JPS61141533A - Molding of tube made of synthetic resin - Google Patents

Abstract

PURPOSE:To reduce the amount of consumption of synthetic resin material and obtain the tube having sufficient flexibility by a method wherein a tubular sheet is bent and both side ends of the tubular sheet are bonded to the lower end of a bulkhead sheet at one place. CONSTITUTION:A T-type sheet 1 is formed into a tube through extrusion molding process (a), in which the T-type sheet 1 consisting of the belt-type tubular sheet 2 and a belt-type bulkhead sheet 3 hung at the center of the lower surface of the tubular sheet 2 are formed through extrusion molding, and a bonding process (c), in which both side ends of the tubular sheet 2 of the T-type sheet 1 molded by extrusion molding through the extrusion molding process (a) is bonded to the lower end of the bulkhead sheet 3. In the bonding process (c), both side ends of tubular sheet 2 of the T-type sheet 1 are abutted against the lower end of the bulkhead sheet 3 by bending both side ends so that the tubular sheet 2 are wound and bent into the direction of wrapping the bulkhead sheet 3 while the abutted both side ends of the tubular sheet 2 are pushed against the lower end of the bulkhead sheet 3 and whereby said three ends are bonded at one place.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for molding a synthetic resin tube whose interior is divided into two parallel parts. The purpose is to easily form a tube.

[Conventional technology]

A synthetic resin tube container with an interior divided into two parallel parts,
This is due to the fact that two contents with different physical properties can be integrally stored and held in one tube container, and these two contents can be extruded simultaneously and in a fixed proportion. , it has demonstrated a number of excellent utility values.

Conventionally, the tube that forms the main body of this type of synthetic resin tube container was formed by extrusion molding a tube piece with a semicircular cross section, and then a tube piece of the same length and dimensions with a semicircular cross section was extruded. This was achieved by assembling the flat wall portions back to back, and inserting and assembling the pair of tube pieces assembled back to back into a tube body having a circular cross section.

[Problem that the invention seeks to solve]

In this way, conventional tubes of this type have a structure in which two tube pieces are inserted in parallel into the tube body that forms the outer wall, so it is difficult to store the contents considering the size of the tube. The actual capacity of the storage space available is small, and therefore it has not been possible to store and hold a sufficient amount of contents.

In addition, since the storage chambers that are divided into sections are formed from individually molded tube pieces, the amount of synthetic resin material consumed to form a unit volume of storage space is reduced. This has the disadvantage that the material cost is relatively high.

Furthermore, since the tube piece is extruded, its wall thickness is relatively large, which causes dissatisfaction with its softness when it is formed into a tube, and the flexibility is not sufficient. There was a problem that a large dead space was created between the tube body and the tube body.

[Means and effects for solving the problems] The present invention has the following features:
This was devised to solve the problems, shortcomings, and dissatisfied points in the above-mentioned conventional methods.When the extrusion molded product is in the form of a sheet, the wall thickness of the sheet-shaped extrusion molded product is made sufficiently thin. This makes it possible to take advantage of the fact that the two storage chambers can be molded into one body.

Hereinafter, the present invention will be described with reference to drawings showing embodiments of the invention.

The method of molding a synthetic resin tube according to the present invention involves hanging a band-shaped partition sheet portion 3 on the center of the lower surface (in FIG. 2, the center of the top surface) of the band-shaped tube sheet portion 2, so that the cross section is T. An extrusion molding process (a) in which a T-shaped sheet 1 is extruded and molded, and both ends of the cylindrical sheet part 2 and the lower end of the partition sheet part 3 of the T-shaped sheet 1 extruded in this extrusion molding process (a). (in FIG. 2, the upper end) and the T.
, the mold sheet l is molded into the tube S.

The T-shaped sheet 1 can be extruded using conventional sheet extrusion molding techniques.
Since the partition sheet part 3 is integrally attached to the cylindrical sheet part, the die head 7 of the extrusion molding machine for extrusion molding the T-shaped sheet 1 is naturally adapted to the cross-sectional shape of the T-shaped sheet 1. It has a special extrusion opening shape.

In addition, this T-shaped sheet l may be extruded from the die head 7 and made into a molded product as it is, but in order to obtain a thinner wall thickness and better physical properties, it may be subjected to a stretching operation after extrusion molding. It is very good.

In the joining process C, the cylindrical sheet portion 2 of the formed T-shaped sheet 1 is
The cylinder sheet part 2 is wound and curved in a direction to wrap around the partition sheet part 3 and the both ends of the cylinder sheet part 3 and the lower end of the partition sheet part 3 are butted against each other, and at the same time, the cylinder sheet part 2 is Both end portions are pressed against the lower end portion of the partition sheet portion 3, thereby joining the three end portions at one place.

