JPH05220811A - Mouthpiece for manufacturing resin composition for molding - Google Patents

Abstract

PURPOSE:To prevent the mixing of an eye mucus-like matter into a product, and to improve the quality of the product by specifying surface roughness in the vicinity of the internal surface of the discharge hole of a mouthpiece and the outlet of the discharge hole in the mouthpiece used as a discharge section at a time when a molten resin composition for molding is discharged in a gut shape. CONSTITUTION:In a mouthpiece 1 used as a discharge section at a time when a resin composition for molding is discharged in a gut shape, surface roughness in the vicinity of the internal surface 3 of the discharge hole 2 of the mouthpiece and the outlet of the discharge hole is formed so as to reach a range of Ra<=5mum, preferably Ra<=1mum by center-line mean roughness (Ra) through a replica method. Accordingly, when the resin composition for molding is manufactured continuously, the quantity of generation of the sublimate of a residual monomer and a residual oligomer contained in a resin often generated near the outlet of the discharge hole of the mouthpiece 1 of an extruder, etc., and resin composition itself, an eye mucus-like colored foreign matter, is reduced.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is used in a discharge part of an extruder, a kneader, a polymerization can, etc. in a manufacturing process of a molten resin and a molding resin composition containing various fillers and additives therein. Concerned about the base.

[0002]

2. Description of the Related Art In order to produce a molding resin composition, a polymer is polymerized from a monomer in a polymerization can, or a polymer and various fillers and additives are blended in an extruder or a kneader.
A method of kneading and extruding these compositions melted from a die having a discharge hole of a predetermined size into a gut shape, cutting and pelletizing them to obtain a pre-molding material is used. The die used in such a method is made of metal and usually has a plurality of ejection holes.

[0003]

When the molding resin composition is continuously manufactured, so-called nymph-like colored foreign matter adheres and accumulates near the outlet of the die discharge hole of an extruder, a kneader, a polymerization can or the like. .. 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 the same, or they are deteriorated and discolored, and are adhered and accumulated in the vicinity of the ejection hole of the die. If the hair-like material adheres to the vicinity of the outlet of the discharge hole of the die and is operated while being accumulated, a part of the material may come off and adhere to the gut-shaped resin composition continuously discharged to be mixed.

When the resin composition having such a messy product adhered is pelletized as it is, and the product is made into a molded product by a method such as injection molding, a colored messy product is formed on the surface of the molded product. There are problems such as appearing and impairing the product quality such as the appearance of the product, resulting in a marked decrease in 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 off the gut before pelletizing, and selective removal of messy products mixed in the product. 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 manufacturer of the molding resin composition needs to solve. On the other hand, as soybeans (bases) for preventing the occurrence of eye drops, for example, as disclosed in JP-A-61-24973, a soybean material for plastic molding composed of ceramics containing 40 wt% or more of zirconia is known. It is an object of the present invention to provide a die for producing a molding resin composition, which can prevent mixing of a messy product into a product and can discharge a molding resin composition having excellent product quality.

[0005]

The die for producing a molding resin composition of the present invention is a die used for an ejection part when ejecting a molten molding resin composition in a gut form. The surface roughness of the inner surface of the discharge hole and the vicinity of the discharge hole outlet of the center line average roughness (Ra) by the replica method is Ra ≦ 5 μm.
It is characterized by being in the range of.

The present invention will be specifically described below. The "molding resin composition" in the present invention means 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 reinforcing fibers, fillers, additives, etc. are added.

