JPS6026975Y2 - annular cap - Google Patents

Description

[Detailed description of the invention] The present invention relates to an annular cap used for manufacturing plastic tubular films made of polyvinyl chloride, polyethylene, nylon resin, etc. This invention relates to an annular cap for a plastic molding phase for the purpose of eliminating marks.

Conventionally, in an annular cap that has an annular manifold below an annular slit and a resin inlet communicating with the annular manifold, the resin that flows into the manifold from the resin inlet is divided into left and right parts and then merges again on the opposite side of the resin inlet. (This part is called the weld part.

), opaque areas called weld marks appear on the resulting tubular film.

In the case of transparent packaging films, this weld mark appears to impair the appearance and reduce the quality of the contents, so the development of an annular cap that eliminates the weld mark has been awaited.

The inventor's invention relates to an annular cap for erasing the above-mentioned weld mark, and its gist is that the annular cap has an annular manifold below an annular slit and a resin inlet communicating with the annular manifold, on the opposite side of the resin inlet. In the manifold section located at , a partition wall that diagonally crosses the manifold is provided upright from the bottom of the manifold, and the top end of the partition wall and the inner wall of the upper surface of the manifold are a plastic molded square annular base having a gap.

The present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 is a vertical cross-sectional view of the annular cap according to the present invention, Fig. 2 is a plan view cut along the line ■-■ in Fig. 1, Fig. 3 is a partial enlarged view of Fig. 2, and Figs. Figure 6 is the IV in Figure 3.
-IV, V-V, VI-VI cut side view.

The molten resin flowing from the resin inlet 1 flows along the annular manifold 3 below the annular slit 2 as indicated by arrows A and B.
The liquid flows to the left and right as shown in FIG.

The resin that has spread to manifold 3 is this manifold 3.
The film rises as shown by arrow C towards the annular slit 2 communicating with the slit 3 and emerges from the upper end of the slit 3 as a thin cylindrical film.

As shown in FIGS. 3 to 6, the weld portion W of the annular cap according to the present invention has a partition wall 4 that diagonally crosses the manifold 3.
The partition wall 4 is provided upright from the bottom of the manifold 3 with a gap between the tip 41 of the partition wall 4 and the upper inner wall surface 31 of the manifold 3.

Since the partition wall 4 is provided diagonally in this way, when the molten resins A and B separated to the left and right come together again,
A large part of resin A and a small amount of resin B, or a large part of resin B and a small amount of resin A gradually cross and merge into slit 2.
As the weld marks rise, weld marks do not occur, or even if weld marks do occur, they are dispersed over a wide area due to cross-merging, making them less noticeable.

As detailed above, if the annular cap of the present invention is used,
The effect is extremely large because a tubular film with an excellent appearance can be obtained and the contents of the package can also be made to look beautiful.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of an annular cap 1 according to the present invention, and FIG.
The figure is a cross-sectional plan view taken along the line ■-■ in Figure 1, Figure 3 is a partial enlarged view of ■ in Figure 2, and Figures 4, 5, and 6 are IV-IV and V-V in Figure 3. , is a cutaway side view taken along line VI-VI. 1 is a resin inlet, 2 is an annular slit, 3 is a manifold, 4 is a partition wall, and W is a weld portion.

Claims (1)

[Scope of utility model registration request] In the annular mouthpiece that has an annular manifold and a resin inlet communicating therewith below the annular slit, a partition wall that diagonally crosses the manifold is provided upright from the manifold bottom in the manifold portion located on the opposite side of the resin inlet. Also, a plastic molded square annular base with a gap between the upper end of the partition wall and the upper inner wall of the manifold.