JPS63265613A - Injection molding machine - Google Patents

Abstract

PURPOSE:To reduce the molding cost and to improve a degree of mixing by stirring, by stirring and mixing calcium carbonate powder with a synthetic resin material in a lower half of a hopper by means of a stirring blade and sending forcibly the mixture to a press sending path by means of a rotating screw set in a feeding path. CONSTITUTION:In an injection molding machine, each flap 18 for controlling the amt. of a synthetic resin storage part 17 and a calcium carbonate storage part 16 is opened and a powder calcium carbonate 20 and a synthetic resin material powder 21 fed in the lower half of a hopper are stirred and mixed by means of a stirring blade 23. Thereafter, an on-off valve 25 for controlling the feeding amt. is opened and the mixed powder is fed from a feed opening 24 into a feed passage 14. The powder fed in the feed passage 14 is moreover stirred and mixed by rotational driving of a rotary screw 25 for feeding and transferring when it is fed in a pressure transferring passage. The powder fed in the pressure transferring passage 14 is molten by means of a heater 10 when it is transferred by means of a pressure transferring screw 11 and then poured and molded in a mold 6.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an injection molding machine that mixes a synthetic resin material and calcium carbonate in a hopper and supplies the mixture to a molding die.

(Prior art) Conventionally, in an injection molding machine, in order to adjust the weight and hardness of the molded synthetic resin, powder of synthetic resin material and calcium carbonate pellets are stirred and mixed using a stirring blade installed in a hopper. The material is dropped from the supply port at the lower end of the hopper to the pressure feed path through the supply path, and is fed under pressure to the molding die by the pressure feed blades of the pressure path.

(Problems to be solved by the invention) Calcium carbonate mixed into synthetic resin materials in the conventional injection molding machine as described above is formed from powder into pellets, and the powder costs about 20 yen per 1 kg. On the other hand, when processed into pellets, it costs 55 to 6 per kg.
There was a problem that the unit price became 0 yen and the unit price became high.

Furthermore, since calcium carbonate is in the form of pellets, there is a problem in that molded products tend to have hardness spots due to poor mixing.

Therefore, it is possible to reduce costs and achieve uniform mixing by using powdered calcium carbonate, which has a low unit price. This method cannot be carried out because the mixed powder with calcium carbonate cannot fall down due to its own weight, and the supply path becomes clogged, making it impossible to supply the powder to the pressure feeding path.

The present invention was proposed in view of the above problems, and an object of the present invention is to provide an injection molding machine that can use powdered calcium carbonate.

(Means for solving the problems) In order to achieve the above object, the injection molding machine according to the present invention has the following features:
The upper half of the hopper is divided by a partition plate to form a synthetic resin storage section and a calcium carbonate storage section, and the lower half of the hopper is equipped with stirring blades, and the synthetic resin is fed from each storage section to the lower half of the hopper. In an injection molding machine that stirs resin and calcium carbonate with a stirring blade and supplies the mixture from a supply port to a molding mold through a supply path and a pressure path, a rotating screw for feeding and conveying is provided in the supply port and a pressure path, and the supply The conveying rotary screw is configured to be rotatably driven by a driving means.

(Function) Powdered calcium carbonate stored in the calcium carbonate storage section of the hopper is stirred and mixed almost evenly with the synthetic resin material by a stirring blade in the lower half of the hopper, and then supplied from the supply port to the supply channel. be done.

In the supply path, the mixed powder of calcium carbonate and synthetic resin material is forcibly fed to the pressure feed path by the supply and conveyance rotary screw, thereby preventing clogging in the pressure feed path.

Moreover, at this time, calcium carbonate is further stirred and mixed into the synthetic resin material by the rotation of the rotating screw.

(Example) Embodiments of the present invention will be described below based on the drawings.

In an injection molding machine 1 shown in FIG. 1, a mold 6 is disposed between a fixed platen 3 fixed approximately at the center of the upper surface of a base 2 and a movable platen 5 that can be moved left and right by a ram cylinder 4. It is being held between
A molding material supply bag 27 is clamped and fixed on the right side of the stationary platen 3.

