JPH0811475A - Method for shaping synthetic resin nib member - Google Patents

Abstract

PURPOSE:To obtain a nib of an ideal shape free from occurrence of scratchy writing or the like by a minimum labor by a method wherein a nib member made of a thermoplastic synthetic resin is sprayed with fine grains under environment not higher than the brittle temperature of the member, and an unwanted fine part of the nib member is removed by the impact force at this time. CONSTITUTION:A nib member made of a thermoplastic synthetic resin (e.g. a polyacetal resin) is cooled to the brittle temperature thereof or lower by the spray of liquid nitrogen or the like. Under this environment, the nib member is sprayed with fine grains (e.g. an approximately cylindrical material of a modified polyphenylene oxide resin with a diameter of 0.51mm and a length of 0.51mm). An unwanted fine part, e.g. what is called a burr, of the nib member is removed by the impact force at this time. As a result, a nib of an ideal shape free from occurrence of scratchy writing or the like can be obtained by a minimum labor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of processing and shaping the details of a thermoplastic synthetic resin nib, more specifically, a fine unnecessary portion (so-called burr etc.) of a flat plate nib having an ink passage.
Related to the removal and shaping method.

[0002]

2. Description of the Related Art Generally, thermoplastic synthetic resin shaped articles are
Fine (about 200 to 800 μm) burrs are often generated. It is often seen especially in those having a complicated shape, but depending on its application, it may cause a serious problem.

When a synthetic resin molded article is used as the pen tip of a writing instrument, the burr greatly affects the handwriting. In order to obtain the handwriting desired from the application, such a fine tip nib for writing fine lines or writing so-called calligraphic characters, or a flat nib, the nib with burr etc. still occurs. Is not preferable,
Until now, the method of removing the oyster with a brush, the cutter
Deburring work such as manually cutting off was done using such as.

[0004]

When a fine nib or a flat pen tip is formed by subjecting a synthetic resin rod body having a communication hole as an ink passage to a secondary process such as cutting or polishing. However, burr is generated due to the processing heat. These burrs are not only different in shape, but are often scaly, and the above method not only requires a great deal of work, but also cannot be removed cleanly.

[0005]

That is, according to the present invention, a pen tip member made of a thermoplastic synthetic resin is sprayed with fine particles in an environment below the embrittlement temperature of the member and the impact force of the pen tip member A gist is a method of shaping a pen tip member made of a synthetic resin, which is characterized by removing fine unnecessary portions.

[0006]

EXAMPLES Examples will be described below. Examples of nibs used in the shaping method of the present invention include a copolymer type of a polyacetal resin, a homopolymer type, a blend type of both, and a mixture of a polyacetal resin and another resin. As a manufacturing method thereof, a polyacetal resin (Duracon U10-01, Polyplastics Co., Ltd.) is attached to an extrusion nozzle for a flat rod, which is attached to a die portion (inner diameter 30 mm) of a single screw type extruder. Extruding a flat rod from the nozzle,
With a take-up machine, the thickness is 1.0 mm, so that it will pass through the cooling water tank.
The external shape of the width of 2.5 mm is formed so as to have the communication hole inside, and at the same time, the length is cut to 15 mm. Then, the end portion on the side serving as the pen tip is cut with a grindstone.

The thus molded product has burrs formed at the corners thereof at the time of molding, and burrs generated by the processing heat during polishing causing the member to adhere to the polishing member and partially expand. . To remove this burr,
The method for shaping the pen tip member of the present invention is adopted. The pen tip from which the burr has been removed by the shaping method of the present invention is made of finer particles than those removed with a brush or a cutter, so the mark after removing the burr does not have a flat surface. , Which is curved.

By applying radiation before cutting the above-mentioned pen tip, the generation of burrs can be suppressed. In the case of polyacetal, the molecule is depolymerized by irradiation. That is, the molecule of polyacetal has an ether bond and an ester bond, and by irradiation,
These bonds are broken. When the ester bond existing at the end is cleaved, it is cleaved more and more in a zipper manner, but the ether bond is more easily cleaved than the ester bond. That is, the ether bond can be cleaved without cleaving the terminal ester bond.

The mechanical properties of the polyacetal resin thus obtained are changed, and particularly the tensile strength and elongation are reduced. Therefore, even if a part of the pen tip member partially expands due to the processing heat generated when cutting and polishing, the pen tip member will be torn off from the pen nib body when it extends beyond a certain amount. That is, the size of the burr can be suppressed. Further, when removing the burr by the method of shaping the pen tip member of the present invention, the burr can be removed with a small impact force, and the time required for the burr removal process can be shortened.

