JP2000141460A - Mandrel for supporting preform - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably support a preform by an mandrel when the preform is introduced into a blow molding machine of a polyester bottle. SOLUTION: The mandrel 1 supporting the mouth cock part of the preform of a polyester bottle is constituted so that an insertion spigot part 12 having a preform contact part 121 and the taper part 122 continued thereto is vertically provided on a pedestal 11 and the rising height h1 of the preform contact part 121 is set to a range of 4-10 mm and the rising height h2 of the taper part 122 is set to a range of 5-10 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preform supporting mandrel which has been improved so that the preform can be stably supported by the mandrel when the polyester bottle is introduced into a blow molding machine.

[0002]

2. Description of the Related Art
When the polyester preform preheated to 100 to 115 ° C. is introduced into a blow molding machine in a state where it is inverted on a mandrel, the mandrel can be inserted into the preform in consideration of the ease of insertion into the preform. 0.2-0.5m between the preform abutment and the inner wall of the preform plug
A mandrel having a gap of about m or a tapered inner insertion opening of a mandrel has been used. Further, in order to eliminate a gap between the mandrel and the preform after insertion, as shown in a partial sectional view in FIG.
A ring spring 52 is fitted to the lower end of the insertion hole 51 of the preform 6, and the elasticity of the ring spring 52 is used between the inner wall of the plug 61 of the preform 6 and the insertion hole 51 of the mandrel 5. Attempts have been made to partially eliminate the gaps between the two.

However, as in the former of the prior art, a gap of about 0.2 to 0.5 mm is formed between the insertion hole 51 of the mandrel 5 and the inner wall of the plug 61 of the preform 6. In the case of insertion while keeping it, as in the latter case, a ring spring 52 is fitted to the lower end of the inner insertion port portion 51 of the mandrel 5 to improve this to partially eliminate the gap. Even in this case, as shown in FIG. 5, the preform 6 is likely to swing unstablely on the mandrel 5, and the preform 6 is damaged by hitting a blow molding die or the like, or the plug portion 61 of the preform 6. There are problems such as deformation of the film and poor thickness.

In order to solve the above-mentioned problems, the present invention sets a preform abutment portion and a tapered portion of a mandrel insertion opening portion in a specific size range so that a preform can be formed by a blow molding die or the like. Accordingly, it is an object of the present invention to provide a mandrel for supporting a preform, which is free from damage, deformation of a plug portion of a preform, and poor wall thickness.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its gist is a mandrel for supporting a preform plug portion of a polyester bottle, wherein the mandrel is provided on a pedestal. A preform contact portion and an insertion insertion portion having a tapered portion connected to the preform contact portion are erected, and the rising height of the preform contact portion is 4 to
A mandrel for supporting a preform, wherein the mandrel is set in a range of 10 mm and a rising height of the tapered portion is set in a range of 5 to 10 mm.

According to the present invention, when the preform is inverted and fitted into a mandrel and introduced into a blow molding machine for heat treatment, the preform is supported on the mandrel in a stable state. As a result, the preform does not swing on the mandrel, and the preform is damaged by hitting a blow molding die or the like,
The deformation and thickness defect of the preform plug are eliminated, and the product yield is improved.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a perspective view showing one embodiment of the present invention, FIG. 2 is a side view showing a state where a preform is attached to one embodiment of the present invention, and FIG. 3 is another embodiment of the present invention. An example is shown in a perspective view, and FIG. 4 is a side view showing a state where a preform is inserted in another embodiment of the present invention.

The present invention is shown in perspective views in FIGS.
As shown in the side views of FIGS. 2 and 4, a mandrel 1 supports a preform plug 21 of a polyester bottle. The mandrel 1 is provided on a pedestal 11 and connected to a preform abutment portion 121. The insertion port portion 12 having the tapered portion 122 to be provided is erected, the rising height h1 of the preform contact portion 121 is set in a range of 4 to 10 mm, and the rising height of the tapered portion 122 is set. h2 is set in a range of 5 to 10 mm, and the preform contact portion 1 of the insertion port portion 12 is set.
A ring spring 13 is fitted on the upper part of the reference numeral 21.

According to the present invention, when the preform 2 is fitted on the mandrel 1 with the preform 2 inverted and introduced into a blow molding machine for heat treatment, the preform 2 does not swing on the mandrel 1, When the preform 2 is damaged by hitting a blow molding die or the like because it is supported by the mandrel 1 in a stable state, and when the deformation and the wall thickness defect of the preform plug 21 are eliminated, the yield of the bottle product is improved. The following effects can be obtained.

Here, the outer diameter of the preform abutment portion 121 has a clearance in the range of 0.1 to 0.3 mm over the entire circumference between the outer diameter of the preform plug portion 21 and the inner diameter of the preform plug portion 21. Combined with the height h2 in the range of 5 to 10 mm, the stability when the preform 2 is inserted is further improved, and the insertability is also good. 0.1 above
The clearance of ~ 0.3mm is for the preform abutment 1
The upper and lower portions of 21 need only be satisfied, and the intermediate height clearance may be larger.

