JPS5913968B2 - Die adapter for multilayer plastic film or sheet molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a die adapter for forming multilayer plastic films or sheets.

Conventional die adapters attached to single-layer dies for molding multilayer plastic films or sheets have the function of simply merging two or more types of resin and guiding them to the die. For this reason (c) At the point where each resin flows independently and merges into one, the direction of flow of each resin changes rapidly, so the boundary surfaces of each layer are disturbed, and even after it is made into a product, the product (2) The flow rate ratio of each resin is controlled by the shape of the die adapter O, and cannot be fixed at a certain level. (3) When a pressure difference occurs between the flows of each resin at the point where the flows of each resin meet, the flow rate ratio explained in (1) can be used to form a multilayer plastic film or sheet. Similar to 15, the boundary surface is disturbed and a good product cannot be obtained.(4) High viscosity resin is wrapped in low viscosity resin and cannot spread sufficiently in the die, resulting in The product is concentrated in a certain area, and the entire product cannot be made into a multilayer plastic film or sheet. Therefore, it is only possible to form a multilayer plastic film or sheet using a limited combination of resins with very small viscosity differences. However, it was 25 mag.

Therefore, in order to resolve these difficulties, (1) Eliminate turbulence at the point where each resin joins, and create a structure in which the thickness ratio of each layer does not vary in the width direction of the product and in the flow direction of the product; 30 (2) Even if the flow rate ratio changes, the resin flow path should be able to be adjusted according to the amount of change. (3) The flow path of each resin should be adjusted at the point where the flows of each resin merge. Eliminate the pressure difference when it occurs 35
(4) It is necessary to have a structure that allows the entire product to have a uniform thickness ratio even if there is a slight viscosity difference without biasing each layer.

An object of the present invention is to obtain a die adapter for molding a multilayer plastic film or sheet that realizes such a structure.

In order to achieve this object, the present invention provides a partition member that separates each resin so as to create a rectifying section where the force direction of the flow is the same as the force direction of the flow after merging, before the resins merge. be installed just before each resin merges, be able to move the partition member to a position where no pressure difference occurs for any merging ratio, and create a rectification section suitable for the combination of resins. The present invention is characterized in that the length of the partition member can be adjusted just as the length of the partition member is adjusted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS. 1 to 5 of the accompanying drawings showing one embodiment thereof.

As shown in FIG. 1, a plurality of resin passages 2 and 3 are provided facing the adapter body 1, and a merging resin passage 4 is provided perpendicularly to these passages, and a symmetrically inclined transition surface is provided at the intersection of these passages. 5,5 will be provided.

In addition, in the main body 1, a pressure difference regulating valve 6 having an inclined surface corresponding to the inclined transition surfaces 5, 5 formed at the tip thereof is moved into the merging resin flow path 4 in a direction perpendicular to the direction of force. Set up freely,
In order to move this pressure difference adjustment valve 6, a pair of adjustment bolts 7 are supported either integrally with the main body 1 or by a pair of supports 8 attached separately to the main body 1. It is brought into contact with the outer surface of the pressure regulating valve 6. Furthermore, a partition plate 10 is attached so as to be movable in the axial direction through the center plane of the pressure regulating valve 6, and the tip portion of this partition plate 10 projects into the merged resin flow path 4. 10, a nut 11 is fixed to the other end, and an adjusting bolt 12 that engages with the nut 12 is rotatable either integrally with the pressure regulating valve 6 or on a support plate 13 attached separately to the pressure regulating valve 6. The partition plate 10 can be moved in the axial direction through the nut 11 in the merging resin flow path 4 by attaching it to the holder and operating the adjustment bolt 12. The present invention has the above configuration, and its operation and effects will be explained next. As shown in FIG. 1, by providing the partition plate 10 so as to protrude into the merging resin flow path 4, the flow of each resin X, Y from each resin path 2, 3 is controlled by the flow of resin After the flow has the same force direction as the flow in the merging resin passage 4, it is possible to merge the flow in the merging resin passage 4 (5).

Therefore, as shown in FIG. 2A, when there is no partition plate as in the conventional case, resins X and Y sent in the direction of force of arrows X and Y through the flow channels 2 and 3 merge. In contrast to the turbulence that occurs at the boundary surface T between the subsequent layers, in the present invention, as shown in FIG. This eliminates the problem, and it is possible to obtain a product with no variation in the thickness ratio of the product flow force direction. Furthermore, by appropriately selecting the cross-sectional shape of the partition plate 10, it is possible to eliminate variations in the thickness ratio in the width direction of the product or to intentionally vary the thickness ratio. For example, the partition plate 10
By making the cross-sectional shapes of Products with different values of the ratio can be obtained. In addition, by adjusting the amount of protrusion of the partition plate 10 into the merged resin flow path 4, a rectification section suitable for the combination of resins X and Y in each resin flow path 2 and 3 is established, This eliminates disturbances in the boundary surface T of each resin layer due to viscosity differences, and makes it possible to obtain a product with a uniform thickness ratio in the width direction of the product.

That is, for example, FIG. 5A shows a cross section of the product in the width direction without the partition plate, and FIG. 5B shows a cross section of the product in the width direction when the partition plate according to the present invention is provided.
As described above, according to the present invention, the partition plate is provided so that it can be moved in the direction of force perpendicular to the flow of resin after merging. By moving to a position that eliminates the pressure difference,
It is possible to eliminate disturbances at the interface between each layer due to pressure differences,
Therefore, a product with no variation in the thickness ratio of the flow force direction is
obtained for any flow rate ratio.

In addition, since the partition plate can be moved into the merging resin flow path in the same force direction as the resin flow after merging,
By adjusting this, it is possible to obtain the length of the rectification section that suits the combination of resins, thereby eliminating the bias in each layer due to viscosity differences, and ensuring a uniform distribution across the width of the product to both ends. It is possible to obtain products with a good thickness ratio.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention, FIG. 2 is an explanatory diagram showing the direction of flow force and the state of the boundary surface before and after the merging of each resin, and FIG. 3 is a diagram of the partition plate. 4 is an explanatory diagram showing a cross section in the product width direction obtained by the partition plate shown in FIG. 3, and FIG. 5A is a cross-sectional view showing an example of the cross-sectional shape. FIG. 5B is a cross-sectional view showing a cross section of the product in the width direction in the case where the length of the rectifying section is appropriate. 1... Main body, 2, 3... Resin flow path, 4
... Merging resin flow path, 6 ... Pressure difference adjustment valve, 10 ... Partition plate.

Claims (1)

[Claims] 1. In an adapter attached to a single-layer die for molding a multilayer plastic film or sheet, the adapter body is provided with a plurality of opposing resin flow channels and a merging resin flow channel perpendicular to these channels, and a resin flow channel is provided at the intersection of these channels. A symmetrically inclined transition surface is provided, and the adapter body is provided with a pressure difference regulating valve having a tip formed with an inclined surface corresponding to the inclined transition surfaces 5, 5 so as to protrude into the merging resin flow path. and movably in a direction perpendicular to the direction of the merging resin flow path, and furthermore, the partition plate is attached so that one end thereof protrudes into the merging resin flow path through the center plane of the pressure difference regulating valve. A die adapter for forming a multilayer plastic film or sheet, characterized in that it is movably attached so as to be adjustable.