JPH07156246A - Method and device for manufacturing sheet-like matter - Google Patents

Abstract

PURPOSE:To save the resin consumption and prevent the resin stagnant in the interior of a die from changing with time by a method wherein molten resin is extruded through a slit gap under the condition that a deckel, which is thinner than the slit gap, is interposed at one end part of the slit gap of a die. CONSTITUTION:A die 1 is equipped with the lead-in port 2 of molten resin, a flow path part for spreading molten resin breadthwise and a slit gap 4, through which spread molten resin is extruded into sheet-like matter. Further, under the condition that at least one end part of the slit gap 4 of the die 1, a deckel 5, the thickness of which is thinner than that of the slit gap 4, is interposed, molten resin is extruded through the slit gap 4. Thus, sheet-like matter 12, the thickness of at least one end part of which is made to be thinner than that of the portion except the one end part just mentioned above, is extruded. Next, by cutting off the sheet-like matter 12 in the portion, which excludes the above-mentioned one end part, to a specific breadth with cutters 10a and 10b, the sheet-like matter is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a synthetic resin sheet material and an improvement in its manufacturing apparatus.

[0002]

2. Description of the Related Art Conventionally, the following are known as a method and an apparatus for forming a sheet-like material which is melt-extruded from a die to have an arbitrary width.

(1) For example, as in the technique disclosed in Japanese Patent Laid-Open No. 49-74749, a sheet material having a certain thickness and width is extruded from a die, and both ends are made to have a desired width in a post process. It is cut to obtain a sheet with the required width.

(2) As in the technique disclosed in Japanese Patent Application Laid-Open No. 49-74749, outer deckles that advance and retreat in the slit width direction are attached to both ends in the width direction of the slit of the die. By changing the length or mounting position, the molten resin immediately before the outer deckle is completely blocked and the extrusion width itself of the sheet material is restricted to a predetermined width.

(3) As in the technique disclosed in Japanese Patent Laid-Open No. 51-2768, an inner deckle having the same shape or the same shape as the flow path section and the slit section inside the die. The width of extrusion of the sheet-like material is regulated to a predetermined width by inserting the tube to block the molten resin in the slit or by changing the insertion amount.

(4) As in the technique disclosed in Japanese Utility Model Laid-Open No. 63-31917, a sheet is formed by introducing molten resin from the side of the die and changing the position of the deckle attached to the introduction side of the slit. Adjusting the extrusion width of the product.

(5) The technique of the above (1) and the above (2),
A combination of (3) and (4).

[0008]

However, in the above-mentioned prior art, when the molten resin has a relatively high viscosity of 10 Pa · S or more and the resin characteristics thereof easily change with time, Attempting to obtain a sheet having an arbitrary width from one die has the following problems. That is, in the technique of the above (1), both ends of the sheet are cut in the post-melting and extruding step to obtain a sheet-shaped article having a required width, and therefore, the sheet-shaped article having the same thickness as the product portion is extruded at both end portions which do not become products. It means that a lot of resin is pushed out in vain.

In the above technique (2), the extrusion width itself of the sheet-like material is restricted to a predetermined width by the outer deckles provided at both ends of the die slit in the width direction. If the molten resin stays in the resin and the characteristics of the molten resin tend to change over time, the quality of the resin deteriorates in the retention area and the quality of the product itself deteriorates. Will be damaged.

In the above technique (3), since the inner deckle is directly inserted into the flow path portion of the die slit, the molten resin does not stay, but the die structure is the same as that of the T die except for the resin introduction portion. Not only limited to the type that has a uniform cross-sectional shape in the width direction of the slit width, but when the viscosity of the molten resin is high and a wide sheet is to be obtained, If a uniform slit gap is set, the thickness of the extruded sheet-like material becomes thinner at the widthwise end portions than at the central portion, which is a drawback due to the die structure. Therefore, in order to make the thickness of the sheet-like material uniform in the width direction, various means for adjusting the slit gap of the die have been proposed, but there is a problem that the structure becomes complicated and complicated adjustment work is required in advance. .