Examples of the amorphous resin include polycarbonate resin, modified polyphenylene oxide resin, polyarylate resin, polysulfone resin, and polyethersulfone resin. When a crystalline resin is used, the moisture adsorbed in the voids generated by the shrinkage during crystallization freezes during cooling and breaks when hitting the pen tip, and burrs cannot be sufficiently removed.

Example 1 DURACON U10-01 was molded into an external shape of 1.0 mm in thickness and 2.5 mm in width by an extruder having a diameter of 30 mm, cut into a length of 15 mm, and a GC46 grindstone was attached. Cutting into a pen tip shape with a processing machine, part 1
000 pieces were cooled to -30 ° C by spraying liquid nitrogen with Quick Trim 1CT (low temperature shot blast deburring machine, manufactured by Osaka Oxygen Industry Co., Ltd.) to embrittle the burrs on the pen tip, and then Noryl as fine particles. SE100J (modified polyphenylene oxide resin, diameter 0.51 mm, length 0.
A 51 mm approximately columnar product, manufactured by Engineering Plastics Co., Ltd., was projected for 10 minutes to obtain a flat acicular resin nib.

Example 2 In the same manner as in Example 1 except that Toughlon AL-0020 (polycarbonate resin, manufactured by Idemitsu Petrochemical Co., Ltd.) was used in place of Noryl SE100J in Example 1, polyacetator was used. A resin-made flat plate nib was obtained.

Example 3 Polyacetal resin was prepared in the same manner as in Example 1 except that Victrex 4100G (polyethersulfone resin, Sumitomo Chemical Co., Ltd.) was used in place of Noryl SE100J. A flat pen tip was obtained.

Example 4 Polyacetal resin was prepared in the same manner as in Example 1 except that U Polymer U-8400 (polyarylate resin, manufactured by Unitika Ltd.) was used in place of Noryl SE100J. A flat plate nib made was obtained.

Example 5 In Example 1, a cut product after extrusion molding was irradiated with 15 kGy of γ-rays having a wavelength of 1/10 8 to 1/10 15 cm, and cut, and the projection time of fine particles was 3 minutes. A flat plate nib made of a polyacetal resin was obtained in the same manner as in Example 1 except that.

Comparative Example 1 P-1 in place of Noryl SE100J in Example 1
A polyacetal resin tabular nib was obtained in the same manner as in Example 1 except that 700 (polysulfone resin, manufactured by ICI, UK) was used.

Comparative Example 2 Example 1 was repeated except that Ultem 2300 (polyetherimide resin, manufactured by Engineering Plastics Co., Ltd.) was used in place of Noryl SE100J in Example 1.
In the same manner as above, a flat acicular resin nib was obtained.

Comparative Example 3 A flat plate made of a polyacetal resin was prepared in the same manner as in Example 1 except that Asahi PPS RC-30JA (polyphenylene sulfide resin, manufactured by Asahi Glass Co., Ltd.) was used in place of Noryl SE100J. The pen tip was obtained.

COMPARATIVE EXAMPLE 4 A polyacetal resin was prepared in the same manner as in Example 1 except that DURACON U10-01 (polyacetate resin, Polyplastics Co., Ltd.) was used in place of Noryl SE100J. A flat pen tip was obtained.

Table 1 shows the results of measuring the number of burrs, the crushing of the pen tip, the variation, and the number of cracks in Examples 1 to 4 and Comparative Examples 1 to 4 as described above.

[0021]

[Table 1]

[0022]

As described above, according to the method for shaping a synthetic resin nib member of the present invention, fine particles are sprayed onto a thermoplastic synthetic resin nib member in an environment below the embrittlement temperature of the member. Since the fine unnecessary portion of the pen tip member is removed by the impact force, it is possible to obtain a pen tip having a clean shape in which handwriting is not disturbed and the like with a minimum of labor.

[Procedure amendment]

[Submission date] September 2, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

Example 5 In Example 1, a cut product after extrusion molding was irradiated with ¹⁵ kGy of a γ ray having a wavelength of 1/10 ⁸ to 1/10 ¹⁵ cm, and was cut to obtain a projection time of fine particles. A flat pen tip made of polyacetal resin was obtained in the same manner as in Example 1 except that the period was 3 minutes.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Wada 4-1-8 Yoshimachi, Soka City, Saitama Pentel Co., Ltd. Inside the grass processing plant

Claims (1)

[Claims] 1. A pen tip member made of a thermoplastic synthetic resin is sprayed with fine particles under an environment of an embrittlement temperature of the member or less, and a fine unnecessary portion of the pen tip member is removed by its impact force. Method for shaping a synthetic resin pen tip member.