JP2004106506A - Thermoplastic resin composition for cleaning - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for cleaning which can realize cleaning work for effectively removing, in a short time, a resin burned product, a carbonized matter and the like deposited on a screw or cylinder inner wall surface of a molding machine without the need to dismantle the molding machine for removing the screw for grinding work and without damage to the screw and the cylinder. <P>SOLUTION: This thermoplastic resin composition for cleaning includes 1 to 120 parts by weight of an amino resin powder incorporated in 100 parts by weight of a thermoplastic resin. A pellet comprising the thermoplastic resin composition and a cleaning method using the same are also provided. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cleaning thermoplastic resin composition used for cleaning a thermoplastic resin processing and molding machine, a pellet comprising the same, and a method for cleaning a thermoplastic resin processing and molding machine using the same.
[0002]
[Prior art]
The thermoplastic resin is obtained by using a molding machine such as extrusion molding, injection molding, etc., and in these molding processes, when the type is frequently changed, the type in the molding machine is changed when the type is changed. Washing is necessary in terms of quality control, and when molding is performed over a long period of time, such as film production, additives such as raw materials resins and plasticizers are added to the resin compound. It becomes very dirty due to seizure on the screw and the inner wall of the cylinder, and adhesion of carbides.
[0003]
Conventionally, if such a state occurs during the molding process, a cleaning operation is required. The operation includes (a) a method of flowing the resin of the type to be switched next without stopping the molding machine, and cleaning. (B) A method of once stopping production, disassembling a molding machine, and cleaning the inside of a screw and a cylinder has been performed.
However, the method of replacing with the next product of the above (a) does not require manual labor, but requires a large amount of resin for replacement, requires time until cleaning is completed, and lowers productivity. is there. In addition, the method of disassembling the molding machine described in (b) is labor-intensive and requires a lot of time for the cleaning operation.
[0004]
As a means for solving these problems, there has been proposed a method of performing cleaning at the time of switching and cleaning at the time of contamination using various thermoplastic resin compositions for cleaning.
Commercially available cleaning resin compositions include those containing glass fibers, but have drawbacks such as abrasion of the screw and the inner wall of the cylinder.
In addition, an ultrahigh molecular weight acrylic resin type may be used, but it is difficult to melt, and a very high load is applied when the screw is rotated, which may cause a mechanical failure.
In addition, surfactants, those containing substances having a cleaning effect such as metal soaps, and resin compositions such as those containing a foaming agent may be mentioned, but these are only necessary to remove burn-in and carbonized resin, There were problems such as a low frictional force and an insufficient cleaning effect.
[0005]
[Patent Document 1]
Japanese Patent Publication No. 55-50502
[Patent Document 2]
JP 2000-319636 A
[0006]
[Problems to be solved by the invention]
The present invention is to disassemble the molding machine, such as resin burns and carbides adhered to the inner wall surface of the screw or cylinder of the molding machine, without taking out the screw and performing polishing work, and also to damage the screw and cylinder. It is another object of the present invention to provide a cleaning resin composition that can perform a cleaning operation effectively in a short period of time.
[0007]
[Means for Solving the Problems]
The present inventors have conducted various studies to solve the above-mentioned problems, and as a result, have found that a resin composition obtained by blending an amino resin, particularly a melamine resin powder with a thermoplastic resin has an excellent cleaning effect. Thus, the present invention has been completed.
That is, the present invention is a thermoplastic resin composition for cleaning, wherein 1 to 120 parts by weight of an amino resin powder is blended with respect to 100 parts by weight of a thermoplastic resin.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
As the thermoplastic resin used in the present invention, high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, polybutene, polyolefins such as polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, Polycondensate resins such as polystyrene, polyacrylonitrile, polymethacrylic resin or MS resin (methyl methacrylate-styrene resin), AS resin (acrylonitrile-styrene resin), ABS resin (acrylonitrile-butadiene-styrene resin), MBS resin ( Methyl methacrylate-butadiene-styrene resin), polyester resin, polyamide resin and the like can be used alone or in combination of two or more.
[0009]
The thermoplastic resin composition for cleaning of the present invention is obtained by blending 1 to 120 parts by weight of an amino resin powder with respect to 100 parts by weight of the above-mentioned thermoplastic resin.
