JPS62259774A - Manufacture of polishing chip - Google Patents

Abstract

PURPOSE:To make it possible to use one kind of polishing chips for both coarse polishing and finishing polishing, by heating and melting a mixture of a thermoplastic material, an organic filler and a volatile material to form the mixture into a rope-like shape, and by cutting the same into pellet-like pieces. CONSTITUTION:A mixture of a thermoplastic material, an inorganic filler and a volatile material is fed into a hopper 2 in an extruder 1 and is then extruded from dies 3 so that the mixture is turned into a rope-like shape. The extruded rope-like mold product 4 is introduced into water 6 in an water tank 5 for cooling. Since at this time the rope-like product 4 is in a condition which is just after extrusion by the dies 3, the moisture component in the product 4 is evaporated so that a foamed structure is formed. The rope-like product 4 is taken out from the water 6 after cooling, and is then cut by a cutter 7 into pellet like chips 8. Each chip 8 is formed on its outer peripheral surface with a skin layer 10 having fine wrinkling like unevennesses, and has its front and rear cut faces from which the foamed structure is exposed so that air pores 13 are opened to form coarsely uneven surfaces 12. By using these chips having the above-mentioned finely uneven surfaces 11 and coarsely uneven surfaces 12, both coarse polishing and finishing polishing may be simultaneously conducted.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a polishing tip used, for example, in barrel polishing, etc. [Background of the Invention] Polishing of metal products such as spoons and pachinko balls, or plastics. For deburring molded products, etc., so-called barrel polishing is applied, in which the object to be processed is filled into a barrel together with a polishing chip, and the barrel is oscillated or rotated to polish the object with the polishing chip. Ru. Such barrel polishing usually includes rough polishing and final polishing.

[Conventional technology]

Conventionally, a mixture of plastic and inorganic filler has been used as a material for this type of polishing tip (Japanese Patent Application Laid-open Nos. 51-147093 and 1982-15746).
No. 9, JP-A-59-129659). In order to carry out rough polishing, a rough polishing tip having a coarsely uneven surface is used, and in order to carry out final polishing, a final polishing tip having a finely uneven surface is used. Since such a method requires two-stage processing, in order to save time and effort, a mixture of rough polishing chips and final polishing chips is used.

Furthermore, attempts have been made to adjust the specific gravity of the polishing chip by providing pores inside the polishing chip, and to reduce the impact force on the workpiece to eliminate scratches on the surface of the workpiece. Japanese Patent Publication No. 50-39870, Japanese Patent Publication No. 1986-
242960).

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, it is necessary to create two types of chips, one for rough polishing and one for final polishing, and when mixing the chips for grooved rough polishing and the chips for final polishing, it is necessary to separate them after use. C-Also, in the polishing tip with pores, the pores are closed inside the polishing tip, so the air trapped in the pores behaves as a completely elastic body, and the object to be processed is However, when the abrasive chip collides with the material to be treated, the perfectly elastic behavior of the air causes the abrasive chip to bounce on the surface of the material to be treated like a rubber ball, and the inorganic filler inside the chip is It does not come into close contact with the surface of the material to be treated, resulting in a significant drop in polishing efficiency. Therefore, such abrasive chips have only been used for loosening soft materials to be treated, such as clothing such as jeans.

[Failure to solve the problem]

The present invention, as a means to solve the above-mentioned conventional problems, heat-melts a mixture of thermoplastic plastic, inorganic filler, and volatile substance in an extruder (1) and extrudes it into a string shape. The present invention provides a method for manufacturing a polishing chip in which the extruded string-like body is cut into predetermined lengths to form pellets after cooling.

The thermoplastic plastics used in the present invention include polyamide, polyethylene, polypropylene, acrylonitrile-butadiene-styrene resin, polyvinyl chloride, etc., but the type of plastic should be selected appropriately depending on the hardness of the material to be treated. It is.

The inorganic fillers used in the present invention include grindstone powder, ceramic powder, glass powder, metal powder, and ceramic fiber.

Powdered hard inorganic materials such as glass fibers and metal fibers.

It is a microscopic body that is fibrous or scaly.

Volatile substances used in the present invention include water, doluol, quidylol, ethyl acetate, and butyl acetate.

Methyl ethyl ketone, methyl isobutyl ketone.

Organic solvents such as methanol, ethanol, inglobanol, butanol, cellosolve acetate, butyl cellosolve, trichloroethane, carbon tetrachloride, mineral spirit, etc. are used.

