JPH11173421A - Transportation of resin granular substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent scraping due to wear of a gasket or deterioration due to the use for a long time to reduce the generation of dust by using a metal gasket or a semimetal gasket as a gasket of a flange joint of a pipe used in the transportation of a resin granular substance. SOLUTION: A metal gasket or a semimetal gasket is used as a gasket of a flange joint when a resin granular substance such as optical polycarbonate granular substance is fed under pressure or is sucked and is transported in a pipe, and an inside diameter thereof is set to be larger than an inside diameter of the pipe by 0 to 6 mm preferably. In this case, the metal gasket is made of a metallic material, and the semimetal gasket is made by combining a metallic material with a non-metallic material, and the non-metallic material is jacket- finished by the metallic material. Moreover, austenite stainless steel is preferably used as the metallic material of the metal gasket or the semimetal gasket.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for transporting resin particulates with reduced dust for producing a molding material, and more particularly, to a gasket for a flange joint of a pipe in contact with a resin. The present invention relates to a method for transporting resin particles in which generation of dust is reduced by using a specific gasket.

[0002]

2. Description of the Related Art Conventionally, a gasket material of a flange joint when a resin granular material is transported in a pipe by pressure feeding or suction is generally obtained by processing a sheet-like material such as asbestos, fluororesin and various rubbers. ing. When these are used as gaskets for pipe flange joints, they are generally resilient, have strong crimping force with the flange surface, and have excellent adhesion, so they can maintain airtightness during pressure feeding or suction. . However, when transporting the resin granules, dust is mixed or adhered to the resin granules due to frictional abrasion or deterioration due to long-term use when the gasket material of the flange joint of the transport pipe comes in contact with the transported object. Due to this phenomenon, it is desired to reduce dust in resins and molded articles that do not like the mixing of dust.

[0003] In particular, molding material products that need to minimize the contamination of dust, such as spectacle lenses, compact disks, laser disks, optical cards, MO disks, DVDs, etc., which make use of the transparency and impact resistance of polycarbonate. In such a case, dust contamination has an adverse effect on the reading and writing of submicron signals, so that reduction of dust is desired.

As a method for reducing dust, Japanese Patent Application Laid-Open No. Hei 6-278787 discloses a method in which a pipe and a storage container are made of a material which has been subjected to an electrolytic polishing treatment. Usually, this method can reduce dust in or adhered to polycarbonate to some extent, but it is difficult to completely prevent it. This is due to the fact that dust cannot be effectively reduced on the surface where the gasket of the flange joint of the pipe comes into contact with the polycarbonate due to dust generation due to friction or deterioration due to long-term use.

Further, as a method for preventing generation of dust during transportation, Japanese Patent Application Laid-Open No. Hei 8-68483 discloses a method using an L-shaped metal protection ring so that a gasket does not come into contact with resin particles. ing. However, in this method, in the case of suction transportation, it is difficult to completely cover the inner wall of the gasket with the L-shaped protection ring, so that there is a possibility that the gasket material may be mixed in and the dust reduction is incomplete.

When the resin particles are dissolved in the solvent, it is easy to remove dust by filtration. However, addition of a poor solvent or removal of the solvent makes it difficult to remove dust after the solidification step in which the polymer precipitates, so it is necessary to suppress the contamination of dust and the generation of dust during pipe transportation. It is.

[0007]

Therefore, it is necessary to transport the resin particles in a sealed state without contacting the outside air by using a pipe and a gasket capable of transporting the resin particles by pressure or suction. It is necessary to use a gasket that prevents dust from being generated and generates no dust.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a method for transporting a transparent resin by pumping or sucking a transparent resin by using a metal gasket or a semi-metal gasket as a gasket of a flange joint of a pipe as a method of transporting the resin granular material. How to transport the body.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The metal gasket of the present invention is a gasket made of a metal material. The semi-metal gasket of the present invention is a gasket made by combining a metal material and a non-metal material, and has a structure in which a non-metal material is jacketed with a metal material. A non-metallic material is used as the core material. As the nonmetallic material, asbestos, various fluororesins, various rubbers and the like are used.

A metal gasket is preferably used in a place for high temperature and high pressure, and a semi-metal gasket is preferably used in a place where a change in temperature and pressure occurs because a gasket structure has excellent adhesion due to a spring action. It is particularly preferable as a gasket for piping for suction transportation.

[0011] The metal thickness of the semi-metal gasket is preferably 0.2 mm or more, more preferably 0.2 to 0.6 mm.
A thickness in the range of mm is preferred. 0.2m thick metal
If the thickness is smaller than m, the semimetal gasket may be cut or deformed due to unevenness of the flange surface, centering, and excessive tightening.

In the present invention, it is preferable to use a gasket whose inner diameter is larger than the inner diameter of the pipe by 0 to 6 mm. If it exceeds 6 mm, a gap with the inner wall is generated at the time of mounting, and the granular material is damaged, generating fine powder and abrading the metal end face, which is not preferable. On the other hand, if it is less than 0 mm, it collides with the inner wall of the gasket and hinders the transportation of the resin particles, which is not preferable.

