JP2009248321A - Vaporized component removal device and extruder using the same, and method for kneading molten resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique capable of sufficiently capturing and discharging a vaporized component when melting and kneading the resin by using a raw material containing a lot of vaporized components. <P>SOLUTION: The vaporized component removal device for removing an organic vaporized component generated in kneading the molten resin comprises an inner sidewall (1) of the vaporized component removal device for capturing a condensate of the organic vaporized component and a groove (3) formed by a weir (2) and the angle (α) between the weir (2) and the inner sidewall (1) of the vaporized component removal device forms an acute angle. The extruder includes the vaporized component removal device, and the method for kneading the resin molten body uses the extruder. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vaporized component removing device (hereinafter also referred to as a vent port) for removing a vaporized component generated when a resin melt composition is produced by a plastic extruder (hereinafter referred to as an extruder). The present invention relates to an equipped extruder and a method for kneading a resin melt using the extruder in order to obtain a resin melt composition excellent in moldability and the like.

  In the extruder, the raw material is plasticized by rotating a screw in a barrel, and extruded while kneading reinforcing fibers and granular fillers. In order to remove vaporized components, moisture and the like contained in the melted raw material inside the extruder under vacuum (hereinafter referred to as degassing), the inside and outside of the barrel are disposed downstream of the kneading part of the extruder. Are connected to a metal plate (hereinafter referred to as a bent metal) having an opening for communicating, and a vaporizing component removing device (vent port) in the form of a cylinder or box. In addition, a vacuum device is connected to the vent port, and vaporized components and moisture generated from the inside of the extruder are discharged from the side of the vent port.

  However, as the operation of the extruder (melting and kneading operation of the plastic composition) is continued using raw materials containing a large amount of vaporized components, the condensed liquid of volatile components of different colors gradually condensed and oxidized and deteriorated on the vent port wall surface. Again flows into the extruder, resulting in a resin melt composition (hereinafter sometimes referred to as pellets) that is different in color from the original composition. In addition, the condensate and the molten resin may adhere to the opening of the bent metal object to form a film, thereby closing the opening.

  When vent clogging occurs, the deaeration efficiency is remarkably lowered, and a large amount of vaporized components remain in the pellets produced by the extruder in such a state and appear as voids. If molding is performed using such pellets, voids are generated inside the molded product, and the measurement time during molding is delayed due to a change in bulk density, and there is a concern that the molding cycle may be delayed. Further, when the vent blockage is severe, the resin melt composition being kneaded cannot be degassed, so that the extruded strands are frequently blown out of bubbles, which may make it difficult to produce pellets. In such a state, the operation of the extruder must be interrupted for maintenance, resulting in a significant hindrance to production efficiency.

Therefore, in order to prevent the vaporized component condensate deteriorated by oxidation from flowing into the extruder or vent clogging, Patent Document 1 discloses a technique for heating a vent port with an inclined groove, and Patent Document 2 discloses that the vent portion is slanted. A device is provided that provides a lid and a horizontal groove to prevent re-flow of volatile agglomerates into the extruder. Patent Document 3 describes a vent apparatus in which a portion for forming a vent block is pushed into an extruder using a screw in order to prevent the block of the vent.
Japanese Patent Laid-Open No. 19-290384 JP-A-18-26998 JP 55-159957 A

  However, in the technique described in Patent Document 1, the shape of the groove for trapping the vaporized component is L-shaped, and the vaporized component begins to condense at the bottom of the groove, and the vaporized component that has been oxidized and deteriorated over time is condensed. There is a possibility that the liquid flows again into the extruder or the condensed liquid is cooled and solidified in the trap groove.

  In the technique described in Patent Document 2, since the groove inside the vent is horizontal, when melt-kneading a material with a large amount of vaporized components, the agglomerate overflows from the groove, and the agglomerated liquid again flows into the extruder. End up. Furthermore, even if suction is performed by a vacuum pump, the temperature may be lowered due to the airflow in the vent port, and the fluidity may be significantly reduced inside the groove to block the flow path.

  In addition, in the vent apparatus in which the portion that forms the vent blockage is pushed into the extruder using the screw described in Patent Document 3, the vent opening area is deprived by the area of the blade of the screw and the resin is reduced. There is a problem that deaeration inside the melt becomes insufficient, and particularly when a resin melt composition containing a large amount of reinforcing fibers and granular fillers is melt-kneaded, the deaeration efficiency is lowered.

