JPH01186316A - Manufacture of thermoplastic resin vessel - Google Patents

Abstract

PURPOSE:To shorten manufacturing steps and to reduce cost by providing a rule forming mold of a predetermined shape protruding on a rolling face for forming a sheet by extruding resin from an extruder, and forming rules simultaneously upon molding of the sheet, and punching it to form a box. CONSTITUTION:Resin extruded from an extruder 1 is held and pressed by a mirror roll or silicon roll 2 and a rule engraving roll 3 having a rule forming die 3a protruded with designated rules on the surface, the resin is formed in a sheet, the die 3 is simultaneously intruded to the sheet face to form rules 4 of predetermined shape. A resin sheet 5 formed with rules is wound on a takeup roll 7 by winding the mirror roll 6, and cooled to become synthetic resin plate 8 having rules 4. This plate 8 is punched in a shape developed from a desired box by a punching blade, the plate is then bent at the rules, and adhered with adhesive. Then, a desired box can be easily formed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to general boxes for storing tape cassettes of video tape recorders, sheets of front discs, video discs, Desotal audio desks, etc. The present invention relates to a method for manufacturing a thermoplastic resin container suitable for storing film-like products.

[Conventional technology]

Conventionally, small-volume thermoplastic resin containers can be molded into three-dimensional shapes by direct injection molding, but in a variety of ways, such as tape cassettes for video tape recorders,
In the case of a case that stores an item with a certain volume or more, it is difficult to three-dimensionally mold the case by direct injection molding, and even if it could be done, the cost would be high. For this reason, a method of manufacturing a box from a developing plate has been used.

Conventionally, the development plate for such synthetic resin containers has been made by extruding a synthetic resin flat plate of a certain thickness from a long piece of F. A board with the dimensions of are doing.

[Problem to be solved by the invention]

However, the conventional manufacturing method described above is inefficient due to the large number of man-hours, lacks uniformity in the strength of the ruled lines, surface shape, thickness of the developed plate, etc., and tends to produce defective products in terms of quality. Due to forced shaping or cutting, ruled lines may be cracked,
Roughness occurs on the ruled groove surface, and furthermore, debris adheres to the cutting surface, damaging the appearance.Also, cutting allowance and notch type are discarded, which is disadvantageous in terms of cost. There were also various inconveniences such as the generation of industrial waste.

In view of the above circumstances, it is an object of the present invention to provide a method for manufacturing a thermoplastic resin container in which a sheet of synthetic resin extruded from an extruder is simultaneously subjected to creasing processing, and the sheet can be punched and made into a box. purpose.

[Means to solve the problem]

The present invention has been made to achieve the above object, and the gist thereof is that when forming a container using a thermoplastic resin sheet, the resin is extruded from an extruder to form a sheet on the roll surface. A method for manufacturing a thermoplastic resin container includes providing a protruding ruled line forming mold with a predetermined shape, forming ruled lines at the same time as forming a sheet, and punching out the ruled lines to form a box.

[Effect]

Since the method of the present invention has the above-mentioned structure, a sheet having a uniform depth and width and smooth ruled lines on the inner surface of the grooves can be obtained at the same time as sheet molding, and by punching this sheet, it can be easily made from synthetic resin. A container is made.

〔Example〕

As the resin to be extruded in the method of the present invention, any general thermoplastic resin can be used, but in particular, polyolefin thermoplastic resin (including copolymers with other thermoplastic resins), polystyrene thermoplastic resin , ABS thermoplastic resin or a mixed resin of two or more of these thermoplastic resins are used, and various polypropylene resins, especially propylene-ethylene random copolymers containing 001 to 2 wt% of various structural nucleating agents, are used to reduce costs and printing. It is suitable in terms of suitability, manufacturing accuracy, dimensional stability, ruled line strength, surface strength, rigidity, and extrusion processability.

These thermoplastic resins include various blowing agents, inorganic fillers normally used as fillers in the field of synthetic resins, white pigments (such as titanium oxide, talc, mica, calcium carbonate, clay, etc.), and various carbon blanks. , various colored pigments, various metal powders (e.g. aluminum powder, tin powder, aluminum paste, etc.), various metal fibers, glass fibers,
Various additives such as organic or inorganic fiber substances such as carbon fibers, various coloring dyes, antistatic agents, various silicones, surfactants, lubricants such as sodium stearate, antioxidants, etc. can be added.

