JP3241200B2 - Thermoplastic resin sheet manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing a thermoplastic resin sheet having a sheet extrusion die and a conduit, and more particularly, to an apparatus for extruding a sheet between an extruder and a cooling step. Installed, each type of molten resin is received from a plurality of extruders, merged in the mold of this device, and when extruded into a sheet, a part or all in the width direction of the sheet is formed into a multilayer sheet. The present invention relates to a thermoplastic resin sheet manufacturing apparatus capable of obtaining a laminated product.

[0002]

2. Description of the Related Art Conventionally, windshield glass used for automobiles and airplanes and tempered glass used for windows of buildings are made of synthetic resin such as polyvinyl butyral between two glass plates. A laminated glass having a structure in which an interlayer film is sandwiched is used. Such a laminated glass has a function of having high strength and preventing fragments from scattering around even if broken.

[0003] The intermediate film used for such a laminated glass is usually provided with an extruder, a die for extruding a sheet attached to the extruder, a cooling device including a rotary drum and the like, and a winding machine. Are obtained through a series of manufacturing steps.

The interlayer film thus obtained is colorless and transparent. However, in the case of windshield glass for automobiles, a colored band having a concentration gradient is provided so as to become gradually thinner from the upper edge toward the lower side, thereby transmitting light. Some limiting interlayers are used.

As a method for obtaining an intermediate film having such a colored band, several techniques have already been developed, one of which is described in Japanese Patent Publication No. 43606/1994. In this technique, a probe formed of a tubular body having a smaller diameter than the manifold, a closed end, and a slit-shaped orifice parallel to the axial direction is provided on a peripheral wall in the mold manifold. Is a technique for molding an intermediate film having a colored body by extruding a non-colored resin and extruding a colored resin from an orifice provided in a probe so that the resin can be sealed in the non-colored resin.

[0006]

However, in the prior art described above, the probe has one end supported by one side of the mold and a pair of support legs (indicated by reference numeral 8 in the same publication) near the other end. (A member to be extruded) is erected in the manifold to reinforce the extrusion pressure of the non-colored resin. However, since the probe is cantilevered in the manifold, it cannot be said that it is sufficient for the extrusion pressure.
The sheet may be inclined in the manifold, and the thickness of the sheet may vary greatly, or the width of the colored band may fluctuate.

[0007] Each of the pair of support legs is formed in an eight-shape with its axis at the root at a position separated from the one end of the probe in the axial direction by a certain distance (see Japanese Patent Publication No. 3
FIG. 4, FIG. 4). That is, when viewed from a direction perpendicular to the axial direction of the probe, the support legs are arranged in an overlapping position. Therefore, when the non-colored resin extruded in the extrusion direction in the manifold collides with the support leg, a boundary of the resin flow is formed, but the boundary of the resin flow formed on both sides of the probe overlaps and is large in the land portion. When formed and formed into a sheet and extruded from the slit, this portion appears as a weld line.

As measures against this weld line, it is conceivable to make the support legs as thin as possible or to make the support legs streamlined in order to reduce the resistance of the molten resin. The opposition to pressure is weaker, and streamlining is not as effective.

The applicant has previously developed a device for supporting a conduit on both side plates of a mold as means for fixing the conduit in the manifold (see Japanese Patent Application Laid-Open No. 4-64424).
If the conduit is long or thin, it may still not be able to sufficiently resist the extrusion pressure of the non-colored resin.

The present invention overcomes the disadvantages of the prior art described above and provides for a solid support of the conduit within the manifold,
An object of the present invention is to provide an apparatus for producing a thermoplastic resin sheet which does not adversely affect the quality of the obtained sheet.

[0011]

An apparatus for producing a thermoplastic resin according to the first aspect of the present invention (hereinafter referred to as "first invention") includes a sheet extrusion die and a conduit. A sheet extrusion molding die includes a manifold, side plates provided at both ends in the width direction of the manifold, a first resin supply path for supplying a first molten resin into the manifold, and a manifold for the first resin. And a land portion formed between the manifold and the orifice.A conduit is disposed in the manifold, and both ends of the conduit are supported by side plates. A second resin supply path for supplying the second molten resin therein, a slit-shaped orifice for pushing the second resin outward is provided, and an inclined surface located on the outlet side of the manifold, At least one pair of support legs capable of withstanding the extrusion pressure of the first resin received by the conduit is provided upright from either the inclined surface of the manifold or the outer wall of the conduit between the conduit and the outer wall surface facing the conduit. At the same time, each of the pair of support legs is provided with a gap in the axial direction of the manifold, thereby achieving the above object.

