JP2564178B2 - Wavy synthetic resin film or sheet with through holes and method for producing the same - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

TECHNICAL FIELD The present invention relates to a corrugated rigid resin film or sheet with a through hole, which is preferably used as a filler for breathable cushioning materials, vegetables and the like, underlays for fresh foods, heat exchangers, spiral filtration devices, etc., and a method for producing the same. .

[Prior art]

(Background) Plastic films and rubber sheets with liquid ribs have been used as stretchable water-blocking materials in the field of civil engineering such as tunnels, culverts, and reservoirs, in addition to buffer materials due to their elasticity in the wavelength direction. It's being used. However, naturally, it cannot be used in a field that requires both buffering property or elasticity and water permeability. Conventionally, as a molding means of a plastic sheet with a through hole, for example, a net-like or lattice-like material is disclosed in
No. 38-21224, No. 39-16936, as described in each gazette,
Means for forming holes in a substantially flat sheet are known.
However, corrugated sheets are generally perforated by secondary processing. (Problems of the prior art) However, the conventional net-like or lattice-like molded product cannot be applied to the purpose of being curved for use because the rigidity increases and the flexibility decreases as the thickness increases. Moreover, since more materials are required, the economical efficiency is reduced. In addition, since the holes formed by the above-mentioned known means are all opened along the direction orthogonal to the plane, the pressure loss becomes large when used as a spacer for a spiral filter, for example.

[Problems to be Solved by the Invention]

Therefore, the present invention provides a novel corrugated plate that has not existed so far, that is, a novel corrugated plate having a through hole on the end surface of each unit channel formed by dividing a wave in the corrugated plate by a channel intersecting the traveling direction. By developing a plate and its forming means, it is an object to solve the drawbacks of the known art described above (problems of the prior art).

[Means for Solving the Problems]

