JP3246869B2 - Sheet-shaped uncured compound punching method and punching jig used in the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of punching an uncured compound, and more particularly to a method of punching a sheet-like uncured compound having relatively low greenness and plasticity and having tackiness. It relates to a jig used for implementation.

[0002]

2. Description of the Related Art Conventionally, various methods, such as a push-cut type, a shearing type, and a big-blade type, have been put into practical use as a method of cutting a sheet-like uncured compound having a high green strength and no tackiness. However, for compounds that have relatively low plasticity with green strength and are sticky, there is only a method that has been used for a long time in various industries, including the food industry, to cut while dusting powder. There was a disadvantage that the dusted powder hindered the subsequent steps. If the powder is not used, the compound sticks to the blade of the cutter, so that the cut compound loses its shape and cannot be cut into the desired shape.

[0003]

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems. As a result, the uncured compound was sandwiched between protective sheets and a green stamping jig was used. The present inventors have found that even a compound having relatively low strength and plasticity and having tackiness can be cut into a desired shape, and arrived at the present invention.

Accordingly, a first object of the present invention is to provide a punching method capable of easily cutting a tacky compound having relatively low green strength and plasticity into a desired shape. A second object of the present invention is to provide a punching jig suitable for a punching method for cutting a tacky compound having relatively low green strength and plasticity into a desired shape.

[0005]

The above objects of the present invention are to provide a first step in which a sheet-shaped uncured compound to be punched is sandwiched between protective sheets, a second step in which a jig is pressed against the protective sheet to move only the compound, Further, the present invention has been achieved by a method of punching a sheet-shaped uncured compound, which comprises a third step of cutting a protective sheet, and a jig for performing the method.

[0006] The first step of the punching method of the present invention is to protect both sides of the compound in order to prevent the compound from sticking to the jig when cutting the adhesive compound with a jig such as a cutter. This is the step of sandwiching between sheets. The protective sheet referred to here is not particularly limited as long as the adhesive compound is not adhered to the jig. Examples of such a protective sheet include a polyethylene film and the like.

[0007] In the present invention, in order to easily maintain the shape of the sheet-like uncured compound, a polyethylene film having good release properties is attached to one side, and
It is preferable that a hard release paper or PET film which easily retains its shape is adhered and the compound is sandwiched. Further, the thickness of each film is not particularly limited, but is preferably 25 to 200 microns from the viewpoint of workability and cost.

[0008] The second step of the punching method of the present invention is to prevent the compound from sticking to the blade of a cutter or the like.
This is a step of moving only the internal compound without cutting the protective sheet. In the present invention, in order to realize this step, a jig having a radius of curvature of 0.5 mm or more at the tip is used. The radius is, in particular, 2.0 to
It is preferably 5.0 mm.

The material of the jig is not particularly limited, but in the present invention, it is preferable to use a material such as plastic or metal. The shape of the tip of the jig may be a plate shape (FIG. 1), a single-blade shape (for example, a parabolic cross section as shown in FIG. 2) or a double-blade shape (FIG. 3). From the viewpoint, it is preferable that the shape is a one-edge shape. Although the jig's descent speed is not particularly limited, it is better to make the jig fast when the plasticity of the compound is low, and it is better to make it slow when the plasticity is high and hard.

The third step of the punching method of the present invention is a step of cutting the protective sheet in order to completely punch out the sheet-shaped uncured compound sandwiched between the protective sheets. To cut the protective sheet, for example, scissors,
A normal cutting instrument, which is appropriately selected from a push cutter, a rotary blade, and the like, may be used.

In the case of cutting into a specific shape, it is preferable to use a beak blade, a blade specially cut out according to a punched target shape, a cast blade, or the like. The blade may be a single blade (FIG. 4) or a double blade (FIG. 5), but is preferably a single blade, particularly from the viewpoint of accurately finishing the compound. The material of the blade is preferably a metal, particularly preferably a steel material.

In the second and third steps of the present invention, different jigs may be used, but depending on the shape,
It can also be performed with one jig. That is, a cut is made in the center of the jig for the second step for moving the compound,
The second step and the third step can be performed with one composite jig so that the sharp blade used in the third step can be pushed out from the cut provided in the central portion (FIGS. 6 and 7).
reference).

In order to carry out the second step and the third step by using this composite jig, first, the outer end has a curvature radius of 0.5.
After pressing the jig having a roundness of not less than mm to move only the compound (FIG. 8), a sharp blade is pushed out from the center of the jig pressed against the protection sheet to cut the protection sheet (FIG. 9). (Figure 1
0). The structure for pushing out the blade from the jig is similar to a two-stage clamping mechanism used in an injection molding machine or a simple mechanism using an elastic body such as a spring (see FIG. 6).

