JPS595549Y2 - Internal condensate removal device in the production of blown film - Google Patents

Description

[Detailed description of the invention] This invention is a device for removing condensate that adheres to the bottom surface of an internal cooling former during the manufacture of an inflation tube in which a raw tube melt-extruded upward from an annular mouthpiece is cooled by an internal cooling former. In the method for manufacturing a stretched blown film, the tube is melt-extruded from an annular die and is once cooled and fixed, then reheated and stretched. It is cooled by air or water cooling, and at the same time is cooled by running along the internal cooling homer inside.

In this case, gases such as various additives melted and extruded on the bottom surface of the internal cooling homer adhere to the bottom surface of the internal cooling homer as condensate during long-term operation. A problem arises in that it adheres to the inner surface of the tube and significantly impairs its value as a product.

In order to prevent this drawback, conventionally, the operation had to be stopped from time to time to wipe off the condensate adhering to the bottom surface of the internal cooling former, making long-term operation impossible.

The present invention relates to an effective device for improving the above-mentioned drawbacks, and the gist thereof is a blown film manufacturing device in which a raw tube melt-extruded upward from an annular die is cooled in an internal cooling former.
A circular body having a diameter slightly smaller than the outer diameter of the internal cooling former and having a number of skewers of the same height on the outer periphery of its upper surface is concentrically placed on the lower surface of the internal cooling former with a slight interval. It is a device in which at least one of the internal cooling former or a circular body is rotatably set, and the condensed liquid adhering to the outer periphery of the lower surface of the internal cooling former is removed by adhering to a skewer and flowing. This is a condensate removal device in which the outer peripheral edge of the lower surface of the cooling homer is sloped downward.

A detailed explanation will be given below based on the attached drawings.

FIG. 1 is an overall front view of a blown film manufacturing apparatus according to the present invention, and FIG. 2 is an enlarged sectional view of section II in FIG. 1.

The original tube is melted and extruded upward from the annular mouthpiece 1, or after being cooled by the internal cooling former 3, it is reheated by the heating heater 4 and stretched, and after being folded, it is nipped by the nip rolls 5, and then the raw tube is transferred to the f'L arrow C direction. will be taken over.

The circular body having an outer diameter slightly smaller than the outer diameter of the internal cooling homer 3 may be a pre-cooling homer 6 provided concentrically and close to the lower surface of the homer 3.

At least one of these homers 3 and 6 is set to be rotatable.

The pre-cooling homer 6 is used to cool the raw tube 2 in advance in order to prevent the raw tube 2 in a molten state from suddenly coming into contact with the internal cooling former 3 and solidifying. It cools the tube 2 without coming into contact with its inner surface.

Both the internal cooling homer 3 and the pre-cooling homer 6 circulate a cooling medium inside the original tube 2, but detailed internal mechanisms, rotation mechanisms, etc. thereof are omitted.

The outer peripheral edge of the lower surface of the internal cooling homer 3 has a lower inclined surface 31 inclined downward.

There are a plurality of skewers v0 on the outer periphery of the upper surface of the pre-cooling homer.
61, the top of which is at the same height and slightly spaced from the lower inclined surface 31 of the internal cooling former 3.

The condensed liquid adhering to the lower surface of the internal cooling homer 3 drips onto the upper surface of the pre-cooling homer 6 which is rotating.

In addition, the condensate E adhering to the lower inclined surface 31 moves slowly along the inclined surface, and before adhering to the inner surface of the original tube 2, it touches the rotating skewer 61 and is transmitted through the skewer 61. The condensed liquid travels from the top surface of the pre-cooling homer 6 along the side surface 62 and drips onto the saucer 7 provided on the top surface of the annular cap 1 without adhering to the inner surface of the raw tube 2, and then the condensate collected in the saucer 7 penetrates into the annular cap 1. It is discharged to the outside through a pipe 8.

The lower outer periphery of the internal cooling former may be flat, but it is preferable to make it a downwardly sloping surface as shown in Figure 2.The condensate moves along the sloping surface and adheres to the skewer and flows, so it is flat. It is effective in removing condensate over a wider range than in the case of

Note that the circular body may be a circular plate-shaped body, and the number of skewers, the rotation speed of the circular body, the distance between the skewers and the lower surface of the inner homeer, and the degree of inclination of the lower surface of the homer are subject to various changes. Since there are several combinations, it is only necessary to select and decide as appropriate.

According to the present invention, the condensate can be effectively removed as described above, and blown films can be manufactured for a long time, which was difficult in the past, so the effects are extremely large.

[Brief explanation of the drawing]

FIG. 1 is an overall front view of the blown film manufacturing apparatus according to the invention, and FIG. 2 is an enlarged sectional view of section II in FIG. 1. 1 is an annular mouthpiece, 2 is an original tube, 3 is an internal cooling homer, 31 is a lower inclined surface, 6 is a circular body (precooling homer), 6
1 is a skewer, D and E are condensates.

Claims (2)

[Scope of utility model registration request] (1) In a blown film manufacturing device in which a raw tube melt-extruded upward from an annular die is cooled in an internal cooling former, the blown film has a diameter slightly smaller than the outer diameter of the internal cooling former, and the outer peripheral edge of the upper surface A circular body having a large number of skewers of equal height is provided concentrically on the lower surface of the internal cooling former with a slight spacing therebetween, and at least one of the internal cooling former or the circular body is set to be freely rotatable; A device that removes condensed liquid that has adhered to the outer periphery of the lower surface of an internal cooling homer by flowing it onto a skewer. (2) The condensate removal device according to claim 1, wherein the outer periphery of the lower surface of the internal cooling former is inclined downward.