JP2676706B2 - Dryer for synthetic resin materials - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a synthetic resin material drying apparatus, and particularly to a synthetic resin pellet-shaped (including bead or disc-shaped) material having a high water absorption rate. For drying equipment for.

(Prior art) For example, pelletized materials such as ABS resin having a high water absorption rate (about 0.1 to 0.8%) are generally heated to 80 to 90 ° C with a hot air dryer or a dehumidifying hot air dryer. The resin material is supplied to the hopper of the injection molding machine after being dried for about 2 to 6 hours to reduce the water content of the resin material to about 0.01%. Insufficient drying of the resin material causes various molding defects such as silver streaks and bubbles due to water vapor.

However, the conventional drying means requires high temperature and long time drying as described above, and requires special drying equipment and a proper space for installing it.

(Problem to be Solved by the Invention) The present invention proposes a drying device with a blow which is completely different from the conventional means, so that the conventional high temperature drying equipment is not required and the synthesis is performed in a short time. It is possible to perform a desired drying of a resin material, which is advantageous in terms of energy, space, and cost, and to provide a drying device capable of significantly increasing the factory productivity of an injection molding factory. It is intended.

(Means for Solving the Problem) That is, the drying device of the present invention is characterized in that a high-speed rotating blade for hitting the pelletized material of the synthetic resin is provided in the drying chamber.

(Function) It is considered that when a hard pellet-shaped resin material is hit with high speed and high frequency, some change that causes a dehydration effect occurs inside the resin material itself.

FIG. 1 is a diagram showing the impact time and the weight change rate of the pellet material when the ABS resin pellet material is introduced into a mixer having a blade rotating at a high speed and is impacted. The weight of the material is 99.7% of the original weight when the impact time (mixer operating time) is 2 minutes, and 9 minutes after 3 minutes.
9.27%, 98.99% in 4 minutes, and it can be seen that the water content is removed depending on each ratio. Reference symbol P in the figure
The point indicated by is the rate of change in weight when the same type of pelletized material is dried for about 4 hours by a conventional hot air box dryer.
This is 9.66%, but with this striking method, it is possible to dry for 4 hours with a dryer in just a few minutes.

The resin material that has undergone this striking step and the material that has been hot-air dried for 4 hours are respectively supplied to an injection molding machine and molded, and when these molded articles are compared, there is almost no difference between the two.

 Details of the example of FIG. 1 are as follows.

Material: ABS resin pellets 20g Mixer: 2 blades Rotation speed 16,000 rpm Operating time (min) 0 2 3 4 Material size 1 3/4 3/5 1/2 Ratio of powdery substance 0 1/4 2 / 5 1/2 Weight% of material 100 99.72 99.27 98.99 Reduction rate% (Dehydration rate) 0 0.28 0.73 1.01 (Example) Explaining together with the following examples, FIG. It is a schematic sectional drawing of a principal part.

In the figure, reference numeral 10 is a known injection molding machine, 11 is its heating cylinder, 12 is inserted into the heating cylinder so as to be rotatable and forward and backward,
A screw, 15 is a feed screw for supplying the resin material to the molding machine, and 16 is its motor. As the molding machine, those without the above feed screw 15 and motor 16,
It goes without saying that various types can be used.

In this embodiment, a drying chamber 20 is attached to the upper part of the feed screw 15. The drying chamber 20 has a substantially cylindrical shape, and at the lower part of the chamber, a high-speed rotating blade 12 for hitting a synthetic resin pellet material is installed. In the embodiment, as the striking blade 21, a combination of two blades whose tips are vertically bent as shown in FIG. Rotated at high speed of rotation. Reference numeral 25 denotes a shutter which opens and closes the lower portion of the drying chamber 20 by a shutter cylinder device 26. Incidentally, reference numeral 29 is a spare hopper space,
The dry resin material that falls when the shutter 25 opens can be temporarily stored here.

A raw material supply hopper 30 is connected to the upper part of the drying chamber 20. Reference numerals 31 and 32 are cylinder type metering shutters for metering and supplying the raw material every one or two shots.

The operation and dehydration rate of the drying apparatus of this embodiment are as described in the previous section and the dehydration rate.

(Effect) As described above, according to the present invention, it is possible to extremely easily and easily dry the resin material required for the injection molding machine by hitting the pellet material of the synthetic resin. became. In particular, as described above, according to the present invention, it becomes possible to perform the same drying in just a few minutes, which has been dried by the conventional dryer for 4 hours. The desired drying of the synthetic resin material can be performed in a short time without requiring any high-temperature drying equipment, which is advantageous in terms of energy, space, and cost. Further, according to the device of the present invention, as described in the embodiment, it has an extremely simple structure and can be directly attached to the injection molding machine and can be supplied to the molding machine while being sequentially dried by a necessary amount. It is possible to improve the quality of the supplied material and facilitate its management, and significantly increase the factory productivity of the injection molding factory.

[Brief description of the drawings]

FIG. 1 is a graph showing the impact time and the weight change rate of pelletized material when a resin material is put into a mixer, and FIG. 2 is a schematic cross-sectional view of a main part of an injection molding machine attached with an example of the inventive device, FIG. 3 is a perspective view showing an example of a hammering blade. 10 …… Injection molding machine, 12 …… Screw, 15 …… Feed screw, 20 …… Drying chamber, 21 …… Blading blade, 22 …… Rotary shaft, 23 …… Motor, 30 …… Material hopper.

Claims (1)

(57) [Claims] 1. A dryer for a synthetic resin material, comprising a blade rotating at a high speed for hitting a pellet-shaped material of the synthetic resin in a drying chamber.