Further, in the technique (4) of introducing the molten resin into the die from the side surface of the die, if the extrusion width is adjusted by the deckle from one side, the center position of the sheet-like material changes,
There is also a problem due to the die structure that it is necessary to adjust the amount of change in the width direction in a later step.

Further, in the above technique (5), (2),
As the technique of (3) or (4), the above (2)
When using the outer deckle of the above, the cut end of the sheet-like material cannot be collected and reused as molten resin.
When the inner deckle of (3) above is used,
(4) When the resin is introduced into the die from the side surface of the die, the above-mentioned problems caused by the die structure cannot be solved.

The present invention has been made in view of the above-mentioned problems of the prior art. It is possible to easily form the width of the sheet-like material extruded from the die to an arbitrary width. By reducing the amount of resin retained in the die as much as possible, the amount of resin consumed per unit length of the sheet material can be saved and the change of retained resin in the die over time can be prevented. It is an object of the present invention to provide a sheet-like material manufacturing method and a manufacturing apparatus therefor capable of simultaneously satisfying the three problems of being able to easily manufacture a sheet-shaped material having an arbitrary width.

[0014]

In order to achieve the above object, a method for producing a sheet material according to the present invention is such that the thickness of the sheet-like material is larger than the thickness of the slit gap at least at one end of the slit gap of the molten resin extrusion die. By extruding the molten resin from the slit gap with a thin deckle interposed, at least one end of the sheet-like material is extruded to form a sheet-like material that is thinner than the thickness of the portion other than the one end, and after that, It is characterized in that the sheet-like material is cut into a predetermined width within a portion other than one end portion.

Further, the sheet material manufacturing apparatus according to the present invention includes a molten resin extrusion die for receiving the molten resin and extruding it into a sheet material having a predetermined thickness, and a cutter for cutting the extruded sheet material into a predetermined width. A device for manufacturing a sheet-shaped product, comprising: a winding device for winding a sheet-shaped product cut into a predetermined width, wherein the molten resin extrusion die is connected to the inlet of the molten resin and the inlet. It has a flow path portion expanded in the width direction and a slit gap that is connected to the flow path portion and pushes out the molten resin, and the thickness of the slit gap is at least at one end in the width direction of the slit gap. It is characterized in that the deckle is set to have a smaller thickness.

Here, the deckle is formed on a first projection portion formed on the flow path portion side and formed of a plurality of discontinuous projections in the die width direction, and on the exit portion side of the slit gap. It is preferable that the second protrusion has a continuous second protrusion in the width direction of the slit gap, and the thickness of the second protrusion is more preferably set to 20 to 80% of the slit gap. preferable.

In the above-mentioned manufacturing apparatus of the present invention, the die is not limited to its shape and type, and for example, a T die, a fish tail die, a coat hanger die, etc., the outlet of the molten resin formed at the die outlet. Any material may be used as long as the molten resin is extruded from the slit gap to form a sheet having a predetermined width. Further, the deckle has at least one end in the width direction of the slit gap, more preferably at both ends,
If it is a member that reduces the extruded thickness of the molten resin, it may be one that inserts a member narrower than the thickness of the slit gap formed separately in the slit gap, the inner wall portion forming the slit gap It may be integrally configured.

[0018]

According to the method and apparatus for manufacturing a sheet material according to the present invention, first, the thickness of the slit gap is adjusted to a predetermined thickness by the adjusting mechanism. Then, when the molten resin is supplied from the inlet of the die by an extruder (not shown), the molten resin reaches the deckle provided in the slit gap portion through the flow path portion. Here, the deckle allows the molten resin, which is successively supplied from the flow path, to flow down immediately before the deckle without any retention as in the prior art, and as a result, the thickness of the final product from the slit gap of the die. Is extruded into a sheet-like article in which a thick portion substantially corresponding to the above and a portion in which at least one end portion of the thick portion is thin are integrated.

The extruded sheet-like material is then cut by a cutter into a final product width in which the thick portion is slightly narrower than the width.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall perspective view of an apparatus for producing a sheet material according to the present invention, and FIG. 2 is a longitudinal sectional view of a die 1 used in the apparatus of FIG.

