JP2009292115A - Resin molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin molding machine which inhibits the breakage of a fibrous filling material and can obtain a sufficient discharge amount. <P>SOLUTION: The resin molding machine includes: a screw 2 which includes a shaft part 21 and flight 22; a cylinder which houses the screw 2; a heater which supplies heat to the cylinder; a first opening by which a fiber-reinforced resin composition is supplied in the cylinder; and a second opening by which the fiber-reinforced resin composition which has been melted is discharged. The screw 2 includes: a feed section 24; a compression unit 25; and a metering section 26 in this order from the first opening side to the second opening side. The ratio D1/D3 of the distance D3 between the periphery 21a of the shaft part 21 of the metering section 26 and the front edge 22a of the flight 22 and the distance D1 between the periphery 21a of the shaft part 21 of the feed section 24 and the front edge 22a of the flight 22 is 1.0 or more and 1.2 or less, and the number of revolution of the screw 2 is 170 rpms or more and 200 rpms or less. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention includes a screw, a cylinder in which the screw is housed, a heater for supplying heat to the cylinder, a first opening provided at the base end of the cylinder, and a second provided at the tip of the cylinder. And an opening for the resin molding machine.

  As a resin composition based on a thermoplastic resin (hereinafter simply referred to as “resin composition”), for example, a pellet-shaped molding material (virgin pellet) is molded into a molded product having a desired shape by injection molding. However, at this time, end materials such as a spool and a runner are generated together with the molded product. Such end materials are separated from the molded product and pulverized, and then granulated by extrusion molding into repellets, which are recycled by mixing the repellets with virgin pellets at a predetermined ratio and performing injection molding. .

  The resin molding machine used for the above-described extrusion molding includes, for example, a screw having a shaft portion and a flight erected from the outer peripheral surface of the shaft portion, a cylinder housing the screw therein, and heat in the cylinder. A heater to be supplied, a hopper port (corresponding to the first opening) provided at the base end of the cylinder and supplied with the resin composition, and provided at the tip of the cylinder and melted in the cylinder And a discharge port (corresponding to the second opening) through which the kneaded resin composition is discharged.

  The screw is arranged on the hopper opening side in the cylinder and has a supply portion in which the outer diameter of the shaft portion is formed constant, and the screw is formed to gradually increase as the outer diameter of the shaft portion is separated from the supply portion. And a metering unit that is connected to the compression unit and is disposed on the discharge port side in the cylinder and has a constant outer diameter of the shaft portion. The distance between the outer peripheral surface of the shaft portion of the supply unit and the tip of the flight is formed to be larger than the distance between the outer peripheral surface of the shaft portion of the measuring unit and the tip of the flight. The ratio of the distance of the supply unit to the distance of the measuring unit (hereinafter referred to as “distance ratio”) is, for example, 2.4 to 3.2 (see, for example, Patent Document 1).

  The above-described end material at the time of injection molding is supplied into the cylinder from the hopper port. And while this end material is conveyed in a cylinder toward a discharge port (screw measurement part side) from a hopper opening (screw supply part side), while receiving a big shearing force by the screw of the structure mentioned above. Heat is supplied from the heater and melted and kneaded sufficiently. After being discharged from the discharge port and formed into a linear shape, it is cut into short pieces and re-pelletized to form repellets.

  By the way, the resin composition mentioned above may be comprised from the base resin which consists of thermoplastic resins, and fibrous fillers, such as glass fiber and a carbon fiber (henceforth a "fiber reinforced resin composition"). ). The mechanical strength of the fiber reinforced resin composition is improved by the fibrous filler.

  However, when the end material of the fiber reinforced resin composition is re-pelletized using the resin molding machine described in Patent Document 1 described above, the shearing force acting on the end material is large, so that the fibrous filler is broken. There was a problem that. And, if the repellet with broken fibrous filler is mixed with virgin pellets and injection molded, the mechanical strength of the molded product is reduced compared to the case of only virgin pellets. There was a problem that recycling was impossible.

Accordingly, the present inventors have focused on the relationship between the shear force acting on the end material and the screw shape, and as a result of repeated studies, the shear force acting on the end material changes depending on the distance ratio of the screw. And found the optimum distance ratio through experiments (Patent Document 2). According to the resin molding machine described in Patent Document 2, by setting the screw distance ratio to be 1.2 or more and 1.95 or less, the shearing force acting on the end material can be made appropriate. It was possible to prevent breakage of the fibrous filler described above.
JP 2002-234063 A Japanese Patent Application No. 2007-272570

  However, in the resin molding machine described in Patent Document 2, since the screw rotation speed is 150 rpm, a sufficient discharge amount cannot be obtained, and a large number of repellets cannot be produced in a short time. there were. Further, if the number of rotations of the screw is increased in order to obtain a sufficient discharge amount, there is a problem that the shearing force acting on the end material is increased, and the fibrous filler is broken.

  The present invention aims to solve the above problems. That is, an object of the present invention is to provide a resin molding machine capable of preventing the fibrous filler from being broken and obtaining a sufficient discharge amount.

  In order to achieve the above object, the invention described in claim 1 includes a screw having a shaft portion and a flight erected from an outer peripheral surface of the shaft portion, a cylinder accommodating the screw therein, A heater for supplying heat into the cylinder; a first opening provided at a base end portion of the cylinder and supplied with a fiber reinforced resin composition comprising a base resin and a fibrous filler; A resin molding machine provided with a second opening provided at a tip of the cylinder and through which the fiber-reinforced resin composition melted and kneaded in the cylinder is discharged, wherein the screw is the first opening. A supply part arranged on the side and having an outer diameter of the shaft part formed constant in the longitudinal direction, a compression part connected to the supply part, an outer diameter of the shaft part connected to the compression part and the longitudinal direction thereof A weighing unit that is uniformly formed in And the ratio of the distance between the outer peripheral surface of the shaft portion of the supply unit and the front end of the flight to the distance between the outer peripheral surface of the shaft portion of the measuring unit and the front end of the flight is 1 The resin molding machine is characterized in that it is not less than 0.0 and not more than 1.2, and the rotational speed of the screw is not less than 170 rpm and not more than 200 rpm.

