JP2003220607A - Apparatus for preventing generation of eye mucus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an apparatus for preventing generation of an eye mucus in order to solve the problem that when molten resin is cut in a strand with an extruder, the eye mucus is generated on a surface of a die plate, grows up, is accompanied by the strand to cause a black point, and the number of times for cleaning the die plate is increased to remove the eye mucus. <P>SOLUTION: The apparatus for preventing generation of the eye mucus comprises a mechanism for heating the die plate by controlling a temperature and a mechanism for vibrating the strand by a gas. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for suppressing the occurrence of dents on a die plate when producing resin pellets by strand cutting of an extruder.

[0002]

2. Description of the Related Art When an extruder is used for strand cutting, mesiness is generated. Meani is generated around the strand holes of the die plate and grows with time. As for the generation of mesiness, strand breakage occurs, or the mesiness is carbonized and carried to the strand, pelletized, enters the product, and becomes a black dot. For that reason, some prior arts for countermeasures against mesiness are disclosed. JP-A-04-325223, JP-A-05-253997, JP-A-05-
In the prior art of Japanese Patent No. 278094, a technique for suppressing the growth of the eyelid is disclosed by expanding the shape of the die plate outlet of the die hole into a conical shape or making a hole larger than a strand hole on the die plate surface. Japanese Patent Laid-Open No. 05-220
The prior art of Japanese Patent No. 813 discloses a technique in which a gas blowing device is used to blow a gas onto the surface of a die plate at 50 to 100 m / sec to blow away the eyelid.

[0003]

However, even the disclosed prior arts have not been able to solve the troubles associated with the occurrence of eye damage. In the technique of processing the die plate holes, cleaning around the die plate holes is incomplete, so that the resin that cannot be removed is carbonized, and the carbides are also entrained in the strands.
The technique of blowing a gas of 50 to 100 m / sec into the die plate holes has a problem that when the die plate hole groups are arranged in two rows, that is, the gas cannot be blown to the lower die hole group. There is a technical problem that the porridge is prevented from being generated and that the porridge is not grown even if the porridge is generated. It is an object of the present invention to provide a porridge generation preventing device that suppresses the generation of porcelain that occurs on the surface of an extruder die plate and suppresses the growth.

[0004]

The inventors of the present invention have made extensive studies as to the purpose of achieving the above-mentioned object, and as a result, the cause of the occurrence of the cause is that the die plate is structurally at the tip of the die portion, and Since it is more protruding, the temperature of the surface of the die plate is lowered, and therefore the temperature of the metal part around the die hole is low, so that the friction is increased, and the mechanism that causes burr is clarified. Further, when the micro-vibration is applied to the strands, the resulting porridge melts and is entrained in the micro-vibrating strands before the porcelain grows, and it is clarified that the porcelain does not grow, reaching the present invention. did.

That is, the present invention is as follows. 1. A strand die plate for an extruder, which has a mechanism for controlling the temperature of the die plate to heat it and a mechanism for vibrating the strand with gas, and a device for preventing the occurrence of burr. 2. 2. The eyelid generation prevention device as described in 1 above, wherein the strand holes of the die plate are arranged in upper and lower two rows. 3. A mechanism for vibrating the strand with gas is 250 ° C to 3
Gas controlled to a temperature of 50 ° C is applied to the strands at a speed of 10 to 10
4. The device for preventing occurrence of eye damage according to 1 or 2 above, which has a mechanism of spraying at 45 m / sec. In the present invention, in the strand cutting of the extruder,
It is an object of the invention to provide an apparatus for preventing the occurrence of eye damage which has a mechanism for controlling the temperature of a die plate to heat it and a mechanism for vibrating a strand with gas.

The present invention will be described in more detail below with reference to the drawings. The outline of the strand cut die plate of the present invention is shown in FIG. In FIG. 1, 1 is a die part, 2 is a die plate, 3 is a strand hole, 4 is a strand, and 5
Is a die plate temperature sensor, 6 is a heater, and 7 is a gas blowing device. The mechanism for controlling the temperature and heating the die plate according to claim 1 of the present invention is as follows.

