JPS6073813A - Apparatus for plasticizing resin - Google Patents

Abstract

PURPOSE:To make the titled apparatus small-sized, to lower the production cost thereof, to shorten the mold starting time, and to lower the loss of material when it is changed, by loading a hole in melting means with a linear resin mate- rial by delivering means, and forcing the resin material against a torpedo so that the resin material is caused to melt due to the heat generated thereby. CONSTITUTION:An linear resin material delivered by pinch rollers 8, 8' is loaded into a hole 17 and is forced against the tip 15 of a torpedo 13. The torpedo is previously heated, the central section of the linear resin material is melted and the linear resin material is further pushed down so that a further wide area of the central section is melted. This process is repeated so that all the cross section of the linear resin material 10 comes in contact with the torpedo 13 and is melted. Then the linear resin material 10 is pused down further, and the melting is carried out successively. The resin in the involved space is heated and melted by heaters 21 and 14, and then if the heating by the heater 14 is improved and at the same time the pinch rollers 8, 8' are rotated to perform the molting operation, the starting is smoothly carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a resin plasticizing apparatus of size A for molding resin materials.

Conventional structure and problems Generally, when molding resin materials, a method is used to keep the resin material in a fluid state and apply pressure to confine it in a mold.This method is used for injection molding, transfer molding, compression molding, etc. Applies to.

In injection molding of thermoplastic resin, which is the most commonly used method, a solidified pellet is supplied to a heated screw cylinder device, and the resin is completely plasticized and melted by shear heat generated by the rotational movement of the screw and heat transferred from the cylinder. was common.

FIG. 1 is a partial cross-sectional view of a general screw cylinder device.

1 is a screw that can rotate around the shaft, 2 is a cylinder that slidably supports the screw 1, 3 is a nozzle hole provided at the tip of the cylinder 2, and 4 is a screw that is wrapped around the cylinder 2 to raise the temperature of the cylinder 2. 5 is a resin material supply port provided in the cylinder 2, and 6 is a hopper for storing the pelletized resin material. The pellet-shaped resin material enters the screw groove 7 from the supply port 2 and is sent forward (towards the nozzle) as the screw 1 rotates. Since the screw groove 7 becomes shallower as it approaches the nozzle side, the pellet-shaped resin material is compressed and subjected to shearing by 10 rotations of the screw, and the heat absorbed from the cylinder 2 is melted.

However, this configuration causes the following problems.

■ In order to remove the material existing in the screw groove 7 and fill it with new material, new material is supplied one after another and gradually replaced. Since the previous resin and the new resin are mixed together and sent, as the concentration of the previous material becomes diluted, the replacement efficiency decreases and a large amount of material and a long time are consumed when changing the material.

■ The device becomes larger because the screw/cylinder is long. As a result, not only does it cause space problems, but it also becomes one more difficult time to change materials as mentioned in (2) above.

■ At the start of molding, it is necessary to heat the cylinder and screw to the same temperature when raising the temperature until the resin in the screw groove is completely melted, which increases the heat capacity9 and takes time to start molding.

■ The screw has a complicated shape and is difficult to process.
The cylinder also requires long holes to be machined, making it difficult to maintain accuracy and requiring a large amount of manufacturing cost.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned drawbacks and provides a resin plasticizing device which is small in size, has low manufacturing costs, and has excellent productivity such as furnace reduction in molding start-up time and reduction in material change loss. It is in.

Structure of the Invention The resin material targeted by the present invention has a linear form, and is obtained by omitting the shredding step, the so-called pelletizing step, in the conventional processing steps for pellet-shaped resin materials. It can also be manufactured using a separate process. That is, the configuration of the present invention includes a means for storing a linear resin material and a means for sequentially feeding out the linear resin material, and further includes a penetrating hole and a torpedo having a heating element in the hole. 9. The linear resin material is loaded into the hole of the melting means by the feeding means, and the linear resin material is applied to the torpedo by the feeding force of the linear resin material by the feeding means. It is designed to press the materials together and melt them using the heat of the torpedo.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Figure 2 shows
In the resin plasticizing apparatus according to the present invention, a part of the feeding means and the resin melting means are shown. Pinch rollers 8, 8' are provided at arbitrarily adjustable distances.
They are configured to rotate in opposite directions, and are configured to transmit the rotational force of the power source to the pinch roller 8 through the gear 9, and from the pinch roller 8 to the pinch roller 8'.

The pinch rollers 8 and 8' hold down the linear resin material 10i with moderate force, and when the pinch rollers 8 and 8' rotate in the directions of the arrows, the linear resin material is pulled out and sent downward as a means for storing it. 9 is issued.

The body 11 is provided with a penetrating hole 12, the hole 12 is provided, and the hole 12 is provided with a torpedo 13.

The torpedo 13 has a heating element 14 in the center, and top and bottom tips 15 and 16'i. The hole 12 consists of a cylindrical hole 17 into which a linear resin is charged, a space 18, 19 which is a combination of a truncated cone and a cone where the torpedo 13 is provided, and a cylindrical discharge hole 20 at the tip of the body. The body 11 is provided with a heating element 21 for keeping the entire body 11 warm.

The body 11 also has a cooling block 2 having cooling holes 23.
2 is fixed. The lead wires of the 24.25i heating element 14 are simply shown.

In the above configuration, the linear resin material fed out from the pinch rollers 8, 8' is loaded into the hole 17 and further pressed against the tip 16 of the torpedo 13.