1 to 3 show an example of an apparatus for carrying out the method of the present invention using the above-mentioned thermoplastic resin.
The figure is a diagram showing how rolls are combined in the device. Reference numeral 1 in the figure is an extruder having a T-die, and the resin extruded from the extruder 1 is placed on a mirror roll or silicone roll (hereinafter referred to as a suppression roll) 2 and on the surface as shown in the front view in Figure 2. The resin is pinched and pressed by the ruled line engraving roll 3 having a protruding ruled line forming mold 3a that forms the ruled lines, and at the same time the resin is formed into a sheet, the ruled line forming mold 3a bites into the sheet surface as shown in FIG. A ruled line 4 having a predetermined shape is formed. The synthetic resin sheet 5 on which the ruled lines 4 are formed is wound around a mirror roll 6 and taken up by a take-up roll 7, and is cooled to become a synthetic resin plate 8 on which the ruled lines 4 are formed.

This plate 8 has a thickness (thickness of the sheet) as shown in FIG.
is usually formed to have a thickness of 0.3 to 3 mm, and is preferably 5% or more and 80% or less, particularly 7% or more and 60% or less, of the thickness of the groove bottom portion 4a of the ruled line 4. If the thickness of the ruled line groove bottom 4a is less than 5%, the strength will be weak, and if it exceeds 80%, it will be difficult to bend along the ruled line.

The plate 8 is punched out into a desired expanded box shape using a punching blade. By bending this spread plate along the ruled line and gluing it with adhesive, a desired box can be easily made.

In addition, in the above explanation, the ruled lines were formed only on one side of the developing plate, but instead of the suppression roll 2, the ruled line forming mold 3a is used.
By using the ruled line engraving roll 3 having the following, ruled lines 4 can be formed on both sides.

In addition, various printing methods [silk screen printing, offset printing, flexo printing,
Grahia printing, tampo printing, electrostatic transfer printing, pot stamping (foil stamping), transfer printing, inkjet printing,
Create a printing layer of one or more colors in one type (by rotating roll printing, etc.)
If necessary, after coating with a primer to improve printing properties or applying a protective layer to protect the printed surface, it is irradiated with cold air, hot air, various types of air, infrared irradiation, ultraviolet ray irradiation, electron beam irradiation, etc. It is also possible to fix the printing layer to the development plate.

Example 1 MFR (230°C, 2, 16 kg) is 0.5 g/1
0 minute ethylene-propylene broth copolymer (ethylene content 18wt%) is 70~yt%, particle size is 30μI
An inorganic filler-containing propylene polymer containing 30 wt% of talc of n is extruded using an extruder 1 with a screw diameter of 65 mm, and molded at a resin temperature of 230°C and a roll surface temperature of 60°C, forming the ruled lines shown in Figure 5. Groove depth 0.7mm, board thickness 0.
An 8mm plate 8 was made. This was punched out with a plate blade 9 having the shape shown in FIG. 6 to obtain a developing plate 10 shown in FIG. This was bent along the ruled line 4, and the overlapping portions were welded by ultrasonic bonding to create a videotape cassette case 11 shown in FIG. 8.

As a result, when the number of boxes manufactured was 300,000, the number of work steps could be significantly reduced compared to the conventional method.

〔Effect of the invention〕

As mentioned above, in the method of the present invention, resin extruded from an extruder is formed into a sheet by rolls, ruled lines are engraved at the same time, and the ruled lines are punched out with a knife of a predetermined shape to form a spread plate. As a result, no labor is required, the box manufacturing process is shortened, and costs are significantly reduced. In particular, it is an extremely excellent method for manufacturing cases for cassettes (viteotape casseros), boxes for mass-produced products such as Fronpicase hemorrhoids, bags, and various other storage containers.

[Brief explanation of the drawing]

1 to 3 are explanatory diagrams showing an example of the method of the present invention. FIG. 1 is a diagram showing the combination of rolls in the device, FIG. 2 is a front view of a ruled line engraving roll, and FIG. Fig. 1 is a cross-sectional view taken along the line ■-■ in Fig. 1, showing the state in which the sheet is formed by the suppression roll and the ruled line engraving roll, Fig. 4 is a cross-sectional view of the ruled line portion of the board, and Fig. 5 is the ruled line engraving. FIG. 6 is a plan view showing the shape of the unsheathed plate, FIG. 7 is a plan view of the unfolding plate, and FIG. 8 is a perspective view of the case for the videotape cartridge. l extruder, 2 press roll, 3 ruled line engraving roll, 3a ruled line forming mold, 4 ruled line, 4a ruled line groove bottom, 5 - synthetic resin sheet with ruled lines formed, 6 mirror roll, 7 - take-up roll, 8 - ruled line Synthetic resin plate (board), 9 punching blades, 10 development plate, 11 case for video tape cassette.

Claims (1)

[Claims] When forming a container using a thermoplastic resin sheet, the resin is extruded from an extruder to form a sheet on the roll surface.
A method for manufacturing a thermoplastic resin container, comprising: providing a ruled line forming mold with a predetermined shape protruding from the surface, forming ruled lines at the same time as forming a sheet, and punching out the formed line to form a box.