JPS5918207B2 - Continuous manufacturing method for plastic sheet with geometric pattern through it - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of patterned plastic sheets, and more specifically to a method for continuously producing plastic sheets having the same geometric pattern running through them on both sides.

Conventional methods for manufacturing patterned plastic sheets include extrusion methods, calender roll methods, and pressing methods; in particular, in the method for manufacturing geometric pattern sheets, a layer of fine particles of a resin composition is deposited on a continuous belt conveyor, and the The fine particles are heated to partially fuse or sinter each particle, and this is formed into a porous aggregate to create a temporary molded body, and the surface of this molded body is printed with a printing device. Apply it in the desired geometric pattern.

Thereafter, this printed porous molded body is passed through a press machine and compressed into a uniform non-porous sheet by applying heat and pressure (hereinafter referred to as the sintering method), which is a relatively superior method. Are known. 5 There is also a method of assembling a desired pattern on a support using a board mold, etc., and simultaneously casting granular materials of each color according to the board pattern to form a patterned sheet (hereinafter referred to as the board mold method). .

However, since the above-mentioned sintering method uses a printing device, only fine particle compositions or paste-like compositions can be used. Since it does not reach the bottom of the porous body sufficiently, only thin sheets with geometric patterns can be produced.

Also, when looking at the cross section of the pattern sheet obtained by the sintering method by cutting it perpendicularly to the back surface, the boundary line between the cross section of one partial pattern and the cross section of the other adjacent partial pattern is It does not appear as a clear straight line from the front side to the back side. Therefore, when the pattern on the surface is worn away, the same clear pattern as the surface does not appear.

Furthermore, adjusting the amount of printing ink applied during this manufacturing process is also troublesome.

Furthermore, in this sintering method, in order to ensure that the particles of the sintered preform, which are present in the pre-sheet stage, sufficiently absorb the ink from the printing device, powder of small particle size is added to the preform composition. As a result, it is not possible to obtain a thick through-geometric pattern sheet in the final product sheet.

Furthermore, in the plate method, the boundaries of the pattern tend to collapse, making it difficult to obtain a clear geometric pattern. Furthermore, there is a drawback that non-uniformity in thickness tends to occur. Regarding the production of a plastic sheet with a geometric pattern penetrating both the front and back sides, the inventors of the present invention filed a patent application in 2013; According to this method, plastic granules are first fed onto a pattern frame type screen, and the plastic granules protrude below the screen along the pattern frame type. The granular material is supplied and filled into the space formed by the guide member, the base member (moving belt), and the screen using a spatula.

Next, this pattern frame type screen is removed, and the temporary formed particulate material forming a part of the geometric pattern created in this way is moved under the next pattern frame type screen by movement of the base member, where it is formed. The next empty space is filled with other plastic particles. The base member is further moved, and the space formed under the next frame-shaped screen is similarly filled with the next plastic granule. Similar operations are repeated until a preformed integral sheet with the desired final geometric pattern is obtained. Therefore, the number of pattern frame type screens required corresponds to the number of unit patterns constituting the final geometric pattern. The thickness of the temporary molded body formed in this manner is adjusted by the height of the particulate guide member provided along the pattern frame mold joined to the screen. In other words, by using a pattern frame mold to which a particulate guide member having a height corresponding to the desired thickness of the temporary formed body is joined, a geometric pattern of the desired thickness can penetrate through the front and back sides and be integrated. A preform from which a worn plastic sheet can be obtained is produced. Next, the patterned temporary molded body is sent into a heating furnace by moving the base member, heated and sintered while being freely exposed to the surrounding atmosphere to form an adhesive sheet, and then formed into a adhesive sheet that conforms to the desired geometric pattern. Processed and potted using an embossing roll or embossing press with a mold surface, an annealing process and a cooling process are performed to form a continuous long strip of plastic sheet with a penetrating geometric pattern. The plastic sheet with a penetrating geometric pattern produced in this way can maintain its original pattern for a long time even if it is abraded. An object of the present invention is to provide a method of manufacturing a sheet with a geometric pattern extending through the front and back sides having more complicated pattern boundaries, which has an excellent production capacity and a shortened manufacturing process, based on the above-mentioned invention.
The outline of the method of the present invention will be explained below with reference to the drawings.

In FIG. 1, rotary screens 1, 2, each having a screen opening having a size and shape corresponding to a desired geometric pattern,
3 are sequentially arranged on the conveyor belt 4, and each rotary screen is rotated in synchronization with the circulation movement of the conveyor belt.

As the rotary screen rotates, the plastic particles 17, 18, 19 are supplied to corresponding locations on the conveyor belt while being leveled by the squeegees 11, 12, 13, and temporarily formed bodies 17'', 18'', 19 ” is formed (second
(see figure). Next, the temporary formed body on the conveyor belt 4 enters a heating furnace 5 together with the conveyor belt, is sintered there, passes through a forming roll 6, and is then wound up as a long sheet 10.