(Outline) In order to achieve the above object, the corrugated synthetic resin film or sheet with a through hole according to the present invention is a corrugated plastic film or sheet, in which each wave is divided by a channel orthogonal to the wave and is divided. It is characterized by having an opening on the side surface of the generated wave. In addition, the method for producing the wavy film or sheet, among the pair of facing toothed rolls,
Between each unit roll that constitutes one toothed roll, made of a hard and rigid material, and its diameter is not larger than the diameter of the tip circle to the left, and is larger than the diameter of the root circle. A spacer is attached between each unit roll that constitutes the other toothed roll with a small-diameter spacer made of an elastic material, and the molten resin material is supplied in a film shape between both rolls that rotate inwardly, after shaping. Characterized by rapid solidification. Various items related to the invention will be described below item by item. (Wavy Film or Sheet) The wavy film or sheet according to the present invention (hereinafter abbreviated as “wavy film”) is essentially polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyethylene terephthalate, polycarbonate, ethylene.
From vinyl acetate copolymer, polyurethane, polyamide, polystyrene and any other thermoplastic resin capable of forming a film,
Injection molding method, compressed air or vacuum molding method, extrusion method, inflation method, spreading method and other means, preferably Japanese Patent Publication No.
It is formed into a corrugated sheet or film having a thickness of several millimeters to several tens of microns by the means described in Japanese Patent Laid-Open No. 62-55497. If necessary, the raw material resin may contain additives such as a plasticizer, a pigment, a dye, a filler, a foaming agent, an ultraviolet absorber and a heat deterioration inhibitor. The above-mentioned sheet basically has a full-wave or half-wave structure with an equal pitch, but it is also possible to use a wavy sheet partially having a liquid structure within the scope of the manufacturing means described later. And the waves can be offset with a pitch less than the full wave with the channel described below as the boundary. However, as its indispensable configuration, it has a channel running in the direction intersecting with the waves. This channel is also in principle in communication from end to end of the sheet, but in some cases it can also be arbitrarily divided in the middle, in which case the wave and the channel are half-waved with respect to each other. It has the appearance of an orthorhombic shape divided by. However, the channel here means a concave portion lower than the height of the wave, but when viewed from the opposite direction, it becomes a rib, and further, as shown in FIG. May exist at the same time. The through hole is formed on the end surface of each wave divided by the channel, that is, on one side surface or both side surfaces of the wave parallel to the channel, but in the case of the manufacturing method described later, it is usually formed on one side surface. It is normal. The structure of a typical liquid sheet will now be described with reference to the accompanying drawings. The example shown in FIG. 1 is the most basic example of the invention. Waves that make up the thermoplastic sheet 1 _A 2,2 ...
Is divided by the channels 3, 3 ... Crossing the wave at right angles to form a large number of independent roof mold sections 2a, 2a.
Through holes 4, 4 ... Are drilled in the end surface of the front side of each independent roof model. The depth of the bottom (valley) 2b of the wave (the distance from the crest surface to the wave bottom) is the same as the depth of the channel 3.
In this figure, the interval l between each channel is constant,
If desired, it may be changed to a non-uniform spacing. Figure 2 is a another example, the channel 3,3 of the sheet 1 _B '
Waves 2 and 2'partitioned by are changed by 1/2 pitch to form a large number of independent roof mold portions 2a, 2a ..; 2'a, 2'a ..
Illustration (In the figure, circles are shown near the eyes when viewed from the paper,
(Clarified by adding a triangle to each part farthest from the eye)
, The same as the row of independent roof type parts 2a, 2a ..
The channels 3 and 3 ', which delimit the rows of, are alternately opposite and thus the channel 3'in the drawing is also understood as a rib. Each through hole is formed on the left side of each independent roof mold portion 2a, 2'a. Sheet 1 _C of FIG. 3 is a further example of the invention, in the form of waves 2 _A and 2 _B trapezoidal having different half-wave out of phase with each other in parallel alternately. The through hole 4 exists on one side surface of each wave. The form of this example is equivalent to the case where the wave and the channel have a diagonally divided appearance, which is separated by half-wave pitch, and from a different viewpoint, a form in which waves with 180 ° different phases are arranged in parallel. Can also be seen. FIG. 4 sheet 1 _D , an example similar to that of FIG.
Unlike the one shown in the figure, the through holes 4 are different in that they are present in one row of each independent roof type part 2a divided by the channels 3,3. (Manufacturing) In principle, the sheet with perforations according to the present invention is, except for the structure of a special type described later, disclosed in Patent No. 14 according to another invention of the inventor.
It is manufactured according to the method of No. 48706 (Japanese Patent Publication No. 62-55497). As described above, as the manufacturing means of the corrugated sheet itself having no through hole, there are injection molding method, compressed air or vacuum molding method, extrusion method,
