JP2512054B2 - Blow molding equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a blow molding apparatus, and more particularly to a blow molding apparatus for laminating a film on an outer peripheral surface of a parison simultaneously with blow molding.

<< Prior Art >> For blow molding in which a film is attached to the outer peripheral surface of a parison simultaneously with blow molding, for example, the one disclosed in JP-A-61-89025 is known.

In these blow moldings, a parison was extruded in a suspended state, a film was set on the outer peripheral surface of the extruded parison, and then pre-blowing was performed in a state in which only the lower part of the parison was pre-pinched.

<< Problems to be Solved by the Invention >> In this way, when the pre-blown parison is placed in the mold and molded by main-blowing, the shape of the molded product causes the film in the pinch portion to break. There has occurred. It is considered that this is because the pinch-off parison has a smaller stretch ratio than the side parison and the film is in poor contact, so that heat is not sufficiently transmitted to the film.

Therefore, an object of the present invention is to provide a blow molding apparatus capable of laminating a film on an outer peripheral surface of a molded product in a good condition.

<< Means for Solving the Problem >> In order to achieve the above object, the blow molding apparatus of the present invention comprises a stretching means for pre-pinching the upper and lower portions of a hanging parison to stretch the parison in the vertical direction, and the stretching means. The pre-blowing means for pre-blowing the parison is provided in synchronism with the stretching operation of the above.

<< Operations and Effects of the Invention >> In the blow molding apparatus of the present invention, the upper and lower parts of the parison are pre-pinched, and pre-blowing is performed while stretching the parison in the vertical direction. Also, sufficient stretching is possible, and the adhesion of the film to the parison is the entire surface,
It becomes good, and the heat of the parison is sufficiently transmitted to the film during pre-blowing to prevent the film from breaking. Further, since the parison is stretched not only in the lateral direction but also in the vertical direction, the difference in the stretching ratio as a whole becomes small.

<Example> A blow molding apparatus according to an example of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a blow molding apparatus 1 having a structure according to an embodiment of the present invention.

The blow molding apparatus 1 includes an accumulator head 3 that pushes out a parison 2 by using a thermoplastic resin that has been heated and melted, a pair of molds 4 and 4 that are symmetrical with respect to a center line of the parison 2, and the parison. Blow pin 5 which blows compressed air into the inside of 2, and a mold after blow molding
Product take-out device 7 for taking out molded article 16 from 4,4
It has and. The product take-out device 7 also operates as an upper pre-pinch device, as will be described later in detail.

The product take-out device 7 has one end fixed to the frame 8 of the blow molding device 1 and extends in a direction (front-back direction) perpendicular to the opening / closing direction (horizontal direction) of the molds 4, 4 and the other end. It is provided with a take-out portion 12 slidably provided along a guide rail 11 fixed to the column 9, and a chain drive portion 13 for sliding the take-out portion 12. The take-out portion 12 is provided in parallel with the guide rail 11 and includes a pair of arms 15 and 15 opened and closed by cylinders 14 and 14, as shown in FIG. Also, blow pin 5
Is held by an elevating device located inside the parison 2 at the time of blow molding by a vertical drive device (not shown), while at the end of blow molding, when the molded product 16 is taken out, its tip is molded. The product 16 is held in a lowered position below the lower end surface.

The blow molding apparatus 1 also includes two film rolls 22, 2 for automatically and continuously supplying a film 17 to be attached to the outer surface of the molded product 16 between the molds 4, 4 and the parison 2.
Equipped with 2. As shown in FIG. 3, the film rolls 22 and 22 are provided behind the molds 4 and 4 on the side opposite to the product take-out device 7 and provided on the bed portion 8a of the frame 8 of the blow molding device 1. The shafts 22a, 22a fixed can be freely rotated respectively.

The film roll 22,22 is a film 17,17 is stored in a roll shape, by rotating in a predetermined direction,
The films 17 and 17 can be supplied into the molds 4 and 4. That is, as shown in FIGS. 1 and 3, after the blow molding is completed, the molds 4 and 4 are opened and the molded product 16 is taken out from the molds 4 and 4 by the product take-out device 7. The film portion 17a on the product take-out side following the portion attached to the outer surface of the molded product 16 of
The film roll 2
2,22 rotate, the films 17,17 are automatically supplied into the molds 4,4, and the attachment parts 17b, 17b are set.

