JP2009096150A - Resin molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin molding machine capable of maintaining the strength improvement of a fiber reinforced resin composition by preventing breakage of a fibrous filler. <P>SOLUTION: The resin molding machine 1 comprises a screw 2 having a shaft part 21 and flights 22; a cylinder 3 holding the screw 2 inside; a hopper opening 4; and a discharge opening 5. The screw 2 comprises a supply part 24 in which the outer diameter of the shaft part 21 is uniformly formed in the longitudinal direction; a compression part 25 continuous with the supply part 24, with outer diameter of the shaft part 21 being formed gradually larger as it goes away from the supply part 24; and a measuring part 26 continuous with the compression part 25, with the outer diameter of the shaft part 21 being uniformly formed in the longitudinal direction. The ratio D1/D3 of a distance D1 between the outer peripheral surface 21a of the shaft part 21 in the supply part 24 and the tip 22a of the flight 22 to a distance D3 between the outer peripheral surface 21a of the shaft part 21 in the measuring part 26 and the tip 22a of the flight 22 is ≥1.2 and ≤1.95. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a resin molding machine including a screw, a cylinder in which the screw is housed, a first opening provided at a base end portion of the cylinder, and a second opening provided at a tip end portion of the cylinder. About.

  A resin composition based on a thermoplastic resin (hereinafter simply referred to as a “resin composition”) is formed, for example, by molding a pellet-shaped molding material (virgin pellet) into a molded product having a desired shape by injection molding. At this time, end materials such as a spool and a runner are generated together with the molded product. Such an end material is separated from a molded product, pulverized, granulated by extrusion molding to form a repellet, and recycled by mixing the repellet with a virgin pellet 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 a base end portion of the cylinder A hopper port for supplying the resin composition into the cylinder, a discharge port for discharging the resin composition melted and kneaded in the cylinder provided at the tip of the cylinder, and heat in the cylinder. And at least a heater for supplying.

  The screw is arranged on the hopper port side in the cylinder and has a supply portion in which the outer diameter of the shaft portion is formed constant. And a measuring portion that is connected to the compression portion 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 measuring unit to the distance of the supply unit 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.
JP 2002-234063 A

  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 such as. And if the repellet with broken fibrous filler is mixed with virgin pellets and injection molded in this way, the mechanical strength of the molded product will be reduced compared to the case of only virgin pellets, so recycling is impossible. There was a problem such as.

  The present invention aims to solve such problems. That is, an object of the present invention is to provide a resin molding machine that can prevent breakage of the fibrous filler and maintain the strength improvement of the fiber-reinforced resin composition.

  In order to solve the above problems and achieve the 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, and housing the screw therein. A 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, and provided at a tip end portion of the cylinder. And a second opening through which the fiber-reinforced resin composition melt-kneaded in the cylinder is discharged, wherein the screw is disposed on the first opening side and the shaft A supply part in which the outer diameter of the part is formed constant in the longitudinal direction, a compression part that is connected to the supply part and that is gradually increased as the outer diameter of the shaft part moves away from the supply part, and the compression Of the shaft and A measuring portion having a constant diameter in the longitudinal direction thereof, and an outer peripheral surface of the shaft portion of the supply portion with respect to a distance between an outer peripheral surface of the shaft portion of the measuring portion and a tip of the flight. Is a resin molding machine characterized in that the distance ratio between the flight and the tip of the flight is 1.2 or more and 1.95 or less.

  A second aspect of the present invention is the resin molding machine according to the first aspect, wherein the supply unit and the compression unit are provided longer than the measuring unit, respectively. Machine.

  According to a third aspect of the present invention, in the resin molding machine according to the first or second aspect, the ratio of the length of the compression section to the length of the measuring section is 2 or more and 4 or less. It is a resin molding machine characterized by being.

  According to a fourth aspect of the present invention, in the resin molding machine according to any one of the first to third aspects, the ratio of the length of the supply unit to the length of the measuring unit is 1 A resin molding machine characterized in that it is 33 or more and 5 or less.

  According to a fifth aspect of the present invention, the resin molding machine according to any one of the first to fourth aspects further includes a heater for supplying heat into the cylinder, A resin molding machine characterized in that a temperature of the heater for supplying heat to a portion where the supply unit is disposed is not lower than -25 ° C and not higher than the melting point of the base resin with respect to the melting point of the base resin. is there.

