JP2687807B2 - Method for discharging molding resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to an extruder, a kneader, a polymerizer in a manufacturing process of a resin melted in a manufacturing process of a resin material and a molding resin composition containing various fillers and additives. The present invention relates to a method of discharging from a die used for a discharging section such as.

[0002]

2. Description of the Related Art Generally, in order to produce a resin material, a polymer is polymerized from a monomer in a polymerization vessel, or a polymer and various fillers and additives are blended and kneaded in an extruder or a kneader, and a predetermined amount is obtained. These compositions melted from a die having a discharge hole of the size are extruded into a gut shape and cut,
A pelletizing method is used. The die used in such a method is made of metal and usually has a plurality of ejection holes.

[0003]

However, if the die used in the discharging portion of the resin material in a molten state such as the extruder, the kneading machine, the polymerization can, or the like continuously discharges the resin material, So-called eye-shaped colored foreign matter adheres and accumulates near the outlet of the die discharge hole. This candy-like colored foreign matter (hereinafter abbreviated as candy-like substance) is a sublimation product of residual monomers or residual oligomers contained in the resin, a condensate of volatile components of various additives, or a resin composition. They are themselves, or they are deteriorated and discolored, and are attached and deposited in the vicinity of the discharge hole of the die. If the hair-like material adheres and accumulates in the vicinity of the discharge hole of the die and is operated while it is operating, a part of the material may come off and adhere to or be mixed with the gut-like resin composition continuously discharged.

When such a resin-based material having such a stain-like substance attached is pelletized as it is into a product, when it is made into a molded product by a method such as injection molding, a colored stain-like substance appears on the surface of the molded product. However, there are problems such as impairing the product quality including the appearance of the product, resulting in a marked decrease in the commercial value. In the past, methods to prevent mixing of messy products into products have been the regular cleaning of the die discharge surface, scraping from the gut before pelletizing, and selection and removal of messy products mixed in products. However, it cannot be said to be sufficient because the removal rate is low and the time required for selection is enormous, and it has been a problem that the resin-based material manufacturer needs to solve. It is an object of the present invention to provide a method of preventing a messy product from being mixed in a product and discharging a resin material having excellent product quality in a gut form.

[0005]

According to the present invention, when a molten molding resin composition is discharged in a gut form from a plurality of die discharge holes, a gas heated to 100 to 400 ° C. is supplied to each discharge hole of the die. The present invention relates to a method for discharging a molding resin composition, characterized in that the resin composition for molding is sprayed from the front surface on the discharge side at an air flow rate of -50 Nl / min and a wind speed of 50-100 m / sec.

Hereinafter, the present invention will be described specifically. The "molding resin composition" in the present invention is a resin (single resin) used for molding such as injection molding and extrusion molding, a composition of a resin and another resin (resin alloy), a single resin or a resin alloy thereof. It is a general term that includes a composition in which a reinforcing resin, a filler, an additive, etc. are added.

The "mold for producing a molding resin composition" is a spinneret used in a discharging part when the above molding resin composition is melted and discharged in a gut shape, and is a fiber-spinning spinneret. It does not include a base or a base for discharging a film. Representative examples of a die for producing a molding resin composition used in the present invention are shown in FIGS. FIG. 1 is a front view (discharging side) of the die, FIG. 2 is a rear view (extruder side), FIG. 3 is a sectional view, and FIG. 4 is an extrusion with a die for blowing heated gas according to the present invention. It is a figure which shows the general view of the discharge condition of a machine and a gut. A plurality of discharge holes 2 pass through the mouthpiece 1, the molten resin composition enters from the direction of arrow A, passes through the discharge hole inner surface 3, passes through the discharge hole outlet, and is extruded into a gut-like cooling water. Cool and solidify in 7. The heated gas (arrow B) is blown to each discharge hole as shown by arrow C through the heated gas blowing device 8 as shown in FIG.

The heated gas in the present invention means a gas heated to a range of 100 to 400 ° C., more preferably 200 to 300 ° C. by an electric heater or the like. The temperature in this range is close to the temperature of the die during the production of the molding resin composition, does not cause clogging of the die, and does not cause unnecessary heating. Examples of the gas include air, nitrogen gas, and steam, but are not particularly limited. However, in view of cost in view of exerting the effect of the present invention, air is most preferable.

It is preferable that the device for spraying the gas has a gas discharge hole for hitting each of the discharge holes of the die. The shape of the gas discharge hole is not particularly limited, such as a circular shape or a slit shape, as long as it corresponds to each of the discharge holes of the resin composition die. In the present invention, the amount of air blown from the discharge hole is generated near the outlet of the discharge hole, and among the adhered / accumulated canny-like substances that include a large amount of sublimate and a large amount of volatile matter, one discharge hole has a maximum of 1
It is necessary to blow a gas of 0 Nl / min to 50 Nl / min.

If the air flow rate is smaller than this, a messy substance due to the sublimate deposits near the discharge hole over time. If the air flow rate is higher than this, problems such as gut breakage and other operational problems occur. In addition, as the wind speed, the resin-like composition is the main body, and, for example, for the main body generated during the production of the glass fiber reinforced grade, the discharge hole is 5
It is necessary to blow a gas with a wind speed of 0 m / sec to 100 m / sec.

If it is lower than this wind speed, it becomes difficult to blow away the dust-like material, and if it is high, problems such as gut breakage occur. Therefore, the amount of air blown is in the range of 10 Nl / min to 50 Nl / min per discharge hole, and the wind speed is in the range of 50 to 100 m / sec.

