JP2001170891A - High polymer material cutting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting method capable favorably finishing a cut surface in cutting a workpiece comprising organic high polymer material. SOLUTION: On the surface of a cutting part of a workpiece W, freezing agent of -50 deg. or less, or favorably -1000 deg.C or less, is applied, while it is cut simultaneously with or immediately after that. Application of the freezing agent is performed even after cutting, and a cutting means and the freezing agent respectively comprise carbon dioxide laser and liquid nitrogen.

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 workpiece made of a polymer material. In particular, the present invention is suitable for cutting thermosetting and thermoplastic plastic materials, etc., where it has been difficult to obtain a clean cut surface.

[0002] Here, a description will be mainly given of a cutting process of a plastic material as an example, but it is of course applicable to a cutting process of other materials, and further to a drilling / grooving process.

[0003]

2. Description of the Related Art Conventionally, plastic cutting methods include cutting with a cutting tool (slicing saw, band saw, circular saw cutting), cutting with abrasive grains (grinding / ultrasonic / injection cutting method), and shearing (shearing method). (Repetitive shearing), heating / melting cutting (frictional heat / electric heat / gas heat / combustion heat), and discharge cutting. (Plastic Processing Technology Handbook Editing Committee, "Plastic Processing Technology Handbook New Edition", published by Nikkan Kogyo Shimbun, published on December 20, 1977, p. 713).

[0004] However, in the case of the above-mentioned conventional cutting method, it was difficult to obtain a clean cut surface on a plastic plate or the like.

[0005] For example, when the cutting speed by a cutting tool is reduced, burnt heat or the like is apt to be generated when the material is thermosetting, and heat fusion or discoloration is caused when the material is thermoplastic. . Conversely, if the cutting speed increases, the cut surface becomes rough, and chipping tends to occur for brittle materials.

[0006] In view of the above, an object of the present invention is to provide a method for cutting a polymer material, which makes it easy to obtain a clean cut surface (cut surface) on a workpiece made of the polymer material.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the inventors of the present invention have worked diligently to develop a cutting part of a workpiece made of a polymer material, and It has been found that a clear cut surface can be obtained by performing the cutting process simultaneously while applying the polymer. Thus, the present inventors have conceived a cutting method for a polymer material having the following structure.

[0008] When cutting a workpiece made of a polymer material, the cut portion of the workpiece is set at -50 ° C.
Hereinafter, it is characterized in that the cutting is performed simultaneously or immediately after desirably applying a freezing agent at -100 ° C or lower.

In the above configuration, the application of the freezing agent may be performed after the cutting. This is suitable for the case where the cut line width is fine and the cut surfaces easily fuse after cutting.

It is desirable that the cutting means is a laser because it is easier to obtain a cleaner cut surface than other cutting means.

A carbon dioxide laser is used as the laser,
It is desirable to use liquid nitrogen as a freezing agent because it is easy to obtain a clean cut surface.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a cutting method according to the present invention will be described.
This will be described in detail with reference to the drawings.

In this embodiment, laser processing is employed as the cutting means. The laser may be a solid-state laser or a gas laser, and among them, a carbon dioxide (CO ₂ ) laser is preferable. This is because the carbon dioxide gas laser is a kind of gas laser which is easy to continuously oscillate and has good coherence (has good directivity), and a laser having a high laser density is easily obtained and is often used as a cutting laser.

FIG. 1 shows a main part of a carbon dioxide gas laser processing apparatus 12 provided with a cooling device used in the present embodiment in a cutting (processing) portion.

The laser processing device 12 includes a laser nozzle (output mirror) 14, a freezing agent application nozzle (ejection nozzle) 16, and a work table 18. Naturally, the laser nozzle 14 is connected to a laser generator (not shown), and the cryogen application nozzle 16 is
The hose is connected to a cryogen storage tank (not shown) via a pump or the like.

Here, the cryogen application nozzle 16 is arranged concentrically with the laser nozzle 14 and has an inner cylinder 16a forming a laser passage hole 15 and a cryogen spray port 17 which is an annular port closed at the upper end together with the inner cylinder 16a. And an outer cylinder 16b forming the outer cylinder 16b. A cryogen supply nipple 20 that is connected to the cryogen ejection port 17 is screw-connected to the outer cylinder 16b, and a cryogen supply hose 22 is connected to the cryogen supply nipple 20. The coating nozzle 16 is usually formed of a metal material such as stainless steel.

