JP3936838B2 - Manufacturing method and manufacturing apparatus for sheet product without foreign matter adhesion - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a manufacturing method and a manufacturing apparatus for a sheet product that is suitable for use in a sheet used for optical applications or a sheet that is post-processed such as coating, and that has no foreign matter adhesion.
[Prior art]
[0002]
Polymethylmethacrylate resin sheets used for optical applications such as light guide plates that constitute so-called backlights in notebook computer displays require high optical properties such as transparency in the sheet itself, and the sheet surface It is also required that there be no scratches or distortion.
On the other hand, in order to use for a specific application, an abrasion-resistant coating liquid or an antireflection coating liquid may be applied to the surface of the sheet for post-processing. Even in such a case, it is required that the sheet surface is not damaged and no foreign matter adheres.
[0003]
For this reason, in a conventional molded sheet such as a thermoplastic resin plate, a surface protective film is attached to the entire surface, and the surface protective film is peeled off during use. That is, the surface protective film is stuck on the surface of the molded sheet immediately after molding so that foreign matter does not directly adhere to the sheet. Thereafter, the sheet is cut into a predetermined width and length. In general, sheet forming (extrusion molding, etc.), surface protective film sticking, and sheet cutting are continuously performed on a continuous production line.
[0004]
FIG. 3 shows a normal production process by this continuous production line. The molded product extruded from the extruder 4 is glossed by a polishing machine 8 comprising a plurality of finishing rolls 5, 6, and 7 (calendar rolls). A molded sheet 1 having a predetermined thickness to which smoothness is imparted is obtained. Next, after the surface protective films 2 and 2 are adhered to both sides by the masking machine 9, the molded sheet 1 is sent to the side cutter 11 through the take-up machine 10, and both sides are continuously sawed by a circular saw or the like. Further, the sheet product 3 is obtained by being cut into a predetermined length by a cross cutter 12 made of a circular saw or the like. The sheet products 3 are sequentially carried out of the line by the stacker crane 13 using a sucker and stacked.
[0005]
However, when the molded sheet 1 is cut, foreign matter such as saw dust is generated and adheres to the surface of the sheet 1 to which the surface protective films 2 and 2 are attached. Therefore, it is necessary to remove the foreign matter. As a foreign matter removal method that is usually used, an offline operator brushes the sheet surface with a brush or a brush, etc., or offline, one sheet at a time, air blow to clean the sheet surface. Foreign matter was removed.
[0006]
However, manual removal of foreign matter offline may cause the following problems.
(1) In the process of shifting the sheet from the continuous production line to the offline, scratches caused by foreign matters such as saw dust are likely to occur on the sheet surface.
(2) Since this is a manual removal operation, variations in foreign matter removal tend to occur.
(3) If foreign matter removal is incomplete and foreign matter remains on the surface of the sheet, when the sheet is stacked and packaged and transported together with other sheets, the foreign matter bites into the sheet with the weight of the stacked sheets, and the sheet Scratches are likely to occur.
[0007]
Sheets used for optical applications such as LEDs, even if they are fine scratches, adversely affect the quality of the final product and cause practical problems.
[0008]
[Problems to be solved by the invention]
The objective of this invention is providing the manufacturing method and manufacturing apparatus of a sheet product which can remove the foreign material on the surface of a sheet | seat on a continuous manufacturing line, and there is no foreign material adhesion.
[0009]
[Means for Solving the Problems]
The method for producing a sheet product according to the present invention for solving the above-mentioned problem is the method of cutting a molded sheet having a surface protective film adhered to a surface into a predetermined length and removing saw dust by air suction during the cutting. The rotating brush is rotated in the sheet conveying direction at a rotation speed faster than the sheet conveying speed to brush the sheet surface, and foreign matter adhering to the sheet surface is removed by air suction.
[0010]
That is, in the present invention, after removing the saw dust when cutting the molded sheet by air suction, by brushing with a rotating brush that rotates a sheet of conveyance faster rotational speed than the speed, the foreign matter adhering to the sheet surface Since it knocks out and then sucks air, it is possible to reliably remove the foreign matter on the sheet surface without unevenness. In particular, when the method of the present invention is used, foreign matter can be removed on the continuous production line, so that it is not necessary to go off-line from the continuous production line to remove foreign matter as in the prior art, and therefore go offline. In this case, it is possible to solve the problem that scratches caused by foreign matters occur.
[0011]
In the present invention, the reason why the rotating brush is rotated in the conveying direction of the molded sheet is that if the rotating brush is rotated in the direction opposite to or perpendicular to the conveying direction, the surface protective film on the sheet surface may be peeled off.