  According to the invention described in claim 1, the screw is arranged on the first opening side and the outer diameter of the shaft portion is formed to be constant in the longitudinal direction, and the shaft portion is connected to the supply portion and the shaft portion. And a measuring part that is formed so that the outer diameter of the shaft gradually increases as the distance from the supply part increases, and a measuring part that is connected to the compressing part and has a constant outer diameter of the shaft part in its longitudinal direction. 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 and the front end of the flight is 1.2 or more and 1.95 or less, The shearing force received by the fiber reinforced resin composition is reduced, the fibrous filler is hardly broken, and the strength improvement property of the fiber reinforced resin composition can be maintained.

  According to the second aspect of the present invention, since the supply unit and the compression unit are provided longer than the measuring unit, the fiber reinforced resin composition is sufficiently preheated in the supply unit and the fiber is reinforced in the compression unit. The fiber reinforced resin composition can be melted by supplying sufficient heat to the resin composition, and the stress that the melted fiber reinforced resin composition is subjected to by the metering section can be reduced by shortening the metering section.

  According to the invention described in claim 3, since the ratio of the length of the compression portion to the length of the measuring portion is 2 or more and 4 or less, the compression portion becomes long and the fiber reinforced resin composition is formed in the compression portion. Sufficient heat can be supplied to melt the fiber reinforced resin composition by this heat, and the measuring section can be shortened to reduce the stress that the melted fiber reinforced resin composition receives in the measuring section.

  According to the invention described in claim 4, since the ratio of the length of the supply section to the length of the measuring section is 1.33 or more and 5 or less, the supply section becomes long and the fiber reinforced resin in the supply section. The composition can be preheated sufficiently, and the stress applied to the melted fiber reinforced resin composition by the shortening of the metering portion can be reduced.

  According to the fifth aspect of the present invention, the heater is further provided for supplying heat into the cylinder, and the temperature of the heater for supplying heat to the portion where the supply portion in the cylinder is disposed is equal to the melting point of the base resin. On the other hand, since it is −25 ° C. or higher and below the melting point of the base resin, the fiber reinforced resin composition is sufficiently preheated in the supply section, and the fiber reinforced resin composition is melted by the heat supplied in the supply section. The stress applied to the fiber reinforced resin composition can be reduced.

  A resin molding machine according to an embodiment of the present invention will be described below with reference to FIGS. A resin molding machine 1 according to an embodiment of the present invention is, for example, an extrusion molding machine that granulates repellets by re-pelletizing end materials such as spools and runners generated together with a molded product at the time of injection molding of a fiber reinforced resin composition. It is. 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 driving 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 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. When the ratio of the length of the screw 2 to the outer diameter of the screw 2 (the length of the screw 2 / the outer diameter of the screw 2, ie, L / D of the screw 2) is 25 or more and 30 or less, the fiber reinforced resin The stress that the composition receives is preferable. 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. Is formed. 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. . 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 the heater 7 while being conveyed, thereby compressing 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 supply unit 24 is provided longer than the weighing unit 26, and the ratio L1 / L3 of the length L1 of the supply unit 24 to the length L3 of the measurement unit 26 is 1.33 or more and 5 or less. If the ratio is less than 1.33, the fiber reinforced resin composition cannot be sufficiently preheated, and if the ratio is greater than 5, it is not possible to secure the metering portion 26 having a sufficient length.

  The compressing unit 25 shears between the heat supplied from the heater 7 described later 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. To melt the fiber reinforced resin composition. The outer diameter of the shaft portion 21 of the compression portion 25 is formed to gradually increase as it moves away from the supply portion 24 toward the measuring portion 26. The compressing unit 25 is provided longer than the measuring unit 26, and the ratio L2 / L3 of the length L2 of the compressing unit 25 to the length L3 of the measuring unit 26 is 2 or more and 4 or less. If the ratio is smaller than 2, the fiber-reinforced resin composition cannot be sufficiently melted, and if the ratio is larger than 4, the measuring part 26 having a sufficient length cannot be secured.

  The measuring unit 26 conveys the fiber-reinforced resin composition melted by the compression unit 25 toward the discharge port 5 by a certain amount at a certain time. The outer diameter of the shaft portion 21 of the measuring unit 26 is formed to be constant in the longitudinal direction, and is larger than the outer diameter of the shaft portion 21 of the supply unit 24. Ratio D1 of the distance D1 between the outer peripheral surface 21a of the shaft part 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 part 21 of the measuring unit 26 and the front end 22a of the flight 22 / D3 is 1.2 or more and 1.95 or less. Therefore, the compression ratio of the screw 2 (according to JIS B8650, the ratio of the spatial volume formed by the one lead groove 23 of the supply unit 24 and the spatial volume formed by the one lead groove 23 of the measuring unit 26 by the screw 2) is conventionally compared. Is also formed small. When the ratio is less than 1.2, the shear force becomes too small to sufficiently melt the fiber reinforced resin composition. When the ratio is greater than 1.95, many fibrous fillers are formed by the shear force. It breaks.

