JPS5931157A - Feed block for manufacturing laminated sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a laminated sheet in which the surface layer made of a common resin also surrounds both edge portions of an intermediate layer made of a different type (J1 resin).
The present invention relates to an improvement of a feed block in an apparatus for extrusion molding (hereinafter referred to as a wrapped laminated sheet).

When manufacturing plastic sheets, it is often necessary to cut out the edges at both ends of the sheet, but in the case of laminated sheets, multiple resins are mixed together, so
The removed portion cannot be reused as molding material.

In that case, if the laminated sheet is made into an envelope type and the edges on both ends to be cut off after molding are made entirely of surface layer forming resin without an intermediate layer, the cut parts will be similar to those of a normal laminated sheet. Unlike other cases, it is made of a single resin, so it can be recycled.

In addition, when manufacturing a laminated sheet with a layer made of resin with strong adhesiveness and hygroscopicity, if the layer is made into an envelope-type laminated sheet with an intermediate layer, the resin will not stick to the roll during the manufacturing process. Various troubles caused by moisture absorption during storage or use can be prevented.

In order to manufacture envelope-type laminated sheets that have various advantages as described above, the resins constituting each layer of the sheet are melted in separate extruders, and then a core-sheath type composite resin is produced in which the intermediate layer-forming resin is placed in the core. Stream and feed to T-gui. For this purpose, there are various structures for the feed block installed between the tip of the extruder's shilling and the T-guy, but the conventional ones all have a circular cross section as shown in Figure 1. However, if you look only at the sheath resin flow 1, it is annular.) A composite resin flow is formed and sent to the T-gui (2
is the core resin flow). When such a feedblock is used, the width of the edge of the sheet extruded from the T-die where there is no intermediate layer (hereinafter referred to as the non-laminated area) depends on the ratio of the thickness of the intermediate layer and the surface layer. , in other words, is mostly determined by the supply ratio of the two types of resins.

Therefore, it has been difficult to adjust the width of the non-laminated portions of the ears depending on the purpose of making the envelope-type laminated sheet.

The present invention has succeeded in solving the above-mentioned drawbacks of the conventional feed blocks, and in the feed block for envelope type laminated sea Y molding, the core resin flow and the sheath resin flow are different from each other. Each resin flow path immediately before and after the confluence point has a substantially rectangular cross section, and two of the rectangular cross sections
It is characterized by being arranged so that the sides are perpendicular to the width direction of the T-die connected to the feed block.

Next, the present invention will be explained by showing specific examples.

FIG. 2 shows the feed block of the present invention with T-die 3,
A sectional view showing the connecting pipe 4 connected to the core resin extruder and the connecting pipe 5 connected to the sheath (B1 resin extruder) (the central axis of this feed block and the resin extrusion port of the T-die 3 are This feed block is made up of a Gui body 6 and a core 7, and the former is connected to the connecting pipe 5, and the latter is connected to the connecting pipe 4, respectively.

The core 7 has a core resin flow path 8 in the center that communicates with the core resin extruder via the connecting pipe 4, and the cross-sectional shape of the core resin flow path 8 is such that the cross-sectional shape of the core resin flow path 8 is larger than the intermediate widened portion 9. is circular, or square at the bottom (however, the reason why the cross-sectional shape of the core part (kj fat channel 8) is not square at the middle part and the upper part is because it is not necessary to make the whole part square, so the upper part can be easily drilled). (It has a circular cross section and has no particular meaning, and the intermediate widened part was only provided because it was necessary for work that involved changing the cross-sectional shape.) Die body 6 and core 7
There is a gap between them to form a sheath resin flow path 10, and this sheath resin flow path 10 communicates with the sheath resin extruder via the connecting pipe 5. Sheath part tj (the cross section of the fat flow path 10 is an upper widened part 1 for making the flow rate uniform over the entire circumference)
1 and the lower widened part 12 is circular (annular),
The portion below the lower widened portion 12 is square. core glS
The composite resin flow path 13, which communicates with the resin flow path 8 and the sheath resin flow path 10, and further passes through the manifold of the 'r-gooey 3 at its tip, also has a square cross section. Figure 3~
Figure 6 - shows the cross-sectional shape of each part as described above;
The figure is section A-A, Figure 4 is section B-B, Figure 5 is section C-0,
FIG. 6 is a cut end view of the DD section.