  The invention described in claim 2 is the invention described in claim 1, wherein a ratio of the length of the supply unit to the length of the measurement unit is 3 or more and 4 or less, and the measurement unit The ratio of the length of the compression portion to the length of is 2.5 or more and 3.6 or less.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the temperature of the heater that supplies heat to a portion of the cylinder where the supply unit is disposed is the decomposition of the base resin. The temperature of the heater that is at least 50 ° C. lower than the start temperature and less than or equal to 20 ° C. lower than the decomposition start temperature, and that supplies heat to the portion of the cylinder where the metering unit is disposed, The temperature is lower than the temperature of the heater that supplies heat to the portion where the supply unit is disposed, and is not lower than a temperature that is 35 ° C. higher than the melting temperature of the base resin and 75 ° C. higher than the melting temperature. To do.

  The invention described in claim 4 is the invention described in any one of claims 1 to 3, wherein the measuring portion is kneaded with the fiber reinforced resin composition at an end portion on the second opening side. It is characterized by having a kneading part that promotes.

  The invention described in claim 5 is the invention described in claim 4, wherein the screw has an extension portion provided continuously to the kneading portion, and an end of the extension portion on the kneading portion side. A third opening for discharging the gas generated in the cylinder is provided near the portion.

  According to the invention described in claim 1, the ratio of the distance between the outer peripheral surface of the shaft portion of the supply unit and the front end of the flight to the distance between the outer peripheral surface of the shaft portion of the measuring unit and the front end of the flight is 1.0 and 1.2 or less, and the rotational speed of the screw is 170 rpm or more and 200 rpm or less. Therefore, the shearing force on the fiber reinforced resin composition and the discharge amount of the fiber reinforced resin composition are Can be properly balanced.

  According to the invention described in claim 2, the ratio of the length of the supply section to the length of the measurement section is 3 or more and 4 or less, and the ratio of the length of the compression section to the length of the measurement section However, since it is 2.5 or more and 3.6 or less, the length of the supply unit can be sufficiently increased with respect to the length of the measurement unit, and therefore the pre-heating of the fiber reinforced resin composition can be sufficiently performed. The length of the compression part can be made sufficiently long relative to the length of the measurement part, and therefore the ratio of the outer diameter of the shaft part of the compression part gradually increasing toward the measurement part. Can be small.

  According to the invention described in claim 3, the temperature of the heater that supplies heat to the portion where the supply portion in the cylinder is arranged is a temperature that is 50 ° C. lower than the decomposition start temperature of the base resin of the fiber reinforced resin composition. In addition, the temperature of the heater is 20 ° C. lower than the decomposition start temperature and the temperature of the heater that supplies heat to the portion in the cylinder where the metering unit is arranged supplies heat to the portion in which the supply unit in the cylinder is arranged Since the temperature is lower than the temperature of the heater to be heated, 35 ° C. higher than the melting temperature of the base resin and 75 ° C. lower than the melting temperature, the supply portion supplies a temperature close to the decomposition start temperature at which the base resin changes in quality. In addition, a temperature higher than the melting temperature of the base resin can be supplied in the metering section.

  According to the invention described in claim 4, since the measuring part includes the kneading part for promoting the kneading of the fiber reinforced resin composition at the end on the second opening side, the fiber reinforced resin composition in the measuring part. The product can be sufficiently kneaded.

  According to the fifth aspect of the present invention, the screw has an extension portion provided continuously to the kneading portion, and discharges the gas generated in the cylinder in the vicinity of the kneading portion side of the extension portion. Since the third opening is provided, the fiber reinforced resin composition sufficiently kneaded by the kneading part can be supplied to the part of the extension part where the third opening is provided.

  As described above, according to the invention described in claim 1, since the shearing force with respect to the fiber reinforced resin composition and the discharge amount of the fiber reinforced resin composition can be appropriately balanced, the fibrous filler Can be prevented, and a sufficient discharge amount can be obtained.

  According to the invention described in claim 2, the fiber reinforced resin composition can be sufficiently preheated, and the outer diameter of the shaft portion of the compression portion gradually increases along the longitudinal direction of the compression portion. Since the ratio can be reduced, the fiber reinforced resin is promoted by sufficiently preheating to promote the melting of the fiber reinforced resin composition, and the ratio of gradually increasing the outer diameter of the shaft portion of the compressed portion is decreased. A shearing force can be slowly applied to the composition, so that breakage of the fibrous filler can be prevented.

  According to the third aspect of the present invention, the supply unit can supply a temperature close to the decomposition start temperature at which the base resin changes in quality, and the metering unit supplies a temperature higher than the melting temperature of the base resin. Therefore, the fiber reinforced resin composition can be sufficiently melted and the molten state can be maintained until the measurement of the fiber reinforced resin composition. It is possible to prevent breakage of the filler and uneven resin of the molded product.

  According to the invention described in claim 4, since the fiber reinforced resin composition can be sufficiently kneaded by the kneading part, the fiber reinforced resin composition after the measurement includes those which are not sufficiently melted. This can be prevented.

  According to the invention described in claim 5, since the fiber reinforced resin composition sufficiently kneaded by the kneading portion can be supplied to the portion of the extension portion where the third opening is provided, Air and volatile substances in the cylinder can be discharged without discharging a fiber-reinforced resin composition that is insufficiently melted from the opening.

(First embodiment)
Hereinafter, the resin molding machine which shows the 1st Embodiment of this invention is demonstrated with reference to FIGS.

  A resin molding machine 1 according to an embodiment of the present invention is an extrusion molding machine that granulates repellets by re-pelletizing scraps such as spools and runners generated together with a molded product at the time of injection molding of a fiber reinforced resin composition, for example. is there. As shown in FIG. 1, the resin molding machine 1 includes a screw 2, a cylinder 3, a hopper port 4 as a first opening, a discharge port 5 as a second opening, and a screw drive unit (not shown). ) And a heater 7. The fiber reinforced resin composition includes a base resin and a fibrous filler.