  As described above, since the measuring unit 26 is shorter than the conventional one, the melted fiber reinforced resin composition cannot be transported toward the discharge port 5 by a certain amount in a certain time, and the shape of the molded product is affected. Since the compression ratio is smaller than before, there is a possibility that the fiber reinforced resin composition cannot be reliably melted and kneaded. However, even if this is the case, when the resin molding machine 1 is an extrusion molding machine that granulates repellets, the strictness required for the shape of the molded product is relatively low. Since it is sufficient if it can be melted reliably, it does not become a big problem.

  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. A wire mesh screen pack 53 is attached to the breaker plate 51. The melted fiber reinforced resin composition from the metering section 26 of the screw 2 passes through the holes of the breaker plate 51, is filtered through the screen pack 53, and is pushed out toward the die 54.

  The breaker plate 51 and the screen pack 53 configured as described above have a function as a filter for removing foreign matters and the like in the melted fiber reinforced resin composition, and increase the back pressure in the cylinder 3 to increase the fiber reinforced resin composition. It also has a function of reliably melting the fiber reinforced resin composition by controlling the flow of the resin. Thereby, for example, the fiber reinforced resin composition can be more reliably melted by the screw 2 having a small compression ratio (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 and the screen pack 53 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 3 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 in the outer wall of the cylinder 3. 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 includes a heater 71 that supplies heat to a portion where the supply unit 24 of the screw 2 in the cylinder 3 is disposed, a heater 72 that supplies heat to a portion where the compression unit 25 is disposed, and a measuring unit 26. The heater 73 that supplies heat to the portion to be heated and the heater 74 that supplies heat to the breaker plate 51 and the die 54 can supply heat at different temperatures to each portion. The temperature of the heater 71 that supplies heat to the portion where the supply unit 24 is disposed is −25 ° C. or higher and lower than the melting point of the base resin with respect to the melting point of the base resin described later, and melts the fiber-reinforced resin composition. Preheat without any problems. The temperatures of the heaters 72, 73, and 74 are set higher than the melting point of the base resin. For example, when the base resin is polybutylene terephthalate, since the melting point is about 225 ° C., the temperature of the heater 71 is about 200 ° C. or more and about 225 ° C. or less, and the temperature of the heaters 72, 73, 74 is about 225 ° C. Higher is preferred.

  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 an epoxy resin, a polyamide resin, a phenol 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. In addition, a fibrous filler is not limited only to these, As long as it is not contrary to the objective of this invention, fibrous fillers other than these may be sufficient.

  Examples of the fiber reinforced resin composition having the above-described configuration include Toraycon 1101-G30 (manufactured by Toray Industries, Inc.) in which 30% of glass fibers as a fibrous filler are 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 this, Unless it is contrary to the objective of this invention, fiber reinforced resin compositions other than this 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. Supply in. The fiber reinforced resin composition is supplied into the groove 23 of the supply part 24 of the screw 2, and when the screw 2 rotates, from the groove 23 of the supply part 24 to the groove 23 of the compression part 25 and the groove 23 of the measuring part 26. It is sequentially transported inward.

  In the supply unit 24, the fiber-reinforced resin composition is sufficiently preheated without being melted by the heat supplied from the heater 71 set to a temperature equal to or lower than the melting point of the base resin. In the compression unit 25, the fiber reinforced resin composition is melted by heat supplied from the heater 72 set to a temperature higher than the melting point of the base resin and a shearing force smaller than that of the conventional one.

  Then, the melted fiber reinforced resin composition passes through the measuring unit 26 provided shorter than the supply unit 24 and the compression unit 25, and is then conveyed to the breaker plate 51, the screen pack 53, and the die 54. The fiber reinforced resin composition passes through the die 54 and is then cooled and solidified. After being formed into a linear shape, the fiber reinforced resin composition is cut into short pieces and re-pelletized to form repellets.