In FIGS. 1 and 2, reference numeral 1 is a die for receiving a molten resin supplied from an extruder (not shown) and extruding it as a sheet-like material 12, the main part of which is a die body 1a and lips 25, 26 ( (See FIG. 3) and a die side plate 19 for sandwiching these members from both sides, and they are integrated by a bolt (not shown). Die 1
In the upper part, there are an inlet 2 for the molten resin, a channel portion 3 for expanding the molten resin received from the inlet inside the tie in the width direction, and a slit gap 4 for extruding the expanded molten resin into a sheet. They are provided in this order, and they are formed so as to communicate with each other as a molten resin flow path. In addition, 27 provided in the lip portion 25 is, for example, a thickness adjusting mechanism of the slit gap 4 including a push bolt, a heat bolt, and the like, and a plurality of them are provided at constant intervals in the die width direction.

Reference numerals 7a to 7c below the die 1 are press rollers for adjusting the sheet 12 which is still in a molten state into the sheet 12 having a predetermined thickness. Also, 8a to 8c
Is a guide roll, 10a, 10b is a sheet-like material 12
Is a cutter that cuts into a product width L, and is supported by a device (not shown) so that it can advance and retreat in the width direction of the sheet-like object and can insert and remove the blade. 9 is the product width L
It is a core that winds up the sheet-like material cut into pieces as a winding roll 11. The two pieces of sheet waste 13 generated on both sides of the sheet 12 are separately wound by a winding device (not shown).

Referring to FIG. 2, the structure of the die 1 will be described in more detail. In the die 1, side plates 19 are fixed by bolts (not shown) on both sides of the die body 1a in which the molten resin flow path is formed. Further, bracket plates 20 are fixed to both sides of the side plate 19 via connecting members 20a. Deckels 5 are provided on both sides of the slit gap 4 formed by the slit inner wall surfaces 23 and 24, respectively, and can be moved forward and backward by the structure described below in the lateral direction of the drawing. Ie each deckle 5
Is a slide block 1 that is integrated with the screw shaft 15.
7 and the screw shaft 15 is attached to the bracket plate 20.
Is rotatably supported by, and a handle 6 is provided at the end of the screw shaft. Therefore, when the left and right handles 6 are rotated, the deckle 5 advances and retreats in the slit gap 4, and eventually, the thick portion 12a from the slit gap 4.
It is possible to extrude the sheet-like material 12 in which the thin portions 12b are integrally formed on both sides of the sheet. Reference numeral 18 denotes a guide plate that holds the deckle 5 from both sides thereof (a direction perpendicular to the plane of the drawing) in order to slide the deckle 5 with high precision without rattling.

As described above, it is one of the features of the present invention that the sheet-like material 12 having the portions 12b thinner than the central portion on both sides of the sheet-like material 12 can be manufactured.
This will be described in detail with reference to FIG. 3 which is a partially enlarged sectional view of the die in the sheet thickness direction and FIG. 4 which is a perspective view of the deckle.