The punching method of the present invention can be applied to any sheet-shaped uncured compound such as ordinary synthetic rubber, urethane rubber, butadiene rubber, ethylene rubber, and fluororubber. In particular, it has a remarkable effect on rubber with low plasticity and adhesiveness, such as silicone rubber with a plasticity of 300 or less by adding a large amount of plasticizer, and can be punched without breaking the intended shape. it can.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The method of punching a sheet-like uncured compound according to the present invention is a first step of sandwiching a sheet-like uncured compound to be punched with a protective sheet. It can be easily implemented by the second step of moving and the third step of cutting the protection sheet.

[0016]

According to the method of the present invention for punching a sheet-shaped uncured compound, a large amount of a plasticizer is added and the plasticity is reduced to 30.
It is particularly effective for compounds having low plasticity and tackiness, such as silicone rubber having a value of 0 or less.

[0017]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.
Unless otherwise specified, “%” described below means “% by weight”.

Embodiment 1 FIG. Using a calendar roll,
Both sides of an uncured silicone rubber compound having a plasticity of 120, extruded to a thickness of 2.5 mm, were covered with a 70 micron polyethylene film. Then the diameter 30
When a tip made of aluminum with a radius of curvature of 2.0 mm was pressed from above the protective film at a speed of 10 cm / sec using a circular jig A having a thickness of 2 mm, the polyethylene film was not cut, and only the silicone rubber compound inside was used. Was displaced (see FIG. 8).

Next, the protective sheet was cut by a 30 mm diameter big blade B having a sharp blade to obtain a 30 mm diameter uncured compound sheet (see FIG. 9). At this time, the compound did not adhere to the jig A for punching or the blade B, and continuous punching work was possible.

Embodiment 2 FIG. Using an extruder, width 5
One side of an uncured silicone rubber compound having a plasticity of 150 and extruded to a thickness of 0 mm and a thickness of 1.5 mm was coated with 125 micron polyethylene terephthalate (PE).
T) Film, the other side was coated with a 40 micron polyethylene film. Next, the radius of curvature of the corner is 4.0 mm
The two tip portions are adjusted so that the gap becomes 0.5 mm, and a sharp single-blade made of steel having a thickness of 0.2 mm is set in the gap, and a spring having a height of 4.0 mm is provided between the two. Is pressed against the uncured compound sandwiched between the protective sheets at a speed of 5 cm / sec.
A punched sheet of uncured compound could be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a plate jig used in a second step of the present invention.

FIG. 2 is a perspective view of a single-edged jig used in a second step of the present invention.

FIG. 3 is a perspective view of a double-edged jig used in a second step of the present invention.

FIG. 4 is a single-edged jig used in the third step of the present invention.

FIG. 5 is a double-edge jig used in the third step of the present invention.

FIG. 6 is a jig of the present invention in which the jig of the second step and the jig of the third step (single blade) are integrated.

FIG. 7 is a jig of the present invention in which the jig of the second step and the jig of the third step (both blades) are integrated.

FIG. 8 is a conceptual cross-sectional view when the uncured compound sheet is cut out in a circular shape using the jig in the second step.

FIG. 9 is a schematic cross-sectional view of an uncured compound when punched out in a third step after being cut off as shown in FIG.

FIG. 10 is a conceptual diagram of a process for cutting out an uncured compound sheet having a semicircular diameter with a jig in which the jig in the second step and the jig in the third step are integrated.

[Explanation of symbols]

 Reference Signs List 1 spring 2 blade 3 uncured compound 4 polyethylene film 5 polyethylene terephthalate film

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B26F 1/00-1/46 B26D 3/00

Claims (4)

(57) [Claims] 1. A first step of sandwiching a sheet-shaped uncured compound to be punched by a protective sheet, a second step of pressing a jig against the protective sheet and moving only the compound, and a third step of cutting the protective sheet. Punching method for uncured sheet compound. 2. The method for punching an uncured sheet compound according to claim 1, wherein the uncured sheet compound is a compound having a plasticity of 300 or less. 3. A jig used in the second step according to claim 1, wherein a radius of curvature of a tip portion of the jig is 0.5 mm or more. Jig for punching. 4. The jig for punching a sheet-shaped uncured compound according to claim 3, wherein the jig has a cut in a central portion, and the cutting blade for the protective sheet is housed so as to be extrudable at the cut.