1. The position of the sensor shown in FIGS. 2 and 3, specifically, the depth direction is preferably 5 to 40 mm of the die surface, and the horizontal and vertical directions may be anywhere inside the heater in FIG. 2. As shown in FIG. 2, the heater covers and heats around the strand hole group. It is preferable that the outer circumference of the strand hole and the end of the heater cover the area around the strand hole so as to be 5 to 20 mm. The heater is preferably a brass cast heater and an aluminum cast heater, and it is preferable that the heater has the same height as the die plate surface as shown in FIG.
The heater is preferably cast and fixed with bolts. If they cannot be fixed with bolts, heat transfer will be insufficient, and the effect of preventing the occurrence of eye damage will be greatly reduced.

The temperature is controlled by using a thermocouple and a heater, but the temperature is set at the die outlet resin temperature of -40 ° C to +40.
The range of ° C is preferred. If the temperature of the resin at the die exit is lower than -40 ° C, the occurrence of mesiness increases. On the other hand, if the temperature is higher than + 40 ° C, the resin is thermally deteriorated and the resin is burnt. The mechanism for vibrating the strand according to claim 1 of the present invention with gas is 2
Gas (air, nitrogen, carbon dioxide) 10 at 50-350 ° C
It is a device that sprays on the entire strand at a speed of -50 m / sec. Strands immediately 2 after exiting the die plate
It is cooled in a strand bath filled with hot water of 5 to 80 ° C., conveyed to a strand cutter having a take-up speed of 10 to 200 m / min, and cut into pellets of 3 mm × 3 mm. The strands are tensioned due to the cutter take-off speed.

When gas is blown to the strand located between the strand hole and the strand bath in FIG. 1, the strand vibrates slightly. According to the present invention, the strand holes of the die plate are not directly sprayed. Spraying directly toward the strand holes is not preferable because strand breakage easily occurs. The position of spraying the strand of the present invention is for the purpose of giving a slight vibration to the strand, and therefore, the vicinity of the middle between the strand outlet and the strand bath is most preferable.

As the extruder of the present invention, a twin-screw co-rotating extruder, a single-screw extruder, and a co-kneader (registered trademark) manufactured by Bus Co. are used. Strand hole diameter of die plate is 1.5 ~
It is about 7 mm. The land length is 3 to 10 strand hole diameter. The number of holes is proportional to the extrusion force. Usually, according to the common sense of those skilled in the art, when the diameter of the strand hole is 4.0 mm, it is set to 5 to 25 kg / H. The strand holes are preferably arranged in a row. For example, when the strand hole diameter is 4 mm and the extrusion amount per hole exceeds 25 kg / H, the strand hole diameter is increased, the extrusion amount is increased, and the take-up speed of the strand cutter is increased to increase the pellet size to, for example, 3 mm. Adjust to × 3 mm. If the cutter take-off speed is too fast and strand breakage occurs, increase the number of strand holes. The holes are arranged in two rows above and below. Usually, they are arranged in two rows, upper and lower, in a staggered arrangement.

The thermoplastic resin of the present invention which is effective in preventing the occurrence of eye drops is polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / α-olefin copolymer. Etc., homopolyoxymethylene, polyoxymethylene copolymer, polyphenylene sulfide, syndiotactic polystyrene, polyamide resin (nylon 6, nylon 66, aromatic polyamide, aromatic
Examples thereof include aliphatic polyamide copolymers) and polyester resins (polybutylene terephthalate, polyethylene terephthalate, etc.). Among them, high density polyethylene, polypropylene, polyoxymethylene, polyphenylene ether, polycarbonate, polystyrene resin, hydrogenated styrene / butadiene block copolymer, hydrogenated styrene / isoprene block copolymer and the like are preferable. Further, these thermoplastic resins may be mixed together.