Examples of the amino resin include an amino component resin obtained by reacting an amino component with formaldehyde, an amino copolycondensation resin obtained by reacting an amino component with formaldehyde, and other amino components that can be cocondensed therewith, and an amino component. A mixed resin of resins can be used.
The amino component includes ureas such as melamine, urea, thiourea, and ethylene urea; guanamines such as benzoguanamine and formoguanamine; phenylacetoguanamine, acetoguanamine, and CTU-guanamine; guanidine, dicyandiamide, and paratoluenesulfonic acid amide. And other amino compounds. These amino components can be used in combination.
[0010]
Among the amino resins, melamine resins are preferably used.
Examples of the melamine-based resin include a melamine resin obtained by reacting melamine with formaldehyde in an amount of about 1 to 4 moles per mole of melamine, melamine and urea such as urea, thiourea, and ethylene urea, benzoguanamine, acetoguanamine, and formaldehyde. Examples thereof include melamine co-condensation resins obtained by reacting at least one component selected from guanamines such as guanamine, phenylacetoguanamine, CTU-guanamine, and other amino compounds with formaldehyde.
A cured product of an amino-based resin, particularly a melamine-based resin, has a hardness (Mohs hardness) of about 3 to 5 and is preferable because it does not damage a screw or a cylinder.
The cured product can be obtained, for example, by the method described in Patent Document 1 or the method described in Patent Document 2, and a re-crushed product of a molded product molded and cured with a molding material mainly containing a melamine resin, Burrs or the like generated during molding can be used, and among them, re-crushed products are preferable.
[0011]
The amino resin powder used in the present invention is preferably a powder having a particle diameter in the range of 1 to 1000 μm, and particularly preferably in a range of 350 to 1000 μm. Here, the powder having a particle diameter in the range of 1 to 1000 μm refers to a powder in which a powder having a particle diameter of 1 μm to 1000 μm is mixed, and usually a powder of 1 to 1000 μm, and a powder of 1 to 350 μm. Powders, powders of 350 to 1000 μm, and the like are mixed in a normal distribution.
When a powder having a particle diameter of 1000 μm or more is present, a very high load is applied to the extruder screw during the washing operation, which may cause a mechanical failure. When present, a physical polishing effect cannot be obtained, and a cleaning effect is hardly obtained.
Further, when the washing operation is performed with the extruder dies, the breaker plate, the screen, etc. attached, the particle diameter of the powder is preferably smaller than the mesh size of the screen. It is in the range of 350 μm, particularly preferably in the range of 1 to 150 μm.
[0012]
The amino resin powder of the present invention is blended in an amount of 1 to 120 parts by weight, more preferably 1 to 50 parts by weight, based on 100 parts by weight of the thermoplastic resin. If the amount is less than 1 part by weight, the cleaning effect cannot be obtained. If the amount exceeds 120 parts by weight, amino-based resin powder remains, and it takes time to remove the amino-based resin powder, which is not a good idea.
The resin composition for cleaning of the present invention may contain a pelletizing aid and a lubricant in order to improve releasability when used for cleaning an extruder, in addition to the amino resin powder.
The amount of the lubricant is 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, per 100 parts by weight of the thermoplastic resin.
If the amount of the lubricant is less than 0.1 part by weight, depending on the resin used and various conditions, a strand may be generated during the extrusion of the strand, causing the strand to be cut off, making stable production difficult. Further, when used for cleaning the extruder, a sufficient releasing effect cannot be obtained, and the resin adheres to the inside of the extruder to cause a residue. Exceeding 10 parts by weight is not preferred because the resin slips inside the cylinder of the extruder and the torque required for cleaning cannot be obtained.
[0013]
Examples of the lubricant include metal soaps such as calcium stearate, zinc stearate, and zinc myristate; fatty acids such as stearic acid, oleic acid and behenic acid; fatty acid esters such as butyl stearate and dodecyl stearate; and stearic acid. Fatty acid partial esters such as monoglyceride, monoglyceride oleate, monoglyceride hydroxystearate, pentaerythritol stearate, polyglycerin stearate, sorbitan triolate, lauric amide, myristic amide, erucamide, oleic amide, stearic acid Fatty acid amides such as amides, fatty acid bisamides such as methylenebisstearic acid amide, ethylenebisstearic acid amide, ethylenebisoleic acid amide, and mixtures thereof It can be used, inter alia metallic soaps are preferred, stearic acid metal salts are particularly preferred.