The both side ends of the cylindrical sheet part 2 and the lower end of the partition sheet part 3 can be joined by using a general cylinder making machine that is used to form a sheet body into a cylinder. The T-shaped sheet 1 may be continuously formed into a tube S using a one-place adhesive method using a tube machine.

Furthermore, the easiest and most reliable way to bond the both ends of the cylindrical sheet part 2 and the top end of the partition sheet part 3 at one point is to press and weld the molded synthetic resin material of the T-shaped sheet 1 in a heated and melted state. However, when the joint part 5 is formed by this pressure welding, the joint part 5 may become somewhat thick as shown in FIG. For this reason, it is desirable that the wall thickness of this joint portion 5 does not protrude significantly from the outer circumferential surface of the molded tube S.

By the way, since the cylindrical sheet part 2 of the extrusion-molded T-shaped sheet 1 has a very simple band-like sheet structure, the cylindrical sheet part 2 that forms the outer peripheral surface of the molded tube S is The top surface is a flat surface.

Therefore, printing using the printing drum 8 on the flat upper surface of the cylindrical sheet portion 2 and surface treatment such as transfer are extremely easy to perform. In between, a surface treatment process such as printing or transfer can be performed on the upper surface of the cylindrical sheet portion 2.

As described above, this surface treatment process has the advantage that it is extremely easy to perform and can be achieved satisfactorily because the upper surface of the cylindrical sheet portion 2 is flat.

In addition, as mentioned above, the T-shaped sheet 1 can be formed with a sufficiently thin wall thickness, so when the tube S is formed from the T-shaped sheet 1 formed with a sufficiently thin wall, the waist A weak tube S will be formed.

Therefore, in such cases, the shaped tube S
It is preferable to laminate a pre-formed outer layer on the outer circumferential surface of the holder in an outer layer lamination step 2.

Lamination molding of the outer layer on the outer peripheral surface of the tube S is not particularly limited, and sheet bodies may be rolled and bonded, but in the case shown in Fig. 7, the outer layer is formed in advance into a cylindrical shape. The tube S is inserted into the cylindrical body 6 and assembled.

In this way, when the outer layer is laminated and molded on the outer circumferential surface of the tube S, even if the joint portion 5 protrudes from the outer circumferential surface of the tube S, the outer circumferential surface of the formed tube body can be made smooth. It can be done.

In addition, this outer layer can be manufactured completely separately from the tube S without considering content resistance.
Since you can freely select and set functions that supplement the physical properties that are lacking in the tube S or enhance the decorative effect of the tube body to be molded, it will work effectively to further enhance the functions of the tube body. Become.

〔Example〕 .

The T-shaped sheet 1 is molded from the goo head 7 so that the cross-section becomes a single-letter shape, and the dimensions of the cylindrical sheet part 2 and the partition sheet part 3 are not particularly limited, but as shown in FIG. As shown in the figure, the tube S has a perfectly circular cross section.
When you want to mold the T-shaped sheet 1, and in order to avoid cutting for size adjustment after extrusion molding the T-shaped sheet 1, the width of the cylindrical sheet part 2 is It is preferable to set the width dimension to approximately 2πR.

By setting the width dimensions of the cylindrical sheet part 2 and the partition sheet part 3 in this way, a tube S with a perfect circular cross section can be formed by simply sending the formed T-shaped sheet ■ directly to the joining process to form the joining part 5. You will be able to do that.

In addition, by setting the width of the partition sheet part 3 to be thicker than 2R, or smaller than 2R, the tube S has a substantially elliptical cross section. You will be able to obtain

In the tube formed by the method of the present invention, as shown in FIG. 1, after the tube is formed, the head of the tube container is integrally joined and assembled in step E to attach the head, and the tube container body, that is, the bottom is opened. Then, the contents are injected into each storage chamber from the open bottom, and finally the open bottom is flattened from the left and right sides. The tube is heated and welded to form a sheet, which completes the forming of the tube container.The width of the tube when it is flattened from the left and right sides is 2π.
When it is R, it becomes πR.

Since this width dimension πR is a much larger value than the width dimension 2R of the partition wall seal part 3, the shape of the bottom seal part of the tube container to be molded will be different from the shape of a normal tube container. Not only that, but the wall thickness at both ends of the flattened bottom becomes nearly twice as thick as that at the center.