The invention according to claim 2 (hereinafter referred to as “second
The apparatus for manufacturing a thermoplastic resin according to the first aspect of the present invention is the apparatus for manufacturing a thermoplastic resin sheet according to the first aspect of the present invention, wherein a portion of the gap between the inclined surface of the manifold and the outer wall surface of the conduit is a portion where the support leg is erected. The gap of the portion where the support leg is not erected, which is located symmetrically with the support leg across the axis of the conduit, is larger than the gap,
Thereby, the above object is achieved.

That is, the thermoplastic resin manufacturing apparatus of the first aspect of the present invention employs means for supporting both ends of the conduit with mold side plates as basic means for holding the conduit in the manifold. A support leg is provided between the pipe and the conduit so that the resin can sufficiently withstand the extrusion pressure of the first resin regardless of the shape and structure of the conduit, and the boundary of the resin flow generated by the support leg overlaps. The aim is to prevent the occurrence of weld lines by erection of the support legs so as not to occur.

The apparatus for producing a thermoplastic resin according to the second aspect of the present invention is the apparatus for producing a thermoplastic resin according to the first aspect, wherein
In the gap between the manifold inclined surface and the outer wall surface of the conduit, a portion where the support leg is not erected, which is located symmetrically with respect to the support leg across the axis of the conduit than a gap between the portion where the support leg is erected. By making the gap larger, more resin flows into the larger gap, and by reducing the amount of resin flowing to the support leg side, the occurrence itself of the boundary of the resin flow generated by the support leg is reduced, The aim is to prevent the occurrence of weld lines.

In the second aspect of the present invention, as a method of increasing the gap between the portions where the support legs are not erected, the manifold inclined surface may be cut or the conduit outer wall surface may be cut. Alternatively, both the inclined surface of the manifold and the outer wall surface of the conduit may be cut.

[0016]

According to the first aspect of the invention, since both ends of the conduit provided in the manifold are supported by the side plates, a basic opposing force against the pushing pressure of the first resin in the manifold is provided. You. Further, since at least one pair of support legs is provided between the manifold and the conduit to reinforce the counterforce, the conduit is deformed even if the design change of the conduit shape and structure is widened. Therefore, there is no large variation in sheet thickness and no variation in the width of the colored band. Further, since each of the pair of support legs is erected with a gap in the axial direction of the manifold, the boundary between the two resin flows due to the first resin generated by the support legs may not overlap at the land portion. Conversely, it is sufficiently repaired while passing through the land portion, and the weld line disappears or leaves an invisible trace.

Further, according to the second aspect of the invention, the gap between the inclined surface of the manifold and the outer wall surface of the conduit is symmetrical to the support leg with respect to the axis of the conduit from the gap where the support leg is erected. Since the gap of the portion where the support legs are not erected is made larger, the resin flows more from the side with the larger gap and the amount of resin flowing to the support legs side decreases, so the support legs The generation of the boundary between the two resin flows due to the generated first resin is reduced, and the weld line disappears or leaves an invisible trace.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1A is a partially cutaway front view showing an embodiment of a manufacturing apparatus common to the first invention and the second invention. FIG. 1B is an orifice of a conduit in the same apparatus. FIG. 2 is an enlarged view of a portion, and FIG. 2 is a sectional view taken along line II-II in FIG.
FIG. 3 is a sectional view taken along the line and viewed in the direction of the arrow.
FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2 and viewed in a direction of an arrow, with a part of a conduit and a mold omitted; FIG. It is a bottom view showing the example set up on the conduit side.

In these figures, reference numeral 1 denotes a die for extrusion molding set in a horizontal direction, and 2 denotes a conduit. The mold 1 includes a manifold 3, side plates 4, 4 provided at both ends in the width direction of the manifold 3, a first resin supply path 5 for supplying a first molten resin into the manifold 3, Orifice 6 that pushes out of manifold 3 to outside
And a land portion 7 formed between the manifold 3 and the orifice 6.

The first resin supply path 5 is connected to a first extruder through a die adapter (not shown), receives the first resin melted and kneaded by the first extruder, and places the first resin in the manifold 3. It is designed to be sent. The first resin supply path 5 may be provided at one end of the manifold 3, or may be provided at a central portion or another position.