Further, in the semi-metal gasket and the metal gasket, it is preferable that the thickness of the gasket at the portion in contact with the resin granules is 3 mm or more. When the thickness of the gasket is less than 3 mm, the non-adhesion to the flange surface is reduced. Also, it is not easy to manufacture and process.

The metal material of the metal gasket or semi-metal gasket of the present invention is selected from the group consisting of martensitic stainless steel, ferritic stainless steel, austenitic stainless steel, nickel, nickel alloy, titanium and titanium alloy. Among these, austenitic stainless steel, nickel or nickel alloy is preferred. Such a material is preferable because it is excellent in abrasion with the resin granules and also excellent in deterioration due to long-term use.

The method of transporting the resin particles is carried out by suction or pressure. 1-7 kg / cm2 in case of pumping,
In the case of suction, it is transported in the pipe at a pressure of -500 mmAq to -5000 mmAq. The resin particles move at a flow rate of 3 to 30 m / sec in the transport pipe.

When transporting resin particles by suction,
It is preferable to provide a dustproof filter at the air intake. In particular, when low dust property is required, an air filter that can remove particles of 0.3 μm or more in an amount of 99.97% or more, which is generally called a HEPA filter (hereinafter, referred to as a HEPA filter) is used. When the resin particles are transported by pressure feeding, a blower is used, and it is preferable to provide a dustproof filter on the discharge side of the blower. Especially when low dust property is required, the above H
An EPA filter is used.

In general, a corrosion-resistant metal pipe which has been subjected to chemical polishing or electrolytic polishing after finishing the inner surface by mechanical polishing is used for the transport pipe.

Examples of the resin granules of the present invention include polyacetal, polypropylene, nylon, polybutylene terephthalate, polysulfone, polycarbonate, polyethylene terephthalate, polyethylene terephthalate copolymer, polymethyl methacrylate, and polystyrene. Among them, it is effective for polycarbonate, polyethylene terephthalate, polyethylene terephthalate copolymer, polymethyl methacrylate and polystyrene. It is particularly effective for optical polycarbonate.

The resin granules to which the present invention can be applied include:
It may be in the form of a slurry, powder, pellets, or the like, and the particle size may be spherical, long, or short. Generally, the particle size of the resin granules is preferably 0.1 to 4.0 mm, and 0.5 to 4.0 mm.
3.0 mm is particularly preferred.

In particular, when the transparent resin particles for optical use are filled in an airtight corrosion-resistant metal container and shipped,
Since a similar contamination may be caused when the shipping container also has a flange at the filling or withdrawing point, a metal gasket or a semi-metal gasket is used.

Here, FIG. 1 and FIG. 2 will be described. FIG. 1 shows a central sectional view when a semi-metal gasket is mounted on a flange joint of a pipe and a plan view of the semi-metal gasket. FIG. 2 shows a partial view of a central sectional view of the metal gasket.

[0022]

EXAMPLES The following test was conducted to confirm the dust reducing effect of the gasket material on the resin particles.

Example 1 SUS304 of austenitic stainless steel manufactured by Nippon Valqua Industry Co., Ltd., product number V / # 540-ZWE
X, 25 metal gaskets having an inner diameter of 88 mm, an outer diameter of 133 mm, and a thickness of 3 mm were attached to a transportation pipe having an inner diameter of 83 mm and a length of 150 m, and were pressure-fed from one storage tank to another storage tank.
A polycarbonate resin granule having an average particle diameter of 0.5 mm was pumped. The transportation conditions of the pressure feeding are as follows.
H, the pumping pressure was 5 kg / cm ² . Also, a HEPA filter was attached to the discharge side of the blower.

Next, 200 g of the polycarbonate resin taken out of the storage tank at the destination was weighed in 3000 ml of methylene chloride.
And filtered through a filter having a pore size of 10 μm, and the amount of dust collected on the filter was examined using a biological microscope. Table 1 shows the results. Further, a solution prepared by dissolving 1 g of a polycarbonate resin in 100 ml of methylene chloride was used in a light scattering type particle sensor at 0.5 to 1.0 μm.
Was measured. Table 1 shows the results.

Example 2 A gasket was manufactured by Nippon Valqua Industry Co., Ltd., the material was nickel alloy Hastelloy C276, and the product number was V / # 540-Z.
Except for changing to a metal gasket having a WX of 88 mm in inner diameter, 133 mm in outer diameter and 3 mm in thickness, transportation of the resin particles was performed in the same manner as in Example 1. The transported resin particles were dissolved in methylene chloride in the same manner as in Example 1, and dust was collected on a filter. Table 1 shows the results. Example 1
The amount of dust was measured by the light scattering type particle sensor in the same manner as in the above.
Table 1 shows the results.

