JPS6131224A - Die for forming inflation film - Google Patents

Abstract

PURPOSE:To improve the quality of a formed product and to reduce the operation of disjointing and cleaning of a die by connecting at least one resin feeding path at innermost position or near said position to one of the cylindrical resin paths situated at the position of outer order than its own internal and external order by way of a pair of dispensing pipes. CONSTITUTION:The cylindrical resin paths 11a, 11b situated inside from the cylindrical resin path 11c to which a feeding path 12a is connected, are connected by the same radial dispensing paths 13b, 13c as the feeding paths 12b, 12c positioned outside by each one in internal and external order. Cylindrical resin paths 11d, 11e are connected by feeding paths 12d, 12e and dispensing paths 13d, 13e with same internal and external order. Therefore, the resin paths 11a-11e are connected to the feeding paths 12a-12e so as to cause one pair to correspond with one pair. Consequently, when molten resin having the property to be deteriorated by the contact with the wall surface of the flow path is desired to be made into the layer adjacent to the intermediate layer or the outer layer of the film layer to be molded, it is effectively used. The deterioration tendency of the resin passing through the feeding path is retarded, and the film with excellent characteristic may be obtained and further the cleaning operation of the die is reduced. The production cost is reduced.

Description

[Detailed Description of the Invention] [Technical Field of Industrial Use] The present invention relates to a die for forming a flat chip film by an inflation method, and in particular to a die for forming multiple film layers. be.

[Prior art]

As shown in FIG. 3, a center-feed die 10 conventionally used for this type of purpose has multiple cylindrical resin paths 11a, 11b, 11C, 11d,
The same number of multiple resin supply passages 12a, 12b, 12c, 12d and 12e are provided for supplying resin to and 11e, respectively, and the inner resin supply passage 12m is connected to the inner cylindrical resin passage +t1a and the outer resin supply passage 12a. 12e is in one-to-one correspondence with the outer cylindrical resin path 11e without changing the order position of inside and outside, and radial distribution paths 16a and 13b, respectively.
, 13d and 13b.

However, depending on the material, the supplied resin tends to deteriorate significantly due to contact with the wall surface of the resin supply channel, but after forming the film, it is difficult to form the resin into layers other than the innermost layer. In such a case, in the conventional die, the resin supply channel is inevitably cylindrical, so the wall surface that the supplied resin comes into contact with becomes wide, and the supply channel is connected to the wall surface of the central supply channel 12a and the next section that is in contact with this. In comparison with the supply channel 12b, the contact with the wall surface is approximately four times as large, and in the cylindrical supply channels 12C to 12e outside this, the wall surface becomes five times as large as the angler's diameter as the diameter doubles. When a resin with a marked tendency toward wall surface deterioration is supplied to a resin supply channel with such a wide wall surface, some of the degraded resin adheres to a part of the resin supply channel and stagnates, and this sometimes peels off from the wall surface. The deteriorated resin formed spots (fish eyes) on the film that was discharged from the annular discharge port and the quality of the finished product deteriorated.

Therefore, in order to maintain the quality of the product, it is necessary to frequently separate the die and clean it to prevent deteriorated resin from accumulating in the resin supply path, which reduces the operating rate of the molding equipment, makes maintenance management troublesome, and reduces the quality of the finished product. It was supposed to drive up costs.

[Problem to be solved]

As mentioned above, the purpose is to improve the shortcomings of conventional devices.
The present invention aims to improve the quality of molded products and reduce the frequent disassembly and cleaning work of the die by making the wall surface contact area smaller than before in the resin supply path, even when the resin has a tendency to surface deteriorate. purpose.

[Means to solve problems]

In this invention, a center-feed type multiple resin supply path to the same number of multiple cylindrical resin paths are communicated in a pair-by-pair correspondence by radial distribution paths, and furthermore, the multiple cylindrical resin paths are merged downstream to form a single In a die that communicates with the annular discharge port of the die, at least one of the resin supply passages that is the innermost or closest to the innermost resin supply passage of the multiple resin supply passages is connected to a cylindrical resin passage that is located in an outer order than its own inner and outer order. [Embodiment] Embodiment 1 The problem was solved by creating a die for forming a blown film, which is characterized in that one of the dies is connected to the die by a set of distribution pipes.[Embodiment] Embodiment 1 10 is an inflation die formed by assembling several die blocks, and the die 1 is used to form a multilayer inflation film.
0 contains concentric cylindrical resin Mlla, llb, 1
1c, 11d, and 11e are formed in multiple layers, and in the die 10, on the upstream side of the cylindrical resin path, there is a concentric cylindrical resin supply path 1 that is on the same axis as these resin paths.
2 as 12 bs 12 cs 12 d and 12
A supply port 14a114 is provided at the upstream end of each of the supply ports 14a and 114c, each of which can be connected to an extruder (not shown).
b, 14c, 14d and 14e are provided in the radial direction. Of the resin supply passages mentioned above, only the resin supply passage 12a at the center is not cylindrical but has a single vertical hole.

Several distribution passages 16a provided radially communicate with the downstream end of the resin supply passage 12a, and the downstream ends of these distribution passages 13a communicate with the cylindrical resin passage 11C forming the intermediate layer in the example of FIG. The upstream ends are connected to each other. Even if the downstream end of the distribution passage 13a is communicated with one of the cylindrical resin passages 11b to 11d other than the cylindrical resin passages 11a and 11e, the present invention is still the same.