It can be molded by inflation method, spreading method, or other means, but from the viewpoint of minimizing secondary processing,
What is considered to be industrially optimal is a method of performing extrusion, molding and punching according to the above-mentioned prior invention. In this case, the resin material in a molten state is submerged in the liquid refrigerant, specifically, is supplied to a pair of rotary gear-shaped molding dies located in the refrigerant at least below the fold line, and at the same time as shaping. Cooling is performed. According to this method, the surface of the resin is immediately solidified by the refrigerant to form a hard skin layer, and the outer shape is well maintained, so that the inner core layer does not lose its shape even at the heat deformation temperature and is flexible as a whole. Keep sex. Therefore, it is easy to hold the curved transfer path required for continuity. As the liquid refrigerant, water, lower alcohol, polyhydric alcohol or the like can be selected, but water is most preferable from the viewpoint of cooling efficiency, price and safety. The temperature of the refrigerant is 10
A temperature of 0 ° C or lower, preferably 60 ° C or lower is desirable. The shaping mold used is a pair of gear-shaped molds, but it is necessary that the tooth tips of both molds and the corresponding troughs mesh with each other in a non-contact manner. By such non-contact bonding, the contact between the sheet in the thermoplastic state and the teeth is performed to the minimum necessary, so that the thickness of the entire sheet is averaged. (Molding Device) FIG. 5 attached shows an outline of the above molding device. The device 11 includes a pair of toothed rolls (molding dies) 13 and 13 'which are half-sunk in a pair of water tanks 12, an upper extrusion die 14, and
It is composed of a pair of guide rolls 15 and 15 'supported inside and outside the water tank. Molten film material Fm extruded vertically from die 14
Is shaped between the toothed rolls 13 and 13 ', and at the same time, it is cooled by the refrigerant W and solidified into the product 1, which is taken out of the system through the guide rolls 15 and 15'. At this time, the distance d from the enclosing line EE to the water surface WL is experimentally determined depending on the type of the target resin. (Molding die) The greatest feature of the manufacturing method of the present invention is a unique molding die. This mold is made of a hard rigid material between the unit rolls constituting one toothed roll of the pair of opposed toothed rolls, and its diameter is larger toward the left as compared with the diameter of the addendum circle. In addition, a spacer having a large diameter larger than the diameter of the root circle and a spacer having a small diameter made of an elastic material are attached between the respective unit rolls constituting the other toothed roll. The attached FIG. 6 is a side view schematically showing a pair of unit molding dies, and FIG. 7 is a front view thereof. The mold is a pair of male molds 13a and 13b and a female mold 13 '.
a, 13'b, a spacer 16 made of an elastic material interposed between the female dies 13a, 13b, a spacer 16 'made of a hard metal interposed between the female dies 13'a, 13'b and an elastic material It is composed of spacers 16 ″. Of the above spacers, the spacer 1 between the male molds 13a and 13b
6 has the same diameter as the root circle C ₁ of the male mold, and the female mold 1
The spacers 16 'and 16 "between 3'a and 13'b each have the same diameter diameter as the tip circle C ₂ of the female mold. And each of these molds has the same diameter as shown in FIG. A required number of them can be rotated inward integrally by transmitting the rotational force from the driving-side helical gear 17 to the driven-side helical gear 17 '. In the above molding die, a pair of male dies 13a and 13b and a pair of male dies The gap g between the female molds 13'a and 13'b is shown in FIG.
Since it corresponds to the channel 3 in FIG. 4, it is possible to form channels (or ribs) of any width by adjusting the thickness of each spacer. Spacer 16 '
The diameters of 16 "and 16" may be larger than the diameter of the tip circle C ₂ by about 1 mm. Further, the special shape as shown in Fig. 4 has a desired unevenness on the female spacers 16 'and 16 ". It becomes possible by adding. Further, the thickness t of each mold determines the building length of the independent roof mold portions 2a and 2'a. It will be easily understood that the phases of adjacent waves can be freely changed by adjusting the phase of 13b for male mold 13a (and 13'b for female mold 13'a). The formation of the through hole 4 is caused by the contact between the inner surface of the hard spacer 16 'on the female die side and the right end of the tooth portion of the male die 13a at a point p (see FIG. 6). At this time, since the spacers 16 and 16 ″ both have elasticity, the thickness of the female and male teeth is 50 μm.
Even if there is a certain degree of error, the error is canceled by the elasticity of the spacer, so that the formation of the through hole is not hindered. Moreover, since the spacer 16 ″ acts as a cushioning material, the wear of the male mold is very slight regardless of the contact between the male mold 13a and the spacer 16 ′, both of which are made of metal. Not only is it easy to design due to its large tolerance to, but it is also easy to repair when worn.Each spacer is preferably made of a low friction resin such as fluororesin or polyacetal, but other polyamides or polyphenylenes are also preferred. It can also be manufactured using an engineering plastic such as oxide or an elastic material such as hard rubber.