The work table 18 may be provided with a transport mechanism that moves by itself or may be fixed. In the case of a fixed type, the laser nozzle 14 can be moved by moving means such as a robot mechanism. The work table 18 may be made of metal, plastic, or ceramic.

At this time, each distance between the laser nozzle 14 and the freezing agent application nozzle 16 and the work table 18 is, for example, 40 mm for the former and 20 mm for the latter. The application nozzle diameter d is 10 mmφ, and the application nozzle gap s is 2 mm.

Next, a method of cutting (working) a polymer material, which is a workpiece W, using the laser processing apparatus 12 having the above configuration will be described.

Here, the polymer material may be synthetic or natural, and may be plastic, rubber, fiber, paper, cloth,
Although it does not matter leather, it is particularly suitable when applied to plastics.

Specifically, examples of the plastic include thermoplastic resins such as polyethylene, polyimide, polypropylene, polystyrene, ABS resin, PVC, acrylic resin, polyacrylonitrile, cellulose acetate, polyamide, polyimide, polycarbonate, saturated polyester, and fluororesin. And thermosetting organic and semi-inorganic materials such as melamine resin, epoxy resin, polyurethane, unsaturated polyester and silicon resin (silicone).

The form of the workpiece W is usually a plate material (including a sheet material, a film material, and a cloth material), a block material, a column material,
The material may be a bar or the like, but may be a three-dimensional molded product or the like, and is not particularly limited as long as it requires cutting.

Among these, a plate material, particularly a thin sheet material or a film material, is desirable because the effects of the present invention can be easily obtained. This is because, when a block material or a thick plate material is used, it is difficult to freeze the lower surface when a freezing agent described later is applied to a cut portion. In the case of a thick wall, it is desirable to provide a freeze coating means on the side opposite to the cut surface.

Then, with the work (workpiece) W placed on the work table 18, the laser processing apparatus 12 is moved in the direction of the white arrow. Naturally, the work W may be moved by the work table 18 with the laser processing device fixed.

The moving speed at this time depends on the material and the thickness of the work W, but is, for example, 5 to 500 mm / s, preferably 50 to 100 mm / s.

At this time, from the freezing agent application nozzle 16
The freezing agent F is in a jetting state, and the laser beam L is being irradiated from the laser nozzle 14.

Here, the supply temperature of the freezing agent F is-
A material having a temperature of 50 ° C or lower, preferably -100 ° C or lower is used. Specifically, liquid nitrogen (−196 ° C.), solid carbon dioxide powder (−54 ° C.) and the like can be used. In the case of solid carbon dioxide powder, spray, rub, and drop apply. In addition,
Freon 1-11.12 and methyl chloride can also be used, but they are not desirable from the viewpoint of environmental destruction.

The injection amount (application amount) of the liquid nitrogen varies depending on the material and plate thickness of the work and the processing speed, but is usually 0.1 to 10 cc / cm ^{2 in} terms of liquid.

The output of the laser beam depends on the material of the work,
Depending on the thickness, for example, 2
It shall be 00-500W.

For this reason, the workpiece is laser-cut simultaneously or immediately after being frozen by the freezing agent, and a clean cut surface C is obtained.

At the time of cutting the workpiece W, processing heat (cutting heat) is generated due to the destruction of the cut portion. However, since the cut portion and its surroundings are frozen with a freezing agent, heat is immediately emitted from the cut portion. , As before, processed product (plastic material)
A clean cut surface can be obtained without causing scorching, fusion, discoloration, etc. on the cut surface C of W. In normal freezing,
Although the tissue destruction of the polymer material (organic / semi-inorganic) occurs, the method of the present invention does not cause tissue destruction and brittle cracks (notches) because it freezes rapidly with a cryogenic freezing agent. , A clean cut surface can be obtained.

If the output of the laser beam is excessive and the work itself is melted, the work itself is frozen immediately thereafter, so that there is no risk of reattachment (fusion) and defective cutting. Therefore, precise cutting with an extremely small cutting line width is possible.

In the above description, the laser beam was frozen immediately before and immediately after the laser cutting. However, the laser beam may be frozen and cut only immediately before using a laser processing apparatus 12A as shown in FIGS. The same parts as those in FIG. 1 are denoted by the same reference numerals, and all or part of their description will be omitted.