The feed block of the present invention has the above-described structure. When the feed block is installed between the T-die 3 and the extruder as shown in Fig. 2 and extrusion molding is performed, the connecting pipe is When the core resin that has entered the core resin flow path 8 via the core resin flow path 8 exits the core resin flow path 8 and enters the composite resin flow path 13, it is transferred from another extruder to the connecting pipe 5 and the sheath portion a. (A composite resin flow with a core-sheath type arrangement is formed by being surrounded by the sheath resin flowing into the composite resin flow path 13 via the fat flow path 10. Then, the core resin flow and the sheath resin flow Since each resin flow path immediately before and after the merging point with the resin has a rectangular cross section as described above, the composite resin flow that is formed has a cross section as shown in Fig. 7. , 14 is a core resin flow that becomes an intermediate layer of the laminated sheet, 15 is a saddle resin flow that becomes a surface layer, and a broken line XX indicates the width direction of the T-die attached to the feed block.

The cross-sectional shape of each resin flow path in the feedblock of the present invention does not necessarily have to be such that a resin flow with a square cross section is formed in both the core and sheath parts as shown in FIG. As in the example shown in the figure, one side of the resin flow has a rectangular cross section, or as in the example in Figure 9, only the two sides parallel to the width direction of the T-die have a slightly curved cross section. (The symbols in both figures have the same meaning as in Figure 7).

11 to 13 are cross-sectional views in the width direction showing examples of enveloped laminated sheets that can be manufactured using the feed block of the present invention, and in each figure, 17a to 17d are intermediate layers; (+a to 18c are surface layers, and 19 is a normal laminate layer that is not an envelope type. If the feedblock of the present invention is used, it is also possible to perform double envelope type lamination as shown in the example in Fig. 12. ffE.Furthermore, the food block of the present invention has a structure in which one or more layers are further laminated on the envelope type laminated sheet, as shown in the example of FIG. It is also applicable when manufacturing a laminated sheet, which is a type laminated sheet, by a single extrusion molding.
In the present invention, the "surface layer" is to be understood as a covering layer in a covering type laminate structure.

Although the feed block of the present invention has the above-described configuration and functions based thereon, the use of the feed block to form an envelope-type laminated sheet has the following advantages.

■ Compared to the case where a composite resin flow with a circular cross section is flattened using a T-die to form an envelope-type laminated sheet, the thickness unevenness of each layer in the width direction is reduced, and the fluctuation in the width of the non-laminated portion of the edge is also reduced. Become.

■ At the feed block outlet, by installing a weir plate 16 whose position is variable in the width direction of the T-Guy and arranged as shown in FIG. The width of the laminated portion can be arbitrarily adjusted without being restricted by the ratio of the thicknesses of the surface layer and the intermediate layer, and without replacing the core 7.

Therefore, the present invention not only facilitates the production of various envelope-type laminated sheets, but is also extremely effective in improving their quality.

[Brief explanation of drawings]

Figure 1: Cross-sectional view of composite resin flow using a conventional feedblock. FIG. 2 2 A sectional view of an embodiment of the present invention. Figure 3: A cutaway end view of the section A-A in Figure 2. Fig. 4: A cutaway end view taken along the line B-B in Fig. 2. Fig. 5: Cut end view of section C-C in Fig. 2. Figure 6: A cutaway end view of the section D-D in Figure 2. Figure 7: Cross-sectional view of the composite resin flow formed by the feedblock of Figure 2. FIGS. 8 and 9: Cross-sectional view of a composite tj (surface part) formed according to another embodiment of the present invention. FIG. An explanatory diagram of a method for adjusting the width of a non-laminated part of a mold laminated sheet. Figures 11 to 13: Cross-sectional views in the width direction of the envelope-type laminated sheet. 1.15: Saddle resin flow 2.14: Core resin flow 3: F-Gui 6: Gui body 72 core 8: Core resin flow path 10: Sheath resin flow path 13: Composite resin flow path 16: Weir Board Figure 6 Figure 7 Child 8 Figure 9 Figure 10 Figure 12 Figure 13 Figure 9

Claims (1)

[Claims] The tips of cylinders of multiple extruders and dies are used to mold a laminated sheet in which the surface layer made of a common resin also surrounds both edge portions of an intermediate layer made of different resins. In a feed flock having a resin flow path that can form a composite resin flow in a core-sheath type arrangement from a plurality of molten resins installed between them and supplied with the extrusion, a core resin flow and a tt@ part resin flow are used. Each resin flow path immediately before and after the convergence point has a substantially rectangular cross section, and two sides of the rectangular cross section are arranged orthogonal to the width direction of the T-Guy connected to the feed block. A feed block characterized by being something.