According to the present invention, there is provided a lightweight synthetic resin corrugated sheet material having a through hole on the end face of a wave, which is a characteristic of the corrugated sheet material and is flexible in the wavelength direction. Since it has good air permeability, it can be expected to have excellent performance not only as an underlay material for fresh foods or a cushioning material, but also as a filler for a cooling tower or a spiral filter. Further, as a manufacturing method thereof, among a pair of facing toothed rolls, between each unit roll constituting one toothed roll, made from a hard rigid material, and its diameter is smaller than that of the tip circle. A large-diameter spacer, which is not as large as the left one and is larger than the diameter of the root circle, and a small-diameter spacer made of an elastic material are attached between the unit rolls constituting the other toothed roll, and they rotate inwardly. By using a means of supplying a molten resin material in a film form between both rolls and rapidly solidifying after shaping, it is possible to economically mass-produce the useful corrugated sheet with through holes as described above. .

【Example】

Hereinafter, embodiments of the invention method will be described with reference to Examples and Comparative Examples, but each exemplification is merely for the purpose of explanation, and is not intended to limit or limit the inventive idea. Example 1 Using the molding die shown in FIG. 8 (see below; reference numeral according to FIG. 6) and using the molding apparatus shown in FIG.
L: D = 25, inner barrel 40mmφ extruder tip barrel temperature 180
℃, screw rotation speed 60 rpm. Coat hanger type T-die (die lip: thickness 1.5 mm, lip length:
220mm), ethylene-vinyl acetate copolymer resin (Sumitomo Chemical's trade name << H2020 >>; vinyl acetate content 15%) 9r.
It was fed into a molding die ^* rotating inwardly at a speed of pm to obtain a corrugated sheet with a through hole having a thickness of 0.4 mm shown in FIG. * Molding die specifications; Gear module = 2, number of teeth 30, outer diameter 64
mm, tooth length approx. 4 mm, tooth width 10 to 10.05 mm, male side Teflon spacer 1.5 mm x 55 mmφ, female side stainless steel spacer 1 mm x
64 mm, same Teflon spacer 0.5 mm × 64 mm Example 2 A molding die shown in FIG. 9 was used, and the experiment of the previous example was carried out by changing the following points. Resin used: Low-density polyethylene (Sumitomo Chemical, MI ≈ 2) Extruder tip temperature: 200 ° C Phase difference between male and female: 1/2 pitch Teflon spacer: 0.5 mm and 1.5 mm thick, Metal spacer: thick 1 mm thick A corrugated sheet with perforations having a thickness of about 0.4 m shown in FIG. 2 was obtained. Example 3 and Comparative Example 1 The molding die shown in FIG. 10 was used, and the experiment of Example 1 was carried out by changing the following points. Resin used: Polypropylene (Unblended by Sumitomo Chemical
H501》 Extruder tip temperature: 220 ℃ * Specifications of molding die: Gear module = 3, number of teeth 20, outer diameter 66
mm, tooth length 6 mm, male side EPDM spacer 4 mm x 52 mmφ, female side stainless steel spacer 3 mm x 66.5 mmφ and 4 mm x 66.5 mm
φ, same Teflon spacer 0.5 mm × 52 mm φ As a result, a sheet with partial through holes shown in FIG. 4 was obtained. That is, the 4 mm thick stainless steel spacer and the male tooth 1
3 A through hole was formed at the contact portion with the side surface (indicated by a circle), but no hole was formed at other portions. From this experiment, it can be seen that the material of the small-diameter spacer may be rubber. Comparative Example 2 Using the mold shown in FIG. 11, a test was conducted according to Example 1 (however, the phase between the male molds was the same). No through holes were formed, probably due to elastic deformation of the metal spacers. From comparison with Example 2, it can be seen that the metal spacer needs to be sufficiently supported by the elastic material.

【The invention's effect】

As described above, the present invention can contribute to various industries by providing a novel corrugated plate with holes and a manufacturing method therefor, which have not existed so far.

[Brief description of drawings]

FIGS. 1 to 4 are partial plan views (A) of various corrugated plates with through holes according to the present invention, and I-I, II-II, and III thereof.
-III and IV-IV sectional view (B), FIG. 5 is a schematic vertical sectional view of a molding apparatus used for carrying out the method of the present invention,
FIG. 6 is a side view schematically showing a pair of unit molding dies, FIG. 7 is a cutaway front view thereof, and FIG. 8 is a typical exploded side view of a molding dies used for carrying out the method of the present invention. FIG. 9, FIG. 9 and FIG. 10 are views similar to FIG. 8 of another molding die used for carrying out the method of the present invention, and FIG. 11 is similar to FIG. 8 of the molding die of the comparative example. FIG. The meanings of the main symbols in the figure are as follows: -1 (1 _A to 1 _D ): whole invention sheet; -2,2 '/ 2 _A , 2 _B : 1 corrugations;-2a, 2 ′ A: Independent roof type part, 2b: Bottom part of corrugated part ・ ・ ・ 4: 2a through hole; ・ 3,3 ′: 2 channel; 11: Inventive sheet forming apparatus as a whole: ・ 12: Water tank; 13 ( 13a, 13b ・ ・), 13 '(13'a, 13'b ・ ・): Toothed roll (molding die) ・ ・ 16,16 ″: 13,13 ′ resin or rubber spacer, 1
6 ': 13, 13' metal spacer; 17: drive gear, 17 ': driven gear. 14: Extrusion die, 15, 15 ': Guide roll; Fm: Molten film material, W: Refrigerant; WL: W water line.

Claims (4)

(57) [Claims] 1. A liquid plastic film or sheet, wherein each wave is divided by a channel intersecting with the wave and has an opening on a side surface of the divided wave. . 2. The film or sheet according to claim 1, wherein the openings are regularly present on one side of the split wave. 3. A pair of facing toothed rolls, between the unit rolls constituting one toothed roll, made of a hard and rigid material, the diameter of which is greater than that of the tip circle on the left side. A large-diameter spacer that is not large and is larger than the diameter of the root circle,
A small diameter spacer made of an elastic material is attached between each unit roll constituting the other toothed roll, and a molten resin material is supplied in a film shape between both rolls that rotate inward with each other,
A method for producing a corrugated film or sheet having a through hole, which comprises rapidly solidifying after shaping. 4. The method according to claim 3, wherein a back plate made of an elastic material is attached to the large diameter spacer.