The conduit 2 is formed of an elongated tubular body having the other end closed by a blind plug, and one end thereof is connected to a crosshead of a second extruder (not shown), and is melt-kneaded by the second extruder. The supplied second resin is received by a second resin supply passage 9 provided at one end of the conduit 2. 1
Numeral 0 is a slit-shaped orifice provided at one end of the conduit 2, which is opened in the same direction as the orifice 6 of the manifold 3, and in which the second resin fed into the conduit 2 balances the pressure. Is pushed out toward the outer side, that is, the direction of the orifice 6 when is held.

FIG. 1B is an enlarged view of the orifice 10 viewed from below, and the tip of the orifice 10 in the resin feeding direction is tapered. The dimensions such as the length and width of the orifice 10 are mainly determined by the dimensions of the sealing sheet formed of the second resin, and the position provided in the conduit 2 is mainly determined by the sealing position of the sealing sheet.

As shown in FIG. 2, the inner wall surface of the manifold 3 has an upper wall surface formed in a semicircular cross section.
The lower wall surface is a straight slope 1 narrowed down in a Y-shape.
1 and 12. This inclined surface 11, 1
2 has a pair of support legs 13 and 14 formed of a columnar body,
Three manifolds 3 are assembled at intervals in the axial direction, and each end is in contact with the outer wall surface of the conduit 2.

The shape of the support legs 13, 14 may be substantially conical, in which case the top of the cone will abut the outer wall of the conduit 2. Although there is no particular limitation on the opening angle of the support legs 13 and 14, it is preferable that each of the angles is 45 ° with respect to the extrusion direction. When a plurality of pairs of the support legs 13 and 14 are provided, it is preferable that the interval between the pairs is at least １ ／ or less of the length of the orifice 6. There is no particular limitation on the number of sets and dimensions, and the point is that it can be installed between the inner wall surface of the manifold 3 and the outer wall surface of the conduit 2, and the conduit 2 can sufficiently oppose the extrusion pressure of the first resin. What is necessary is just to be comprised.

The support legs 13 and 14 may be provided on the manifold inclined surfaces 11 and 12 or may be provided on the outer wall of the conduit 2 as shown in FIG. Or it may be fixed to both. However, the resin extruded in contact with the inclined surfaces 11 and 12 of the manifold 3 is mainly located on the surface of the sheet to be molded. The leading end is liable to be damaged by being rubbed on the inclined surfaces 11 and 12, and the damaged portion may appear as streaks on the sheet, which is not preferable. In addition, as will be described later, when the structure for moving the conduit 2 in the axial direction is adopted, the support legs 13 and 14 are, of course, connected to the manifold inclined surface 1.
1, 12, or any surface of the outer wall surface of the conduit 2 must be free.

As shown in FIG. 3, each of the support legs 13 and 14 has a gap S in the axial direction of the manifold 3.
(Slightly shifted) from each other. The gap S varies depending on the type of the first resin, the melt viscosity and the extrusion pressure, the material, shape and size of the conduit 2, the manifold 3, and the support legs 13 and 14, or other factors. , About 10 to 500 mm, and 1
If the distance is less than 0 mm, the boundary of the first resin flow may overlap at the land portion 7, and the effect of preventing the occurrence of weld lines may not be exhibited. On the other hand, if it exceeds 500 mm, the conduit 2 may bend without being able to withstand the pushing force of the first resin, and the reinforcing effect of the conduit 2 may not be exhibited.

In the case of this embodiment, the position of the conduit 2 in the axial direction can be adjusted by a predetermined distance.
In the drawings, reference numerals 15 and 15 denote sleeves, each having a built-in packing, and when the conduit 2 moves in its axial direction,
The first resin is prevented from leaking from the support portions of the side plates 4 and 4. A male screw 16 is engraved on the outer peripheral surface of the other end of the conduit 2. An adjusting nut 17 is provided on the right sleeve 15.
Is inserted so as to be rotatable around an axis, and on its inner peripheral surface, a female screw 18 that can be screwed to the male screw 16 is engraved.
The rotation of the adjusting nut 17 enables the conduit 2 to move in the axial direction. In the case of such a device, the position of the colored band can be changed even during operation of the device, and when the conduit 2 is set so that the orifice 10 and the orifice 6 are located close to each other, the colored band can be changed. Can also be changed.

In order to form an intermediate film having a colored band having a concentration gradient such that the thickness gradually decreases from the upper edge to the lower side using the above-described apparatus of the present invention, first, an almost transparent polyvinyl butyral resin is used. From the first extruder via the first resin supply path 5 into the manifold 3. When the first resin fills the inside of the manifold 3 and reaches a balanced pressure, the first resin is pushed out of the orifice 6 through the land 7.