[0012]
A sheet product manufacturing apparatus according to the present invention suitable for carrying out the above-described method of the present invention includes a cutting means for cutting a molded sheet with a surface protective film pasted into a predetermined length, and sawdust when cutting the molded sheet. A first air suction device that sucks in, a rotating brush that brushes the surface of the cut sheet rotated at a rotational speed faster than the sheet conveying speed in the sheet conveying direction, and foreign matter on the brushed sheet surface. And a second air suction device for air suction. Preferably, the cutting means, the rotating brush, and the second air suction device according to the present invention are installed in this order along the conveying direction of the molded sheet.
[0013]
That is, according to the manufacturing apparatus of the present invention, it is possible to perform the process from the attachment of the surface protective film to the suction removal of the foreign matter on the continuous production line, and there is no manual removal of the foreign matter offline. In order to carry out, the trouble that the damage | wound resulting from a foreign material generate | occur | produces when shifting to a offline from a continuous production line is eliminated.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. 1 and 2 show a cutting step and a foreign matter removing step in a continuous production line for sheets according to this embodiment. That is, in this continuous production line, as shown in FIG. 1 and FIG. 2, the molded sheet 1 having the surface protective film adhered to the surface thereof has a predetermined width on both sides by the side cutter 11 (first cutting means). And then continuously cut into a predetermined length by the cross cutter 12 (second cutting means). As the side cutter 11 and the cross cutter 12, for example, a circular saw or the like is used. Above the cross cutter 12, an air suction device 16 for sucking scattered saw dust is provided. Thereafter, the sheet 1 is brushed by the rotating brush 14 that rotates in the conveying direction of the sheet 1, and then the foreign matter on the surface is sucked by the air suction device 15.
[0015]
As shown in FIG. 3, the molded sheet 1 has surface protective films 2 and 2 attached to both surfaces in a peelable manner. The molded sheet 1 is not particularly limited, and examples thereof include a thermoplastic resin plate made of acrylic resin such as polymethyl methacrylate, polycarbonate, polyvinyl chloride, polystyrene, polyethylene, polypropylene, and the like. These thermoplastic resin plates can be manufactured not only by extrusion molding but also by continuous belt molding in which molding is performed between two belts.
[0016]
As the surface protective films 2 and 2, for example, an adhesive layer made of EVA, low density polyethylene or the like is provided on one side of a base film such as polyethylene, polypropylene or polyethylene terephthalate. The thickness of the surface protective films 2 and 2 is preferably about 30 to 120 μm. The surface protective film 2 may be affixed only to one side of the sheet 1.
[0017]
The rotating brush 14 includes a rotating roll 14a arranged in the width direction of the sheet 1 orthogonal to the conveying direction of the sheet 1, and a brush 14b planted on the surface thereof. The brushes 14b are densely planted over the entire circumference of the rotary roll 14a and over the entire width direction of the sheet 1 so as to contact the surface of the sheet 1 without a gap.
[0018]
The material of the brush 14b is preferably one that does not damage the surface of the sheet 1 and that has sufficient hardness to knock out foreign matter such as saw dust adhering to the surface of the sheet 1, such as horse hair and wool. Examples thereof include synthetic fiber yarns such as animal hair, nylon, polyester, polypropylene, and polyvinyl chloride, and natural fiber yarns such as silk, cotton, and hemp. The thickness and length of the hair are not particularly limited because they are related to the hardness of the hair, etc., but the thickness is about 0.01 to 1 mm from the surface of the planted rotating roll 14a. The length should just be about 20-60 mm. A large number of these bristles are bundled, and the ends of the bristles are inserted into a large number of planting holes (not shown) drilled in the peripheral surface of the rotating roll 14a, and fixed with an adhesive or the like, thereby rotating the rotating roll 14a. The brush 14b planted on the peripheral surface can be obtained.
[0019]
The diameter of the rotating roll 14 a defines the length (brush contact length) c at which the brush 14 b contacts the surface of the sheet 1 together with the length of the brush 14 b. The brush contact length c is usually about 1 mm or more, and if the brush contact length c is shorter than this, the brush contact length c is not sufficient to knock out foreign matters such as saw dust adhering to the surface of the sheet 1. On the other hand, the upper limit of the brush contact length c is not particularly limited. However, when the brush contact length c is increased, the diameter of the rotary roll 14a and the length of the brush 14b must be increased. Considering these, the diameter of the rotating roll 14a is suitably about 30 to 100 mm.
[0020]
Since the rotating brush 14 rotates in the conveyance direction of the sheet 1, it is preferable that the rotation speed on the surface of the rotating brush 14 is faster than the conveyance speed of the sheet 1, so that foreign matter on the surface of the sheet 1 can be knocked out efficiently. . The rotation speed of the rotary brush 14 may be about 50 to 2000 rpm, preferably about 80 to 1800 rpm.
[0021]
The air suction device 15 is installed in the vicinity of the rotating brush 14 on the downstream side of the rotating brush 14. The air suction device 15 is preferably as close to the rotating brush 14 as possible, and if the gap between them becomes large, there is a possibility that the foreign matter knocked out by the rotating brush 14 cannot be sufficiently sucked and removed. The gap between the rotating brush 14 and the air suction device 15 is usually 30 mm or less, preferably 20 mm or less.
