JPH0342226A - Preparation of synthetic resin tube having irregular patterns - Google Patents

Abstract

PURPOSE:To prepare a synthetic resin tube showing a three-dimensional appearance and a high-grade appearance and having irregular patterns by holding a transparent resin between different two-color opaque colored resins and successively arranging all of the resins in an annular stripe state to emit the same under rotation in a molten state. CONSTITUTION:The annular emitting part 1 of a die is divided into a large number of emitting orifices at an equal interval and different two-color opaque resins 2, 3 and a transparent resin 4 are successively arranged to those emitting orifices in an annular stripe state so as to hold the resin 4 between the opaque resins 2, 3. The resins 2, 3 are thermoplastic and supplied in a molten state to be extruded in a tubular form while the annular emitting part 1 is rotated. At this time, the resins 2, 3, 4 are extruded in the annular stripe state but, since the flow velocities of the resins are different between the contact part and non-contact part of the die at the time of rotation, positional shift is generated between the resins and a shape is collapsed to develop irregular patterns such as grain patterns. A molded product formed by the integral injection molding of a neck part 6 having an extraction port provided thereto by drilling and a shoulder part 7 is thermally welded to the upper end opening part of the formed tube 5 and the lower end opening part of the body part of the tube 5 is heat- sealed as shown by a numeral 8 to complete a tube container.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a synthetic resin tube that exhibits an irregular pattern such as wood grain on the surface, and more specifically to a method for manufacturing a synthetic resin tube for use in cosmetics. This invention relates to a method for manufacturing synthetic resin tubes with excellent decorative properties for tube containers and the like.

(Prior Art) Most conventional tubes for tube containers are extrusion molded from monochromatic synthetic resin, and when beautiful decorative patterns are to be added to the surface, secondary processing such as transfer painting is used.

Further, Utility Model Application No. 55-161846 is known as a tube formed by extrusion molding of a plurality of resins.

(Problem to be solved by the invention) However, when the former type of painting is done by secondary processing such as etc., it is difficult to reveal a pattern with three-dimensional space, and furthermore, the pattern may peel off due to friction with the outside, or There is a problem that the decorative surface is damaged when the cosmetic adheres to the surface, and furthermore, the cost of secondary processing is high, resulting in a relatively expensive product.

In addition, in the latter method, two or more types of resins are simply arranged alternately along the axial direction, resulting in a monotonous pattern that lacks a sense of luxury.

The present invention was made in view of the above-mentioned conventional problems, and its purpose is to eliminate defects caused by secondary processing and to develop a method for manufacturing synthetic resin tubes having irregular patterns that give a three-dimensional and luxurious appearance. It is on offer.

(Means for Solving the Problems) In order to achieve the above object, according to the method of the present invention, a transparent resin is sandwiched between two different opaque colored resins, and these are sequentially arranged in an annular stripe shape. The opaque colored resin is discharged while rotating in a molten state, and irregular patterns such as wood grain are exposed to the outside by the opaque colored resin.

(Function) The resin discharged in an annular stripe directly contacts the inner surface of the die part during rotation, so the flow velocity of the resin differs between the die contact area and the non-contact area, resulting in misalignment, and furthermore, the fluidity of the resin may be affected. The shape will collapse and irregular patterns such as wood grain patterns will appear.

(Embodiments) Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a diagram showing an annular arrangement of resin in a discharge part 1 of a die for extrusion molding a tube of a tube container according to the present invention.The annular discharge part 1 of this die is divided into a number of discharge ports at equal intervals, A transparent resin 4 is sandwiched between two opaque resins 2 and 3 of different colors at these discharge ports.
These are sequentially arranged in an annular stripe shape. These resins 2 and 3 are thermoplastic resins, and are supplied in a molten state to the above-mentioned discharge ports, and extruded from these discharge ports into a tube shape while rotating the annular discharge portion 1 of the die. At this time, resins 2, 3, and 4 are extruded in an annular stripe shape, but since they directly touch the inner surface of the die part during rotation, the flow velocity of the resin is different between the die contact area and the non-contact area, and the resin is extruded in a stripe shape. The extruded resin will be misaligned between the two, and furthermore, its shape will be distorted due to the fluidity of the resin, resulting in an irregular pattern such as a wood grain pattern.

At the upper end opening of the tube 5 formed as described above, a molded product obtained by integrally injection molding the 0 part 6 having an extraction port and the shoulder part 7 as shown in FIG. 2 is heat welded. The lower end opening of the body is heat sealed 8 to complete the tube container.

(Effects) As described above, according to the present invention, a transparent resin is sandwiched between two opaque colored resins having holes, and these are sequentially arranged in an annular stripe shape and rotated in a molten state. Since the opaque colored resin is sandwiched between the transparent resins, irregular patterns such as wood grains, which give a three-dimensional and luxurious feel, are revealed. Furthermore, since the colored resin that reveals the pattern forms the body of the tube itself, there is no fear that the pattern will peel off, making it possible to provide a highly decorative tube with low manufacturing costs.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a die discharge section for extrusion molding a synthetic resin tube according to the present invention, and FIG. 2 is a tube formed by extruding a wood grain pattern from the die discharge section of FIG. 1. FIG. 2 is a side view showing an example of a tube container.

Claims (1)

[Claims] Transparent resin is sandwiched between two different colors of opaque colored resin, and these are sequentially arranged in an annular stripe shape, which is then discharged while rotating in a molten state, and the opaque colored resin creates irregular patterns such as wood grain. A method for manufacturing a synthetic resin tube characterized by a tube made of synthetic resin that is exposed to the outside.