  Therefore, the object of the present invention is to form a groove capable of collecting the vaporized component cooled by the inner wall of the vent port without being interrupted when the resin is melt-kneaded using a raw material containing a large amount of vaporized component, Condensation that has been collected by discharging the condensate that has been collected by giving a moderate heat to the groove and giving it a proper inclination to flow out of the system reduces the generation of colored pellets and reduces the voids inside the produced pellets. Another object of the present invention is to provide a technique capable of producing pellets excellent in moldability.

  In order to solve the above problems, a vaporization component removal apparatus according to the present invention is a vaporization component removal apparatus that removes an organic vaporization component that is generated during resin melt kneading, and vaporizes to collect the condensate of the organic vaporization component. It has a groove (3) formed by the inner wall (1) of the component removal device and the weir (2), and the angle (α) between the weir (2) and the inner wall (1) of the vaporization component removal device has an acute angle. It consists of what is characterized by making.

  The groove (3) for collecting the condensate of the organic vaporized component has an acute angle groove (3) formed by the vaporized component removing device inner side wall (1) and the weir (2), which basically has no flat groove bottom surface. ), The collected condensate can be given moderate fluidity at all times, and the condensate condensate at the bottom of the groove is prevented from being deteriorated, discolored or solidified. Thus, efficient and rapid discharge to the outside of the system becomes possible. As a result, the collected condensate is prevented from flowing into the extruder again, and the generation of different color pellets is suppressed, and the voids inside the produced pellets can be reduced by appropriately removing the organic vapor components. .

  In the vaporization component removal apparatus according to the present invention, the vaporization component removal apparatus inner wall (1) preferably extends in the vertical direction, and the vaporization component removal apparatus inner wall (1) and the weir (2) are interposed. The formed angle (α) is preferably an acute angle. Since the inner wall (1) of the vaporization component removing device extends in the vertical direction, the collected condensate can naturally flow down vertically, and the fluidity of the collected condensate in the groove (3) is good. Maintained.

  Further, in the extending direction of the groove (3), it is preferable that the groove (3) is provided with an inclination that allows the condensate collected in the groove (3) to flow. . If comprised in this way, it will become possible to provide fluidity | liquidity along the inclination to the condensate collected in the groove | channel (3), and the collected condensate will face a system more appropriately. Will be discharged.

  Further, the outer periphery of the vaporization component removal apparatus is heated, and the difference between the temperature of the tip (4) of the weir (2) and the temperature of the inner wall (1) of the vaporization component removal apparatus is in the range of 0 to 70 ° C. Is preferred. As described above, by providing the vaporized component removing device part with appropriate heat, better fluidity can be secured, and the condensed organic vaporized component can be expected to be vaporized again.

  The present invention also provides an extruder equipped with the vaporizing component removing apparatus as described above. In such an extruder, it is possible to appropriately discharge and remove the organic vaporized component out of the system at the time of kneading the resin melt, and it is possible to produce pellets having desired excellent characteristics.

  The present invention also provides a method for kneading a resin melt characterized by kneading the resin melt using such an extruder. Thereby, generation | occurrence | production suppression of a different color pellet and the reduction | decrease of the space | gap inside the produced pellet are attained, and it becomes possible to manufacture the pellet excellent in the moldability.

  According to the present invention, the organic vaporized component condensed by being cooled at the inner wall of the vent port is transmitted to the heated inner wall of the vent port, and the condensate is trapped by an acute groove formed by the inner wall of the vent port and the weir. Thus, it is possible to prevent the occurrence of abnormal color tone pellets caused by the reconstitution of the vaporized component that has deteriorated or discolored into the extruder. Moreover, it can also be expected that the condensed organic vaporized component is vaporized again by heating even in the trapped groove. Furthermore, since no vent clogging occurs, the organic vaporized component generated in the extruder is continuously removed from the resin melt, so that pellets with less voids can be obtained. Conventionally, it has been necessary to stop these problems once to solve them, and there has been a problem that the production efficiency is lowered. However, the present invention eliminates the need for stopping and greatly improves the continuous productivity. Moreover, when the pellet manufactured using the vent port of this invention is injection-molded, it becomes possible to obtain the pellet which does not have a different color pellet and an internal void.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
1 and 2 show a vaporization component removing device (vent port) according to an embodiment of the present invention, and show a cross section in a state where the vent port is installed in an extruder. The vent port according to the present invention has a groove 3 formed by an inner wall 1 of the vent port and a weir 2 for collecting the condensate of the organic vaporized component. In the present embodiment, the vent port inner wall 1 extends in the vertical direction. FIG. 2 is an enlarged view of the groove 3 formed by the inner wall 1 and the weir 2 of the vent port. Here, the groove 3 is (1) the angle of the groove 3 formed by the inner wall 1 and the weir 2 of the vent port. (Α) forms an angle of 15 to 45 ° with respect to the vertical direction, and (2) the temperature difference between the temperature of the vent port inner wall 1 and the temperature of the tip 4 of the weir 2 is 0 to 70 ° C. It is preferable that it is the range of these. Further, the heating device 5 can be easily installed on the outer surface of the vent port, and in order to increase heat transfer efficiency, it is preferable that the number of protruding portions is as small as possible. Further, the groove 3 extends outside the system. In the extending direction of the groove 3, the groove 3 is directed downward to allow the condensate collected in the groove 3 to flow. It is preferable that the inclination β is given, and this makes it possible to discharge the condensate out of the system appropriately and smoothly. The heating device 5 needs to be selected depending on the nature of the organic vaporized component to be exhausted. However, a ribbon heater, a metal band heater, a heating cable, an embedded cartridge heater, and a steam capable of heating the outer surface of the vent port. Anything such as piping may be used. In consideration of safety, a jacket heater with an excessive temperature rise prevention device is preferable.

  FIG. 3 shows an example of an extruder in which the vent port according to the present invention as described above is installed. The basic structure of the vent port according to the present invention is such that the extruder has a screw 7 in the barrel 6, and a vent hardware 8 is inserted into an opening that communicates the inside and the outside of the barrel 6. Since it is the structure to install, about the basic structure of the extruder to install, the structure similar to the conventional extruder may be sufficient. 1 and 2 show a case where a twin-screw extruder is used, of course, the present invention is not limited to this, and a single-screw type or a multi-axis type may be used.

  In the method for producing a resin melt composition using the present invention, the raw material supplied from the raw material supply unit 9 into the barrel 6 is melt-kneaded in front of the barrel 6 by heating the barrel 6 and rotating the screw 7. It is carried while being. At that time, it is preferable to supply the granular filler and / or reinforcing fiber from the auxiliary raw material supply units 10a and 10b in the middle of the barrel 6 into the molten resin melt. By doing so, each raw material is uniformly melted and kneaded between the inside and the downstream of the barrel 6 to form a resin melt composition. When this resin melt composition reaches the opening 8a of the bent metal piece 8, the pressure is released here, and the organic vaporized components and the like contained in the resin melt composition are separated and discharged from the opening 8a. The

  At that time, in the conventional vent port shown in FIG. 4, the vaporized component is condensed by the organic vaporized component coming into contact with the inner wall 11 and the top plate 12 of the vent port whose temperature is lowered by the outside air. Then, it flows down to the bent metal 13 and eventually drops again from the vent opening 13a into the extruder. Further, a part of the condensate staying on the bent metal 13 becomes a black or brown condensate due to oxidative degradation, drops into the extruder through the bent metal 13, and is extruded as a different color pellet. In addition, the higher the melting point of the condensate, the easier it is to cool and solidify by the air flow at the vent opening 13a, and if the solidified material continues to accumulate in the vent opening 13a, the vent will be blocked. Furthermore, fragments of the organic vaporized component cooled and solidified may fall and be transported to the die of the extruder in an unmelted state, clog the holes of the die, and the strands may not be drawn.

  However, in the present invention, by heating the outer wall surface and the top plate of the vent port from the outer surface by the jacket heater 5, it is possible to reduce organic vaporized product condensation on the vent port inner wall 1. Even if it is condensed, dripping into the extruder can be prevented by trapping the condensate in the groove 3 provided on the inner wall 1 of the vent port. Also, in the vent blockage, the inside of the vent port is maintained near the melting point of the condensate due to the effect of heating, so that the vent blockage is reduced and the deaeration capability can be kept high.

  When the present invention is used for melt kneading, applicable resins include nylon, polybutylene terephthalate (hereinafter referred to as PBT), liquid crystal polyester (hereinafter referred to as LCP), and polyphenylene sulfide (hereinafter referred to as PPS). Etc. can be suitably used when melt kneading. For example, the temperature inside the vent is controlled to be 180 to 225 ° C for nylon, 180 to 260 ° C for PBT, and the vent port internal temperature is preferably maintained to 200 to 330 ° C for LCP and PPS. Is preferred.

  Moreover, the kneading method of the resin melt of the present invention is also suitable for manufacturing reinforcing fibers and / or granular fillers containing a surface treatment agent. In particular, it can be preferably applied to the production of a composition containing 5 to 70 parts by weight of reinforcing fibers and / or granular fillers with respect to 100 parts by weight of the resin melt composition. Here, as the reinforcing fiber, those conventionally used as the reinforcing fiber of the resin melt composition can be used. Glass fiber, carbon fiber, asbestos fiber, carbon fiber, graphite fiber, metal fiber, potassium titanate whisker, boron Aluminum Whisker, Magnesium Whisker, Silicon Whisker, Slag Fiber, Gypsum Fiber, Silica Fiber, Silica / Alumina Fiber, Zirconia Fiber, Boron Nitride Fiber, Silicon Nitride Fiber and Boron Fiber, etc. Inorganic Reinforced Fiber, Polyester Fiber, Nylon Fiber Organic fiber such as acrylic fiber, regenerated cellulose fiber, acetate fiber, kenaf, ramie, cotton, jute, hemp, sisal, flax, linen, silk, manila hemp, sugar cane, wood pulp, paper waste, waste paper and wool . In addition, as the granular filler, those conventionally used as the granular filler of the resin melt composition can be used, and the silicate mineral, the silicate mineral and various minerals are pulverized into a plate shape and a needle shape. And granular materials are preferably used. Specific examples include bentonite, dolomite, montmorillonite, barlite, finely divided silicic acid, aluminum silicate, silicon oxide, dosonite, shirasu balloon, clay, sericite, feldspar powder, talc, calcium carbonate, lithium carbonate, kaolin, zeolite ( (Including synthetic zeolite), talc, mica, synthetic mica and wollastonite (including synthetic wollastonite), glass flakes, glass beads, hydrotalcite and silica.

  In this embodiment, the vent port of the present invention, the conventional vent port of FIG. 4 and the vent port described in Japanese Patent Laid-Open No. 19-290384 are installed in a ZSK-90 R240P extruder manufactured by Werner, respectively. After installing a commercially available jacket heater 5 (manufactured by YAGAMI: model GYG) on the outer wall surface, a resin in which 30 to 70 parts by weight of a filler component such as glass fiber and calcium carbonate is blended with PPS while heating the part to 330 ° C. The melt composition was melt-kneaded for 24 hours, and the presence or absence of occurrence of different color pellets was confirmed using a color difference sorter.

  As a result, when a conventional vent port was used, different color pellets were generated after 4 hours. Also, in the vent port created in Japanese Patent Laid-Open No. 19-290384, although the frequency of occurrence was suppressed, different color pellets were generated in 20 hours. On the other hand, when the vent port of the present invention was used, there was no occurrence of different color pellets. Details of the results are shown in Table 1.

  In this example, the weirs 2 were made with the length of the weir 2 of the vent port of the present invention being 7 mm and 70 mm, and PPS was melt-kneaded in the same manner as in Example 1. Specifically, the colored pellet generation time is measured at the vent port of a 70 mm weir, and after the vacuum pump is stopped, the upper lid of the vent device is opened and a surface thermometer (an upright meter) is opened from the top immediately after opening. The temperature of the vent port inner wall and the weir tip 4 was measured using a handy type thermometer (HA-400E). For the vent port provided with a 7 mm weir, the operation time was adjusted as described above. The results are shown in Table 2.

  The temperature difference between the inner wall surface of the vent port and the tip of the weir 4 was 67 ° C. in which the different color pellets were generated by the 70 mm weir. On the other hand, in the 7 mm weir, the temperature difference was 17 ° C., and it was found that the occurrence rate of different color pellets decreased as the temperature decreased. Even if the state of the internal condensate was visually confirmed, the vent port having a 7 mm weir was in a state of less condensate adhering to the backside surface of the weir.

  Like this embodiment, the groove 3 is formed by providing the vent port inner wall 1 and the weir 2 in the range of 5 to 50 mm, and the jacket heater 5 is installed on the outer surface of the vent port, and the temperature is set to 230 to If the temperature is maintained at 330 ° C., the generation of organic vaporized component condensate is suppressed, the generation of different color pellets and further the blocking of the vent can be suppressed, and a thermoplastic resin pellet with few voids can be produced.

The schematic block diagram of the apparatus which concerns on an example at the time of carrying out injection molding of the pellet produced in the said Example is shown in FIG.
The injection molding mechanism feeds the raw material into the raw material hopper 14 and transports the resin while plasticizing in the direction of the nozzle 17 by the rotation of the screw 15 and the heat of the barrel 16. At this time, the bubbles in the pellet are compressed, driven toward the tip of the nozzle 17, and discharged together with the resin. After the clamping, the nozzle 17 is brought into close contact with the mold 18, and the plasticized resin melt 20 (molded product) filled in the tip of the nozzle by the hydraulic piston 19 is injected into the mold 18 and filled in the mold 18. Is done.