  The screw 2 is formed in a long and substantially cylindrical shape as a whole. The screw 2 is formed of a metal member having high wear resistance in order to reduce wear caused by the fibrous filler. As shown in FIG. 2, the outer diameter D of the screw 2 (that is, the double value of the distance between the axis of the screw 2 and the tip 22a of the flight 22 described later) is formed to be substantially constant. The screw 2 is formed such that the ratio of the length L of the screw 2 to the outer diameter D of the screw 2 (the length of the screw 2 / the outer diameter of the screw 2, that is, the L / D of the screw 2) is 36. Yes. The screw 2 has a shaft portion 21, a flight 22, and a groove 23.

  The shaft portion 21 is formed in a long cylindrical shape. The flight 22 is erected from the outer peripheral surface 21 a of the shaft portion 21. The flight 22 is provided over substantially the entire length of the shaft portion 21 in the longitudinal direction, and is formed in a spiral shape. The groove 23 includes an outer peripheral surface 21a of the shaft portion 21 and an outer surface of the flight 22 that is substantially orthogonal to the outer peripheral surface 21a of the shaft portion 21 and is opposed to each other with a space therebetween, and has a substantially U-shaped cross section. It is formed in a shape. The grooves 23 are formed between the flights 22 formed in a spiral shape, and are formed in a spiral shape on the outer peripheral surface of the screw 2 in the same manner as the flights 22. The fiber reinforced resin composition is conveyed from the hopper port 4 toward the discharge port 5 through the groove 23.

  The screw 2 includes a supply unit 24 arranged on the hopper port 4 side, a compression unit 25 connected to the supply unit 24, and a measuring unit 26 connected to the compression unit 25 and arranged on the discharge port 5 side. Yes. The supply unit 24, the compression unit 25, and the measuring unit 26 are names of parts along the longitudinal direction of the screw 2, respectively. The supply unit 24, the compression unit 25, and the measuring unit 26 are provided side by side along the longitudinal direction of the screw 2.

  The supply unit 24 conveys the fiber reinforced resin composition supplied from the hopper port 4 into the cylinder 3 toward the compression unit 25, and preheats the fiber reinforced resin composition by heat supplied from the heater 7 during the conveyance. And supplied to the compression unit 25. The outer diameter of the shaft portion 21 of the supply portion 24 is formed constant in the longitudinal direction.

  The compressing unit 25 is a fiber by shearing force generated between the heat supplied from the heater 7 and the inner surface of the cylinder 3 while the fiber reinforced resin composition conveyed from the supply unit 24 is conveyed toward the measuring unit 26. The reinforced resin composition is melted. The outer diameter of the shaft portion 21 of the compression portion 25 is formed constant in the longitudinal direction or gradually increased toward the measuring portion 26 away from the supply portion 24.

  The metering unit 26 transports the fiber reinforced resin composition melted in the compression unit toward the discharge port 5 by a certain amount (that is, by metering) at a certain time. The outer diameter of the shaft portion 21 of the measuring unit 26 is formed constant in the longitudinal direction, and is the same as the outer diameter of the shaft portion 21 of the supply unit 24 or larger than the outer diameter of the shaft portion 21 of the supply unit 24. ing. Moreover, the measurement part 26 is provided with the kneading part 26a for accelerating | stimulating kneading | mixing of a fiber reinforced resin composition in the edge part by the side of the discharge outlet 5, and its vicinity.

  As shown in FIG. 3, the kneading part 26a has, for example, a BM type screw shape having a subflight 221 formed so as to be inclined more in the circumferential direction than the flight 22, and a weighing part as shown in FIG. 26 is formed in the shape of a dalmage type screw having a concave portion and a convex portion which are inclined in the same direction with respect to the axial center direction of the screw 2 and are alternately arranged.

  Thus, by providing the kneading part 26a in the measuring part 26, the fiber reinforced resin composition can be sufficiently kneaded, and the fiber reinforced resin composition remaining without being melted until reaching the measuring part 26 is surely obtained. Therefore, it is possible to prevent the fiber reinforced resin composition remaining undissolved from staying in front of the discharge port 5, so that the discharge amount from the discharge port 5 can be made constant.

  The screw 2 has a distance D1 between the outer peripheral surface 21a of the shaft portion 21 of the supply unit and the front end 22a of the flight 22 with respect to a distance D3 between the outer peripheral surface 21a of the shaft portion 21 of the measuring unit 26 and the front end 22a of the flight 22. The ratio D1 / D3 (that is, the above-described distance ratio) is 1.0 or more and 1.2 or less. The screw 2 is rotated at a rotation speed of 170 rpm or more and 200 rpm or less. If this ratio D1 / D3 is less than 1.0, or if the rotational speed is less than 170 rpm, the shear force becomes too small to sufficiently melt the fiber reinforced resin composition. In particular, when the ratio D1 / D3 is smaller than 1.0, the fiber-reinforced resin composition is not compressed, so that air or the like contained in the fiber-reinforced resin composition cannot be removed. Moreover, when ratio D1 / D3 becomes larger than 1.2, or when rotation speed becomes larger than 200 rpm, a shear force will become large too much and many fibrous fillers will break.

  Further, in the screw 2, the ratio L1 / L3 of the length L1 of the supply unit 24 to the length L3 of the measuring unit 26 is 3 or more and 4 or less, and the compression unit 25 has a length L3 of the measuring unit 26. The length L2 is formed so that the ratio L2 / L3 is 2.5 or more and 3.6 or less. By doing so, the fiber reinforced resin composition can be sufficiently preheated and melted in the supply unit 24, and breakage of the fibrous filler due to the pressure in the compression unit 25 can be prevented. In particular, the length L1 of the supply unit 24 is preferably formed to be the same as or approximately the same as the length L2 of the compression unit 25 and longer than the length L3 of the measuring unit 26. In the present embodiment, the length L1 of the supply unit 24 is 500 mm, the length L2 of the compression unit is 500 mm, and the length L3 of the weighing unit is 140 mm.

  As shown in FIG. 1, the cylinder 3 is provided in a cylindrical shape and accommodates the screw 2 therein. The cylinder 3 is formed of a metal member having high wear resistance in order to reduce wear caused by the fibrous filler. The inner diameter of the cylinder 3 is formed substantially constant and is slightly larger than the outer diameter of the screw 2.