The cylindrical resin passages 11a and 11b located 11 inside of the cylindrical resin passage 11c with which the resin supply passage 12a communicates are radial distribution passages 13b and 16C similar to the resin supply passages 12b and 12c in which the order of the inside and outside is on the outside. As for the cylindrical resin passages 11d and 11e, the resin supply passages f2 (1, 12a
and are communicated through distribution paths 13d and 13e, respectively.

Therefore, the cylindrical resin paths 11a to 11e and the resin supply path 12
M to 12e are connected in a one-to-one correspondence.

Therefore, in this embodiment, the supply ports 14a to 14
An extruder is connected to each of the extruders 14a and 14b, and resins that are particularly susceptible to surface deterioration due to contact with the die are connected to the supply port 14a.

When molded in this way, the resin that has passed through the innermost resin supply path 12a with the smallest surface area passes through the distribution path 15a, passes through the middle of the multiple cylindrical resin paths 11c, and passes through the multiple cylindrical resin paths 11a together with the resin in other thread paths. It is extruded from the merging path 16 and the annular discharge port 17 of 11e to 11e, and is expanded and formed into a layer sandwiched between other layers.

In this embodiment, if the resin layer, which has a large number of layers and is prone to surface deterioration, is supplied to a layer close to the outer layer, the arrangement 816a becomes longer, making it difficult to process the die and When the fluid loss head becomes too large,
In some cases, it may be better to guide the second resin supply path 12b from the inner flange to the outside to supply resin that is likely to deteriorate the surface of this resin supply path 12b, and this type of design change is also within the scope of this invention. to go into.

Embodiment 2 This is shown in FIG. 2, and differs from Embodiment 1 in that the two yarn paths 12a and 12b located on the inside are both located on the outside of the cylindrical resin path 11.
C111d is connected to distribution a and ilb, respectively. The rest is the same as the first embodiment.

In this embodiment, if the resin that is likely to cause surface deterioration is supplied to the resin supply paths 12g and 12b, it passes through the distribution path 13a or 15b, and then passes through the cylindrical resin path 11c, respectively.
, 11d, and is formed into a multilayer film.

In the embodiments 1 and 2, the distribution channels 1.3a to 13e are bored in one die block 10a,
The distribution channels, in which the internal and external orders are interchanged at the upstream end and the downstream end, are bored through each other.

〔Effect of the invention〕

If the apparatus of the present invention having the structure and operation as described above is used, among the film layers to be formed which are easily deteriorated by the molten resin in the die 10 coming into contact with the flow channel wall surface, the meson < is the outer layer. It can be used when you want to form a layer close to that of the resin supply path 12a, the female eyebrow 2b, and the resin that passes through the t'12a and 12b. The period (time) from one cleaning to the next cleaning is long, which increases the operating efficiency of film forming, reduces cleaning work, and reduces costs. Furthermore, the structure itself is not complicated and can be assembled and disassembled in the same way as conventional ones.

7. Other aspects of this invention. It goes without saying that the film molding die can also be used for molding multilayer films made of resin that do not cause surface deterioration.

is the narrowest, and its surface area is 4 to 1/4 compared to the next resin supply channel 12b, and 1/4 compared to the outer one.
Since the surface area is 1/6 to 1/2o, it exhibits the effect of slowing down the surface deterioration most significantly, and cleaning caused only by this resin is significantly reduced and may be unnecessary in some cases.

In the second embodiment, it is possible to mold even when there are two types of materials that are likely to cause surface deterioration, and the desired effect is achieved.

In other embodiments, a five-layer film molding die is shown as an example, but even if the number of layers is three or more that can be currently molded, multiple cylindrical resin paths and resin supply paths corresponding to the number of layers may be provided. It can be implemented by, and falls within the scope of this invention.

[Brief explanation of drawings]

The drawings show what is incorporated into the present invention, and FIG. 1 is a vertical side view of Embodiment 1, FIG. 2 is a vertical side view of Embodiment 2, and FIG. 6 is a half-cut vertical side view of a conventional die. It is. Code 10...Die, 11a, 11b, 11c, 11d, 11e...-Cylindrical resin path, 12a, 12b, 12c, 12d, 12e=Resin supply path, 15a, 13b, 15c, 13d, 1
5e-distribution path, 17... annular discharge port; Patent applicant Plako Co., Ltd. Figure 1

Claims (1)

[Claims] 1) From the center-feed type multiple resin supply passages to the same number of multiple cylindrical resin passages, each by a radial distribution passage,
In a die in which the multiple cylindrical resin passages are connected in a one-to-one correspondence, and the multiple cylindrical resin passages are further merged on the downstream side and communicated with a single annular discharge opening, Inflation film molding characterized in that one resin supply path is communicated with one of the cylindrical resin paths located at a position outside its own internal and external positions through a set of distribution pipes. die. 2) A combination of a resin supply path and a cylindrical resin path, which are in communication with the inner resin supply path and a cylindrical resin path at an outside order than the inside and outside order through a distribution path, is provided. A die for forming an blown film according to claim 1. 3) There are two combinations of resin supply passages and cylindrical resin passages that communicate with the inner resin supply passage and the cylindrical resin passages on the outer side than the inside and outside order through a distribution passage. A die for forming an blown film according to claim 1