[0014]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the present invention is not limited to these Examples and the like.
(Reference Example 1)
Using a resin composition containing 45 parts by weight of a plasticizer, 1.5 parts by weight of a calcium-zinc heat stabilizer, and 2.5 parts by weight of diglycerin monoolate per 100 parts by weight of polyvinyl chloride having an average degree of polymerization of 1300. Then, the film was extruded at a cylinder temperature of 180 ° C., a T-die of 190 ° C. and a screw rotation speed of 68 rpm by a single screw extruder with a cylinder diameter of 40 mm and L / D = 28, and a film was continuously produced for two weeks. As a result, the extruder was in a state in which the resin and carbides seized on the screws and the inner wall of the cylinder had adhered.
[0015]
(Reference Example 2)
A polyethylene resin composition containing 2% by weight of an antifogging agent in an ethylene vinyl acetate copolymer having a vinyl acetate content of 15% (manufactured by Nippon Unicar Co., Ltd .; NUC-3758: trade name) was prepared. The film was extruded with a 40 mm single screw extruder at a cylinder temperature of 160 ° C., a die temperature of 185 ° C. and a screw rotation speed of 70 rpm, and the production of a film by inflation was continuously performed for three months. As a result, the extruder was in a state in which the resin and carbides seized on the screws and the inner wall of the cylinder had adhered.
[0016]
(Reference Example 3)
A black-colored resin molding material of ABS resin (acrylonitrile-butadiene-styrene resin) was diced at a cylinder temperature of 200 ° C. and a screw rotation speed of 30 rpm using a single screw extruder with a cylinder diameter of 30 mm at L / D = 25. 200 g were extruded without mounting. The entire amount of the charged resin was not extruded, and some resin adhered to the screw and the inner wall of the cylinder and remained.
[0017]
(Reference Example 4)
200 g of polypropylene (PP) black resin was extruded at a cylinder temperature of 190 ° C., a die temperature of 190 ° C. and a screw rotation speed of 30 rpm using a single screw extruder with a cylinder diameter of 30 mm and L / D = 25. An 80-mesh screen and a breaker plate are mounted between the screw and the die. Part of the PP black resin adhered to the screw surface and remained in the cylinder.
[0018]
[Melamine resin powder production example 1]
The cured melamine resin molded product was roughly pulverized with a shear crusher, and the coarsely crushed product was further finely pulverized with a shear / friction type pulverizer to obtain a pulverized melamine resin molded product.
On the other hand, a sieve of 20 mesh (opening of 840 μm) was set as an upper sieve, and a sieve of 32 mesh (opening of 500 μm) was set as a lower sieve in a vibrating sieve, passed through a 20 mesh sieve and remained on a 32 mesh sieve. Can be collected. In addition, by setting the tapping ball under the 32 mesh sieve, it was possible to sieve continuously without clogging.
The pulverized material obtained by the above-mentioned fine pulverization was continuously charged into the vibrating sieve machine set as described above to obtain a pulverized material. The particle size of the pulverized product was 99.6% by weight for the pulverized product having a particle size of 350 μm to 1000 μm, and 0.4% by weight was 10% to 350 μm.
[0019]
[Melamine resin powder production example 2]
After obtaining a pulverized product of the melamine-based resin molded product in the same manner as in Production Example 1 of melamine-based resin powder, a 70-mesh (210-μm opening) sieve is passed through an upper sieve, and a 285-mesh (50-μm opening) sieve is passed down. Set in a vibrating sieve as a sieve. Those remaining on the 70 mesh screen and those passing through the 70 mesh screen and remaining on the 285 mesh screen can be recovered and sent to the grinding step again. By applying ultrasonic vibration from an ultrasonic generator to the 285 mesh sieve, the sieve can be continuously sieved without clogging.
The pulverized material obtained by the above-mentioned pulverization was continuously charged into the vibrating sieve set as described above, and a pulverized material passed through a 285 mesh sieve was obtained. The particle size of the pulverized product was 99.5% by weight for the pulverized product having a particle size of 1 μm to 150 μm, and 0.5% by weight for the pulverized product having a particle size of 1 μm or less.
[0020]
(Production Example 1)
4.2 kg of the polyvinyl chloride compound and 0.8 kg of the crushed product of the melamine-based resin powder production example 1 (19 parts by weight with respect to 100 parts by weight of the thermoplastic resin) are rotated at 500 rpm by a 20-liter high-speed mixer. Stir and mix for 2 minutes.
This mixture is fed to a single screw extruder with L / D = 28 and a cylinder diameter of 40 mm, a strand is extruded at a cylinder temperature of 170 ° C., a die temperature of 180 ° C. and a screw rotation speed of 30 rpm, cooled in a water bath, and cut with a pelletizer. Thus, a pellet-shaped composition was obtained.
[0021]
(Production Example 2)
4 kg of low-density polyethylene resin (manufactured by Nippon Unicar Co., Ltd .; DFD-0118: trade name) and 1 kg of the crushed product of melamine-based resin powder production example 1 (25 parts by weight with respect to 100 parts by weight of thermoplastic resin) were used for 20 The mixture was stirred and stirred at a rotation speed of 500 rpm for 2 minutes with a 1-liter high-speed mixer.
This mixture is fed to a single screw extruder with L / D = 28 and a cylinder diameter of 40 mm, and a strand is extruded at a cylinder temperature of 140 ° C., a die temperature of 150 ° C. and a screw rotation speed of 30 rpm, cooled in a water bath, and cut with a pelletizer. Thus, a pellet-shaped composition was obtained.
[0022]
(Production Example 3)
3.5 kg of low-density polyethylene resin (manufactured by Nippon Unicar; DFD-0118: trade name) and 1.5 kg of crushed product of melamine resin powder production example 1 (43 parts by weight based on 100 parts by weight of thermoplastic resin) Was mixed with a 20-liter high-speed mixer at 500 rpm for 2 minutes with stirring.
This mixture is fed to a twin screw extruder with L / D = 28 and a cylinder diameter of 30 mm, a strand is extruded at a cylinder temperature of 140 ° C., a die temperature of 150 ° C., and a screw rotation speed of 140 rpm, cooled in a water bath, and cut with a pelletizer. Thus, a pellet-shaped composition was obtained.
[0023]
(Production Example 4)
3.5 kg of low-density polyethylene resin (manufactured by Nippon Unicar Co., Ltd .; DFD-0118: trade name) and 1.5 kg of crushed material of melamine resin powder production example 2 (43 parts by weight based on 100 parts by weight of thermoplastic resin) Was mixed with a 20-liter high-speed mixer at 500 rpm for 2 minutes with stirring.
This mixture is fed to a twin screw extruder with L / D = 28 and a cylinder diameter of 30 mm, a strand is extruded at a cylinder temperature of 140 ° C., a die temperature of 150 ° C., and a screw rotation speed of 140 rpm, cooled in a water bath, and cut with a pelletizer. Thus, a pellet-shaped composition was obtained.
[0024]
(Production Example 5)
3.5 kg of AS resin (acrylonitrile-styrene resin), 1.5 kg of crushed product of melamine resin powder production example 1 (43 parts by weight with respect to 100 parts by weight of thermoplastic resin), 0.175 kg of zinc stearate ( 5 parts by weight based on 100 parts by weight of the thermoplastic resin) were mixed by stirring at a rotation speed of 500 rpm for 2 minutes using a 20-liter high-speed mixer.
This mixture is fed to a single-screw extruder with L / D = 28 and a cylinder diameter of 40 mm. The strand is extruded at a cylinder temperature of 200 ° C., a strand die temperature of 210 ° C. and a screw rotation speed of 30 rpm, naturally cooled, and cut with a pelletizer. Thus, a pellet-shaped composition was obtained.
[0025]
(Production Example 6)
2.5 kg of low-density polyethylene resin (manufactured by Nippon Unicar Co., Ltd .; DFD-0118: trade name) and 2.5 kg of the crushed product of melamine-based resin powder production example 2 (100 parts by weight based on 100 parts by weight of thermoplastic resin) Was mixed with a 20-liter high-speed mixer at 500 rpm for 2 minutes with stirring.
This mixture is fed to a twin screw extruder with L / D = 28 and a cylinder diameter of 30 mm, a strand is extruded at a cylinder temperature of 190 ° C., a die temperature of 190 ° C. and a screw rotation speed of 140 rpm, cooled in a water bath and cut with a pelletizer. Thus, a pellet-shaped composition was obtained.
[0026]
(Production Example 7)
3.5 kg of polypropylene resin (manufactured by Idemitsu Petrochemical Co., Ltd .; F-200S: trade name) and 1.5 kg of crushed material of melamine resin powder production example 2 (43 parts by weight based on 100 parts by weight of thermoplastic resin) ) Was mixed with a 20-liter high-speed mixer while stirring at a rotation speed of 500 rpm for 2 minutes.
This mixture is fed to a twin screw extruder with L / D = 28 and a cylinder diameter of 30 mm, a strand is extruded at a cylinder temperature of 190 ° C., a die temperature of 190 ° C. and a screw rotation speed of 140 rpm, cooled in a water bath and cut with a pelletizer. Thus, a pellet-shaped composition was obtained.
[0027]
(Production Example 8)
To 4.2 kg of the polyvinyl chloride compound, 0.8 kg of the crushed product of the melamine-based resin powder production example 1 (19 parts by weight based on 100 parts by weight of the thermoplastic resin) was stirred and mixed to obtain a thermoplastic resin composition for cleaning. A mixture of products was obtained.
(Production Example 9)
4 kg of low-density polyethylene resin pellets (manufactured by Nippon Unicar Co., Ltd .; DFD-0118: trade name) and 1 kg of crushed material of Production Example 1 of melamine-based resin powder (25 parts by weight based on 100 parts by weight of thermoplastic resin) The mixture was stirred and mixed to obtain a mixture of the cleaning thermoplastic resin composition.
(Production Example 10)
2.0 kg of a low-density polyethylene resin pellet (manufactured by Nippon Unicar; DFD-0118: trade name) and 3.0 kg of a crushed product of melamine resin powder production example 2 (150 parts per 100 parts by weight of thermoplastic resin) Parts by weight) with stirring to obtain a mixture of the thermoplastic resin composition for washing.
[0028]
Embodiment 1
After removing the T-die, breaker plate, and screen from the extruder in the state of Reference Example 1, extruding the residual resin in a state where the screw is visible, the cylinder temperature was set to 135 ° C., and the screw rotation speed was set to 10 rpm. Washing was performed by supplying and extruding 3 kg of the pellet mixture of No. 1. When the number of revolutions is set to 30 rpm when the mixture starts to be discharged from the tip, a dark colored substance containing burnt resin or carbide is discharged. When the color of the discharged matter disappeared, the entire resin mixture was extruded.
After the cleaning work, when the screw was pulled out, there was no resin seizure or carbide attached and the plating surface had a metallic luster, and the inner wall of the cylinder was illuminated with a flashlight and investigated. The reflected light was obtained, and it was confirmed that there was no dirt.
[0029]
Embodiment 2
With respect to the extruder in the state of Reference Example 2, the die, the breaker plate, and the screen were removed, and the residual resin was extruded in a state where the screw was visible. Thereafter, the cylinder temperature was set to 140 ° C., and the screw rotation speed was set to 10 rpm. Washing was performed by feeding and extruding 3 kg of the pellet mixture of No. 2. If the number of revolutions is set to 30 rpm when the mixture starts to be discharged from the front end portion, a dark colored substance containing the burnt resin or carbide is discharged. When the color of the discharged matter disappeared, the entire resin mixture was extruded.
When the screw is pulled out, there is no burnt resin or carbide attached and the plated surface has a metallic luster, and the inner wall of the cylinder is illuminated with a flashlight and investigated, and it is possible to obtain uniform and sufficient reflected light It was confirmed that there was no dirt.
[0030]
Embodiment 3
The pellet composition of Production Example 5 was supplied to the extruder in the state of Reference Example 3 at a cylinder temperature of 200 ° C. and a screw rotation speed of 30 rpm, and extruded to perform displacement washing. The mixture was discharged from the tip together with the black colored resin of ABS remaining inside. The black color of the discharged material gradually became light, and after about 8 minutes, the black coloration completely disappeared.
The amount of resin discharged by this time was about 360 g. Thereafter, all the pellet-shaped composition of Production Example 5 was charged and cut off, and an uncolored ABS resin was supplied and extruded under the same conditions to confirm residual stain and residual resin. After the introduction, the ABS resin was discharged from the tip, and the residue of Production Example 5 was not confirmed. In addition, black coloring of the discharged ABS resin was not confirmed.
[0031]
Embodiment 4
After removing the T-die, breaker plate, and screen from the extruder in the state of Reference Example 1, extruding the residual resin in a state where the screw is visible, the cylinder temperature was set to 135 ° C., and the screw rotation speed was set to 10 rpm. Washing is performed by supplying and extruding 3 kg of the pellet composition of No. 8. When the mixture started to be discharged from the tip, the rotational speed was set to 30 rpm, and a dark colored substance containing burnt resin and carbide was discharged. When the color of the discharged matter disappeared, the entire resin mixture was extruded.
After the cleaning work, when the screw was pulled out, there was no resin seizure or carbide attached and the plating surface had a metallic luster, and the inner wall of the cylinder was illuminated with a flashlight and investigated. The reflected light was obtained, and it was confirmed that there was no dirt.
[0032]
Embodiment 5
With respect to the extruder in the state of Reference Example 2, the die, the breaker plate, and the screen were removed, and the residual resin was extruded in a state where the screw was visible. Thereafter, the cylinder temperature was set to 140 ° C., and the screw rotation speed was set to 10 rpm. Washing was performed by supplying and extruding 3 kg of the pellet composition of No. 9. When the number of revolutions was set to 30 rpm when the mixture began to be discharged from the tip, a dark colored substance containing a burned resin or carbide was discharged. When the color of the discharged matter disappeared, the entire resin mixture was extruded.
When the screw is pulled out, there is no burnt resin or carbide attached and the plated surface has a metallic luster, and the inner wall of the cylinder is illuminated with a flashlight and investigated, and it is possible to obtain uniform and sufficient reflected light It was confirmed that there was no dirt.
[0033]
Embodiment 6
The pellet composition of Production Example 4 was supplied to the extruder in Reference Example 4 at a cylinder temperature of 190 ° C. and a screw rotation speed of 30 rpm, and extruded to perform displacement washing. The mixture was discharged from the tip together with the PP black colored resin remaining inside. The black color of the discharged material gradually decreased, and the black color disappeared completely after about 15 minutes.
The amount of resin discharged by this time was about 506 g. Thereafter, all the granular composition of Production Example 4 charged was cut out, and a non-colored PE resin was supplied and extruded under the same conditions to confirm residual stain and residual resin. After the introduction, the PE resin was discharged from the tip, and the residue in Production Example 4 was slightly confirmed, but could not be confirmed. Black coloring of the discharged PE resin was not confirmed.
[0034]
Embodiment 7
The pellet composition of Production Example 6 was supplied to the extruder in the state of Reference Example 4 at a cylinder temperature of 190 ° C. and a screw rotation speed of 30 rpm, and was subjected to displacement washing by extruding. The mixture was discharged from the tip together with the PP black colored resin remaining inside. The black color of the discharged material gradually faded, and after about 10 minutes, the black coloration completely disappeared.
The amount of resin discharged up to this time was about 390 g. Thereafter, all of the charged particulate composition of Production Example 6 was cut out, and a non-colored PE resin was supplied and extruded under the same conditions to confirm residual stain and residual resin. After the introduction, the PE resin was discharged from the tip, and the residue in Production Example 4 was slightly confirmed, but could not be confirmed. Black coloring of the discharged PE resin was not confirmed.
[0035]
[Comparative Example 1]
Washing was carried out under the same conditions as in Example 1 except that 6 kg of vinyl chloride compound was used instead of the resin of Production Example 1.
After the washing operation, the screw was pulled out, and it was confirmed that the burnt resin remained adhered to the root portion of the flight. In particular, a large amount of adhesion was observed near the tip of the screw.
