JPH0615995A - Production of penpoint made of synthetic resin - Google Patents

Abstract

PURPOSE:To produce a penpoint made of a synthetic resin reduced in the irregularity of ink emitting properties and excellent in capillary force by producing an inner member having ribs protruding to a communication hole from the outer peripheral part thereof and reduced in the wall thickness of the outer peripheral part thereof at the parts of the ribs by extrusion molding and covering the outer periphery thereof with an outer member. CONSTITUTION:A penpoint P made of a synthetic resin having through holes 5 to which capillary force necessary as ink passages is applied formed by the ribs 6 protruding from the outer peripheral part 4 thereof is produced. In this production method, an inner member B having the ribs 6 protruding to the through-holes 5 from the outer peripheral part 4 thereof and reduced in the wall thickness of the outer peripheral part 4 at the parts of the ribs 6 is produced by extrusion molding and the outer periphery thereof is covered with an outer member C. As a result, the penpoint made of a synthetic resin suppressed in the irregularity of ink emitting properties and excellent in capilary force while suppressed in percent defective can be produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a synthetic resin nib having a through hole in which a capillary force necessary for an ink passage is provided by a rib protruding from an outer peripheral portion.

[0002]

2. Description of the Related Art A typical method for producing a synthetic resin nib of the type described above is by extrusion molding. That is, the synthetic resin melted by heating to a temperature between the softening temperature and the decomposition temperature is extruded from the tip nozzle of the extruder,
It is manufactured by the basic process of thinning to a predetermined diameter.

[0003]

If an attempt is made to obtain an article having a sufficient capillary force, the variation in the ink ejection properties of the obtained article will increase, and the defective rate will increase.

Description will be made with reference to the attached FIG. The pen tip A has an outer peripheral portion 1, a through hole 2, and a rib 3. In order for the pen tip A to have a sufficient capillary force, the gap between the ribs 3 must be small. The practical method is the circle drawn by the dotted line in the figure (hereinafter, "rib gap circle").
That is) to reduce the diameter. The smaller the diameter of the rib gap circle, the stronger the capillary force.

However, if the gap between the ribs 3 is made smaller in this way, although it is obtained to some extent, it is not necessary to consider the variation in the ink ejection property as a problem, but the one having a stronger capillary force than that. In order to obtain the above, the drawback due to the increase in the variation in the ink ejection property becomes larger than the improvement in the capillary force. Specifically, when a thin wire-shaped product is cut at various places, it can be seen where the ribs 3 are partially integrally connected and where they are not. After all, the defect rate increases and the trouble of selection is added.

[0006]

SUMMARY OF THE INVENTION The present invention provides a method for manufacturing a synthetic resin nib having a through hole in which a capillary force required as an ink passage is imparted by a rib protruding from the outer peripheral portion. It has a rib protruding to the
In addition, a method for manufacturing a synthetic resin pen nib is characterized in that after manufacturing by extruding a rib having a thin outer peripheral portion, the outer periphery is covered with the outer member by using this as an inner member. Use as a summary.

Hereinafter, description will be given through an example of the case of obtaining the one as shown in FIG.

FIG. 1 shows the inner member B. It has an outer peripheral portion 4, a through hole 5, and a rib 6. It may be obtained in the same manner as a conventional synthetic resin nib manufactured by extrusion molding. A so-called monofilament self-fusion method can also be adopted. Further, the material is also appropriate such as nylon, polyacetal, polyester, polyimide, and polyether ether ketone. However, the thickness of the rib 6 of the outer peripheral portion 4 is thin. This is the portion shown as the recessed portion 7. still,
Originally, the cross-sectional shape of the inner member B is appropriate, and therefore the number and shape of the ribs are also appropriate, and it is not necessary to reduce the wall thickness of the outer peripheral portion of all the ribs. The thin shape represented by the recess 7 is also appropriate.

The inner member B is covered with an outer member. The coating method is appropriate, such as extrusion molding in the manner of covering the electric wire using a crosshead base, appropriately cutting the inner member B as necessary, and injection molding it as an insert. Therefore, the shape of the coated article may be, for example, a fountain pen nib shape or the like, other than the straight rod shape having an appropriate cross section. The material of the outer member is basically the same as that of the inner member B, but if the material having a lower softening temperature than the inner member B is selected, the coating becomes easy.