Specifically, the coating nozzle main body 24, which is a block, has a frozen agent jetting port (arc-shaped opening) 17A and a laser beam passage hole 15A concentrically located with the laser nozzle 14. A cryogen supply nipple 20A is screwed into the cryogen ejection port 17A. Further, an electric heater 26 for preventing the freezing of the outlet of the cryogen supply nipple 20A is embedded.

In the above embodiment, the freezing agent jetting means has been described as an example integrated into the laser processing apparatus. However, it may be moved separately and independently. Further, the case where the cryogen is ejected in a gaseous state is taken as an example. However, the cryogen is kept in a liquid state and immediately before laser processing, is applied with a coating gun (usually connected to the cryogen tank via a hose via a pump). May be applied by flowing down or dripping.

Further, a laser has been described as an example of the cutting means, but a water knife (water jet), and further, the cutting means: cutting with a blade, cutting with abrasive grains (grinding / ultrasonic / jet cutting method), It is also applicable to shearing, heating / melting cutting, electric discharge cutting.

[0037]

According to the method for cutting a polymer material of the present invention,
As described above, -50 is added to the surface of the cut portion of the workpiece.
With a configuration in which cutting is performed simultaneously or immediately after applying a freezing agent at a temperature of not more than 0 ° C., a clean cut surface (cut surface) is easily obtained on a workpiece (work) made of a polymer material.

The reason is presumed to be that the use of a freezing agent at -50 ° C. or lower results in the polymer material (organic / semi-inorganic) being cut in a state where no tissue destruction occurs.

In fact, when a polyacryl plate was cut with a carbon dioxide gas laser while applying liquid nitrogen, a fine and clean cut surface was obtained on the cut surface, but when cutting without applying liquid nitrogen, the cutting was performed. Melt dripping occurred on the surface, and a practical cut surface could not be obtained.

Naturally, since the area around the cutting line is also frozen, even if the cutting width is extremely small and the cut surfaces are in contact with each other as in the conventional case, the heat required for heat fusion is removed. Therefore, there is no need to cut while separating the cut surface, and a stable cutting operation can be performed.

Under conditions where heat fusion is easy, applying a freezing agent to the portion immediately after cutting can more reliably prevent fusion of the cut surfaces.

In the above publication ("Plastic Processing Technology Handbook"), it is necessary to cool the workpiece and tool as much as possible during cutting in order to minimize the influence of the generation of processing heat. From a viewpoint, it is described that "it is necessary to use an air jet or a liquid coolant, or to try sub-zero cutting" (see p. 703). However, the description does not suggest the present invention.

That is, the liquid coolant is described in parallel with the air jet and is used in place of air. In some cases, the use of water or the like, or at most an antifreeze liquid slightly lower than the freezing point, is used. Presumed. It is also presumed that sub-zero cutting is also performed in a sub-zero atmosphere, and that the entire material is embrittled at low temperature (because it is not instantaneously frozen) and cracks are likely to occur.

As an example of a laser processing method, Japanese Patent Application Laid-Open No.
Japanese Patent No. 118052, Japanese Patent Application Laid-Open No. 6-198485, and the like, a method of cooling and processing a metal material is known.
The effect on the metal material is similar to the effect on the workpiece, and does not affect the invention of the present invention.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a laser processing apparatus that can be used in the present invention.

FIG. 2 is a cross-sectional view showing another example of a laser processing apparatus that can be used in the present invention.

FIG. 3 is a view taken along line 3-3 in FIG. 2;

[Explanation of symbols]

 12, 12A Laser processing device 14 Laser nozzle 16, 16A (freezing agent) application nozzle 18 Work table

Claims (5)

[Claims] 1. When cutting a workpiece made of a polymer material, simultaneously or immediately after applying a freezing agent at -50 ° C. or lower to the surface of the cut portion of the workpiece, A method for cutting a polymer material. 2. The method according to claim 1, wherein the temperature of the freezing agent is -100 ° C. or lower. 3. The method for cutting a polymer material according to claim 1, wherein the application of the freezing agent is further performed after the cutting. 4. The method according to claim 3, wherein the cutting means is a laser. 5. The method according to claim 4, wherein a carbon dioxide laser is used as the laser and liquid nitrogen is used as the freezing agent.