On the other hand, a polyvinyl butyral resin colored in an appropriate color such as blue or green is supplied from the second extruder into the conduit 2 via the second resin supply path 9. The second resin is conduit 2
When the interior is filled and a balanced pressure is reached, the orifice 10
As soon as it is extruded from the first resin, it joins with the resin flow of the first resin, and becomes a form sealed in the first resin. Then, as shown in FIG. 6, an intermediate film F having a colored band 19 having a smooth concentration gradient is formed from one end of the sheet to a position of a certain size.

(Example 1)

Molding device The above-mentioned molding device is used as it is. [Mold] Manifold dimensions: 430R (radius) x 1600 (length) mm Land portion dimensions: 50 mm Mold set temperature; 200 ° C [Conduit] Overall length ( 2300 mm diameter; 32 mm orifice length; 300 mm maximum gap between orifices; 2.5 mm adjustable dimension; 100 mm [gap between manifold inclined surface and conduit outer wall surface] 3.5 mm [support leg] ] 3.5 m long consisting of a columnar body with a diameter of 6 mm
m, three sets each including one pair of the pair, and the gap S is 15 mm.

Using the above molding apparatus, extrusion molding was performed continuously under the above molding conditions, and the width was 1300 mm and the average thickness was 0.7.
A 5 mm intermediate film F was formed.

FIG. 5 is a sectional view showing an example of the second invention cut along the line VV in FIG. 1A and viewed in the direction of the arrow.

According to the second aspect of the present invention, the support leg 13 is located symmetrically with respect to the support leg 13 with respect to the axis of the conduit 2 from the gap A between the inclined surface 11 of the manifold and the outer wall surface of the conduit 2. The gap B between the manifold inclined surface 12 (12b) at the portion where the support legs are not erected and the outer wall surface of the conduit 2
Are larger, and the support legs 14 have a gap difference that is exactly opposite to that of the support legs 13, so that the respective manifold inclined surfaces 11, 12 are formed in an uneven shape.

The size of the gap B between the manifold inclined surface concave portion 12b and the outer wall surface of the conduit is not particularly limited, but is 1.5 times the size of the gap A between the manifold inclined surface 11 and the outer wall surface of the conduit. It is desirably about 2 times.
If the size of the gap B is less than about 1.5 times the size of the gap A, the amount of resin flowing to the support leg side does not become sufficiently small, so that the occurrence of the boundary of the resin flow cannot be sufficiently suppressed. If it exceeds about twice, a problem on the rigidity of the mold occurs.

(Embodiment 2)

Forming Apparatus Using the forming apparatus shown in FIGS. 1 and 5, [Gap between the inclined surface of the manifold and the outer wall surface of the conduit] Gap A; 3.5 mm Gap B; 5.5 mm [Support legs] 6 mm in diameter 3.5m long made of cylindrical body
m, three pairs of one pair are arranged, and the gap S is 50 mm [the width of the gap B between the concave portion of the manifold inclined surface and the outer wall surface of the conduit in the manifold axial direction] 50 mm (centering on the support legs) An intermediate film F having a width of 1300 mm and an average thickness of 0.77 mm was obtained in the same manner as in Example 1 except that the left and right sides were each 25 mm).
Was molded.

(Comparative Example)

An intermediate film F having a width of 1300 mm and an average thickness of 0.75 mm was formed in the same manner as in Example 1 except that the supporting legs were not provided in the forming apparatus.

FIG. 7 shows the result of measuring the thickness in the width direction of the intermediate film obtained in Example 1, and the results in Example 2 are shown.
FIG. 8 shows the result of measuring the thickness in the width direction of the intermediate film obtained by the above method. FIG. 9 shows the measurement results of the thickness in the width direction of the intermediate film obtained by the comparative example. The thickness was measured using an electronic micrometer manufactured by Anritsu Corporation.

As is clear from the graphs of FIGS. 7 and 8, the thickness error of the first embodiment is +0.010 mm, −0.00 mm.
015 mm, and the thickness error of Example 2 is +0.010
mm and −0.010 mm, the thickness error of the comparative example was +0.8, as is clear from the graph of FIG.
0 mm and -0.55 mm. Therefore, when the apparatus of the first invention and the second invention are used, a sheet having a very small thickness error range in the width direction of the obtained sheet can be obtained.

[0043]

As described above, according to the present invention, since both ends of the conduit provided in the manifold are supported by the side plates, the basic opposition to the extrusion pressure of the first resin in the manifold is achieved. Power is provided. Further, since at least one pair of support legs is provided between the manifold and the conduit to reinforce the counterforce, the conduit is deformed even if the design change of the conduit shape and structure is widened. Without any variation in sheet thickness,
No variation occurs in the width of the colored band.