  The hopper port 4 is an opening continuous in the cylinder 3. The hopper port 4 is provided at the base end portion 3 a of the cylinder 3. The fiber reinforced resin composition is supplied into the cylinder 3 through the hopper port 4. A hopper 41 arranged in the vertical direction is attached to the hopper port 4. The entire shape of the hopper 41 is formed in a substantially funnel shape. In the hopper 41, the fiber reinforced resin composition obtained by pulverizing the above-mentioned mill ends is stored, and the fiber reinforced resin composition is supplied to the hopper port 4.

  The discharge port 5 is an opening continuous in the cylinder 3. The discharge port 5 is provided at the tip 3 b of the cylinder 3. The fiber reinforced resin composition melt-kneaded in the cylinder 3 is discharged out of the cylinder 3 through the discharge port 5. A breaker plate 51 and a die 54 are attached to the discharge port 5.

  The breaker plate 51 is formed of a metal member or the like and is formed in a flat plate shape. The breaker plate 51 is provided with a plurality of holes penetrating the plate along the thickness direction of the plate.

  The breaker plate 51 having the above-described configuration also has a function of reliably melting the fiber reinforced resin composition by increasing the back pressure in the cylinder 3 and controlling the flow of the fiber reinforced resin composition. Thereby, for example, the fiber reinforced resin composition can be more reliably melted by the screw 2 having a small ratio D1 / D3 (that is, a small shearing force).

  The die 54 is formed of a metal member or the like, and is formed in a cylindrical shape, for example. The molten fiber reinforced resin composition that has passed through the breaker plate 51 passes through the die 54 and is formed into a desired shape.

  The screw drive unit is composed of a motor or the like. The screw driving unit pivotally supports the screw 2 accommodated in the cylinder so as to be rotatable about its axis, and rotationally drives the screw 2 about the axis.

  As shown in FIG. 1, the heater 7 is embedded along the outer wall of the cylinder 3 over the entire circumference. The heater 7 is a belt-like plate heater. Of course, the heater 7 may be a band-shaped band heater. The heater 7 supplies heat into the cylinder 3, and the fiber reinforced resin composition in the cylinder 3 is melted (heated and fluidized) by this heat. A plurality of heaters 7 are provided along the longitudinal direction of the cylinder 3.

  The heater 7 heats across the heater 71 that supplies heat to the portion of the cylinder 3 where the supply portion 24 of the screw 2 is disposed, the portion where the supply portion 24 is disposed, and the portion where the compression portion 25 is disposed. Heater 72 for supplying heat, heater 73 for supplying heat to the part where the compression part 25 is arranged, heater for supplying heat across the part where the compression part 25 is arranged and the part where the metering part 26 is arranged 74 and a heater 75 for supplying heat to the breaker plate 51 and the die 54, and heat at different temperatures can be supplied to each part.

  The heater 71 and the heater 72 are temperatures that are at least 50 ° C. lower than the decomposition start temperature, which is a temperature at which the base resin of the fiber-reinforced resin composition described later changes, and are at temperatures that are 20 ° C. lower than the decomposition start temperature (preferably decomposition). The temperature is set to be supplied to the cylinder 3 at a temperature 20 ° C. lower than the start temperature. In addition, the heater 73 and the heater 74 are at a temperature lower than the heater 71 and the heater 72 and at a temperature that is 35 ° C. higher than the melting temperature at which the base resin melts and 75 ° C. higher than the melting temperature ( The temperature is preferably set at 35 ° C. higher than the melting temperature).

  In the present embodiment, a base resin having a decomposition start temperature of 350 ° C. and a melting temperature of 225 ° C. is used, and the heater 71 and the heater 72 are each set to supply heat of 330 ° C. to the cylinder 3, The heater 73, the heater 74, and the heater 75 are each set to supply heat of 260 ° C. to the cylinder 3.

  These settings are merely examples. For example, the temperature of the heater 71 is 50 ° C. lower than the decomposition start temperature and 20 ° C. lower than the decomposition start temperature (preferably 20 ° C. lower than the decomposition start temperature). (Low temperature) is set to be supplied to the cylinder 3, and the temperature is set so that the temperature gradually decreases from the heater 72 toward the heater 74, and the heater 74 is set to a temperature 35 ° C. higher than the melting temperature and 75% higher than the melting temperature. You may set so that the temperature below the high temperature (preferably the temperature higher by 35 ° C. than the melting temperature) may be supplied to the cylinder 3.

  The fiber reinforced resin composition is composed of a base resin and a fibrous filler. As the base resin, an unsaturated polyester resin is often used. Examples of the unsaturated polyester resin include polyethylene terephthalate, polybutylene terephthalate, and polycyclohexane terephthalate. The base resin may be polypropylene, polyethylene, polyamide resin, or the like. In addition, base resin is not limited only to these, Base resins other than these may be sufficient unless it is contrary to the objective of this invention.

  Examples of the fibrous filler include glass fiber (glass fiber), carbon fiber, and aramid fiber. The fibrous filler is added to the base resin and improves the mechanical strength of the base resin. When the fibrous filler has a relatively high hardness, when the fiber reinforced resin composition is melted in the cylinder 3 and receives a large shearing force, the fibrous filler is broken and the strength improvement by the fibrous filler is improved. It will decline. The fibrous filler is not limited to these, and other fibrous fillers may be used as long as the object of the present invention is not violated.

  Examples of the fiber reinforced resin composition described above include Toraycon 1101-G30 (manufactured by Toray Industries, Inc.), in which 30% glass fiber as a fibrous filler is contained in polybutylene terephthalate as a base resin. This fiber reinforced resin composition has an initial shape of a pellet shape. In addition, a fiber reinforced resin composition is not limited only to these, As long as it is not contrary to the objective of this invention, fiber reinforced resin compositions other than these may be sufficient.

  When the fiber reinforced resin composition is molded using the resin molding machine 1 having the above-described configuration, first, the above-described end material is put into the hopper 41 and the end material is inserted into the cylinder 3 from the hopper port 4 of the cylinder 3. The fiber reinforced resin composition to be supplied into the inside is supplied into the groove 23 of the supply part 24 of the screw 2, and the screw 2 rotates to measure the inside of the groove 23 of the supply part 24 to the groove 23 of the compression part 25. It is sequentially conveyed into the groove 23 of the portion 26.

