JPS6227653B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field of the Invention> The present invention relates to a method for blow-molding synthetic resin in which a foreign object such as a partition plate is inserted and integrally molded.

<Problems to be Solved by the Invention> After a foreign object such as a partition plate is covered with a molten resin tube that is drawn out and hangs down, a pair of split molds arranged relative to each other are closed and moved to sandwich the foreign object and open a hollow space. In the molding method, at least a part of the edge of the foreign object facing the split mold is precisely spaced from the inner surface of both split molds by the molding thickness of the molten resin cylinder when the closing movement of the split mold is completed. It is necessary to be located in

Therefore, when a molten resin cylinder is lowered from a die to cover a foreign object using the conventional method, there is a problem that part of the resin cylinder comes into contact with the edge of the foreign object during its descent and becomes unable to descend. If the diameter of the molten resin cylinder is increased to avoid this, when the split mold closes and moves, the ends (burrs) of the resin cylinder that are pinched between the abutting end surfaces of the split mold become larger, making it difficult to remove. Not only that, but there was also the problem of deterioration of quality.

<Object of the invention> The present invention can achieve the following without increasing the die diameter.
The object of this invention is to solve this problem by molding the foreign matter by surely covering it with the molten resin tube that is fed out.

<Structure of the Invention> This invention dispenses a molten resin cylinder and places a foreign object such as a partition plate supported by a vertically moving member under a hanging die, and covers the foreign object with the molten resin cylinder fed out from the die. In this method, a molten resin tube is hollow-molded by sandwiching a foreign object by closing a pair of left and right split molds that move horizontally to open and close. A method of hollow molding for inserting a foreign object such as a partition plate, which is characterized in that a resin cylinder is expanded in the left and right direction and divided into two parts, which are then fed out and lowered.

<Example> Examples will be described below based on the drawings.

The die 1 has divided parts, ie, embedded parts 2, 2', at the front and rear of the outlet, and has a pair of left and right semicircular outlets 3,
Divide into 3'. Reference numeral 4 denotes a vertically movable support member for arranging a partition plate 5 as a foreign object at a predetermined position, and is provided below the central axis between the outlet ports 3 and 3'. 6 and 6' are left and right split molds that move to open and close.

First, the partition plate 5 is held on the rod part 4' of the vertically movable support member 4, and is moved upwardly to a predetermined position below the die 1, and then a semi-cylindrical shape The parisons 7 and 7' are fed out and lowered.

Conventionally, when the parison is lowered in a cylindrical shape, the parison is lowered with the same diameter as the die diameter because of the tension that holds the cylindrical shape. As the tension is released at the dividing plane, the embedded parts 2 and 2' are forced into two left and right parts, and a split opening A with a wider bottom is gradually created under the embedded parts 2 and 2'. Therefore, the parisons 7 and 7' descend while expanding to the left and right at the opening of the split opening A, and in this way, the parisons 7 and 7' descend with sufficient margin without making any contact with the partition plate 5 on the way down. This will cover the partition plate 5. When the parisons 7, 7' completely cover the partition plate 5, they operate in the direction of closing the split molds 6, 6'. The split molds 6 and 6' are divided into two to create parisons 7 and 7' with both wings slightly expanded.
When the parisons 7, 7' support the partition plate 5, the partition plate 5 is released from the holding of the partition plate 5 by the rod part 4', and the rod part 4' is lowered to form the split molds 6, 6'. After retracting downward, the end surfaces of the parisons 7 and 7' are butted together by the subsequent approaching operation of the split molds 6 and 6', and a molded product having the inner shape of the split mold is formed by injecting gas in a conventional manner.

The end faces of the enclosed parisons 7, 7' and between the parisons 7, 7' and the partition plate 5 are tightly crimped by the abutting pressure of the opening/closing molds 6, 6'.

Note that when the partition plate 5 is made of the same material as the parisons 7, 7', they can be joined particularly closely.

After the predetermined mold clamping cooling time, the split molds 6, 6'
moves open to take out the molded product and prepare it for the next molding.

Foreign objects such as partition plates can be changed into various three-dimensional shapes as long as they do not impede gas injection, so foreign objects such as partition plates can be changed into various three-dimensional shapes, so it is possible to use resin gasoline tanks for automobiles with multiple wave shields inserted, or partition plates inside. It is now possible to mold large resin tanks such as toilet tanks, septic tanks, and sedimentation tanks in one piece, and to divide the area from the mouth of the bottle to the bottom of a resin bottle or water bottle into two chambers. It can be applied to molding of molded articles in which both sides contain different liquids.

<Effects of the Invention> As described above, according to the present invention, dividing portions are provided at the front and rear positions of the die so that the molten resin tube is expanded from side to side and descends in parts, so that the diameter of the die can be increased. Without this, foreign objects such as partition plates can be covered with plenty of room, and therefore, hollow molded products into which foreign objects can be inserted can be molded with excellent quality and with as little burr as possible. effect occurs.

[Brief explanation of the drawing]

Figure 1 is a front view showing the partition plate surrounded by left and right semi-cylindrical parisons that are drawn out from the die and descended, Figure 2 is a partial plan view of the same, and Figure 3 is a modified example of the partition plate. Fig. 4 is a partially enlarged view showing the effect of the parison being cut left and right and expanding and descending by the embedded member which is the dividing part; 1 is the die; 2 and 2' are the embedded parts; 3 and 3' is a semi-circular outlet, 4 is a vertical movement support member, 5 is a partition plate, 6,
6' is an open/close type, 7, 7' is a divided parison,
A is a cut.

Claims (1)

[Claims] 1 Place a foreign object such as a partition plate supported by a vertically movable member under a die that draws out and hangs a molten resin tube, and after covering the foreign object with the molten resin tube that is fed out from the die, horizontally open and close it. In a method of hollow-molding a molten resin cylinder by sandwiching a foreign object by closing and moving a pair of left and right split molds, a dividing part is provided at the front and rear positions of the die, and the dividing part expands the molten resin cylinder in the left and right direction. A hollow molding method for inserting a foreign object such as a partition plate, which is characterized in that it is divided into two pieces while being opened, and is fed out and lowered.