JPS6178622A - Manufacture of hinge of plastic - Google Patents

Abstract

PURPOSE:To enable a plurality of elongated hinges to be made in many directions, by plastically deforming linearly a member of a crystalline polymer under a pressure exceeding the yield strength. CONSTITUTION:A member 1 of a crystalline polymer is placed in a clearance between rollers 2, 2' and is pressed therebetween to be formed with a hinge 3. The pressure applied by the rollers 2, 2' must be a pressure exceeding the yield strength of the member 1 for allowing the member to be plastically deformed linearly. Since the member is plastically deformed linearly under a certain pressure when the hinge is formed, the member is not required to be heated and bent. Therefore elongate hinges extending in many directions can be easily manufactured. All the required parts can be cut in a subsequent step.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a method of manufacturing a plastic hinge.

BACKGROUND OF THE INVENTION Conventionally, plastic hinges have been manufactured by molding a crystalline polymer such as polypropylene into a thin shape and then aligning the hinge by heating and bending.

Since this glass hinge does not have a gap in the hinge portion unlike a hinge that is attached with a single metal fitting, it is advantageous in preventing leakage f'L of liquid or gas in a container or the like.

Problems to be Solved by the Invention However, in the conventional manufacturing method using orientation by heating and bending, it is difficult to produce large-sized foldable materials such as tenters, hinged building materials, foldable leisure boats, and simple ducts. It is remarkable that it is so long and has many hinges in multiple directions. In other words, a hot plate is brought into contact with the part that will form the hinge to completely soften the plastic, and while the plastic is being softened, the plastic part of the hinge part can be arranged by repeating the bending process many times. When forming a long hinge, it is difficult to repeatedly bend the entire hinge uniformly.

Furthermore, when forming a hinge in a direction that intersects a previously formed hinge, heating and bending is not possible unless the member is partially cut, and the hinge formed previously cannot be heated or bent. It is also troublesome to bring the hot plate into contact with the hinge portion to be formed next.

In view of the above-mentioned points, the present invention allows partial cutting of a member to be carried out in a subsequent process and can be performed at once, regardless of orientation by heating and bending, and a large number of long hinges can be attached in multiple directions. The purpose is to provide a method for manufacturing plastic hinges.

Means for Solving the Problems In order to solve the above problems, the present invention provides a working hinge characterized in that a member made of a crystalline polymer is linearly plastically deformed under a pressure higher than its yield point strength. When forming a tube, it is only necessary to linearly plastically deform it under a constant pressure, and there is no need for heating and bending as in the conventional case, so long, multi-directional hinges can be easily manufactured using VC. Cut the necessary parts all at once in the subsequent process.
It's okay. It was confirmed that the hinge according to the present invention has durability comparable to that of a conventional hinge using orientation by heating and bending.

Example Next, the present invention will be explained in detail.

The member 1 made of crystalline polymer has a yield point strength of 600
Kv/cIr1” polypropylene (MFR: 1,
0) An extrusion channel was used. Thickness 4■, size 100
It is 0X2000+w+. As shown in FIG. 1, the member 1 was introduced into the gap between the rollers 2 and 2' and rolled out to a thickness of 1.5 to 2 m to form a hinge 3 with a length of 2 m.

At this time, the pressure due to low 22 and g is 2000Ktv'
She is c♂.

Form a hinge 3 to fix one end of the 9 test piece, and the other end KI
While applying a load of K9, repeatedly bend between 90° and 180° (bending speed 2 times/5ea).
After repeating it more than 0,000 times, confirm that there is no change.

As described above, holes are formed in multiple directions, and then predetermined places are cut to produce a returnable food container (folded type).

Effects of the Invention As described above, the present invention allows hinges to be formed while keeping members in a flat state, making it possible to efficiently manufacture long hinges and multiple hinges in multiple directions, and providing sufficient durability. The industrial value of these products is extremely great.

[Brief explanation of drawings]

FIG. 11 is an explanatory diagram showing the entire state of forming a hinge in the present invention.

Claims (1)

[Claims] A method for manufacturing a plastic hinge, characterized by linearly plastically deforming a member made of a crystalline polymer under pressure greater than its yield point strength.