If there is large unevenness in the wall thickness of the bottom to be welded and sealed as described above, there is a problem that the pressure welding seal formation on the bottom of the tube container may cause breakage or pinholes in the bottom of the seal.

Therefore, as shown in FIG. 5 and FIG. 4
If the width of the partition sheet portion 3 is set to be πR when stretched, this The partition sheet part 3 located at the bottom of the tube container is stretched to the same size as the flattened tube, and as a result, the thickness of the bottom of the flattened tube container becomes uniform. Become.

Therefore, it is possible to completely prevent the various inconveniences mentioned above due to uneven wall thickness at the bottom of the flattened tube container.

[Effects of the Invention] As is clear from the above description, the method for molding a synthetic resin tube according to the present invention involves curving the cylindrical sheet portion and bonding both side ends of the sheet portion and the lower end of the partition sheet at one place. It is possible to form a tube whose interior is divided into two in parallel by the bulkhead sheet, so the internal space can be divided into two on the left and right.
Molding of the divided synthetic resin tubes can be achieved extremely easily, and the volume of the divided storage chambers can be increased without waste, and the two storage chambers can be formed using a single bulkhead sheet. Since the T-shaped sheet, which is a sectioned tube-forming element, can be formed sufficiently thin, the amount of synthetic resin material consumed can be reduced, and a sufficiently flexible tube can be obtained. Furthermore, with only minor processing changes to the die head, it can be easily and successfully implemented using stacked forming equipment.

In addition, when performing surface treatment on the top surface of the tube sheet, since the top surface of the tube sheet is a completely flat surface, surface treatments such as printing and transfer can be easily and successfully achieved. Become.

Furthermore, when forming an outer layer on the outer circumferential surface of the tube, it is possible to not only increase the mechanical strength of the tube body to be formed, but also to obtain an extremely smooth outer circumferential surface. It exhibits many excellent effects such as the ability to freely add other desired physical properties.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of steps in an example of a tube container forming method using the forming method according to the present invention. FIG. 2 is a partial perspective view showing the state of extrusion molding of the T-shaped sheet used in the method of the present invention. FIG. 3 is a partial perspective view showing the state of printing, which is one of the surface treatments, on the upper surface of the cylindrical sheet portion of the T-shaped sheet. FIG. 4 is an overall perspective view showing a state in which a tube is formed using the T-shaped sheet shown in FIG. 2. FIG. 5 is a partial perspective view of a T-type sheet in which a bellows portion is molded in the center portion of the partition sheet portion. FIG. 6 is an overall perspective view showing a state in which a tube is formed using the T-shaped sheet shown in FIG. 5. FIG. 7 is an overall perspective view showing the operation of assembling the outer layer cylinder, which is an example of outer layer lamination molding, to the tube. Explanation of symbols 1; T-shaped seat; 2; cylinder seat portion; 3; partition sheet portion;
4: Bellows portion, 5: Joint portion, 6: Outer layer cylinder, 7: Die head, 8: Printing drum, S: Tube.

Claims (4)

[Claims] (1) A band-shaped partition sheet (3) is hung from the center of the lower surface of the band-shaped cylindrical sheet part (2) to form a T-shaped sheet (1) with a T-shaped cross section by extrusion. Sheet (1)
A method of forming a synthetic resin tube, in which a tube (S) is formed by mutually joining both ends of the cylindrical sheet part (2) and the lower end of the partition sheet part (3). (2) A T-shaped sheet (1) with a T-shaped cross section is formed by extrusion, with a band-shaped partition sheet part (3) hanging down from the center of the lower surface of the band-shaped cylindrical sheet part (2). Mold sheet (1
) is subjected to a surface treatment such as printing or transfer on the upper surface of the cylindrical sheet part (2), and then the T-shaped sheet (1) is applied to both side ends of the cylindrical sheet part (2) and the partition wall sheet part (3). ) by mutually joining the lower ends of the tube (S)
A method for forming synthetic resin tubes. (3) A T-shaped sheet (1) having a T-shaped cross section by hanging a band-shaped partition sheet part (3) at the center of the lower surface of the band-shaped cylindrical sheet part (2) is extruded, and the T-shaped sheet part (1) is formed by extrusion. Mold sheet (1
) is formed into a tube (S) by mutually joining both side ends of the cylindrical sheet part (2) and the lower end of the partition sheet part (3), and further the outer circumferential surface of the tube (S) is A synthetic resin tube molding method in which an outer layer is layered on top. (4) A method for molding a synthetic resin tube as set forth in claim 1, in which the central portion of the partition sheet portion (3) is bent to form a bellows structure (4).