FIG. 2 shows an example after the outer member is coated in this manner. Although shown as a pen tip P, it has the same overall shape as the pen tip A of FIG. Also,
The outer member is indicated by reference numeral C.

The diameter of the rib gap circle shown by the dotted line is shown in FIGS.
2 is smaller than that of FIG. This is because the inner member B is deformed by coating the outer member C.

[0012]

The outer member pressurizes the inner member to be coated. This pressure causes the inner member to deform inward. Moreover, at this time, the thin portion of the outer peripheral portion of the inner member is selectively deformed. That is, the rib portion is largely deformed. As a result, the ribs have a small gap therebetween and have a strong capillary force.

[0013]

【Example】

<Example 1> Molten polyacetal (Grade U10-01, manufactured by Polyplastics Co., Ltd.) was extruded into a rod shape by an extruder. This is the fabrication of the inner member, and the shape of the obtained material is almost the same as that shown in FIG. The major difference is that short ribs other than the ribs 6 are provided between the ribs 6 (total 3). The nozzle of the extruder has a diameter of 30.
mm, the thickness of the flesh for producing the rib gap circle is 0.
It is 50 mm.

A crosshead base (set temperature:
Extrusion machine equipped with 195 ° C (nozzle diameter: 30 mm)
Was used to coat the outer member. The material of the outer member is also polyacetal (made by Polyplastics Co., Ltd., grade M90-
01). The outer shape of the obtained product is round as shown in FIG.

This was cut and the tip portion was shaped (so-called core slit) to obtain a pen tip having a total length of 30 mm.

<Second Embodiment> In the first embodiment, instead of using an extrusion molding machine equipped with a crosshead base, insert molding using an injection molding machine (set mold temperature: 80 ° C.,
Same as Example 1 except that the outer member was coated with the same nozzle temperature: 190 ° C., the same resin pressure: 50 kg / cm ² ) and the cutting and tip shaping processes were slightly changed accordingly. . The obtained product has an overall shape like a fountain pen nib, and its total length is also 30 mm.

<Comparative Example> In Example 1, except that the nozzle of the extruder was processed to produce the inner member, and the outer member was not covered, and the nib was used as it was.
Same as. Here, as for the processing of the nozzle, the thickness of the wall portion for producing the rib gap circle was made extremely thin to 0.03 mm, and the concave portion 7 portion of FIG. 1 was eliminated to obtain a circular cross section. That's just what I did.

Each of 50 pieces obtained in each example was prepared and the diameter of the rib gap circle was measured.
Table 1 shows the results of measuring the ink discharge amount by assembling 0 pieces each into a writing instrument (so-called raw ink type writing instrument like a fountain pen; using commercially available water-based ink). In addition, the diameter measurement value of the rib gap circle in Table 1 is obtained from the length (100 times value) of the rib gap circle drawn by a compass for projection using a 100 × projector (unit: mm). Moreover, the measured value of the ink discharge amount is J at a load of 100 g and a writing angle of 60 °.
It is a value obtained by calculating the ink weight loss value when writing (0 m to) 200 m on ISP-3201A paper (unit:
g).

[0019]

[Table 1]

[0020]

As is apparent from Table 1, according to the present invention, a synthetic resin nib having an excellent capillary force can be manufactured while suppressing the variation in ink dischargeability, and thus suppressing the defective rate. be able to.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an inner member for explaining an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a pen tip for explaining an embodiment of the present invention.

FIG. 3 is a transverse cross-sectional view of a pen tip for explaining a problem to be solved by the invention.

[Explanation of symbols]

 A pen tip B inner member C outer member P pen tip 1 outer peripheral portion 2 through hole 3 rib 4 outer peripheral portion 5 through hole 6 rib 7 concave portion

Claims (1)

[Claims] 1. A method of manufacturing a synthetic resin pen tip having a through hole in which a capillary force required as an ink passage is imparted by a rib protruding from the outer peripheral portion, the rib having a rib protruding from the outer peripheral portion into the through hole, A method of manufacturing a synthetic resin nib, characterized in that a rib having a reduced outer peripheral thickness is manufactured by extrusion molding, and then this is used as an inner member and the outer periphery is covered with the outer member.