Therefore, the conduit is firmly supported in the manifold, and the thickness of the obtained sheet is less varied, and the width and thickness of the colored band or its position in the sheet are not changed, so that a sheet of excellent quality can be formed. Device.

Further, since each of the pair of support legs is erected with a gap in the axial direction of the manifold, the boundary between the two resin flows of the first resin generated by the support legs is as follows: There is no overlap at the land portion, and conversely, it is sufficiently restored while passing through the land portion, and disappears or leaves an invisible trace.

Furthermore, of the gap between the inclined portion of the manifold and the outer wall of the conduit, the gap between the portion where the support leg is erected is located symmetrically with respect to the support leg with respect to the axis of the manifold. Since the gap between the portions that are not erected is made larger, the amount of resin flowing to the support leg side is reduced, so that the boundary itself between the two resin flows due to the first resin generated by the support leg is reduced. The weld line disappears or leaves an invisible trace.

The apparatus of the present invention can be used for forming an intermediate film having a colored band, which is used as a material for windshield glass used for automobiles, airplanes and the like, and tempered glass used for windows of buildings and the like.
Alternatively, it is suitable for use in forming a multi-layered laminated sheet having a multi-functional structure made of different kinds of resins.

[Brief description of the drawings]

FIG. 1A is a partially cutaway front view showing one embodiment of the manufacturing apparatus of the present invention, and FIG. 1B is a cross-sectional view showing an enlarged part of the same apparatus. FIG.

FIG. 2 is a cross-sectional view taken along line II-II in FIG.

FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2 and viewed in a direction of an arrow, with a part of a conduit and a mold omitted.

FIG. 4 is a bottom view showing an example in which the support legs are erected on the conduit side in the apparatus of the present invention shown in FIGS.

FIG. 5 is a cross-sectional view showing one example of the second invention cut along a line VV in FIG.

FIG. 6 is an explanatory view showing only a main part of an intermediate film having a colored band formed by the apparatus of the present invention.

FIG. 7 is a graph showing a variation in thickness of an intermediate film formed in Example 1.

FIG. 8 is a graph showing a variation in thickness of an intermediate film formed in Example 2.

FIG. 9 is a graph showing a variation in thickness of an intermediate film formed by a comparative example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Extrusion molding die 2 Conduit 3 Manifold 4 Side plate 5 First resin supply path 6, 10 Orifice 7 Land part 9 Second resin supply path 11, 12 (12a, 12b) Inclined surface 13, 14 Support leg 15 Sleeve 19 Colored belt S Gap between a pair of support legs A Gap between the inclined surface of the manifold where the support legs are erected and the outer wall surface of the conduit B Support legs that are symmetrically located with the support legs across the axis of the conduit are not erected Gap between the manifold inclined surface of the part and the outer wall surface of the conduit F Intermediate film

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-205122 (JP, A) JP-A-4-64424 (JP, A) JP-A-4-259525 (JP, A) JP-A-4-205 64426 (JP, A) JP-A-4-244825 (JP, A) JP-B 1-443606 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 47/00-47 / 96

Claims (2)

(57) [Claims] 1. A mold for extruding a sheet and a conduit, the mold for extruding the sheet comprising a manifold, side plates provided at both ends in a width direction of the manifold, and a first plate in the manifold. A first resin supply path for supplying the molten resin, a slit-shaped orifice for extruding the first resin outward from the manifold, and a land formed between the manifold and the orifice. A conduit is provided, the conduit is supported at both ends by side plates, has a second resin supply path for supplying a second molten resin into the manifold, and has a slit-shaped orifice for pushing the second resin outward. Is provided, between the inclined surface located on the outlet side of the manifold and the outer wall surface of the conduit facing the inclined surface, at least one pair capable of withstanding the extrusion pressure of the first resin received by the conduit. The support legs are erected from either the inclined surface of the manifold or the outer wall surface of the conduit, and each of the pair of support legs is provided with a gap in the axial direction of the manifold. Manufacturing equipment for thermoplastic resin sheets. 2. A support leg, which is located symmetrically to the support leg with respect to an axis of the conduit, from a gap between a portion where the support leg is erected among the gap between the manifold inclined surface and the outer wall surface of the conduit. The apparatus for producing a thermoplastic resin sheet according to claim 1, wherein a gap between the portions not provided is made larger.