Thermoplastic resin fillers applicable to the present invention include heavy calcium carbonate, colloidal calcium carbonate, soft calcium carbonate, silica, kaolin, clay, titanium oxide, barium sulfate, zinc oxide, alumina, magnesium hydroxide, Talc, mica, glass flake, hydrotalcite, needle-like filler (wollastonite, potassium titanate, basic magnesium sulfate, celite, xonotlite, aluminum borate), glass beads, silica beads, alumina beads, carbon beads, glass Balloons, metallic conductive fillers, non-metallic conductive fillers, carbon, magnetic fillers, piezoelectric / pyroelectric fillers, slidable fillers, sealing material fillers, ultraviolet absorbing fillers, vibration damping fillers and glass fibers, Carbon fiber,
Metal fibers, conductive fillers (Ketjen black, acetylene black), anti-drip agents (Teflon (registered trademark), silicone resin), flame retardants, oils, stabilizers, lubricants, compatibilizers, and other additives You may add.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described based on the following examples. The extruder is a twin-screw co-rotating extruder ("ZSK-" manufactured by Warner & Freidler).
25 ", L / D = 42), and the screw configuration was changed. Unless otherwise specified, the extrusion conditions are thermoplastic resins such as polyphenylene ether 68w manufactured by Asahi Kasei Corporation.
A master batch melt-kneaded with t% and an General Purpose Polystyrene 685 manufactured by A & M Polystyrene Co., Ltd. is fed from 100 parts by weight of TOP, and a supply amount is 2
The rotation speed was 0 kg / H and the screw rotation speed was 300 rpm. The barrel temperature was set to 290 ° C. 2 strand holes
The number of holes was 4 mm.

[0014]

Example 1 Since the die outlet resin temperature was 350 ° C, the die plate temperature was set to 350 ° C. The gas blowing device used air, and the temperature was set so that the air temperature at the gas outlet of the blowing device was 300 ° C. The gas flow rate at the gas outlet of the spraying device is 40 m at 350 ° C.
/ Sec. The conditioned air was blown onto the strands using a gas blowing device. The occurrence of dents was small and the dents on the die plate were removed once every 8 hours.

[0015]

Comparative Example 1 The set temperature of the die plate of Example 1 was set to 28
It carried out on the same conditions as Example 1 except having set it as 0 degreeC. Increasing number of eyebrows. Removal of the die plate
It was once every 1.5 hours.

[0016]

COMPARATIVE EXAMPLE 2 The procedure of Example 1 was repeated except that the gas blowing device of Example 1 was removed. The generation of dents increased more than in Example 1, and the dent removal of the die plate was performed once every 3 hours.

[0017]

Comparative Example 3 The procedure of Comparative Example 1 was repeated except that the gas blowing device of Example 1 was removed. The amount of porridge generated was further increased compared to Comparative Example 1. The die plate was removed every 1.0 hour.

[0018]

Example 2 Example 1 was repeated with 40 parts by weight of polyphenylene ether manufactured by Asahi Kasei Corporation, 15 parts by weight of polystyrene 685 manufactured by A & M Polystyrene Co., 15 parts by weight of high-impact polystyrene H9302, and diameter of 13
30 parts by weight of μm glass fiber was extruded under the same conditions as in Example 1. The die exit resin temperature was 342 ° C. Extrusion was performed under the same conditions as in Example 1 except that the die plate set temperature was 340 ° C., the temperature of the gas blowing device was 340 ° C., and the gas flow rate was 40 m / sec. The occurrence of dents was small, and the dents on the die plate were removed once every 6 hours.

[0019]

[Example 3] The operating conditions of Example 1 were 600 rpm, the extrusion rate was 40 kg / H, the die plate had a strand hole diameter of 3.5 mm, and the die plate had a staggered arrangement of two upper and three lower strand holes. Example 1 except that
The same conditions were used. The occurrence of dents was small and the dents on the die plate were removed once every 8 hours.

[0020]

[Effects of the Invention] By using the apparatus for preventing the occurrence of dents of the present invention, the occurrence of dents can be suppressed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a die portion according to the present invention.

FIG. 2 is a front view of a die section according to the present invention.

FIG. 3 is a cross-sectional view of a die unit according to the present invention as seen from below.

[Explanation of symbols]

1: Die part 2: Die plate 3: Strand hole 4: Strand 5: Thermocouple for measuring die plate temperature 6: Brass cast heater 7: Gas blowing device

Claims (3)

[Claims] 1. A strand die plate for an extruder, which has a mechanism for controlling the temperature of the die plate to heat it and a mechanism for vibrating the strand with a gas, and a device for preventing generation of porcelain. 2. The eyebrow generation preventing device according to claim 1, wherein the strand holes of the die plate are arranged in upper and lower two rows. 3. A mechanism for vibrating the strand with gas is 2
The burn-in prevention device according to claim 1 or 2, which has a mechanism for blowing a gas, which is controlled at a temperature of 50 ° C to 350 ° C, to the strand at a speed of 10 to 45 m / sec.