  In the supply unit 24, the fiber reinforced resin composition is preheated and melted by the heat supplied from the heater 71 and the heater 72. The fiber reinforced resin composition melted in the supply unit 24 is conveyed to the compression unit 25, and the fiber reinforced resin composition is measured while maintaining the molten state by the heat supplied from the heater 72 and the heater 73 in the compression unit 25. To the unit 26.

  The melted fiber reinforced resin composition is maintained in a molten state by the heat supplied from the heater 74 in the metering unit 26 and further kneaded in the kneading unit 26a, and then the breaker plate 51 and the die To 54. The fiber reinforced resin composition is cooled and solidified after passing through the die 54, and after being formed into a linear shape, the fiber reinforced resin composition is shortly cut and re-pelletized to form a repellet.

  In this embodiment, the distance between the outer peripheral surface 21a of the shaft portion 21 of the supply unit 24 and the front end 22a of the flight 22 with respect to the distance D3 between the outer peripheral surface 21a of the shaft portion 21 of the measuring portion 26 and the front end 22a of the flight 22 is determined. Since the ratio D1 / D3 of the distance D1 is 1.0 or more and 1.2 or less, and the rotational speed of the screw 2 is 170 rpm or more and 200 rpm or less, the shear force and the fiber against the fiber reinforced resin composition The discharge amount of the reinforced resin composition can be appropriately balanced.

  The ratio L1 / L3 of the length L1 of the supply unit 24 to the length L3 of the measuring unit 26 is 3 or more and 4 or less, and the length L2 of the compression unit 25 with respect to the length L3 of the measuring unit 26 is Since the ratio L2 / L3 is 2.5 or more and 3.6 or less, the length L1 of the supply unit 24 can be made sufficiently longer than the length L3 of the measuring unit 26, and therefore, the fiber reinforcement The preheating of the resin composition can be sufficiently performed, and the length L2 of the compression unit 25 can be made sufficiently longer than the length L3 of the measurement unit 26. The rate at which the outer diameter of the 25 shaft portions 21 gradually increases can be reduced.

  Further, the temperature of the heater 71 and the heater 72 for supplying heat to the portion where the supply unit 24 in the cylinder 3 is disposed is equal to or higher than a temperature lower by 50 ° C. than the decomposition start temperature of the base resin of the fiber reinforced resin composition. The temperature of the heater 74 that is 20 ° C. lower than the start temperature and supplies heat to the portion of the cylinder 3 where the metering unit 26 is disposed is heated to the portion of the cylinder 3 where the supply unit 24 is disposed. Since the temperature is lower than the temperature of the heater to be supplied, 35 ° C. higher than the melting temperature of the base resin and 75 ° C. lower than the melting temperature, the temperature close to the decomposition start temperature at which the base resin changes in the supply unit 24 is set. In addition, the metering unit 26 can supply a temperature higher than the melting temperature of the base resin.

  In addition, since the measuring unit 26 includes the kneading unit 26a that promotes kneading of the fiber reinforced resin composition at the end on the discharge port 5 side, the fiber reinforced resin composition can be sufficiently kneaded in the measuring unit 26. it can.

  As described above, according to the present invention, the shearing force on the fiber reinforced resin composition and the discharge amount of the fiber reinforced resin composition can be appropriately balanced, so that the fibrous filler can be prevented from being broken and sufficient. A discharge amount can be obtained.

  Further, the fiber reinforced resin composition can be sufficiently preheated in the supply unit 24, and the rate at which the outer diameter of the shaft portion 21 of the compression unit 25 gradually increases along the longitudinal direction of the compression unit 25 is reduced. Therefore, the fiber reinforced resin composition is promoted by sufficiently preheating to promote the melting of the fiber reinforced resin composition and the ratio of the outer diameter of the shaft portion 21 of the compression portion 25 gradually increasing. A shearing force can be slowly applied to the object, and therefore breakage of the fibrous filler can be prevented.

  Further, since the supply unit 24 can supply a temperature close to the decomposition start temperature at which the base resin changes in quality, and the metering unit 26 can supply a temperature higher than the melting temperature of the base resin, the fiber reinforced resin composition Can melt the product sufficiently, and can maintain the melted state until the measurement of the fiber reinforced resin composition. Therefore, the fiber reinforced resin composition may be broken due to insufficient melting of the fiber reinforced resin composition or the molded product. Resin unevenness can be prevented.

  In addition, since the fiber reinforced resin composition can be sufficiently kneaded by the kneading part 26a, the fiber reinforced resin composition after the measurement is not included in an insufficiently melted state, and the breaker plate 51 and the die 54 It can prevent that the fiber reinforced resin composition which was not melt | dissolved before is staying.

(Second Embodiment)
Below, the resin molding machine which shows the 2nd Embodiment of this invention is demonstrated with reference to FIG. The first embodiment described above is a no vent type resin molding machine that does not include a vent hole for extracting air or the like in the cylinder. However, the second embodiment is a vent type resin that includes a vent hole. It is a molding machine.

  FIG. 5 is a view showing a bent type resin molding machine 1A according to the present invention. As shown in FIG. 5, the resin molding machine 1A includes a screw 102, a cylinder 3, a hopper port 4 as a first opening, a discharge port 5 as a second opening, and a vent as a third opening. A hole 6, a screw drive unit (not shown, the same as in the first embodiment), and a heater 8 are provided. In the figure, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  The screw 102 is formed in a long and substantially cylindrical shape as a whole. The screw 102 is formed of a metal member having high wear resistance in order to reduce wear caused by the fibrous filler. The outer diameter of the screw 102 (that is, the double value of the distance between the axis of the screw 2 and the tip 22a of the flight 22 described later) is formed to be substantially constant.

  The screw 102 includes a shaft portion 21 formed in a long columnar shape, and a flight 22 standing from the outer peripheral surface of the shaft portion 21 and formed in a spiral shape over substantially the entire length in the longitudinal direction of the shaft portion 21. The outer peripheral surface of the shaft portion 21 and the outer surface of the flight 22 that are substantially orthogonal to the outer peripheral surface of the shaft portion 21 and face each other with a space therebetween, and the cross-sectional shape is formed in a substantially U-shape. And a groove 23. Similarly to the flight 22, the groove 23 is also formed in a spiral shape over substantially the entire length in the longitudinal direction of the shaft portion 21.