The rotary screen used in the method of the invention is made, for example, of a thin metal plate and has guiding elements 14 for feeding the granular formulation around the screen openings, which have a shape corresponding to a geometric pattern.
, 15, and 16 are integrally bonded and molded (see FIGS. 3 and 4).

Therefore, there are more advantages than in the case of the invention of Japanese Patent Application No. 149154/1980, namely, the installation area of the rotary screen is less than 1/3 of that when using a flat screen.
Continuous transportation of raw materials and products is possible, which significantly improves productivity (for example, when making a product with a width of 1800 m and 71 L,
The winding speed of the product is 3 m/min in the case of a flat screen, but it is improved to 15 m/min with the method of the present invention), and since continuous conveyance is performed, a homogeneous product can be obtained. is obtained. The invention will be explained in more detail by the following examples.

EXAMPLE A dry blend having the following composition was extruded and ground using a shear grinder to produce a granular composition that passed through a 15-mesh sieve.

To 100 parts of the above granular composition, 20 parts of a paste resin (for example, Zeon 135J, manufactured by Nippon Zeon Co., Ltd., 200 mesh), 15 parts of a plasticizer, and 0.5 parts of a stabilizer are mixed.

In other words, the granular powder-free product is such that the granular composition and paste resin are uniformly distributed throughout the mixture, and fine particles can flow more or less freely around the particles of the composition as cores. make. The above formulation example shows an example of raw materials for carrying out the production method of the present invention, and additives may be used as long as they are not blended with granular powder that has properties suitable for carrying out the present invention. , the amount added can be changed appropriately. Furthermore, there are no particular limitations on the size and shape of the individual particles of the granules used in the present invention, and they may have any size and shape as long as they can pass through the mesh-like screen portion of the rotary screen. . In addition to vinyl chloride resin, raw material resins for the granular composition used in the present invention include vinyl resins such as vinyl acetate and vinyl fluoride polymers, or mixtures thereof, and other copolymerizable monomers. copolymers, polyethylene, polypropylene, butadiene,
Styrene copolymers and the like are suitable.

Further, pigments of colors corresponding to the respective pattern portions are added to prepare a granular powder-free material containing the same number of pigments as the number of colors of the patterns constituting one unit pattern sheet. Three pigment formulations were prepared in this example. Next, the manufacturing process of the present invention will be explained with reference to the drawings.

The above three types of unblended granular powder are charged uniformly in the width direction to each of the rotary screens 1, 2, and 3 using a screw conveyor or a tube conveyor.

Each of the rotary screens 1, 2, and 3 is provided with screen openings V, 2'', and 3'' each having a shape corresponding to the corresponding pattern portion, as shown in a developed view in FIG.
Guide members 14, 15, 1 are provided around this screen opening.
6 is provided. Furthermore, squeegees 11, 12, and 13 are built inside the rotary screen, respectively, and the unblended granular powders 17, 18, and 19 are applied to the ends of thin metal or plastic covers 21, 22, and 23, and the squeegees are from the gap (approximately 10 mm) with the conveyor belt 4.
Supply evenly on top like 17″, 18″, 19″ (
Figure 3). It is preferable that the tip of the squeegee has a blade shape by cutting the unmixed granular powder supply side so that the granular material can be smoothly supplied from the screen opening. Covers 21, 22, and 23 provided inside the rotary screen cooperate with each squeegee to uniformly and smoothly feed particulate matter from the screen opening onto the conveyor belt. In this way, the unblended granular powder is supplied onto the conveyor belt 4 in the order of the rotary screens 1, 2, and 3 corresponding to the predetermined pattern portions to form temporary formed bodies 1r, 18'', and 19''. It is formed. The conveyor belt is supported by a support roll 20 and continuously circulated by a drive roll 8 and a belt reversing roll 9 at both ends thereof. This conveyor belt is made of polytetrafluoroethylene reinforced with glass fibers, and can withstand the heat in the heating furnace and can be used for a sufficiently long period of time. The conveyor belt can also be constructed from product back-up material. Temporary molded body 17 on the conveyor belt
'', 18'', and 19'' are transported to a heating furnace (ambient temperature: 200'C) by a conveyor belt and heated and sintered.