As shown in FIG. 3, the deckle 5 includes a first projection portion 21 formed on the flow path portion 3 side and formed of a plurality of discontinuous projections in the die width direction, and an exit portion of the slit gap 4. 2nd formed on the side and continuous in the width direction of the slit gap
And the protrusions 22 of the two
Both 1 and 22 project in the thickness direction of the slit gap 4 (leftward in FIG. 3). That is, the first protrusion 21
As shown in FIG. 4, the protrusions 21 and the valleys 34 are alternately arranged at regular intervals, and the second protrusions 22 are formed as a continuous, integrated body. The reason why the first projection 21 is discontinuous and the second projection 22 is continuous is that the former allows the molten resin to pass through during the extrusion even in the deckle 5 part. The latter is exactly the thin portion 1 on both sides of the sheet-like material 12.
This is to form 2b. In this case, the height of the first protrusion 21 is preferably as thick as possible in order to prevent rattling in the thickness direction as long as the deckle 5 can slide in the width direction of the slit gap 4 without hindrance.
Specifically, the thickness of the slit gap 4 is preferably 85% or more, and more preferably 95% or more. On the other hand, the height 29 of the second protrusion 22 is equal to the height of the inner wall surface 2 of the slit.
3 is a gap 28 between the sheet-like material 12 and the thin portion 12
It is set to a height corresponding to the thickness t of b. The height has an optimum value depending on the characteristics of the synthetic resin, does not impair the moldability of the synthetic resin, and limits the residence time of the synthetic resin. It is preferable to make it large enough not to exceed it. In consideration of the above, the specific height is preferably about 20 to 80% of the thickness 30 of the slit gap. Therefore, as shown in FIG. 3, the height of the second protrusion 22 of the deckle 5 is lower than the height of the first protrusion 21, and this height regulates the amount of the sheet waste 13. Will be done. The gap between the slit inner wall surface 24 and the deckle 5 is designed to prevent molten resin from flowing into this portion.
By providing the deckle 5 on the slit inner wall surface 24 side as much as possible, the above-mentioned gap is narrowed. next,
An embodiment of a method for manufacturing a sheet-like material according to the present invention will be described with reference to FIGS.

First, the handle 6 of FIG. 2 is rotated to slide the deckle 5 in the width direction of the slit gap 4 so that the facing distance P of the deckle 5 is set to be slightly wider than the sheet width L of the final product. , Thickness adjusting mechanism 27
Is adjusted so that the gap thickness 30 of the slit gap 4 becomes a thickness T (see FIG. 4) slightly thicker than the thickness of the final product. Then, the molten resin is supplied to the inlet 2 of the die 1 from an extruder (not shown). The molten resin supplied to the inlet is expanded in the sheet width direction in the flow path portion 3 and reaches the slit gap 4. Here, as shown by the outline arrow in FIG. 4, unlike the conventional device, the die 1 causes the molten resin to flow down from the plurality of valleys 34 of the deckle 5 without retaining any molten resin even in the upper portion of the deckle. When the molten resin reaches the second protruding portion 22, the thickness t of both end portions 12b of the sheet-shaped material is regulated to be thinner than the thickness T of the central portion, so that from the slit gap 4, FIG. As indicated by the chain double-dashed line, the sheet-like material 12 is extruded having a thickness T at the central portion and having a thickness t smaller than the thickness at the central portion at both ends thereof. Then, the sheet-like material 12 extruded from the slit gap 4 is pressed by the press rollers 12a ...
After press-adjusting to a predetermined thickness with 12c, the thick portion 12a is cut with a cutter 11 into a final product width S that is slightly narrower than the facing interval P of the deckle 5, and the core 9 is wound with a winding roll 11a. To wind up. on the other hand,
The sheet waste 13 is separately wound by a winding device (not shown).

The outline of the method for producing a sheet material according to the present invention has been described above. Here, the pair of left and right deckles 5 is used.
Among them, the first and second protrusions 21 and 22 are not provided on either one of the deckles, and the one having a thickness almost equal to the slit gap 4 unlike the deckle of the conventional device closes the slit gap 4. By doing so, it is possible to extrude a sheet-shaped article having a thin portion 12b only at one end, and even in such an embodiment, the amount of resin consumption required for producing the sheet-shaped article per unit length is reduced. be able to. Therefore, the manufacturing apparatus and the manufacturing method of the present invention need only form a thin portion at least at one end of the sheet-like material, and needless to say, it is more preferable if both ends are thin. Further, in the sheet-like material manufacturing apparatus of the present invention, even if the deckle of the conventional apparatus is replaced with the one having the above-described structure and slides, the conventional apparatus can be made into a very simple structure without major modification. The effects of the invention can be easily obtained. Also, in the manufacturing method of the present invention, the extrusion speed and the extrusion thickness of the sheet material are not limited at all.

[0029]

The present invention has the following excellent effects.