  Even after the mold 18 is filled, the resin shrinks due to the cooling of the resin, so that the injection pressure remains applied to maintain the filling rate in the mold. The filled state is maintained at a low pressure, and the mold 18 is cooled and solidified to a temperature that does not hinder removal.

  With the end of plasticization, the mold 18 begins to open, the injection device moves backward, and the nozzle 17 that has touched the mold 18 is separated from the mold 18. The molded piece is separated from the mold when the molded product ejecting device 21 is operated.

  This example compares the quality of a molded product when a molded product is manufactured by the injection molding process using pellets prepared by each of two types of vent ports used in Example 2. The result performed about the various thing shown in Table 3 as a resin melt composition is shown.

The pellets prepared without installing the vent port of the present invention had a bulk density of fine pellets of a thermoplastic resin pellet having a filler content of 40% because a large amount of fine voids remained due to a decrease in internal degassing capacity. It was 0.724 g / cm ³ in the pellet containing 648 g / cm ³ and 70%.

  The pellets were polished to confirm the presence of voids therein, but a large amount of voids were present. The bulk density was measured based on JIS standard K6721.

  Further, although molding was attempted using the pellets, it could not be completely deaerated inside the molding machine and remained as a void inside the molded piece. If voids remain as voids in the molded product, the strength of the molded product is reduced, leading to troubles at customers.

On the other hand, the thermoplastic resin pellet prepared by installing the vent port of the present invention, winding the jacket heater around the outer surface of the vent port, and maintaining the temperature of the bent hardware at 270 to 330 ° C. There were very few voids, and the bulk densities were 0.742 (filler content 40%) and 0.833 g / cm ³ (filler content 70%), respectively, and the bulk density was high. Even when the pellets were molded, there were almost no voids inside the molded piece.

The thermoplastic resin composition used in this example is as follows.
-Toray Industries, Inc. PPS: A305MX01 (glass fiber 45%, calcium carbonate 5%)
・ Toray Industries, Inc. PBT: 1101GX65B (40% glass fiber)
-Nylon manufactured by Toray Industries, Inc .: CM3001RHB1 (15% glass fiber, 25% wollastonite)

  The vaporizing component removing apparatus according to the present invention and the extruder and the resin melt kneading method using the apparatus can be applied to any application that requires removal of the vaporizing component generated when the resin melt composition is produced. .

It is a cross-sectional view of the state which installed the vaporization component removal apparatus (vent port) which concerns on one embodiment of this invention in the extruder. FIG. 2 is a partially enlarged cross-sectional view of the apparatus of FIG. It is a schematic longitudinal cross-sectional view of the extruder which installed the vaporization component removal apparatus (vent port) which concerns on one embodiment of this invention. It is a cross-sectional view of a conventional vent port. It is a schematic longitudinal cross-sectional view of the injection molding machine to which this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vent port inner wall 2 Weir 3 Groove 4 Tip of weir 5 Heating device 6 Barrel 7 Screw 8 Vent metal 8a Opening part 9 Raw material supply part 10a, 10b Sub raw material supply part 14 Raw material hopper part 15 Screw 16 Barrel 17 Nozzle 18 Mold 19 Hydraulic piston 20 Plasticized resin melt (molded product)
21 Molded product ejection device

Claims (6)

  A vaporization component removing device for removing an organic vaporized component generated during resin melt kneading, and a groove formed by an inner wall (1) and a weir (2) of the vaporized component removing device for collecting the condensate of the organic vaporized component The vaporization component removal apparatus having (3), wherein the angle (α) between the weir (2) and the vaporization component removal apparatus inner wall (1) forms an acute angle.   The vaporization component removal apparatus according to claim 1, wherein the inner wall (1) of the vaporization component removal apparatus extends in a vertical direction.   The inclination which enables the condensate collected in this groove | channel (3) to flow is given to this groove | channel (3) in the extension direction of the said groove | channel (3). Vaporization component removal device.   The outer periphery of the vaporization component removal device is heated, and the difference between the temperature of the tip (4) of the weir (2) and the temperature of the inner wall (1) of the vaporization component removal device is in the range of 0 to 70 ° C. The vaporization component removal apparatus in any one of 1-3.   An extruder comprising the vaporized component removing apparatus according to any one of claims 1 to 4.   A resin melt kneading method comprising kneading a resin melt using the extruder according to claim 5.

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