JPH08252800A - Cutting method for thermoplastic resin sheet - Google Patents

Abstract

PURPOSE: To manufacture a resin sheet of sharp cut section without generating chips by bringing a blade whose temperature is higher than that of the resin sheet by the prescribed value into contact with this resin sheet while the temperature of the thermoplastic resin sheet is not less than the heat deformation temperature after the resin sheet passes a finishing roll. CONSTITUTION: Finishing rolls 2, 3, 4 which are generally plural in number, and at least two, cool the molten resin to be extruded from a die 1, and generally is of glazed type to make the surface of the resin smooth. The thermoplastic resin sheet 5 passing through the finishing rolls, 3, 4 is not sufficiently cooled yet, and cooled and solidified in the receiving process. While the temperature of the resin sheet 5 is above the heat deformation temperature(HDT), the resin sheet is cut by a blade 6. The temperature of the blade 6 is HDT+(100-250) deg.C. If the temperature of the blade 6 is below HDT+100 deg.C, chips are generated, and in addition, the shear friction during the cutting is increased to make it difficult to achieve the cutting itself.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting a thermoplastic resin plate.

[0002]

2. Description of the Related Art Thermoplastic resin plates are continuously manufactured by an extrusion molding method or a calender roll method. The resin plate produced by these methods is cut to align the ends. Further, cutting is performed to take out a plate having a desired size. Depending on the thickness of the resin plate, the cutting is performed by using a normal blade, such as a knife, a saw blade or laser light.

[0003]

When a resin plate is cut by a normal blade, the shearing friction at the time of cutting is large, and the resin plate is liable to be cracked, and the resin plate is so thin that it is called a so-called film. Not only can it be applied, but cutting chips are generated during cutting. Further, when the resin plate is cut with a saw blade, a large amount of cutting dust is generated, and the cutting dust damages and contaminates the surface of the resin plate. The method using laser light requires a special device such as a laser light generator, requires safety and health measures for humans when handling the laser light, and deteriorates the resin at the cut portion of the resin plate.

Therefore, the present invention provides a cutting method that is inexpensive and simple, does not generate cutting chips, does not deteriorate the resin, is easy to maintain, and is highly safe.

[0005]

The present invention provides a method for producing a resin plate by passing a molten thermoplastic resin through a plurality of finishing rolls, and after passing through the finishing rolls, the temperature of the resin plate is A method for cutting a thermoplastic resin plate, characterized in that a blade having a temperature of HDT + (100 to 250) ° C. is brought into contact with the resin plate while the temperature is not lower than the heat distortion temperature (HDT).

Examples of the thermoplastic resin in the present invention include resins such as acrylic resin, polycarbonate, styrene resin, vinyl chloride resin, polyolefin and polyester. Heat distortion temperature of these resins (HD
T) is the temperature measured according to ASTM D648.

A method for producing a resin plate from the molten thermoplastic resin of the present invention through a plurality of finishing rolls is a well-known method for producing a resin plate / sheet / film. For example, "Handbook of Plastic Processing Technology" (Showa 54)
October 20, 2014, published by Nikkan Kogyo Shimbun), pages 254 to 260
Page: “Plastic sheet extrusion technology” (May 1969)
Published by Industrial Research Council on May 29: "Plastics"
Vol.33, No.10 (October 1982 issue, Industrial Research Society) pages 49-56, "Molding technology for plastic sheets with improved appearance": Japanese Patent Publication No. 61-46305 "Extruder", "die", "polishing roll unit (polishing roll machine)", "roller table", "take-off roll", "edge trimming device",
There is so-called extrusion molding that uses a device of the configuration "cutting and stacking device". Others "Plastic Processing Handbook"
Pp. 323-360, there is a so-called calendering method using a device of "kneading device" for resin and "calender roll".

The finishing rolls are usually at least two and a plurality of rolls, and are usually glossy rolls for cooling the molten resin and smoothing the surface thereof. In addition, when attaching various patterns and textures to the surface of the resin plate,
In some cases, rolls with the pattern or grain are used.

