JPS62246830A - Method for molding hollow glass vessel - Google Patents

Abstract

PURPOSE:To the titled vessel which is free from the trace of a matchmark of a finishing mold on the outer surface and is free from the generation of a twist and has vertical projected patterns on the inner surface by using a plunger provided with plural vertical recessed grooves on the outer surface and rotating a bottom mold in speedy velocity in same rotating direction as a neck ring in a time of blow molding. CONSTITUTION:A glass gob 4 is fed into a crude mold 3 and a plunger 6 is intruded therein to mold a parison 1 and after hang this parison 1 via a neck ring 2 and transferring it into a finishing mold 8, the parison 1 is blow-molded into a hollow glass vessel 21 while rotating the neck ring 2. In this case, plural vertical projected patterns 30 are formed on the inner surface of the parison 1 by using the plunger 6 provided with plural vertical recessed grooves 7 on the outer surface. Further in case of blow-molding the parison 1 in the finishing mold 8, a bottom mold 10 is rotated in the velocity speedier than the rotating velocity of the neck ring 2 in same rotating direction as the neck ring 2. The titled vessel which is free from the trace of a matchmark of the finishing mold on the outer surface and is free from the generation of a twist and has vertical projected patterns on the inner surface is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a method for forming glass containers by round blowing.

(Prior Art) Conventionally, a rotary blow molding method is well known as a method for molding a hollow glass container having a beautiful outer surface without any trace of a finishing mold, which is a split mold. In addition, in this rotary blow molding method, it is also known that during parison molding, a plunger having a plurality of uneven patterns on its outer surface is pushed into a glass gob to form a plurality of uneven patterns on the inner surface of the parison.

However, in the conventional rotary blow molding method, the parison is blow molded while being rotated in a fixed direction within the finishing mold, so the outer surface of the parison is damaged by the frictional resistance between the inner surfaces of the finishing mold and the bottom mold. For example, when a parison 1 having a vertical convex pattern 30 extending in the axial direction on the inner surface as shown in FIG. 3 and FIG. Due to this influence, the glass container 20 has a twisted convex pattern 31 as shown in FIG.

Therefore, in the conventional rotary blow molding method, it is impossible to prevent the occurrence of twisting. For example, a glass container 22 having a vertical convex pattern 32 on the inner surface without any twisting as shown in FIG. was difficult. Therefore, in order to improve the apparatus for rotary blow molding of glass containers, JP-A-61
Although the invention described in Publication No. -31320 has been proposed,
It is composed of a very complicated mechanism, and it is also difficult to incorporate it into conventional rotary blow molding equipment.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned drawbacks and provides a rotary blow molding method that provides a molded glass container with a beautiful outer surface without any traces of finishing mold seams. This method was developed with the aim of providing a method for forming a hollow glass container, which has the following advantages and can provide a glass container having a vertical convex pattern on the inner surface without causing twisting as in the prior art.

(Means for Solving the Problems) The present invention involves supplying a glass gob into a mold, pushing a plunger to form a parison, suspending the parison through a neck ring to a finishing mold, and then transferring the parison to a finishing mold. In a method of blow molding a parison into a hollow glass container while rotating a parison, a plurality of vertical convex patterns are formed on the inner surface of the parison by a plunger having a plurality of vertical grooves on the outer surface, and the parison is blow-molded into a finishing mold. When performing blow molding, the bottom mold is rotated in the same direction as the rotation direction of the neck ring and at a speed faster than the rotation speed of the neck ring.

(Example) Next, the present invention will be described in more detail with reference to illustrated examples.