[0012]

[Operation] In the manufacturing process of a molding resin composition, a mesicle-like substance is generated and adheres / deposits in the vicinity of the outlet of a discharge hole of a die used in a discharge part of an extruder, a kneader, a polymerization can or the like.
This is because a sublimable substance or a volatile condensate in the discharged resin composition adheres to the vicinity of the die discharge hole and is oxidatively deteriorated and discolored or deposited on the die discharge surface. It is considered that the surface is scraped off and adheres and deposits.

Therefore, the atmosphere of the die discharge part containing a large amount of sublimate and volatile matter is 10 Nl / min to 5 per discharge hole.
It is considered that it is constantly renewed by blowing a gas with an air volume in the range of 0 Nl / min to prevent the sublimable substance and the condensate of volatile matter from adhering to and depositing on the die discharge part. In addition, like the glass fiber reinforced grade, the surface of the die which is scraped off at the die discharge part causes the discharge to become 5
By blowing a gas having a wind speed in the range of 0 m / sec to 100 m / sec, the gas can be blown off from the surface of the die discharge side, and it is possible to prevent the dust-like substance from being mixed into the product.

As the gas used here, 100 to 40
By making the gas heated to 0 ° C., more preferably 200 to 300 ° C., while sufficiently exhibiting the above effects,
In addition, there is no problem in operation such as clogging of the discharge hole and break of gut due to cooling of the mouthpiece discharge part.

[0015]

EXAMPLES The present invention will be specifically described below with reference to examples. Example 1 Nylon 6; 70 parts by weight and glass fiber (E
Glass chopped strand); after melt-kneading 30 parts by weight, extruded as shown in FIG. 4 to form a strand,
This was cut and pelletized. As the mouthpiece of the discharge part, a gas spray nozzle having a discharge hole diameter of 4 mm and a discharge hole number of 60, and having a fine hole adapted to spray gas to each discharge hole was provided. Air is used as the gas,
As the heater, a commercially available electrically heated hot air generator was used. The amount of mixture in the product was measured by weight. The results are as shown in Table 1.

[0016] As is clear from Levels Nos. 1, 4, and 6, when the air flow rate is less than 10 Nl / min, the amount of messy material mixed in the product is 10 to 15 ppm regardless of the temperature of the air, which is a level that cannot be used as a product. Met.

Further, as is clear from the levels No. 2 and 3,
When the air temperature was less than 100 ° C., the mouthpiece discharge holes were clogged when the air velocity and the air volume were increased to the point where the dust-free material was blown off or not accumulated, making it impossible to continue production. The air temperature is 25, as in Level Nos. 9, 10, and 12.
Even if it is as high as 0 ° C or 400 ° C, which does not cause clogging of the mouthpiece discharge hole, the air volume is 50Nl per discharge hole.
/ Minute or the wind speed exceeds 100 m / sec with respect to the discharge hole, gut breakage frequently occurred and production could not be continued.

As can be seen from the levels No. 5, 7, 8, and 11, the temperature, the air volume, and the air speed of the air to be blown are 10
0 ℃ ~ 400 ℃, the air volume is 10Nl / min ~ 50Nl / min per discharge hole, the wind speed is 50 ~ 100m / discharge hole
It can be seen that by setting the number of seconds, the amount of the messy product mixed in the product can be reduced to zero without causing clogging of the discharge hole or break of the gut.

[0019]

INDUSTRIAL APPLICABILITY In the process of producing a molding resin composition,
In the die used in the discharge part of extruders, kneaders, polymerization cans, etc., by spraying preheated gas from the discharge side front surface to each discharge hole of the die, sticking of canny-shaped material to the vicinity of the discharge hole of the die By preventing the accumulation and blowing away the dust-like substance from the mouthpiece discharge hole, it is possible to prevent the dust-like substance from being mixed into the product and to prevent the product value of the product from being deteriorated due to the mixture of the stain-like substance.

The temperature of the air is 100 ° C to 400 ° C.
More preferably, the air flow rate is 200 to 300 ° C., the air flow rate is 10 Nl / min to 50 Nl / min per discharge hole, and the wind speed is 50 to 100 m / sec with respect to the discharge holes, so that the discharge holes are not clogged or the gut is broken. It can be said that the method is a very effective method for producing a resin composition for molding in that it is possible to prevent the mixture of a messy product into a product without causing it.

[Brief description of the drawings]

FIG. 1 is a front view (discharging side) of a die of the present invention.

FIG. 2 is a rear view (extruder side) of the die of the present invention.

FIG. 3 is a sectional view of a die of the present invention.

FIG. 4 is a diagram showing an outline of an extruder equipped with a die for blowing heated gas of the present invention, and a discharge state of a gut.

[Explanation of symbols]

1 Mouth 2 Discharge hole 3 Discharge hole inner surface 4 Extruder body 5 Polymer gut 6 Cooling bath 7 Gut cooling water 8 Heating gas spraying device

Claims (1)

(57) [Claims] 1. When a molten resin composition for molding is discharged in a gut form from a plurality of die discharge holes, a gas heated to 100 to 400 ° C. is supplied to each discharge hole of the die with an air flow rate of 10 to 50 Nl / min. And a method for discharging a molding resin composition, which comprises spraying from the front surface on the discharge side at a wind speed of 50 to 100 m / sec.