As shown in FIG. 4, cutting parts 23, 23 for cutting the films 17, 17 are provided on the inner surface of the molds 4, 4 in the vicinity of the end near the product take-out device 7. At the time of blow molding and blow molding, when the left and right molds 4, 4 are closed, the film 1
It is designed to cut 7,17.

The product take-out device 7 will be described in more detail. The product take-out device 7 includes a sliding member 10 slidably attached to the guide rail 11 and fixed to a part of the chain of the chain drive unit 13. Have Two air cylinders 18, 18 are mounted downward on the side of the sliding member 10, and the take-out portion 12 is fixed to the lower end of the piston rod of the air cylinders 18, 18.
Therefore, the take-out portion 12 can be moved up and down by the action of the air cylinder 18. With such a configuration, the product removing device 7 can function as an upper pre-pinch device.

A lower pre-pinch device 30 having substantially the same structure as the take-out portion 12 is provided on the bed portion 8a of the frame 8 below the molds 4,4. The lower pre-pinch device 30 includes arms 31 and 31 corresponding to the upper pre-pinch device, that is, the arms 15 and 15 of the product take-out device 7. The arms 31 and 31 are the air cylinders 32 shown in FIG. , 32 can be moved up and down, and although not shown, they can be moved to and from each other by air cylinders corresponding to the air cylinders 14, 14 of the product take-out device 7. ing.

Using the blow molding device 1 configured as described above,
In order to form a molded product having a film attached to the outer surface, first, the parison 2 having a thermoplastic resin as a base material is extruded by the accumulator head 3 and the film is formed on both outer sides thereof.
Set 17,17. After this, the blow pin 5 is set inside the parison 2, and then the upper part of the parison 2 is pre-pinched by the arms 15, 15 of the product take-out device 7, while the lower part is pre-pinched by the arms 31, 31 of the lower pre-pinch device 30. At this time, the location of the pre-pinch of this parison is, as shown in FIG. 5, in the upper pinch portion, below the upper portion of the cavity of the molds 4, 4, while the lower pinch portion is located. It is usually desirable that the part is located above the pinch part.

With the pre-pinch condition described above, air cylinders 18 and 32
Is operated to pull the parison 2 in the vertical direction, and the parison is stretched in the vertical direction. Therefore, the product take-out device 7 and the lower pre-pinch device 30 make the parison stretching device 40.
Is configured. Simultaneously with this stretching, compressed air is blown into the parison from the blow pin 5 to perform pre-blowing. By this pre-blow, the parison is stretched mainly in the lateral direction. Therefore, parison 2 is
Since it is stretched in the vertical and horizontal directions, the film 17
Is adhered to the parison 2 in a good condition on almost the entire surface thereof, and is sufficiently heated by the parison, so that a part thereof is not damaged.

In this way, after the pre-blow is performed, the mold is closed and the main blow is performed to form the molded product 16 having the film 17 laminated on the surface. After this molding is completed, the product take-out device 7 performs its original function to form the molded product.
After pinching the upper part of 16 and opening the molds 4, 4,
Take 6 out of molds 4,4. With the above, one cycle of the molding process is completed.

In the above embodiment, as the upper pre-pinch device,
Although the product taking-out device is also used, it goes without saying that the upper pre-pinch device may be configured independently.

[Brief description of drawings]

FIG. 1 is a front view of a blow molding device having a structure according to an embodiment of the present invention, FIG. 2 is a plan view of a take-out portion of a product take-out device used in the blow molding device, and FIG. FIG. 4 is a schematic plan view of the blow molding apparatus shown in FIG. 4, FIG. 4 is a horizontal sectional view of a mold incorporated in the blow molding apparatus, and FIG. 5 is drawing of a parison and pre-blowing using the blow molding apparatus of the present invention. FIG. 4 is a vertical cross-sectional view showing the state. 1 ... Blow molding device, 2 ... Parison 4 ... Mold, 5 ... Blow pin 7 ... Product take-out device (upper pre-pinch device) 30 ... Lower pre-pinch device 40 ... Stretching device

Claims (1)

(57) [Claims] 1. A blow molding apparatus for laminating a film simultaneously with blow molding on an outer peripheral surface of a hanging parison,
A blower comprising: pre-pinch upper and lower parts of the parison to stretch the parison in the vertical direction; and pre-blowing means for pre-blowing the parison in synchronization with the stretching operation of the stretcher. Molding equipment.