Figures 1 and 2 show the molding process of the present invention, with Figure 1 being a longitudinal sectional view of the process of molding the parison 1, and Figure 2 being a longitudinal sectional view of the finishing process. As shown in FIG. 1(a), first, when the glass gob 4 is fed into the set mold 3 with the neck ring 2 placed on the upper end, the plunger ring 5 is inserted into the plunger ring 5 as shown in FIG. 1(b). The guided plunger 6 is pushed into the mold 3 to form the parison 1.The outer surface of the plunger 6 is provided with a plurality of vertical grooves 7 extending in the axial direction. As shown in FIG. 4, a plurality of vertical convex patterns 30 extending in the axial direction are formed on the inner surface of the parison 1 in correspondence with the concave grooves 7. In this case, instead of the concave grooves 7 provided on the plunger 6, Of course, it is also possible to provide a convex strip and form a concave pattern corresponding to the convex strip on the inner surface of the parison 1.

Next, the parison 1 formed in the above process is suspended by a neck ring 2 and transferred to a finishing process, which is a subsequent process. As shown in FIG. 2, the parison 1 suspended into the finishing mold 8 via the neck ring 2 is blown with blow air (indicated by an arrow) from the blow head 9 placed on the top of the neck ring 2. When the glass container 21 is filled, it expands to follow the shape of the cavity formed by the finishing mold 8 and the bottom mold 10, thereby forming the glass container 21. In this blow molding process, the neck ring 2 rotates in the direction shown by the arrow, so the glass container 21 has a beautiful outer surface without any traces of the joints of the finishing mold 8, which is a split mold.

The bottom mold 10 constituting the cavity has a pulley 11.1.
It is connected to a motor 14 by a timing belt 13 via a timing belt 13, and has a mechanism that can rotate independently. It is rotating faster than the rotational speed. The reason why the rotation speed of the bottom mold 10 is set higher than the rotation speed of the neck ring 2 is as follows.
This is to prevent frictional resistance between the outer surface of the parison 1 and the finishing mold 8 and the bottom mold 10, and in particular, the bottom of the parison 1 only rests on the bottom mold 10 and is not chucked in the same way, so that it may slip. Since rotation loss occurs, the rotation speed of the bottom mold 10 needs to be faster than the rotation speed of the neck ring 2 in order to maintain the same rotation speed as the neck ring 2 in the lower part of the parison including the bottom part. It became clear.

The relationship between the rotational speeds of the neck ring 2 and the bottom mold 10 is determined according to the glass container to be molded.
In the case of rotations per second, as shown in FIG. 5, almost no twisting occurs, and a glass container 22 having a convex pattern 32 extending straight in the axial direction on the inner surface can be formed.

In order to obtain such a glass container 22, the rotation speed of the bottom mold 10 is set to 1.2 to 1.2 to the rotation speed of the neck ring 2.
It is preferable to set it to about 3 times.

(Effects of the Invention) As is clear from the above description, the present invention can produce glass that has a convex pattern on its inner surface that extends straight in the axial direction without twisting, which was impossible with the conventional rotary blow molding method. Since the container can be molded and has a very simple structure, it can be incorporated into a conventional rotary blow molding device very easily. Furthermore, since the rotation of the bottom mold can be selected in any direction and speed, it is possible to mold glass containers of various shapes, from products with no twist at all to products twisted at any angle. .

As described above, the present invention exhibits various effects and greatly contributes to the development of the glass container manufacturing industry.

[Brief explanation of drawings]

Figures 1 and 2 show examples of the present invention; Figure 1 is a longitudinal sectional view of the parison forming process, Figure 2 is a longitudinal sectional view of the finishing process, Figure 3 is a front view of the parison, and Figure 4 is a longitudinal sectional view of the parison forming process. is A in Figure 3.
5 is a front view of a glass container obtained by the present invention, and FIG. 6 is a front view of a glass container obtained by a conventional method.

Claims (1)

[Claims] (1) After supplying the glass gob into the rough mold, push the plunger to form a parison, suspend and transfer the parison to the finishing mold via the neck ring, and then blow the parison into a hollow glass container while rotating the neck ring. In the molding method, a plurality of vertical convex patterns are formed on the inner surface of the parison by a plunger having a plurality of vertical grooves on the outer surface, and when the parison is blow-molded in a finishing mold, the bottom mold is placed in the neck ring. A method for forming a hollow glass container, characterized by rotating in the same direction as the rotation direction and at a faster speed than the rotation speed of the neck ring.