Since the torpedo is heated in advance, the center of the linear resin is strongly melted. As the center melts, the linear resin material is further pushed down and melts over a slightly wider area than before. This is repeated until the entire cross section of the wire-shaped resin material 1o comes into contact with the torpedo 14 and melts. As it melts, the linear resin material 1° is pushed down and melts one after another.

The space 1B is a space with a ring-shaped cross section whose inner and outer diameters widen as it moves downward, but its cross-sectional area is designed to gradually become narrower as it moves downward, to prevent air from being entrained. . The molten resin passes through the space 19 and is discharged from the discharge hole 20. This discharge pressure is adjusted by the rotational force of the pinch rollers 8, 8'.

When starting molding with the space filled with resin in advance, the entire body is heated by the heating element 21 for heat retention and the heating element 14 to melt the resin in the space, and then the calorific value of the heating element 14 is greatly increased. If the pinch rollers 8 and 8' are rotated at the same time to perform the melting operation, the start-up 9 will be smooth.

If there is a possibility that the molten resin will flow back from the clearance between the linear resin material 10 and the hole 17, this can be prevented by flowing a refrigerant through the cooling hole 23 of the cooling block 22 to cool the upper part of the body.

At this time, the heat-retaining heating element 21 serves to cool the entire body and prevent the nozzle from clogging.

3 and 4 are shown to explain the actual injection molding operation, and the linear resin material 27 charged into the body 26 from below is melted by the torpedo 28. The discharge hole 29 of the body 26 communicates with the nozzle hole 31 of the capsule 30, and the discharge pressure of the molten resin pushes up the slidable piston 32 in the capsule 3o, storing the molten resin in the capsule. Once a predetermined amount of molten resin has been stored in the capsule, the calorific value of the torpedo is reduced and delivery of the linear resin material is stopped.

FIG. 4 shows a molding machine for performing injection molding using the resin plasticizing apparatus according to the present invention and the capsule shown in FIG. Injection piston driven by injection cylinder, 36 lower mold, 37 upper mold, 38 fixed plate, 39 movable plate driven by mold clamping cylinder 33, 40 linear resin material 41'f: winding A bobbin serves as a storage means, and 42 is a shaft that rotatably supports the bobbin 40i. Reference numeral 43 denotes means for feeding the linear resin material, and as shown in FIG. 2, it is composed of a pinch roller or the like. 44 is the body of the resin melting means, and the shaft 42. The feeding means 43 and the body 44 are both fixed to the main body of the molding machine. 45 is a capsule, 46 is a piston shaft, 47 is a head that holds the capsule, keeps the resin warm in a molten state, and moves up and down; 48 is a mechanism that drives the head 47 up and down, and a mechanism that drives itself horizontally along a bar 49. Drive with mechanism 48' shows drive 48 in a position where piston 46 coincides with injection piston 35.

In the above configuration, the linear resin material stored in the bobbin 40 is sent to the resin melting means 44 by the feeding means 43, and the molten resin is stored in the capsule 45. After that, the capsule 45 is once removed from the top, transferred to the injection cylinder side, stopped at a position where the axis of the injection piston 35 and the axis of the piston 46 coincide, and then lowered again to the nozzle hole (not shown) of the capsule 45. The capsule 45 and the upper mold 37 are brought into contact with each other so that the sprue holes 5o of the upper mold 37 communicate with each other. The lower mold 36 and the upper mold 37 are brought into contact with each other in a thunder-clamped state in advance, and then the capsule 45 and the upper mold 37 are brought into contact with each other, and then the injection piston 36 is driven. is filled with. After that, the resin in the mold is cooled, and the mold is opened and the molded product is taken out, as in a normal molding method. In addition, it is desirable that the heater of the torpedo generates heat as much as possible at the point where the linear resin material comes into contact.
) Efficiency can be increased by employing a structure known as a runner chip.

Effect of the invention As described above, the present invention has the following effects.

■ The device is compact.

■ Resin flows smoothly and material diameter is easy.

■ The heat capacity of the part to be heated is small, and the heat generating part and the resin melting part are close to each other, so the start-up is quick.

■ Manufacturing costs are low because of the simple structure without precise machining or complicated machining.

■ By having multiple plasticizing devices and capsules, it is possible to immediately switch to different materials.

[Brief explanation of the drawing]

FIG. 1 is a partially broken sectional view of a conventional plasticizing device, and FIG. 2 is a partial sectional view of a plasticizing device in an embodiment of the present invention.
FIG. 3 is a partial sectional view of one step of molding using a plasticizing device according to an embodiment of the present invention, and FIG. 4 is a partially sectional front view of a molding machine equipped with a plasticizing device according to an embodiment of the present invention. It is. 10.27.41... Linear resin moon phase, 4o... Bobbin, 8...-pinch roller, 12... Hole, 13
゜28... Torpedo, 14 ・Heating element, 21・
・・Heating element for heat retention, 22...Cooling block, 44
...Resin melting means. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) Consisting of a means for storing a linear resin material, a means for sequentially feeding out the linear resin material, and a resin melting means having a torpedo having a through hole and a heating element in the hole, A resin plasticizing apparatus configured to charge a linear resin material into a hole of the melting means by the feeding means and melt the resin by pressing the resin material against the torpedo. (2) The resin plasticizing apparatus according to claim 1, further comprising a cooling means provided on the linear resin inlet side of the resin melting means. (3) The resin plasticizing apparatus according to claim 1, further comprising a heat-retaining heating element provided outside the hole of the resin melting means.