JPH081069Y2 - Width guide plate for plastic sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Use of the Invention) The present invention relates to a guide plate for determining the width of a plastic sheet, which is formed by sheeting rubber or resin with an extruder with a calendar roll.

(Prior Art) There is an extrusion molding method as one of the methods for molding an unvulcanized rubber or a thermoplastic resin into a sheet. This molding method comprises a pair of rolls at the tip of a screw type extruder having a screw arranged in a cylinder, the material to be molded is softened by heating in a cylinder and extruded by a screw, and then this is rolled between rolls. It is made into a sheet shape through.

FIG. 4 is a top view of the (screw type) extruder in this prior art, FIG. 5 is a side view thereof, and FIG. 6 is a front view of a main part.

That is, in the figure, it is a sheeting device in which a (screw type) extruder A and a calendar roll B are combined, and two screws 2 are provided in a cylinder 1 of the extruder A.

Then, between the extruder A and the calender roll B, guide plates 3 are provided on both sides for guiding the extruded material to be molded to the calender roll.

However, the material to be molded melted or softened in the cylinder 1 is sequentially moved by the screw 2 and extruded from the cylinder 1 into the bank 4 sandwiched between the calender roll B and the guide plates 3 and 3.

After that, the extruded material to be molded passes between the calender rolls B and is molded into a sheet having a predetermined thickness.

(Problems of Prior Art) However, in such a prior art, the upper roll B ₁ is movable up and down (arrow) in order to adjust the thickness of the sheet to be formed. Therefore, depending on the adjustment position of the upper roll B _1, the gap w is opened between the side guide plate 3 and the roll B ₁ though it is extremely narrow as shown in FIG. 7.

In such a case, the material to be molded extruded into the bank 4 by the extruder A also enters into the slight gap w, and the material entered into the gap w is the side guide plate 3.
It moves while being twisted between the roll and the roll B ₁ to form a small protrusion rounded into a so-called twist shape, and passes between the rolls in this state.

This state is shown in FIG. 8, and rolls B ₁ and B ₂
On both sides of the material to be molded passing therethrough, the twisted small projections 5 are formed by entering the gap between the roll B ₁ and the side guide plate 3 as described above. .

Therefore, on both sides of the sheet-shaped compact C formed by passing between the rolls B ₁ and B ₂ in this state, the small projections 5 pass between the rolls, and so-called whiskers 6 are still attached. This results in the sheet molded body C. FIG. 9 is a cross-sectional view of the molded body C in the width direction.

From such a fact, the shape of the formed sheet (C) is not as desired, and the workability is deteriorated. What is worse is that the whiskers 6 fall off from the sheet formed body C. Contamination and the like at the work site cause a noticeable deterioration of the environment. On the other hand, the beard 6 that has fallen may be mixed into other materials, which may cause troubles.

(Purpose of the Invention) The present invention is intended to prevent the occurrence of whiskers in the extruded sheet molded body, to maintain a work environment with a good environment, and to prevent the occurrence of troubles due to mixing with other materials. There is something.

(Structure of Device) The present invention adopts the following structure in order to achieve the above object.

That is, a sheet of a material to be molded consisting of an extruder typified by a screw type with an opening at the extruding tip, a pair of upper and lower calender rolls facing the tip opening, and left and right side guide plates forming a bank between them is formed. In the apparatus for forming a sheet-like shape, the interval defined by the left and right side guide plates is set to be slightly narrower than the width of the desired sheet molded product until just before the material to be molded is fed to the calendar roll, A guide plate for determining the width of a plastic sheet, characterized in that the material to be molded is expanded to have substantially the same spacing as the width of the desired sheet molded article immediately before being fed,
Preferably, it faces the calender roll into which the material to be molded is fed, and expands to approximately the same width as the width of the desired sheet molded product by about 10 mm to 30 mm, and is further divided by the left and right side guide plates. This is a width-setting guide plate for a plastic sheet, in which the interval is made 30 mm to 70 mm narrower than the width of the desired sheet molded product until just before the material to be molded is fed to the calendar roll.

More specifically, on the left and right side guide plates corresponding to the upper roll, 15 mm to 35 mm on the side forming the bank.
About 20 mm, and preferably about 20 mm from the tip of the side guide plate facing the calender roll, and preferably 20 mm at the same interval as the width of the desired sheet molded product. .

(Function) Since the present invention employs such a configuration, whiskers causing various inconveniences are completely eliminated from both sides of the sheet molded product.

The function of the present invention can be explained as follows. That is, a twisted small protrusion is formed between the upper roll and the portion where the distance between the left and right side guide plates is narrowed, but the left and right side guides reach the tip of the side guide plate. Since the distance between the plates is widened, the material to be molded also instantaneously spreads outward along with this.

The spread of this material will be supplied between the rolls without time to form the twisted small projections, and at the same time, the twisted small projections formed at the narrow spaces of the side guide plates will be formed by this material. Since the sheet is covered and absorbed, the disorder of the sheet is eliminated, and a sheet molded product having sharp edges on both sides cut with a knife is obtained.

From the opposite viewpoint, small protrusions and whiskers generated between the side guide plate and the roll are generated within the width of the sheet molded product that is finally desired by regulating the distance between the side guide plates, and then this regulation is performed. By releasing it, a sheet molded product having a desired width is obtained, and the whiskers are absorbed at the widthwise ends of the sheet molded product.