[0022]
Foreign matter removal is performed on the back surface (lower surface) of the sheet 1 by an air suction device 17 disposed on the upstream side of the cross cutter 12. A fixed brush (not shown) is attached to the air suction device 17, and when the brush contacts the back surface of the sheet 1, foreign matter is dropped and removed by suction.
The rotating brush 14 and the air suction device 15 may be provided on both surfaces (upper and lower surfaces) of the sheet 1 that has passed through the cross cutter 12 to remove foreign matters on both surfaces.
[0023]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
[0024]
EXAMPLE In producing a polymethyl methacrylate plate, as shown in FIG. 3, the thickness of the polymethyl methacrylate molded sheet 1 extruded from the extruder 4 and conveyed through the polishing machine 8 is thickened by the polishing machine 9. A polyethylene film having a thickness of 90 μm (surface protective films 2 and 2) was attached. The polyethylene film used was provided with an adhesive layer on the surface overlapped with the molded sheet 1, and the adhesive strength was 30 g / 25 mm. After sticking, both sides of the polymethylmethacrylate plate were sawed with the side cutter 11 to adjust the width to 1000 mm, and then sawed into a length of 2000 mm with the cross cutter 12.
After cutting, as shown in FIGS. 1 and 2, the rotary brush 14 and the air suction device 15 provided on the sheet conveyance path downstream from the cross cutter 12 are continuously passed to remove foreign matters such as saw dust. . The gap between the rotating brush 14 and the air suction device 15 was adjusted to 15 mm.
The details of the used rotating brush 14 are as follows.
(1) Brush 14b
Material: Horse hair Length: 40mm (It is the length protruding from the brush planting hole)
Thickness (diameter): 0.08mm
(2) Rotating roll 14a
Material: Polyvinyl chloride Diameter: 60mm
Diameter of brush planting hole: 5mm
Distance between brush planting holes: 10 mm
The height of the rotating brush 14 was adjusted so that the brush contact length (c) was 2 mm with respect to the polymethyl methacrylate plate. Then, the rotating brush 14 was rotated (forward rotation) at 90 rpm along the conveyance direction of the polymethyl methacrylate plate. The air suction device 15 has an air suction port having a width of 80 mm and a length of 2200 mm on the lower surface.
As described above, the polymethyl methacrylate plate that has passed through the rotating brush 14 and the air suction device 15 is transferred to the off-line, the presence or absence of foreign matter such as saw dust is visually observed, and the polymethyl methacrylate plate is further moved off-line. It was observed whether or not there was a flaw due to foreign matter on the surface of the film. As a result, no foreign matter was adhered to the surface of the polymethyl methacrylate plate, and no scratches due to the foreign matter were observed.
[0025]
Comparative Example Except that the rotating brush 14 and the air suction device 15 were not provided, the polymethyl methacrylate plate was sawn in the same manner as in the example, and moved to an off-line to visually observe the presence or absence of foreign matter and scratches caused by the foreign matter. did. As a result, foreign matter adhered to the surface of the polymethyl methacrylate plate, and scratches due to the foreign matter were observed.
[0026]
【The invention's effect】
According to the present invention, since the foreign matter on the surface of the sheet can be removed on the continuous production line, it is possible to solve the problem that the scratch caused by the foreign matter occurs when shifting from the continuous production line to offline. effective.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing a part of a continuous production line for molded sheets according to an embodiment of the present invention.
2 is a schematic perspective view showing a part of the same continuous production line as FIG. 1. FIG.
FIG. 3 is a schematic explanatory view showing a normal continuous production line for producing a sheet product.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Molding sheet 2 Surface protection film 3 Sheet product 11 Side cutter 12 Cross cutter 14 Rotating brush 15 Air suction device

Claims (3)

After cutting the molded sheet with the surface protective film pasted to a predetermined length and removing the saw dust by air suction at the time of cutting , the rotating brush is faster in the sheet conveying direction than the sheet conveying speed. The method of manufacturing a sheet product without adhesion of foreign matter, characterized in that the surface of the sheet is brushed by rotation and the foreign matter attached to the surface of the sheet is removed by air suction. Cutting means for cutting the molded sheet with the surface protective film pasted to a predetermined length, a first air suction device for sucking the sawdust when cutting the molded sheet, and the sheet conveying direction more than the sheet conveying speed A rotating brush that brushes the surface of a sheet that has been rotated and cut at a high rotational speed, and a second air suction device that sucks air from the surface of the brushed sheet, and has no foreign matter attached. Sheet product manufacturing equipment. The manufacturing apparatus according to claim 2, wherein the cutting means, the rotating brush, and the second air suction device are installed in this order along the conveying direction of the molded sheet.

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