The sheet that has been sintered into one piece is made of Bakatsuprol 7.
(for example, a rubber, paper, or metal roll) and a forming roll 6 (for example, an emboss roll, a flat roll) placed opposite the roll is used to perform a forming process that matches the pattern. The roll pressure is 2 to 10 kg/Cml and the temperature is 70°C. The sheet that has been subjected to a predetermined forming process is air-cooled and wound up as a continuous long belt sheet product 10. The rotary screen can be manufactured by a conventional method in textile printing technology, for example, by electroforming to create a shielding part other than the pattern (a part through which the unmixed granular powder does not pass) and a mesh-like screen part of the pattern part. Other methods include, for example, the corrosion method in which the screen portion is corroded into a mesh shape, the lacquer method in which a pattern is created using a photo-curing photosensitive agent, or the reinforcing material is placed on the entire surface of the mesh cylinder and further reinforced with resin, etc. It can also be manufactured by cutting out the necessary opening. The guide member provided on the circumference of the rotary screen is attached along the opening of the rotary screen by adhesive, heat fusion, welding, or the like.

The height of this guide member can be appropriately selected depending on the thickness required for the final sheet with a penetrating geometric pattern, but in this example, the thickness is 2.5 m77! The height of the guide member was set to 4.0 m1L in order to obtain a sheet product. In addition, the guide member has an acute angle θ wedge-shaped cross section in order to easily separate from the temporary molded body by rotation of the rotary screen and prevent the temporary molded body from collapsing when detached.
~40 sharpness is appropriate (see Figure 3). In addition, when feeding particulate matter onto the conveyor belt from the screen opening, any particulate matter that leaks from the tip of the squeegee and adheres to the inner wall of the rotary screen is sucked out by the suction nozzle 24 provided inside the rotary screen. Return it to the storage tank of
Can be used repeatedly.

Further, the rotary screen is constructed such that end rings are attached to the openings at both ends to reinforce the ends, and hooks, pulleys, etc. are attached to the end rings so that the rotary screen can be driven.

Next, the configuration of a screw conveyor as an example of a supply means will be explained.

The screw conveyor 1 consists of an outer cylinder and a screw 1, and is equipped with a material inlet in the form of a hopper at the rear of the outer cylinder, and a residual material outlet for discharging residual material at the front end, and has a material inlet and a residual material outlet. A flat material supply nozzle whose width is at least equal to the product width, that is, the screen opening width of the rotary screen, is provided between the rotary screen and the rotary screen. Then, the material is inputted from the material inlet of the hopper, conveyed by the screw, and filled into the rotary screen through the supply nozzle. Excess material is discharged from the residual material outlet and circulated in the material storage tank, making it possible to reuse it. By appropriately selecting the opening size and shape of the supply nozzle, it is possible to supply an appropriate amount of material resin particles into the rotary screen within the angle of repose without oversupplying or undersupplying. becomes. This is because the structure of the screw conveyor is relatively simple, so there is no risk of resin particles clogging or staying inside the screw conveyor, and smooth supply is possible. Therefore, there is no need for a detection device for material supply within the rotary screen, and there is an advantage in that it is only necessary to check the supply of resin material at the material inlet. The thickness of the sheet product according to the invention is from 1 to 5 m1L or more.

The thickness of the temporary molded body depends on the apparent specific gravity of the temporary molded body, but is generally about 150% of the thickness of the final product sheet. In the above example, there are three types of colors of the pattern; red pigments such as molybdenum, red red pigment, and parallax; yellow pigments such as zinc yellow, zinc chromate, and benzidine yellow; and blue pigments such as cobalt blue and ultramarine blue. However, by providing rotary screens corresponding to the desired number of colors, even more diverse patterns can be created. In addition, since the plastic sheet with the penetrating geometric pattern of the present invention is formed from granular materials, it is possible to combine the colors of the granular materials in a complex manner within one design that forms part of the pattern. You can create sheets with rich patterns.

When the device of the present invention is operated, the rotation of the rotary screen and the movement of the conveyor belt are perfectly synchronized, and the screen openings of the rotary screen and the corresponding positions on the conveyor belt meet in perfect alignment. do.

By operating these continuously, extremely high productivity can be ensured. Furthermore, the installation area of the manufacturing device can be reduced to one-third or less compared to a flat screen device.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a diagrammatically illustrated apparatus for carrying out an embodiment of the invention; FIG.
-A is a plan view of the conveyor belt in part A, FIG. 3 is an enlarged sectional view of the main parts near the rotary screen 3, and FIG. 4 is a developed view of the rotary screens 1, 2, and 3 shown in FIG. be.

Claims (1)

[Claims] 1. In a method of manufacturing a plastic sheet by continuously forming a temporary molded body using plastic granules as a raw material and heating and sintering this, the required number of rotary screens containing plastic granules are placed above the conveyor belt as required. The rotary screen is equipped with a screen opening shaped to correspond to each pattern and a guide member provided around the opening, and a conveyor belt that continuously moves the plastic particles from each rotary screen. 1. A method for continuously manufacturing a plastic sheet with a penetrating geometric pattern, characterized by sequentially supplying a plastic sheet with a penetrating geometric pattern to form a temporary molded body corresponding to each pattern portion, and then heating and sintering the temporary formed body and winding it up.