JPS5828095B2 - Tasou Oshidashiyosa Kyuradai - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a circular extrusion method for multilayer extrusion that allows the thickness of each layer of a single resin, especially the thickness of the inner layer, to be easily adjusted.
It's about the die.

There has also been a circular die for multilayer extrusion capable of correcting the deflection of an inner resin layer during resin extrusion, as described in Japanese Utility Model Publication No. 46-36550.

However, since this die is equipped with a torus that crosses the outer layer resin flow path for inner layer lip adjustment, this torus partially disturbs the flow of the outer layer resin, especially when extruding thin products such as films. In this case, it is unsuitable as it becomes a major cause of uneven thickness and generation of die marks.

The present invention is a circular die particularly suitable for multilayer extrusion of films, and its gist is that a core metal and a flange connected to the bottom of the core metal are installed in a die ring having a resin flow path for the outer layer. From the resin guide hole which is slidable and penetrated into the flange, through the manifold provided at the joint surface of the core metal and flange, to the inner layer extrusion gap formed by the die ring and the core metal. The present invention is characterized in that the inner layer resin flow path is formed by successive communication, and a bolt for sliding the flange is provided passing through the die ring, and the above structure successfully achieves the intended purpose.

Hereinafter, an example of the embodiment of the present invention shown in the drawings will be explained. The figure shows an example of a circular die for two-layer extrusion, and the die ring 1 has a resin guide hole 12, a manifold 13, a gap 14, and a lip gap 2. It is the same as the conventional method to provide an outer layer resin flow path consisting of a resin flow path and to form a gap 4 for extruding the inner layer between the core metal 3 inserted into the die ring, but the present invention provides a flange 5 with a larger diameter than the bottom of the flange 5
is fixed by a port 6, and this flange 5 is slidably mounted in the cavity 7 of the die ring 1, and a sliding bolt 8 is provided to the flange 5 from the outside of the die ring 1. The gap 4 is adjusted by moving the core bar 3.

The resin entering from the inner layer resin injection port 9 communicates with a resin introduction hole 10 provided through the flange 5 and is connected to a manifold 11 provided on the joint surface of the core metal 3 and the flange 5. It passes through the gap 4 and is extruded from the inner layer extrusion lip gap 18 located above the gap 4.

The resin entering from the outer layer resin injection port 15 passes through the manifold 13 and the gap 14 provided in the die ring 1, and is extruded from the lip gap 2 for extruding the outer layer.

This lip gap 2 is adjusted by moving the lip 16 with an adjustment bolt 17, and the outer layer B extruded from the lip gap is combined with the inner layer A extruded from the lip gap 18 for extruding the inner layer into two layers. form a tube.

In the present invention, as described above, the flange 5 fixed to the core metal 3 is slid by the sliding bolt 8 provided from the outside of the die ring 1, and the core metal 3 is moved via the flange 5 to open the inner layer extrusion gap 4. Because of this adjustment, not only can the uneven thickness of the inner layer A be freely adjusted at any time during extrusion work without any problems such as cracks, etc., but this adjustment does not impede the flow of the outer layer resin, and therefore the thickness of the outer layer can be changed. There is no occurrence of die marks or die marks, which has a great effect on improving product quality.

[Brief explanation of the drawing]

The figure is a sectional view showing an example of implementation of the present invention. 1 is a tiling, 2 is a lip gap for outer layer extrusion, 3 is a core bar, 4 is a gap for inner layer extrusion, 5 is a flange, 6 is a bolt, 7
is a cavity, 8 is a sliding bolt, 10 is an inner layer resin guide hole, 11
12 is a manifold, 12 is an outer layer resin guide hole, 13 is a manifold, 16 is a lip, and 17 is an adjustment bolt.

Claims (1)

[Claims] 1. A core metal and a flange connected to the bottom of the core metal are slidably provided in a die ring having a resin flow path for the outer layer, and the core metal and flange are connected through a resin guide hole penetrating the flange. Through a manifold provided on the surface, the inner layer extrusion gap formed by the die ring and the core metal is sequentially communicated to form a resin flow path for the inner layer, and the sliding bolt of the flange is passed through the die ring. A circular die for multilayer extrusion characterized by the following: