means for solving problems]

The present invention has been made in order to efficiently obtain a wrinkle-free and flexible resin foam, which has been difficult to achieve with the conventional techniques as described above. By using a far-infrared heater as a heat source, the foam to be treated is heated from the core, and the surface and core are uniformly and instantly heated to soften them.

That is, in the method for producing a flexible resin foam according to the specific invention of the present application, when softening the thermoplastic resin foam as a material by heating it below its melting point and stretching it, the resin foam is heated and plasticized with far infrared rays.

During that time, it is stretched.

In the method for producing a flexible resin foam of the present invention, the stretching may be carried out only in the longitudinal direction, and in this case, the stretching of the material is preferably carried out by the difference in peripheral speed between the entry and exit Vintage rolls.

Furthermore, in the method for producing a flexible resin foam of the present invention, stretching may be performed only in the transverse direction, and in this case, the stretching of the material is preferably performed by widening using a tenter.

Furthermore, in the method for manufacturing a flexible resin foam of the present invention,
Stretching may be carried out in two orthogonal directions, for example the longitudinal and transverse axes, in which case it may be carried out in both directions simultaneously or first in the longitudinal direction and then in the transverse direction.

Also, according to the second invention as an apparatus used in the manufacturing method according to the specified invention of the present application.

A pinch roll stand for pinching and feeding out the thermoplastic resin foam of the material, a far-infrared heater placed behind the pinch roll stand, and a far-infrared heater placed behind the far-infrared heater and Provided is a flexible resin foam manufacturing apparatus characterized by comprising an output side pinch roll stand that bites and feeds out the heated resin foam at a faster peripheral speed than an input side pinch roll stand, thereby achieving instantaneous uniform heating of the material. Continuously high efficiency of softening and longitudinal stretching is achieved.

Further, according to the sixth invention as an apparatus used in the method of the specified invention, it is provided with a tenter for widening the thermoplastic resin foam of the material and a far-infrared heater for heating the resin foam on the tenter. An apparatus for manufacturing a flexible resin foam with characteristics is provided, and this LVC achieves softening of the material by instantaneous uniform heating and continuous high efficiency of transverse and widening stretching.

Furthermore, according to the fourth invention, which is also an apparatus used in the method of the specified invention, there is provided an entry side pinch roll stand for biting and feeding out the thermoplastic resin foam as the raw material, and an entry side pinch roll stand disposed behind the entry side pinch roll stand. a first far-infrared heater; an outlet pinch roll stand that is disposed behind the first far-infrared heater and pinches and sends out the resin foam at a faster peripheral speed than the input pinch roll stand; Provided is a flexible resin foam manufacturing apparatus characterized by comprising a tenter disposed behind a side pinch meal stand and a second far-infrared heater for heating the resin foam on the tenter. It is possible to achieve softening through instantaneous uniform heating and continuous high efficiency stretching in the longitudinal and lateral directions.

[Effect]

In the above-mentioned method and apparatus for producing a flexible resin phonium of the present invention, (10) is a far infrared ray having a wavelength of 25 μm or more, and a thermoplastic resin foam of the material, such as a cellular polyvinyl acetate or a heptacopolymer, is used. When the band-shaped foam is heated, the thermal motion of the molecules inside the resin film A is excited, and the temperature of both the core and the surface increases uniformly in a short time. Therefore, if stretching is applied during such instantaneous and uniform heating, the stretching will be done uniformly in the thickness direction of the resin foam, and there will be no contact with moisture as in conventional methods, thereby eliminating unnecessary wrinkles. A smooth and flexible resin foam with one surface can be obtained without any particles being generated on the surface. Furthermore, if the film is stretched in both axial directions, it will become flexible in both the vertical and horizontal directions, and if it is stretched only in either the vertical or horizontal directions, it will become flexible only in the direction perpendicular to these directions.

As mentioned above, far infrared ray heating heats the inside of the resin foam to a uniform temperature that is even with the surface. 1) For example, in the case of the polyvinyl acetate strip foam mentioned above, 2) the surface temperature is about 60°C below its MP (melting point) of 70°C, and it is not necessary to heat it to a temperature higher than that. It was confirmed that the

In the present invention, auxiliary heating using ordinary air, steam or other heat medium, or infrared rays for the purpose of heat retention after heating with far infrared rays is not prohibited.

[Embodiments of the invention]

Next, a method for manufacturing a flexible resin foam and an apparatus therefor according to the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a sectional view showing an embodiment of the haiku-making device of the present invention, and FIG. 2 is a plan view thereof.

Symbols common to both figures (1) is the input side pinch roll stand, (2) is a far-infrared heater with a wavelength of 25 μm or more, and (3) is a structure that serves as a heat retention enclosure, Seals are not required at the inlet and outlet. (4) is the outlet pinch roll stand. This outlet pinch roll has a high circumferential speed on the input side pinch roll. F is a resin form of the raw material, which is rewound from an unwinding roll (not shown) and placed in the direction shown by the arrow in FIG.
1), heated by a far infrared heater (2), plasticized, and then inserted into the output side pinch roll stand 4). In this example, the following tenter (
5) and is wound onto a winding roller (g). As shown in the figure, a plurality of far-infrared heaters (2) are installed at the front stage of one structure (3), each at the top and bottom, taking into account factors such as MP, thickness, width, and stretching ratio of the material resin foam. If the material resin foam is made of polyvinyl acetate, the temperature at the surface position of the resin foam F passing through the above-mentioned structure (31) may be 70° C. or lower. However, the material resin foam to which the present invention is applied is not limited to this polyvinyl acetate, but can also be applied to other resin foams.