The molding material supply device 7 includes a molding material pumping section 7a extending from the right side of the fixed platen 3 to outside the right end of the base 2, and a molding material mixing supply section 7b. As shown in FIG. 2, the molding material pressurizing section 7a has a pressurizing passage 9 formed therein, a heater 10 is provided on the outer periphery of the pressurizing passage 9, and a pressurizing screw 11 provided within the pressurizing passage 9 is provided with a pressurizing passage 9. It is configured to be rotationally driven by a drive device 12 provided at the right end of the molding material pumping section 8 .

As shown in FIG. 2, the molding material mixing supply section 7b is composed of a cylindrical hopper 13 and a supply path 14 that communicates the inside of the hopper 13 with the pressure feeding path 9. The upper half of the interior is partitioned by a partition plate 15 to form a calcium carbonate storage section 16 and a synthetic resin storage section 17, and the lower half of both storage sections 16 and 17 are opened and closed by a control device (not shown). Measuring flap 18
Powdered calcium carbonate 20 is stored in the calcium carbonate storage section 16, and synthetic resin material powder such as polypropylene (P-P) or ethylene vinyl alcohol (E-V-A) is stored in the synthetic resin storage section 17. 21 is stored.

The lower half of the hopper 13 is provided with stirring blades 23 which are rotatably driven by motors 22 attached to the outer surfaces of both front and rear walls thereof, and the supply port 2 at the lower end of the hopper 13.
4 is provided with an on-off valve 25 for controlling the supply amount.

The supply passage 14 that communicates the supply port 24 with the pressure passage 9 is provided with a spiral supply conveyance rotary screw 25 that is rotationally driven by a drive means 28 such as a motor. The peripheral edge of the blade 25a is a scraping blade 2 formed to protrude inward from the inner surface of the supply path 14.
It is formed so as to be close to the inner edge of 7.

In the injection molding machine 1 configured as described above, the one-ift flaps 18 of each of the synthetic resin storage section 17 and the calcium carbonate storage section 16 are opened, and powdered calcium carbonate 20 and synthetic resin are supplied to the lower half of the hopper 13. Resin material powder 21
After the powders are stirred and mixed by the stirring blade 23, when the on-off valve 25 for supply amount control is opened, the mixed powders are supplied to the supply path 14 from the supply port 24.

The powder supplied to the supply path 14 is further stirred and mixed when it is supplied to the pressure feeding path by the rotational drive of the supply conveyance rotary screw 25.

The powder supplied to the pressure feeding path 14 is transferred to the pressure feeding screw 11.
When being transported, it is melted by a heater 10 and is injected into a molding die 6 to be molded.

Incidentally, as shown in FIG.
9 is provided so that the powder is melted in the supply path 14, further stirring and mixing effects can be expected.

(Effects of the Invention) As described above, the present invention allows use of powdered calcium carbonate that tends to cause clogging in the supply channel, and can significantly reduce molding costs.

In addition, the calcium carbonate is a powder, and the stirring blades in the lower half of the hopper and the rotating screw in the feed channel
Since the mixture is stirred and mixed several times, the degree of stirring and mixing is greatly improved.

[Brief explanation of drawings]

The drawings show embodiments of the present invention; FIG. 1 is an overall front view of an injection molding machine, FIG. 2 is a longitudinal sectional front view of the main parts, and FIG. 3 is a modification of the bell equivalent to FIG. 2. 9... Hopper, 15... Partition plate, 16... Calcium carbonate storage section, 17... Synthetic resin storage section, 20.
...Powdered calcium carbonate, 21 Synthetic resin material powder, 23
... Stirring blade, 24... Supply port, 25... Rotating screw, 28... Drive means.

Claims (1)

[Claims] 1. The upper half of the hopper is divided by a partition plate to form a synthetic resin storage section and a calcium carbonate storage section, and a stirring blade is installed in the lower half of the hopper, so that the material is fed from each storage section to the lower half of the hopper. In an injection molding machine that stirs synthetic resin and calcium carbonate with a stirring blade and supplies the mixture from a supply port to a molding mold through a supply path and a pressure path, a rotating screw for feeding and conveying is provided in the supply port and the pressure path. , an injection molding machine comprising: a rotary screw for supply and conveyance that can be rotationally driven by a driving means;