  The screw 102 includes a first stage portion S1 disposed on the hopper port 4 side, and a second stage portion S2 disposed on the discharge port 5 side that is connected to the first stage portion S1. The first stage portion S1 and the second stage portion S2 are names of parts along the longitudinal direction of the screw 102, respectively.

  The first stage portion S1 is formed in the same shape as the screw 2 in the first embodiment described above, and the supply portion 24, the compression portion 25, and the measuring portion 26 are arranged from the proximal end portion 3a of the cylinder 3 to the distal end portion. They are sequentially connected toward 3b. In addition, the metering unit 26 is provided with a kneading unit 26a at an end on the discharge port 5 side and in the vicinity thereof.

  The second stage portion S2 corresponds to an extension portion in the claims, and is provided continuously to the end portion on the discharge port 5 side of the first stage portion S1. The second stage part S2 is arranged in the vicinity of the discharge port 5 and connected to the vent part 27 connected to the measuring part 26 of the first stage part S1, the second compression part 28 connected to the vent part 27, and the second compression part 28. A second metering unit 29. The vent part 27, the second compression part 28, and the second metering part are names of parts along the longitudinal direction of the screw 102, respectively.

  The vent portion 27 is formed such that the outer diameter of the shaft portion 21 is smaller than the measuring portion 26 of the first stage portion S1 and is constant in the longitudinal direction. The second compression portion 28 is connected to the vent portion 27 and is gradually formed larger as the outer diameter of the shaft portion 21 is separated from the vent portion 27. The second measuring unit 29 is connected to the second compressing unit 28, and the outer diameter of the shaft portion 21 is formed constant in the longitudinal direction. In this embodiment, the length of the vent part 27 is 300 mm, the length of the second compression part 28 is 125 mm, and the length of the second measuring part 29 is 250 mm.

  The vent hole 6 is an opening continuous in the cylinder 3. The vent hole 6 is opened upward in the vicinity of the end portion connected to the first stage portion S1 of the second stage portion S2 (that is, in the vicinity of the end portion on the kneading portion 26a side of the second stage portion S2). Yes. The vent hole 6 discharges air or a volatile substance contained in the fiber reinforced resin composition from the cylinder 3 to prevent bubbles from being generated in the molded product.

  The heater 8 is the same as the heater 7 in the first embodiment, and is embedded along the outer wall of the cylinder 3 over the entire circumference. The heater 8 heats across a heater 81 that supplies heat to a portion of the cylinder 102 where the supply portion 24 of the screw 102 is disposed, a portion where the supply portion 24 is disposed, and a portion where the compression portion 25 is disposed. A heater 82 for supplying heat, a heater 83 for supplying heat to a portion where the compression unit 25 is arranged, a portion where the compression unit 25 is arranged, a portion where the measuring unit 26 is arranged, and a portion where the vent portion 27 is arranged The heater 84 that supplies heat across the two, the heater 85 that supplies heat across the portion where the vent portion 27 and the second compression portion 28 are arranged, and the second compression portion 28 are arranged. A heater 86 that supplies heat across the portion to be disposed and the portion where the second metering portion 29 is disposed, a heater 87 that supplies heat to the portion where the second metering portion 29 is disposed, the breaker plate 51 and the die 54 Each part has different temperature It is capable of supplying.

  The heater 81, the heater 82, and the heater 83 are temperatures that are at least 50 ° C. lower than the decomposition start temperature of the base resin of the fiber reinforced resin composition and at most 20 ° C. lower than the decomposition start temperature (preferably the decomposition start temperature). The temperature is set to be supplied to the cylinder 3. In addition, the heater 84, the heater 85, the heater 86, and the heater 87 have a temperature lower than that of the heater 81, the heater 82, and the heater 83, and a temperature that is 35 ° C. higher than the melting temperature of the base resin described above and The temperature is set to be supplied to the cylinder 3 at a temperature not more than 75 ° C. higher than the melting temperature (preferably a temperature higher than the melting temperature by 35 ° C.).

  In this embodiment, a base resin having a decomposition start temperature of 350 ° C. and a melting temperature of 225 ° C. is used, and the heater 81, the heater 82, and the heater 83 each supply heat of 330 ° C. to the cylinder 3. The heater 84, the heater 85, the heater 86, and the heater 87 are each set to supply heat of 260 ° C. to the cylinder 3.

  These settings are merely examples. For example, the temperature of the heater 81 is 50 ° C. lower than the decomposition start temperature and 20 ° C. lower than the decomposition start temperature (preferably 20 ° C. lower than the decomposition start temperature). (Low temperature) is set to be supplied to the cylinder 3, and the temperature is set to gradually decrease from the heater 82 toward the heater 87, and the heater 87 is at least 35 ° C. higher than the melting temperature and higher than the melting temperature. You may set so that the temperature below 75 degreeC high temperature (preferably temperature 35 degreeC higher than melting | fusing temperature) may be supplied to the cylinder 3. FIG.

  When the fiber reinforced resin composition is molded using the resin molding machine 1A having the above-described configuration, first, the above-described end material is put into the hopper 41, and the end material is inserted into the cylinder 3 from the hopper port 4 of the cylinder 3. The fiber reinforced resin composition to be supplied into the inside is supplied into the groove 23 of the supply part 24 of the screw 102, and when the screw 102 rotates, the groove 23 of the supply part 24, the groove 23 of the compression part 25, and the metering are measured. In the groove 23 of the part 26, in the groove 23 of the vent part 27, in the groove 23 of the second compression part 28, and in the groove 23 of the second measuring part 29, the material is sequentially conveyed.

  In the supply unit 24, the fiber reinforced resin composition is preheated and melted by the heat supplied from the heater 81 and the heater 82. The fiber reinforced resin composition melted in the supply unit 24 is conveyed to the compression unit 25, and the fiber reinforced resin composition is measured while maintaining the molten state by the heat supplied from the heater 82 and the heater 83 in the compression unit 25. To the unit 26.

  The melted fiber reinforced resin composition is maintained in a molten state by the heat supplied from the heater 84 in the metering unit, and after being further kneaded in the kneading unit 26a, while passing through the vent unit 27, Air or volatile substances contained in the fiber reinforced resin composition are discharged from the cylinder 3 through the vent hole 6.

  Then, the fiber reinforced resin composition that has passed through the vent portion 27 is compressed again in the second compression portion 28 while maintaining the molten state by the heat supplied by the heater 85, the heater 86, and the heater 87. After being measured to a predetermined discharge amount by the second measuring unit 29, it is transported to the breaker plate 51 and the die 54. The fiber reinforced resin composition is cooled and solidified after passing through the die 54, and after being formed into a linear shape, the fiber reinforced resin composition is shortly cut and re-pelletized to form a repellet.

  In the present embodiment, the screw 102 has a second stage part S2 provided continuously to the kneading part 26a, and the gas generated in the cylinder 3 is discharged near the kneading part 26a side of the second stage part S2. Therefore, the fiber reinforced resin composition sufficiently kneaded by the kneading portion 26a can be supplied to the portion of the second stage portion S2 where the vent hole 6 is provided.

  As mentioned above, according to this invention, in addition to the effect in 1st Embodiment, the fiber reinforced resin composition fully kneaded by the kneading part 26a in the part in which the vent hole 6 of 2nd stage part S2 was provided. Therefore, air and volatile substances in the cylinder 3 can be discharged without discharging a fiber-reinforced resin composition that is insufficiently melted from the vent hole 6.

  The present inventors, as the resin molding machine 1 shown in the first embodiment described above, and a fiber reinforced resin composition, Toraycon 1101-G30 manufactured by Toray Industries, Inc. (length of fibrous filler before molding 410 μm, melted) The effect of the present invention was confirmed by performing the following test using a temperature of 225 ° C. and a decomposition start temperature of 350 ° C.).

(Test 1)
In Test 1, the relationship between the shape of the screw 2 of the resin molding machine 1 (that is, the ratio D1 / D3 described above) and the number of rotations of the screw 2, the discharge amount of the resin molding machine 1 and the length of the fibrous filler. Confirmed.

Incorporated into the resin molding machine 1, the ratio L / D of the total length L to the outer diameter D is 36, the length L1 of the supply unit 24 is 500 mm, the length L2 of the compression unit 25 is 500 mm, and the length L3 of the weighing unit 26 is A plurality of screws formed to be the same at 140 mm and have different ratios D1 / D3 (ratio D1 / D3 = 1, 1.2, 1.4, 1.6, 1.8). 2 is produced. Then, the temperature of the heater 71 is set to 330 ° C., the temperature of the heater 72 is set to 330 ° C., the temperature of the heater 73 is set to 260 ° C., the temperature of the heater 74 is set to 260 ° C., and the temperature of the heater 75 is set to 260 ° C. 2, the number of rotations is 90, 130, 170, 200, and 250 rpm, extrusion is performed, and the discharge amount of the fiber reinforced resin composition and the length of the fibrous filler contained in the discharged fiber reinforced resin composition (The average length of 200 arbitrarily selected fibrous fillers) was measured and determined based on the following criteria.
○ The discharge amount is 100 kg / h or more and the length of the fibrous filler is 400 μm or more × The discharge amount is less than 100 kg / h or the length of the fibrous filler is less than 400 μm.

  From the measurement result of Table 1, the above-mentioned criterion is satisfied only when the ratio D1 / D3 is 1 or 1.2 and the rotational speed is 170 rpm or 200 rpm (ie, ◯), otherwise The amount of discharge was insufficient or the length of the fibrous filler was shortened, so that the determination criteria were not satisfied (ie, x). Accordingly, the ratio D1 / D3 of the screw 2 is set to 1.0 or more and 1.2 or less, and the rotation speed of the screw 2 is set to 170 rpm or more and 200 rpm or less, thereby preventing breakage of the fibrous filler. It was revealed from the above-mentioned measurement that a sufficient discharge amount can be obtained.

(Test 2)
In Test 2, the shape of the screw 2 of the resin molding machine 1 (that is, the length L1 of the supply unit 24, the length L2 of the compression unit 25, the length L3 of the measuring unit 26) and the molten state of the fiber reinforced resin composition And the relationship was confirmed.

Built in the resin molding machine 1, the ratio L / D between the total length L and the outer diameter D is 36 and the ratio D1 / D3 is 1.2, and the length of the supply unit 24 with respect to the length L3 of the measuring unit 26 The ratio L1 / L3 of the length L1 and the ratio L2 / L3 of the length L2 of the compression unit 25 to the length L3 of the measuring unit 26 are different from each other (ratio L1 / L3 = 0.5 to 6.5 with an interval of 0.00). A plurality of screws 2 formed so as to have an interval of 0.5 in steps of 5 and a ratio L2 / L3 = 0.5 to 6.5 (part of intervals are 0.6 or 0.4) are manufactured. Then, the temperature of the heater 71 is set to 330 ° C., the temperature of the heater 72 is set to 330 ° C., the temperature of the heater 73 is set to 260 ° C., and the temperature of the heater 74 is set to 260 ° C. The discharged fiber reinforced resin composition was visually observed, and the molten state was determined based on the following criteria.
○ The fiber reinforced resin composition is uniformly kneaded and sufficiently melted.
× The fiber reinforced resin composition has uneven melting, and a portion where the melting was insufficient was confirmed.
Table 2 shows the determination results.

  From the determination result of Table 2, the determination result is good only when the ratio L1 / L3 is 3, 3.5, or 4 and the ratio L2 / L3 is 2.5, 3, or 3.6. (I.e., ◯). Otherwise, the determination result was incorrect (i.e., x). Therefore, the fiber reinforced resin composition can be sufficiently melted by setting the ratio L1 / L3 of the screw 2 to 3 or more and 4 or less and setting the ratio L2 / L3 to 2.5 or more and 3.6 or less. Was revealed from the above measurements.

(Test 3)
In Test 3, the relationship between the temperature setting of the heater 7 of the resin molding machine 1 and the melted state of the fiber-reinforced resin composition and the broken state of the fibrous filler was confirmed.