The mixing ratio of the above plastic and the above inorganic filler varies depending on the hardness of the material to be treated, etc., but it is usually plastic 1
00 parts by weight, the inorganic filler is mixed in an amount of 30 to 80 parts by weight.

The amount of the volatile substance added to the mixture of the plastic and the inorganic filler can be adjusted in various ways depending on the boiling point of the volatile substance, the desired foaming state, the type of plastic, etc. When water is used, the amount is 0.5 to 2.5% by weight, preferably 1 to 2% by weight, based on the plastic.

If the amount of water added is less than the above range, the chips obtained will be in a low foaming state and the cushioning effect will not be sufficient.
If it exceeds the above range, foaming will be excessive and it will be difficult to extrude it into a string from an extruder.

[Effect]

The effects of the present invention are as follows.

When a mixture of a thermoplastic plastic, an inorganic filler, and a volatile substance is heated and melted using an extruder and extruded into a string, the volatile substance is released into the air immediately after the molten mixture is extruded from the die of the extruder. The extruded string-like body is made into a foamed structure.
A skin layer is formed on the circumferential surface of the string-like body, that is, the contact portion with the inner wall of the die, and the pores in the string-like body are not open, and only fine wrinkles are formed on the surface of the skin layer. When the string-like body is cut to a predetermined length, pores in the string-like body are opened at the cut surface. Therefore, according to the manufacturing method of the present invention, a polishing chip having a finely uneven surface on the peripheral surface and a coarsely uneven surface on the cut surface can be obtained.

The polishing tip of the present invention and the material to be treated are mixed.

When the mixture is placed in, for example, a barrel and shaken or rotated, the material to be treated is first roughly polished by the coarsely uneven surface of the polishing chip by the plastic that constitutes the chip and the inorganic filler it contains, and then by the finely uneven surface. The finish is polished. During such a polishing process, the polishing tip collides with the surface of the material to be treated, and the polishing tip is deformed by the impact, but at this time, the air in the pores is expelled to the outside from the opening. Therefore, the abrasive tip does not behave as a perfectly elastic body and does not bounce like a rubber ball on the surface of the material to be treated, but it collides with good cushioning properties, and the inorganic filler inside the abrasive tip is tightly attached to the surface of the material to be treated. Contact.

〔Effect of the invention〕

Therefore, in the present invention, rough polishing and final polishing can be performed simultaneously with one type of polishing tip.
Due to its good cushioning properties, it is possible to efficiently polish the surface of the treated material without damaging it.

〔Example〕

1250 parts by weight of nylon, 50 parts by weight of whetstone powder, 1.5 parts by weight of water
Part by weight of the mixture is put into the hopper (2) of the extruder (1) shown in Fig. 1 and extruded into a string from the die (3), and the extruded string-like molded product (4) contains water N (5). The string-like molded product (4) is put into the water (6) in the die (3) and cooled.
Immediately after being extruded, the moisture inside evaporates and forms a foamed structure. After cooling, the string-like molded product (4) is taken out from the water (6) and cut into pellet-like chips (8) by a cutter (7). As shown in FIGS. 2 and 3, the chip (8) has a peripheral surface that is fused with the die (3) of the extruder (1); a skin layer 1101 having fine wrinkle-like unevenness is formed thereon. The surface of the skin layer (Ill) becomes a finely uneven surface (6), and the foamed structure is exposed on the front and rear cut surfaces by the cutter, and the pores α■ are opened to form a coarsely uneven surface (6). When polishing is performed using a polishing chip (8) having such a finely uneven surface α1) and a coarsely uneven surface t1→, rough polishing and final polishing can be performed simultaneously.

In addition to the above embodiments, the chip (8) may be coated or impregnated with an antistatic agent, or the antistatic agent may be kneaded into plastic. Addition of the antistatic agent as described above prevents polishing powder from electrostatically adhering to the chip (8).

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention,
FIG. 1 is a manufacturing process diagram, FIG. 2 is a sectional side view of the proboscis, and FIG. 3 is a perspective view of the chip. In the figure (1)...Extruder (4)...String-like molded product (8)...Chip patent applicant Aron Kasei Co., Ltd.] Diagram 2 Diagram ''+3 Diagram

Claims (1)

[Claims] A mixture of a thermoplastic plastic, an inorganic filler, and a volatile substance is heated and melted in an extruder and extruded into a string, and the extruded string is cut into a predetermined length before or after cooling. A method for manufacturing a polishing chip, characterized in that the chip is made into a pellet.