The "mold for producing a molding resin composition" is a die used in a discharging part when the above molding resin composition is melted and discharged in a gut shape, and is composed of fibers (filaments). It does not include a spinneret for discharging or a spinneret 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, and FIG. 2 is a rear view (extruder side). A plurality of ejection holes 2 penetrates the die 1, and the molten resin composition enters from the direction of arrow A, passes through the inner surface 3 of the ejection hole, is extruded in a gut shape from the outlet of the ejection hole, and is cooled and solidified. .. 4 is the vicinity of the outlet of the discharge hole. In the present invention, the inner surface of the discharge hole of the die (3)
And the surface roughness near the outlet of the discharge hole (4) is expressed by the center line average roughness (Ra) by the replica method, Ra ≤ 5
.mu.m, preferably Ra.ltoreq.1 .mu.m.

The center line average roughness Ra referred to here is JIS
It is a value defined by B 0601 and measured by the replica method. The replica method is a method for measuring the surface roughness inside the discharge part of the die as follows. Generally, a die used in an extruder, a kneader, or a discharge part of a polymerization can has a complicated shape, and it is difficult to measure the surface roughness inside the discharge hole or around the discharge hole.

The replica method used here is to make a replica inside the discharge hole with a rapid hardening resin and measure the surface roughness of the replica to obtain Ra. The rapid curing resin used here is "Technobit 304
0 ”(New Metals End Chemical Corporation) is a methylmethacryl-based room temperature quick-curing resin. The surface roughness is measured by a stylus method using a surface roughness meter (SURFCOM1014B) manufactured by Tokyo Seimitsu Co., Ltd. It was measured.

The inner surface of the discharge hole is a flow path for extruding the resin composition provided on the die at a predetermined diameter and a predetermined speed. The vicinity of the outlet of the discharge hole means the circumference of the hole on the discharge side and its periphery. Both of these are in the range of Ra ≤ 5.0 µm, preferably Ra ≤ 1.0 µm. In addition, the angle between the resin flow path and the die discharge surface in the discharge part is
90 ° ± 5 ° if the surface roughness Ra ≦ 5.0 μm is satisfied
Is desirable.

Surface roughness Ra ≤ 5.0 μm, preferably R
The range of a ≤ 1.0 μm may be satisfied when the die is manufactured, or Ra may be 5.0 μm when used for a certain period.
Even if it exceeds m, the effect can be reproduced by polishing so that Ra ≦ 5.0 μm. Surface roughness Ra ≤
As a method for satisfying 5.0 μm, for a die having a shape as shown in FIGS. 1 to 3, there are electric discharge machining for forming a discharge hole at the time of producing the die, and reaming etc. as a polishing process of the die after use.

Generally, a die used in the production of a reinforced resin composition, such as a glass fiber reinforced resin composition or an inorganic filler reinforced resin composition, has a high wear rate, a high surface roughness rate, and a hollow-shaped article. Is likely to occur. However, if Ra ≦ 5.0 μm, preferably Ra ≦ 1.0 μm by polishing, it can be reused, and the messy product can be greatly reduced. Therefore, the effect of the present invention in the reinforced resin composition is particularly remarkable from the viewpoint of the effect of preventing the generation of porcelain particles and the economical effect.

Further, the surface roughness of the inner surface of the die of the die and the vicinity of the outlet of the die is the center line average roughness (Ra), Ra ≤ 5.0.
μm, preferably, use a die in the range of Ra ≦ 1.0 μm, and on top of that, use a gas with a temperature and air volume that does not cause clogging of the die discharge hole, such as air, nitrogen, or steam. By spraying, it is possible to completely prevent mixing of the messy product into the product. The temperature of the gas to be sprayed is 100 ° C to 400 ° C, preferably 2
The range of 00 ℃ -300 ℃ is good. Further, the air volume is preferably 10 Nl / min to 50 Nl / min and the air velocity is 50 to 100 m / sec per discharge hole.