Incorporated into the resin molding machine 1, the ratio L / D of the total length L to the outer diameter D is 36, the length L1 of the supply unit 24 is 500 mm, the length L2 of the compression unit 25 is 500 mm, and the length L3 of the measuring unit 26 Is manufactured with a diameter of 140 mm and a ratio D1 / D3 of 1.2. The rotational speed of the screw 2 is set to 180 rpm. The combinations of temperatures of the heater 71 and the heater 72 and the heater 73 and the heater 74 are different from each other (the heater 71 and the heater 72 = 200, 230, 260, 300, 330, 360, the heater 73 and the heater 74 = 200, 230, 260, 300, 330, 360), the temperature of the heater 75 is set to be the same as the temperature of the heater 74, extrusion molding is performed, and the discharged fiber reinforced resin composition is visually observed and discharged. The state of breakage of the fibrous filler contained in the obtained fiber reinforced resin composition was confirmed (presence or absence of breakage of arbitrarily extracted 200 fibrous fillers), and the determination was made based on the following criteria .
◎ Good melt condition and almost no breakage of fibrous filler (breakage ratio less than 5%)
○ Good melt condition and little breakage of fibrous filler (breakage ratio less than 20%)
△ Good melting state and little breakage of fibrous filler (breakage ratio less than 20%) but long staying in cylinder causes base resin to be decomposed × insufficiently melted, molten state is good but fibrous filler Table 3 shows the results of determining whether or not the base resin is decomposed (breakage ratio is 20% or more).

  From the determination results shown in Table 3, only when the temperature of the heater 71 and the heater 72 is 300 ° C. or 330 ° C. and the temperature of the heater 73 and the heater 74 is 260 ° C. or 300, the allowable determination result (that is, ◎ , ◯, Δ), and otherwise, at least one of the molten state of the fiber reinforced resin composition and the broken state of the fibrous filler was judged to be incorrect (ie, x). Therefore, the temperatures of the heater 71 and the heater 72 that supply heat to the supply unit 24 are 300 ° C. or higher and 330 ° C. or lower (that is, a temperature that is 50 ° C. lower than the decomposition start temperature and 20 ° C. lower than the decomposition start temperature). And the temperature of the heater 74 for supplying heat to the measuring unit 26 is 260 ° C. or higher and 300 ° C. or lower (that is, 35 ° C. higher than the melting temperature and 75 ° C. lower than the melting temperature). Thus, it has been clarified from the above-mentioned measurement that the molten state of the fiber reinforced resin composition can be improved and the breakage of the fibrous filler can be reduced. In particular, by setting the temperature of the heaters 71 and 72 to 330 ° C. and the temperature of the heaters 73 and 74 to 260 ° C., the best melted state can be obtained and breakage of the fibrous filler can be prevented. I understood.

  In addition, the structure shown in the resin molding machine of each embodiment mentioned above is an example, Comprising: A screw shape, heater arrangement | positioning, temperature, etc. are suitably adjusted with the structure of a resin molding machine, the kind of fiber reinforced resin composition, etc. Is.

  In addition, embodiment mentioned above only showed the typical form of this invention, and this invention is not limited to embodiment. That is, various modifications can be made without departing from the scope of the present invention.

It is sectional drawing of the resin molding machine which shows the 1st Embodiment of this invention. It is a side view of the screw of the resin molding machine of FIG. It is a figure which shows an example of a kneading part. It is a figure which shows another example of a kneading part. It is sectional drawing of the resin molding machine which shows the 2nd Embodiment of this invention.

Explanation of symbols

1, 1A resin molding machine 2, 102 screw 3 cylinder 4 hopper port (first opening)
5 Discharge port (second opening)
6 Vent hole (third opening)
7, 8 Heater 21 Shaft part 22 Flight 23 Groove 24 Supply part 25 Compression part 26 Weighing part 26a Kneading part 27 Vent part 28 Second compression part 29 Second measurement part D1 The outer peripheral surface of the shaft part of the supply part and the tip of the flight Distance D3 Distance between the outer peripheral surface of the shaft portion of the measuring portion and the tip of the flight L1 Length of the supply portion L2 Length of the compression portion L3 Length of the measuring portion S1 First stage portion S2 Second stage portion (Extension part)

Claims (5)

A screw having a shaft portion and a flight erected from the outer peripheral surface of the shaft portion; a cylinder housing the screw therein; a heater for supplying heat into the cylinder; and a base end portion of the cylinder A first opening through which a fiber-reinforced resin composition comprising a base resin and a fibrous filler is supplied, and the melt-kneaded material provided in the tip of the cylinder and melt-kneaded in the cylinder. In a resin molding machine provided with a second opening from which the fiber-reinforced resin composition is discharged,
The screw is disposed on the first opening side and the shaft portion has a constant outer diameter formed in the longitudinal direction thereof, a compression portion connected to the supply portion, a compression portion connected to the compression portion, and the compression portion A measuring portion having an outer diameter of the shaft portion formed constant in its longitudinal direction, and
The ratio of the distance between the outer peripheral surface of the shaft portion of the supply unit and the front end of the flight to the distance between the outer peripheral surface of the shaft portion of the measuring unit and the front end of the flight is 1.0 or more. And 1.2 or less,
The resin molding machine characterized in that the number of rotations of the screw is 170 rpm or more and 200 rpm or less. The ratio of the length of the supply unit to the length of the measuring unit is 3 or more and 4 or less,
2. The resin molding machine according to claim 1, wherein a ratio of a length of the compression unit to a length of the measuring unit is 2.5 or more and 3.6 or less. The temperature of the heater that supplies heat to a portion of the cylinder where the supply unit is disposed is not less than 50 ° C. lower than the decomposition start temperature of the base resin and not more than 20 ° C. lower than the decomposition start temperature. With
A temperature of the heater that supplies heat to a portion of the cylinder in which the metering unit is disposed is lower than a temperature of the heater that supplies heat to a portion of the cylinder in which the supply unit is disposed; The resin molding machine according to claim 1, wherein the temperature is 35 ° C. higher than the melting temperature and 75 ° C. lower than the melting temperature.   The said measurement part is equipped with the kneading part which accelerates | stimulates kneading | mixing of the said fiber reinforced resin composition in the edge part by the side of the said 2nd opening, The Claim 1 characterized by the above-mentioned. Resin molding machine. The screw has an extension part connected to the kneading part; and
The resin molding machine according to claim 4, wherein a third opening for discharging gas generated in the cylinder is provided in the vicinity of the end of the extension portion on the kneading portion side.

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