The resin plate that has passed through the finishing roll is not yet sufficiently cooled, and is cooled and solidified in the process of being taken. Therefore, in the present invention, cutting is performed while the temperature of the resin plate is equal to or higher than the heat deformation temperature of the resin. If the temperature at the time of cutting is lower than the heat distortion temperature, chips will be generated at the time of cutting, or shear friction at the time of cutting will be large, which makes cutting itself difficult. The heat distortion temperature (HDT) + 50 ° C. is preferable.

The blade used for the cutting of the present invention is thin and has a straight or gentle curved shape like a razor blade or a woodworking knife. The thickness of the blade is selected according to the ease of cutting and the strength of the blade according to the thickness of the resin plate to be cut and the shear friction.

When cutting with the blade, the temperature of the blade is HDT + (100 to 250) ° C. If the temperature of the blade is less than HDT + 100 ° C., not only chips are generated, but also shear friction at the time of cutting becomes large and cutting itself becomes difficult. When the temperature exceeds HDT + 250 ° C, not only the cut surface becomes non-smooth, but also the cut portion remelts.

The blade and the thermoplastic resin plate may be brought into contact with each other by moving the blade, but when the resin plate is moving, fixing the blade provides stable cutting. Further, in order to reduce the shearing friction at the time of cutting, it is preferable that the resin plate and the blade are contacted at an acute angle.

[0013]

Industrial Applicability According to the method of the present invention, it is possible to produce a resin plate having a clean cut surface without generation of chips. This method is suitable for trimming the resin plate into a predetermined size.

[0014]

EXAMPLES The present invention will be described below with reference to examples.
The invention is not limited by these examples. A set of apparatuses used in the examples is shown in FIG. Details of the apparatus used are as follows.・ Plastic extrusion plate manufacturing equipment: Hitachi Zosen Co., Ltd. 3 units with a screen diameter of 120 mm, a single screw extruder, and a roll diameter of 350 mmφ. -Blade: NT Cutter L-500 type manufactured by NT Corporation-Blade heater: Electric soldering iron with a transformer attached to the power supply-Measurement of surface temperature of resin plate: Kos infrared radiation thermometer CT- Type 30

Example 1 Acrylic resin (SUMIPEX HT manufactured by Sumitomo Chemical Co., Ltd.)
-55X HDT; 95 ° C) was used to produce a resin plate having a thickness of 0.25 mm and a width of 1300 mm. A blade having a temperature of 250 ° C. was installed at a position where the resin temperature was 95 ° C., and 100 mm from both ends of the resin plate was cut at a line speed of 7 m / min. No cutting powder was generated at the cut portion, and re-fusion was not observed.

Example 2 Acrylic resin (SUMIPEX HT manufactured by Sumitomo Chemical Co., Ltd.)
-018E HDT; 100 ° C), thickness 1.8 mm, width 12
A resin plate of 00 mm was manufactured by extrusion molding. A blade having a temperature of 300 ° C. was installed at a position where the resin temperature was 120 ° C., and 100 mm from both ends of the resin plate was cut at a line speed of 3 m / min. No cutting powder was generated at the cut portion, and re-fusion was not observed.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the resin temperature of the resin plate was 70 ° C. and the blade was not heated. Although remelting was not observed at the cut portion, chips were generated.

[Brief description of drawings]

FIG. 1 is a schematic view of an apparatus used in an example of the present invention.

[Explanation of symbols]

 1: Die 2: 1st finishing roll 3: 2nd finishing roll 4: 3rd finishing roll 5: Thermoplastic resin plate 6: Blade 7: Heater

Claims (1)

[Claims] 1. A method for producing a resin plate from a molten thermoplastic resin through a plurality of finishing rolls, wherein the temperature of the resin plate after passing through the finishing rolls is a heat distortion temperature (H).
HDT + (100-250) ° C while above DT)
A method for cutting a thermoplastic resin plate, characterized in that a blade having the temperature of (1) is brought into contact with the resin plate.