[0015]

In the manufacturing process of the molding resin composition, a messy product is generated, adheres and deposits near the outlet of the discharge hole of the die used for the discharge part of the extruder, the kneader, the polymerization can or the like. It is considered that this is due to the surface roughness inside the discharge hole and in the vicinity of the discharge hole outlet. That is, if the surface roughness is rough, the surface of the discharged resin composition is likely to be scraped off, or the surface of the resin composition may be easily attached or deposited. Therefore, it is considered that by reducing the surface roughness inside the discharge hole of the mouthpiece and in the vicinity of the discharge hole outlet, the generation of the candies can be reduced. In the present invention, specifically, the surface roughness inside or around the discharge hole of the die is the center line average roughness (Ra), Ra ≤
By setting it in the range of 5.0 μm, preferably Ra ≦ 1.0 μm, it is possible to suppress the generation of the dust-like substance to 1/5 to 1/20.

[0016]

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, the diameter of the discharge hole is 4 mm, the number of discharge holes is 60, and the surface roughness near the discharge hole inner surface and discharge hole outlet is the center line average roughness (Ra) = 0.9 μm by the replica method as shown in FIG. Using a die, the generation amount (weight) of the wastewater was measured.

The results are shown in Table 1. Example 2 In a twin-screw extruder, nylon 66; 70 parts by weight and glass fiber (E
30 parts by weight of glass was melt-kneaded and then extruded to form a strand, which was cut and pelletized. At that time, as the mouthpiece of the discharge part, as the surface roughness of the discharge hole inner surface and the vicinity of the discharge hole outlet,
The center line average roughness (Ra) by the replica method (Ra) = 0.9 μm was used to measure the amount of generation of the porcelain particles using a die as shown in FIG.

The results are shown in Table 1. Examples 3 to 4 and Comparative Examples 1 to 2 The resin compositions having the compositions shown in Table 1 were measured for Ra in Table 1 in the same manner as in Example 1 to measure the generation amount of the porridge. The results are summarized in Table 1.

[0019] As is clear from the table, the center point average roughness Ra is about 5.0μ.
At m or less, nylon 6 / GF = 70 is generated.
2.5ppm or less in the formulation of / 30, nylon 66 / GF = 70 /
With 30 compounding recipes, it was 1.3 ppm or less. With such an amount of the jelly-like substance generated, a slight amount of the jelly-like substance generated can be blown off by, for example, air blowing around the mouthpiece discharge hole, and mixing into the product can be prevented. On the other hand, when Ra exceeds 5.0 μm and, for example, 8.5 μm, the amount of porcelain-like material generated is larger than that of Ra ≦ 5.0 μm.
It increased 5 to 20 times. If the generation amount of the body-like substance is about 10 ppm or more, it is difficult to easily remove it on the die discharge surface, and it is deposited and colored on the die discharge surface (near the outlet) and mixed into the product.

[0020]

INDUSTRIAL APPLICABILITY In the manufacturing process of the molding resin composition,
In a die used in the discharge part of extruders, kneaders, polymerization cans, etc., the surface roughness of the discharge hole inner surface and the discharge hole outlet vicinity,
Center line average roughness (Ra) by the replica method, Ra ≤ 5.0
By setting the thickness to be in the range of μm, preferably Ra ≦ 1.0 μm, it is possible to obtain the effect of significantly reducing the generation of the meandering substance. Furthermore, by significantly reducing the generation of porcelain products, even small amounts of porcelain products can be easily removed on the surface of the die by a method such as air blowing, which prevents contamination of the porcelain products into the product. Therefore, it is possible to prevent the deterioration of the commercial value of the product due to the contamination of the messy product.

[Brief description of 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 an overall perspective view showing an extruder equipped with a die 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 Discharge hole outlet vicinity 5 Extruder body 6 Polymer gut 7 Cooling bath 8 Gut cooling water

Claims (1)

[Claims] 1. A spinneret for use in a spout when a molten molding resin composition is spouted in a gut form, wherein the surface roughness of the spinneret on the inner surface of the spout and in the vicinity of the exit of the spout is replica method. The center line average roughness (Ra) according to the invention is in the range of Ra ≦ 5 μm, and a die for producing a molding resin composition is provided.