When the ring spring 13 is fitted, it is resiliently urged in the expanding direction and contracts when the preform plug part 21 is inserted, so that the preform plug part 21 has good insertability. Thereafter, the inner wall surface of the preform plug 21 can be pressed and fixed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in a perspective view in FIG. 1, a mandrel according to the present invention has an inner insertion opening 1 having a preform abutting portion 121 and a tapered portion 122 formed continuously on the pedestal 11.
2, the outer diameter d1 of the preform contact portion 121 of the mandrel 1 is 20.45 to 20.
It is set in the range of 57 mm, and a slight clearance in the range of 0.1 to 0.3 mm is held between the preform plug 21 and the inner diameter. Also, the preform contact portion 12
1 is set in the range of 4 to 10 mm, and in this case, the outer diameter d2 of the tip of the tapered portion 122 is 20.
3 to 20.5 mm range and the tapered portion 12
2, the rising height h2 is set in the range of 5 to 10 mm.

When the rising height h1 of the preform contact portion 121 is set below the above range and less than 4 mm, the preform 2 tends to be unstable on the mandrel 1 and 10 mm above the above range. Exceeding is not preferable because the insertability of the mandrel 1 into the preform 2 is deteriorated. When the rising height h2 of the tapered portion 122 is set to be less than the above range and less than 5 mm, or set to be more than 10 mm and more than the above range, the insertability of the mandrel 1 to the preform 2 is reduced. It is not preferable because it becomes worse.

Preferably, the insertion port 12 is
A ring spring 13 elastically urged outward is fitted on the upper portion of the preform contact portion 121. As another example of the present invention, as shown in a perspective view in FIG.
1 is formed on both the upper and lower sides with the constricted portion 123 interposed therebetween, and a taper portion 122 continuously provided on the upper side of the preform contact portion 121 is preferably used. In this case, the ring spring 13 is fitted to the upper preform contact portion 121.

The preform contact portion 121 of the mandrel 1 of the present invention has the same outer diameter d1 over the range of its rising height h1.
Since only a slight gap of 0.1 to 0.3 mm is left between the outer diameter dimension d1 of the preform plug part 21 and the inner diameter dimension of the preform plug part 21, a pressing guide or the like is used. ,
It is necessary to insert the preform 2 into the mandrel 1 such that the flange or the bottom of the preform plug 21 is pressed down.

However, the inverted preform 2
When fitting to the mandrel 1, the insertion hole 12
When the plug 21 of the preform 2 is smoothly inserted into the mandrel 1 and the ring spring 13 is attached to the upper part of the preform abutting portion 121, the ring spring is guided. 3 is trying to spread outward due to the urging force.
Since the preform 2 is fixed by pressing the inner wall surface of the preform 2, the preform 2 does not swing on the mandrel 1 and is stable.

According to the present invention, when the preform 2 is introduced into a blow molding machine in a state in which the preform 2 is inverted on the mandrel 1 and is subjected to heat treatment, the preform 2 does not swing on the mandrel 1 as in the related art, and is stable. Since the preform 2 is supported by the mandrel 1 in the deformed state, the problems such as the preform 2 being damaged by hitting a blow molding die or the like, and the deformation and wall thickness defect of the preform plug 21 are eliminated. Yield is improved.

[0018]

Since the present invention has the above-described structure, the following effects can be obtained. That is, according to the present invention, when the preform is inserted in a state in which the preform is inverted on the mandrel, introduced into the blow molding machine and subjected to heat treatment, the preform is supported by the mandrel in a stable state. This has the effect of improving the product yield by eliminating damage to the molding die or the like, deformation of the plug part of the preform and poor wall thickness.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention.

FIG. 2 is a side view showing a state where a preform is attached to one embodiment of the present invention.

FIG. 3 is a perspective view showing another embodiment of the present invention.

FIG. 4 is a side view showing a state where a preform is inserted in another embodiment of the present invention.

FIG. 5 is a partial cross-sectional view showing a state in which a preform is inserted into a mandrel in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mandrel 11 Pedestal 12 Internal insertion opening 121 Preform contact part 122 Taper part 123 Constricted part 13 Ring spring 2 Preform 21 Plug part h1 Rise height of preform contact part h2 Rise height of taper part d1 Outer diameter of preform contact part d2 Outer diameter of tip of taper part

Claims (2)

[Claims] 1. A mandrel for supporting a preform plug of a polyester bottle, the mandrel having, on a pedestal, an internal insertion opening having a preform contact portion and a taper portion connected to the preform contact portion. The preform abutment portion has a rising height set in a range of 4 to 10 mm, and the tapered portion has a rising height set in a range of 5 to 10 mm. Mandrel. 2. The preform supporting mandrel according to claim 1, wherein a ring spring is fitted on an upper portion of the preform abutting portion of the insertion hole.