Example 3 A gasket was manufactured by Nippon Valqua Industry Co., Ltd., the material was SUS316L of austenitic stainless steel, and the product number was V / #.
N520F-Z6HX, inside diameter 88mm, outside diameter 134m
m, thickness of core material 3mm, thickness of semi-metal 0.4mm
The resin granules were transported in the same manner as in Example 1, except that the semimetal gasket was replaced with a polycarbonate resin granule having an average particle diameter of 2.8 mm. The transported resin particles were dissolved in methylene chloride in the same manner as in Example 1, and dust was collected on a filter. Table 1 shows the results. Further, the amount of dust was measured by the light scattering type particle sensor in the same manner as in Example 1. Table 1 shows the results.

Example 4 The gasket was manufactured by Nippon Valqua Industry Co., Ltd., the material was nickel alloy Hastelloy C276, and the product number was V / # N520F.
Except for changing to a semi-metal gasket of -Z6X, inner diameter 88 mm, outer diameter 134 mm, core material thickness 3 mm, and metal thickness 0.4 mm, the resin granular material was transported in the same manner as in Example 1. The transported resin particles were dissolved in methylene chloride in the same manner as in Example 1, and dust was collected on a filter. Table 1 shows the results. Further, the amount of dust was measured by the light scattering type particle sensor in the same manner as in Example 1. Table 1 shows the results.

Example 5 A gasket was manufactured by Nippon Valqua Industry Co., Ltd., the material was SUS316L of austenitic stainless steel, and the product number was V / #.
540-ZWHX, inner diameter 88mm, outer diameter 133mm, metal thickness 3mm, attached 25 pipes of 150m,
Suction transported from one storage tank to another. Average particle size 0.5m
m of the polycarbonate resin granules was transported by suction. The conditions of the suction transport are as follows: transport volume 4 t / H, pumping pressure -2000 m
mAq. A HEPA filter was used for the air intake. The transported resin particles were dissolved in methylene chloride in the same manner as in Example 1, and dust was collected on a filter.
Table 1 shows the results. Further, the amount of dust was measured by the light scattering type particle sensor in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 1 A gasket was manufactured by Nippon Valqua Industry Co., Ltd., product number V / # 1.
500AC, inner diameter 90mm, outer diameter 134mm, thickness 3m
Except for changing the asbestos gasket to m, the resin particles were transported in the same manner as in Example 1. The transported resin particles were dissolved in methylene chloride in the same manner as in Example 1, and dust was collected on a filter. Table 1 shows the results. Further, the amount of dust was measured by the light scattering type particle sensor in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 2 A gasket was manufactured by Nippon Valqua Industry Co., Ltd., product number V / # 7.
035, inner diameter 90 mm, outer diameter 134 mm, core agent thickness 2.0, VALFLON thickness 0.4 m, changed to Teflon VALFLON flowless gasket, and changed to polycarbonate resin granules with an average particle diameter of 2.8 mm. Except for this point, the resin particles were transported in the same manner as in Example 1.
The transported resin particles were dissolved in methylene chloride in the same manner as in Example 1, and dust was collected on a filter. Table 1 shows the results. Further, the amount of dust was measured by the light scattering type particle sensor in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 3 A gasket was manufactured by Nippon Valqua Industry Co., Ltd., Model V / # 1.
500AC, inner diameter 90mm, outer diameter 134mm, thickness 3m
Except for changing to the asbestos gasket of m, the resin granular material was transported in the same manner as in Example 5. The transported resin particles were dissolved in methylene chloride as in Example 1, and dust was collected on a filter. Table 1 shows the results. Further, the amount of dust was measured by the light scattering type particle sensor in the same manner as in Example 1. Table 1 shows the results.

[0032]

[Table 1]

[0033]

The transportation of the resin particles of the present invention prevents the abrasion of the gasket or the deterioration due to long-term use, and prevents dust from being mixed into the resin particles. Useful for

[Brief description of the drawings]

FIG. 1A is a center sectional view showing a positional relationship between a pipe flange and a semi-metal gasket when a semi-metal gasket is mounted. FIG. 1B is a plan view of the semimetal gasket.

FIG. 2 is an enlarged center cross-sectional view of a metal gasket.

[Explanation of symbols]

 1 Semi-metal gasket metal jacket 2 Semi-metal gasket packing 3 Metal gasket

Claims (8)

[Claims] 1. A method for transporting resin particulates, wherein a metal gasket or a semi-metal gasket is used as a gasket for a flange joint of a pipe. 2. The method for transporting resin particles according to claim 1, wherein the resin particles are transported in a sealed state without contacting with outside air. 3. An inner diameter of a gasket is 0 to 6 from an inner diameter of a pipe.
2. The method for transporting resin particulates according to claim 1, wherein a gasket larger by mm is used. 4. The method according to claim 1, wherein the metal part of the gasket is made of a metallic material made of austenitic stainless steel, nickel or a nickel alloy. 5. The method for transporting resin particles according to claim 1, wherein the resin particles are transparent resin particles. 6. The method for transporting resin particles according to claim 1, wherein the resin particles are transparent thermoplastic resin particles. 7. The method for transporting resin particles according to claim 1, wherein the resin particles are polycarbonate particles. 8. The method for transporting resin particles according to claim 1, wherein the resin particles are polycarbonate particles for optical use.