JPS6037781B2 - extrusion die - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an extrusion molding die that can be applied to flat dies (including multilayer dies), round dies, and the like.

Figure 1 is a side sectional view of a conventional straight manifold type extrusion molding die, Figure 2 is a sectional view from A to A in Figure 1, Figure 3 is a sectional view from B to B in Figure 1, and Figure 4. is a side cross-sectional view of a conventional coat hanger type extrusion molding die, and FIG.
It is a sectional view of C.

First of all, to explain the straight manifold type shown in Figs. 1 to 3, the manifold bodies 1 and 2 are firmly fastened with bolts 3, and the resin flowing from the resin inlet 4 enters the manifold 5 and follows the arrow shown in Fig. 2. It is expanded in the direction of the die and extruded through the slit 6 as shown in FIG. The choke bar 7 is moved or deformed in the pushing or pulling direction by the bolt 8, so that the gap between the slits 6 can be adjusted. Reference numeral 9 denotes an adjustment lip, which is attached to the manifold main body 2 with a bolt 10 (loosely inserted into the notch 7a of the choke bar 7), and can be adjusted in the push-pull direction with an adjustment bolt 11.

Reference numerals 12 and 13 denote side plates, which are attached to the manifold bodies 1 and 2.

However, in the case of the straight manifold type,
Although it has a simple structure and a small cross-sectional dimension, it has the disadvantage that a uniform flow rate distribution cannot be obtained throughout the die.

That is, in general, the resin flows easily at the center of the manifold and the slit, but not at both ends, making it difficult to obtain a uniform film product. Next, the coat hanger type shown in Figures 4 and 5 will be explained. The difference between this type and the straight manifold type is that the manifold 5a is moved from the center of K to both ends in order to equalize the flow distribution. On the other hand, as shown in FIG. 5, the cross-sectional area is gradually decreased and the slit 6a is obliquely formed, and the length of the slit 6a is also gradually decreased.

Therefore, it is possible to make the flow rate distribution uniform to some extent, but since the manifold 5a is inclined, the cross-sectional dimension becomes large and it is difficult to process the manifold 5a.

Further, even if the flow rate distribution was calculated to be uniform, in reality, a so-called opening occurred at the die outlet due to the resin pressure, making it impossible to obtain a uniform extrusion amount. In other words, since the dimension L that receives resin pressure gradually decreases from the die center to both ends, the opening amount M is different between the die center and both ends, and it is extremely difficult to maintain the calculated uniformity. It was difficult.
The present invention was proposed in order to eliminate the above-mentioned conventional drawbacks, and the manifold shape is a straight manifold, and following the manifold, a passage whose length gradually increases from the center of the die to both ends of the die is formed. By forming slits whose length gradually decreases, this extrusion molding tatoo can have the same uniform flow distribution as the coat hanger type, and also eliminates the uneven opening, which is a drawback of the coat hanger type. We aim to provide the following.

Embodiments of the present invention will be described below with reference to the drawings. In the description of the embodiments of the present invention, parts that are the same as those of the prior art will be described using the same reference numerals. First, Figures 6 to 9
In the first embodiment shown in the figure, 1 and 2 are manifold bodies;
3 is a bolt that fastens the main bodies 1 and 2; 4 is a resin inlet; 5 is a bolt that fastens the main bodies 1 and 2;
is a straight manifold, 7 is a choke bar pushed by bolt 8, 9 is an adjustment lip, 10 is a bolt, 11
1 is an adjustment bolt for adjusting the adjustment lip 9, and 12 and 13 are side plates, all of which have the same construction as the conventional device shown in FIGS. 1 to 3. Next, to explain the difference between the apparatus according to the embodiment of the present invention and the conventional one, reference numeral 14 is a passage formed following the straight manifold 5 and having a somewhat smaller gap than the straight manifold 5, as shown in FIGS. 6 to 9. As shown in the figure, the length gradually increases from the center of the die toward both ends of the die.

Further, the slit 15, which is formed next to the passage 14 and has a much smaller gap than the passage 14, has a length that gradually decreases from the center of the die toward both ends of the die. Note that the gap in the passage 14 is large enough to allow pressure loss to be ignored.
This is what you decide. Next, to explain the operation, the resin flowing from the resin inlet 4 enters the manifold 5 and is expanded as shown by the arrow in FIG. oxidation and extrusion.

Next, FIGS. 10 to 14 show other embodiments, in which the passage 14
is formed following the straight manifold 5, and the 11th
As shown in FIGS. 13 to 13, the length gradually increases from the center of the die toward both ends. On the other hand, the length of the slit 15' decreases gradually from the center of the die toward both ends of the die, and the gap increases from the center of the die toward both ends, as shown in FIG. There is. In this embodiment, the gap between the slits 15' increases from the center of the die toward both ends as shown in FIG. 14, so the flow rate distribution is further improved compared to the first embodiment. Uniformity can be measured. As described above in detail, the present invention has a straight manifold shape, resulting in a simple structure and easy processing.

Further, since the manifold is a straight manifold, the cross-sectional dimension is small, and the dimension L that receives resin pressure is the same throughout the entire center, so the opening amount M is uniform throughout the entire center. In addition, even though it is a straight manifold, it is possible to achieve a uniform flow rate distribution, and even after receiving resin pressure, the opening back M can be maintained uniform throughout, making it possible to perform uniform extrusion as calculated.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a conventional straight manifold type extrusion molding machine 1, Fig. 2 is a sectional view taken from A to A in Fig. 1, and Fig. 3 is a sectional view taken from B to B in Fig. 1. FIG. 4 is a side sectional view of a conventional coat hanger type extrusion molding die, FIG. 5 is a sectional view taken from C to C in FIG. 4, and FIG. 6 is a front view of an extrusion molding die showing an embodiment of the present invention. A sectional view, FIG. 7 is a sectional view from D to D in FIG. 6,
Figure 8 is a sectional view from E to E in Figure 6, and Figure 9 is a sectional view from F to Figure 6.
F sectional view, FIG. 10 is a front sectional view of an extrusion molding die showing another embodiment, FIG. 11 is a GG sectional view in FIG. 10, and FIG. 12 is a H-day sectional view in FIG. 10. 13 is a cross-sectional view from 1 to 1 in FIG. 10, and FIG. 14 is a cross-sectional view from J to J in FIG. 10. Explanation of the main parts of the diagram, 1, 2... Manifold body, 5... Straight manifold, 14.
...Aisle, 15...Slit. Figure 14 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Hakama Figure 11 Figure 12 Figure 13

Claims (1)

[Claims] 1 The manifold shape is a straight manifold,
An extrusion molding die characterized in that, following the manifold, a passage whose length gradually increases from the center of the die toward both ends of the die and a slit whose length also gradually decreases are formed.