The tenter (5) is provided to stretch the material resin foam F, which has been stretched in the vertical axis direction, in the horizontal axis direction. Like a normal tenter, the ears on both sides of the resin foam are made into nine individual grips in a row.
The gripping tool moves rearward along a widening rail U that widens toward the rear, thereby widening the width, that is, stretching in the transverse axis direction.

In addition, a companion far-field heater (7) is installed at the front stage of the tenter (5) to perform the plasticization necessary for widening there, and is provided with only upper pressure. (8) is one of seven. (9) is a smoothness adjustment handle of the tenter (5), α°C is a motor necessary for driving, and (6) is a continuously variable transmission.

In addition, in the structure of one structure (31 and (8)), the heat source used there is far infrared rays, and the 710 thermal reaction temperature is relatively low at around 70 degrees Celsius, so it is necessary to use insulation material.
Since there is no need to seal the inlet and outlet of the tube as described above, any simple structure that prevents the heater from being exposed and prevents outside air from entering will suffice.

〔Effect of the invention〕

If the manufacturing method of the flexible resin foam of the present invention is applied, far infrared light with a wavelength of 25 μm or more is used as the heat source for plasticization. Smooth and flexible resin foam with a sealed feel! High-performance straw can be manufactured continuously using relatively simple manufacturing equipment without using any equipment or decompression/vacuum equipment. Furthermore, if necessary, it is also possible to create a resin foam that is flexible only in the vertical and horizontal directions of deviation.

[Brief explanation of drawings]

The figures show an embodiment of the manufacturing apparatus flJ of the present invention, with FIG. 1 being a sectional view and FIG. 2 being a plan view. The symbol (1) in the figure is a stretchable pinch roll stand, (2)
is a far-infrared heater, (31 is a furnace tank, (4) is a pinch roll stand on the outlet side, (5) is a tenter, (6) <6')
Fill A is a moving gear, (7) is a far-infrared heater, (8) is a furnace vessel, and F is a resin foam material. Agent Patent Attorney Sanro Kimura Figure 2 9: Towards the Theme Expression Layered Evidence - Talk 10? Take-up roller 11 Ni (3--y-12J Niita-ku^ 13:J Mua Road L--1 and 1.8 to 1) Display Patent Application 1986-29415 2. Title of the invention: Flexible resin foam Manufacturing method and its device type Posse 6, Detailed description of the invention column and drawings in the oil surface specification specification -7 Ura 11 Sanya, -'-)') (1)
Page 10, line 12, page 12, line 7 of the specification. On page 14, line 11, “25 μm or more” was replaced with “4 to 5 μm”.
0 μm”. (2) Delete the five characters "Only at the top" in lines 6 to 2 from the bottom of page 16 of the specification. (3) Correct Figure 1 of the drawing to corrected Figure 1. 8. List of attached documents

Claims (11)

[Claims] (1) Manufacturing a flexible resin foam characterized by heating the thermoplastic resin foam as a material below its melting point and stretching it to soften it, by heating the resin foam with far infrared rays to plasticize it and stretching it. Method. (2) The method for producing a flexible resin foam according to claim 1, wherein the stretching is performed only in the longitudinal direction. (3) The method for producing a flexible resin foam according to claim 2, wherein the stretching is performed by a difference in circumferential speed between an input pinch roll and an output pinch roll. (4) The method for producing a flexible resin foam according to claim 1, wherein the stretching is performed only in the transverse direction. (5) The method for producing a flexible resin foam according to claim 4, wherein the stretching is performed by widening using a tenter. (6) The method for producing a flexible resin foam according to claim 1, wherein the stretching is performed in two orthogonal directions. (7) The method for producing a flexible resin foam according to claim 6, wherein the stretching is first carried out in the longitudinal direction and then in the transverse direction. (8) The method for producing a flexible resin foam according to claim 1, wherein the stretching is performed simultaneously in two orthogonal directions. (9) An entry side pinch roll stand that bites and feeds the thermoplastic resin foam material, a far infrared heater placed behind the entry side pinch roll stand, and an input side placed behind the far infrared heater. A flexible resin foam manufacturing device characterized by being equipped with a discharge side pinch roll stand that bites and sends out heated resin foam at a peripheral speed faster than that of the pinch roll stand. (10) An apparatus for producing flexible resin foam, comprising a tenter for widening the thermoplastic resin foam as a raw material, and a far-infrared heater for heating the resin foam on the tenter. (11) An entry side pinch roll stand that bites and feeds the thermoplastic resin foam material, a first far-infrared heater placed behind the entry side pinch roll stand, and placed behind the first far-infrared heater an output pinch roll stand that bites and sends out the resin foam at a faster peripheral speed than the input pinch roll stand; a tenter placed behind the output pinch roll stand; and a tenter that heats the resin foam on the tenter. A flexible resin foam manufacturing apparatus characterized by being equipped with a second far-infrared heater.