(1) In the method for producing a sheet material according to the present invention, when the molten resin is extruded from the die into a sheet shape, at least one end in the width direction of the sheet material is made thinner than the thickness required as a product. Since it is extruded with a thickness and then cut into an arbitrary final product width other than the portion where the thickness is thin, a sheet-like material having an arbitrary width can be easily obtained, and sheet scraps that are cut and collected or discarded. Since its thickness is thinner than that of the product portion, it is possible to reduce the amount of resin consumption required to manufacture a sheet-shaped material having a unit length.

(2) In the sheet-like material manufacturing apparatus according to the present invention, the thickness of the deckle provided at least at one end in the slit gap of the die is thinner than the thickness of the portion other than the one end, and Even in this deckle portion, since the molten resin has a function of continuously flowing during extrusion of the molten resin, the molten resin is not completely blocked at the end portion in the die width direction unlike the conventional device.

Therefore, it is possible to reduce the amount of resin consumption necessary for producing a sheet-shaped product having a unit length as much as possible, and the molten resin does not stay in the die for a long time unlike the conventional apparatus, so that the elapsed time can be reduced. Change does not occur.

(3) Further, the sheet-like material manufacturing apparatus according to the present invention can be easily obtained by inserting the deckle having the above-mentioned structure into the slit gap of the conventional die, so that it is limited to the die shape to be used. Instead, it can easily accommodate any type of die. Then, since it is later cut into the final product width by a cutter provided as a separate member, a sheet-shaped article having an arbitrary width can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an embodiment of a manufacturing apparatus according to the present invention.

2 is a cross-sectional view in the width direction of a die used in the apparatus of FIG.

3 is a partially enlarged cross-sectional view of a die used in the apparatus of FIG. 1 in a sheet thickness direction.

4 is a perspective view of a deckle used in the die of FIGS. 2 and 3. FIG.

[Explanation of symbols]

1 ... Die 2 ... Resin introduction part 3 ... Flow path part 4 ... Slit gap 5 ... Dickel 6 ... Handle 7a-7c ... Press roll 8a-8c ... Guide roll 9 ... Core 10a, 10b …… Cutter 11 …… Winding roll 12 …… Sheet-like material 12 a …… Thick portion of sheet-like material 12 12 b …… Thickness of sheet-like material 12 13 …… Sheet scrap 15 …… Screw shaft 16 ...... Guide 17 …… Slide block 19 …… Die side plate 21 …… First protrusion 22 …… Second protrusion 23,24 …… Slit inner wall surface 25,26 …… Lip portion 27 …… Thickness adjusting mechanism 29: Thickness of second protrusion 28: Slit gap (thickness t of thin portion 12b)
34 ………… Tanibe

Claims (4)

[Claims] 1. At least one end of a sheet-shaped article by extruding a molten resin from the slit gap with a deckle thinner than the thickness of the slit gap interposed at least at one end of the slit gap of the molten resin extrusion die. Characterized in that a sheet-like material having a thickness smaller than that of a portion other than the one end is extruded, and then cut into a predetermined width within the portion other than the one end of the sheet-like material. A method for manufacturing a sheet material. 2. A molten resin extrusion die that receives a molten resin and extrudes it into a sheet having a predetermined thickness, a cutter that cuts the extruded sheet into a predetermined width, and a sheet that is cut into a predetermined width. A manufacturing apparatus for a sheet-like material, comprising: a winding device, wherein the molten resin extrusion die has an inlet for the molten resin, and a flow path portion connected to the inlet and expanded in the width direction, There is a slit gap that is connected to the flow path portion and that pushes out the molten resin, and at least one end portion in the width direction of the slit gap is provided with a deckle that has a thickness smaller than the thickness of the slit gap. An apparatus for manufacturing a sheet-like material, which is characterized in that 3. The first deckle includes a plurality of protrusions formed on the flow path portion side and discontinuous in the die width direction.
3. The apparatus for manufacturing a sheet-like material according to claim 2, further comprising: a protrusion and a second protrusion that is formed on the outlet side of the slit gap and that is continuous in the width direction of the slit gap. 4. The sheet-shaped product manufacturing apparatus according to claim 3, wherein the thickness of the second protrusion is 20 to 80% of the thickness of the slit gap in the thickness direction.