(Example) FIG. 1 shows a side guide plate D devised by the present invention.
FIG. 9A is a perspective view of the side guide plate D showing an example of the present invention, and FIG. 9B is an overall view showing an example of the side guide plate D similarly.

In the figure, the side guide plate D is, for example, a flange 11 and is abutted and fixed to the front end portion of the extruder A.
On the other side, an arc surface 12 facing the calender rolls B ₁ and B ₂ ,
Have 13. The side guide plates D are such that the surfaces forming the banks 4, that is, the surfaces of the side guide plates D facing each other when they are installed in the extruder A are made slightly narrower than the desired width of the sheet molded product. In the illustrated example, the side guide plate D has a wall thickness of t,
In the example shown in (b), the upper half of the side guide plate D facing the upper roll B ₁ which is particularly problematic has a thick wall.
In this example, the wall thickness t is 20 mm.

In other words, since the thick portion 14 has a thickness t and is formed on both side guide plates D, the width of the bank 4 is only 2t larger than the desired width of the sheet molded product, that is, 40 mm in this example. It is becoming narrower.

The greatest feature of this side guide plate D is that it faces the roll B and opens just by this narrowing just before the material to be molded is sent to the roll B. In the illustrated example, the thick portion 14 described above is used. Is cut out by t.

In other words, the material to be molded, which has been narrowed by 2 t from the desired width by the bank 4, is suddenly expanded by the amount of the notch 15 and fed into the roll. In this example, 15 mm is cut away from the tip of the side guide plate D facing the roll B.

Now, FIG. 2 is an enlarged conceptual diagram showing the generation state of the small protrusions 5 and the whiskers 6 when the side guide plate D is used.

As you can see in the figure, side guide plate D and upper roll B ₁
Since it becomes a little audible between and, the material to be molded inevitably enters this gap and causes the small protrusions 5 of the conventional twisting shape.
Will be formed.

However, in the side guide plate D of the present invention, since the material to be molded is provided with the above-mentioned cutout portion 15 immediately before being fed into the roll B, the material to be molded is fed into the roll B after being expanded by that amount. Needless to say, the material to be spread, which is spread by the notch portion 15, is sent between the rolls B to form a sheet molded product without any time to form small protrusions having a twisted shape.

At this time, the whiskers 6 formed by the deformation of the small protrusions 5 are absorbed by the sheet portion C'of the material to be spread, and are buried in the material of the sheet portion C '. .

FIG. 3 shows a cross section in the width direction of the sheet molded product C, and shows that the whiskers 6 are buried in the C ′ portions at both ends of the sheet molded product C.

Therefore, the edge portion of the sheet molded product C is extremely favorably molded, and the sheet molded product has a sharpness like a knife cut.

(Effect) Since the present invention uses the side guide plate having the above-described structure, both ends of the sheet molded product absorb the whiskers caused by the gap between the guide plate and the roll, which improves the workability. Also, the beard was completely removed from the sheet molded product, and all the inconveniences caused by this were solved, and the industrial practical value is extremely high.

[Brief description of drawings]

FIG. 1 is a perspective view of a side guide plate of the present invention,
(A) is a main part showing an example thereof, (B) is an overall view showing the same example, and FIG. 2 is an enlarged conceptual view showing the generation state of small protrusions and whiskers when the side guide plate of the present invention is used. , Third
FIG. 4 is a cross-sectional view in the width direction of a sheet molded product obtained by using the side guide plate of the present invention, FIG. 4 is a top view of a screw type extruder in this prior art, FIG. 5 is its side view, FIG. 6 is a front view of a main part, FIG. 7 is an enlarged side view showing the relationship between the side guide plate and the upper roll in the prior art, and FIG. 8 is a small protrusion generated on both sides of the material to be molded and the sheet molded product. FIG. 9 is an enlarged perspective view showing the occurrence of whiskers and whiskers, and FIG. A ...... extruder, B ...... calender rolls, B ₁ ...... on the roll, B ₂ ...... under roll, C ...... sheet materials, C '......
Both ends of the sheet molded product, D ... Side guide plate, w ... Gap, 1 ... Cylinder, 2 ... Screw, 3 ... Guide plate, 4 ... Bank, 5 ... Twist-like small protrusion, 6 ... …
Whiskers, 11 ... Flanges, 12,13 ... Arc surface, 14 ... Thick part, 15 ... Notched part.

Claims (3)

[Scope of utility model registration request] 1. A sheet-shaped molding material comprising an extruder having an extrusion tip opening, a pair of upper and lower calender rolls facing the tip opening, and left and right side guide plates forming a bank therebetween. In the device, the space defined by the left and right side guide plates is set to be slightly smaller than the width of the desired sheet molded product until just before the molding material is fed to the calender roll, and the calender roll is molded material. A guide plate for determining the width of a plastic sheet, characterized in that it is expanded to have a width substantially the same as the width of a desired sheet molded product immediately before being fed. 2. The plastic sheet according to claim 1, wherein the plastic sheet is expanded so as to face the calender roll into which the material to be molded is fed, and approximately 10 mm to 30 mm before the width of the desired sheet molded article. Width guide plate. 3. The width defined by the left and right side guide plates is 30 mm to 70 mm larger than the desired width of the sheet molded product until just before the molding material is fed to the calender roll.
The width determining guide plate of the plastic sheet according to claim 1, wherein the guide plate is narrowed by mm.