A buff was attached to the grinder and friction was removed by high-speed rotation in order to remove the remaining deposits without damaging the screw, but it took two hours or more to complete the removal. In addition, if the removal operation takes a long time, the temperature of the screw decreases, making removal more difficult.At the same time, it takes time to raise the temperature for resuming the production after washing, and overall time loss is reduced. It was big.
[0036]
[Comparative Example 2]
Washing was performed under the same conditions as in Example 2 except that 6 kg of a low-density polyethylene resin (manufactured by Nippon Unicar; DFD-0118) was used instead of the resin of Production Example 2.
After the washing operation, the screw was pulled out, and it was confirmed that the burnt resin remained adhered near the screw tip.
The operation of removing the remaining deposits was the same as in Comparative Example 1, and the removal operation was difficult and the overall time loss was large.
[0037]
[Comparative Example 3]
Substitution washing was performed under the same conditions as in Example 3 except that an AS resin (acrylonitrile-styrene resin) was used instead of the resin of Production Example 5. The black coloring of the ejected matter was confirmed even after 8 minutes from the introduction of the resin, and completely disappeared after about 16 minutes. The amount of resin discharged up to this time was about 580 g.
Thereafter, all of the AS resin charged was cut out, and a non-colored ABS resin was supplied and extruded under the same conditions to check for residual stain and residual resin.
After the charging, it was confirmed that a transparent AS resin was discharged from the tip, and the AS resin remained inside. Subsequently, the yellow-white ABS resin was discharged, but a slight black coloring was confirmed, and it was confirmed that the replacement washing was not complete.
[0038]
[Comparative Example 4]
Washing was performed under the same conditions as in Example 5 except that a PE resin (DFD-0118) was used instead of the resin of Production Example 4. The color of the discharged material gradually became black, and after about 33 minutes, the black color completely disappeared.
The amount of resin discharged up to this time was about 1063 g. After that, when the die and the breaker plate were removed and the screw was extracted, the unremoved black stain was adhered to the flight root of the compression part.
[0039]
[Comparative Example 5]
Washing was performed under the same conditions as in Example 7 except that the resin of Production Example 10 was used instead of the resin of Production Example 6. After the introduction, the mixture was discharged from the front end together with the PP black colored resin remaining inside, but the discharge amount gradually decreased, and after about 6 minutes, the discharge of the mixture was stopped.
When the screw was pulled out, the mixture stopped at the portion where the screw reached the compression section beyond the supply section. Therefore, the washing operation could not be performed.
[0040]
【The invention's effect】
According to the present invention, by adding an amino resin powder to a thermoplastic resin and performing extrusion washing, it is possible to effectively remove burned resin and carbide without damaging the screw or cylinder inner wall surface. The work load and time required for cleaning the garbage can be greatly reduced.

Claims (10)

A thermoplastic resin composition for cleaning, comprising 1 to 120 parts by weight of an amino resin powder per 100 parts by weight of a thermoplastic resin. The thermoplastic resin composition for cleaning according to claim 1, wherein the compounding amount of the amino resin powder is 1 to 50 parts by weight. The thermoplastic resin composition for cleaning according to claim 1 or 2, wherein the particle diameter of the amino resin powder is in the range of 1 to 1000 µm. 4. The thermoplastic resin composition for cleaning according to claim 3, wherein the amino resin powder has a particle diameter in a range of 1 to 350 [mu] m. The thermoplastic resin composition for cleaning according to claim 3, wherein the particle diameter of the amino resin powder is in a range of 350 to 1000 µm. The thermoplastic resin composition for cleaning according to any one of claims 1 to 5, wherein the amino resin powder is a melamine resin powder. The thermoplastic resin composition for cleaning according to any one of claims 1 to 6, wherein the amino resin powder is a re-crushed product of a cured molded product. A pellet-like thermoplastic resin composition for cleaning, wherein the thermoplastic resin composition for cleaning according to any one of claims 1 to 7 is in the form of pellets. The heat for cleaning according to any one of claims 1 to 8, wherein the thermoplastic resin composition for cleaning contains 0.1 to 10 parts by weight of a lubricant with respect to 100 parts by weight of the thermoplastic resin. Plastic resin composition. A method for cleaning a thermoplastic resin processing and molding machine, comprising using the thermoplastic resin composition for cleaning according to any one of claims 1 to 9 for cleaning a thermoplastic resin processing and molding machine.