  According to this embodiment, the screw 2 is arranged on the hopper port 4 side and the outer diameter of the shaft portion 21 is formed constant in the longitudinal direction, and the supply portion 24 is connected to the supply portion 24 and the shaft portion 21 A compression unit 25 having an outer diameter that gradually increases as the distance from the supply unit 24 increases, and a measuring unit 26 that is connected to the compression unit 25 and that has a constant outer diameter of the shaft portion 21 in its longitudinal direction. In addition, the distance D1 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 unit 26 and the front end 22a of the flight 22 Since the ratio D1 / D3 is 1.2 or more and 1.95, the shearing force applied to the fiber reinforced resin composition is reduced, the fibrous filler is not easily broken, and the fiber reinforced resin composition is improved in strength. Can maintain That.

  Since the supply unit 24 and the compression unit 25 are provided longer than the measuring unit 26, the fiber reinforced resin composition is sufficiently preheated by the supply unit 24 and sufficient heat is applied to the fiber reinforced resin composition by the compression unit 25. Can be supplied to melt the fiber reinforced resin composition, and the measuring unit 26 can be shortened to reduce the stress that the melted fiber reinforced resin composition receives in the measuring unit 26.

  Since the ratio L2 / L3 of the length L2 of the compression portion 25 to the length L3 of the measuring portion 26 is 2 or more and 4 or less, the compression portion 25 becomes long and the compression portion 25 is sufficient for the fiber reinforced resin composition. Heat can be supplied and the fiber reinforced resin composition can be melted by this heat, and the weighing unit 26 can be shortened to reduce the stress that the melted fiber reinforced resin composition receives on the weighing unit 26.

  Since the ratio L1 / L3 of the length L1 of the supply unit 24 to the length L3 of the measuring unit 26 is 1.33 or more and 5 or less, the supply unit 24 becomes long, and the fiber reinforced resin composition is added by the supply unit 24. While being able to preheat enough, the measurement part 26 becomes short and the stress which the fiber-reinforced resin composition which fuse | melted receives in the measurement part 26 can be made small.

  The heater 7 for supplying heat into the cylinder 3 is further provided, and the temperature of the heater 71 for supplying heat to the portion of the cylinder 3 where the supply unit 24 is disposed is −25 ° C. or higher with respect to the melting point of the base resin. And since it is below melting | fusing point of base resin, while a fiber reinforced resin composition is fully preheated in the supply part 24, a fiber reinforced resin composition does not melt | dissolve with the heat supplied by the supply part 24, and fiber reinforced resin Stress applied to the composition can be reduced.

  Moreover, the inventor of this invention manufactured the resin molding machine 1 described in embodiment mentioned above, and confirmed the effect of this invention.

Example 1
Ratio D1 of the distance D1 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 unit 26 and the front end 22a of the flight 22 A plurality of screws 2 having different / D3 were prepared, and the end materials of the fiber reinforced resin composition were re-pelletized using these screws 2 in the resin molding machine 1 having the above-described configuration. Only the glass fiber was taken out by dissolving the base resin of the obtained repellet in a solvent, and the length of the glass fiber was visually measured from a micrograph of the glass fiber.

  In addition, the screw 2 prepares a total of four ratios D1 / D3 of 1.5, 1.8, 3.0, and 3.8. Each screw 2 has an outer diameter of 20 mm and L / D. 25, the length L1 of the supply unit 24 was 200 mm, the length L2 of the compression unit 25 was 240 mm, the length L3 of the weighing unit 26 was 80 mm, and the rotation speed was 150 rpm.

  Moreover, the resin molding machine 1 was set to D2025 type (made by Toyo Seiki Co., Ltd.). The temperature of the heater 71 was 200 ° C., the temperature of the heater 72 was 250 ° C., the temperature of the heater 73 was 260 ° C., and the temperature of the heater 74 was 270 ° C. Moreover, as a fiber reinforced resin composition, Toraycon 1101-G30 (made by Toray Industries, Inc.) was used.

  The results of Example 1 (each average value of N = 5) are shown in FIG. In FIG. 3, the horizontal axis represents the distance between the outer peripheral surface 21 a of the shaft portion 21 of the supply portion 24 and the front end 22 a of the flight 22 with respect to the distance D3 between the outer peripheral surface 21 a of the shaft portion 21 of the measuring portion 26 and the front end 22 a of the flight 22. The ratio D1 / D3 of the distance D1 between them is shown, and the vertical axis shows the length (GF length) (μm) of the glass fiber in the obtained repellet. As shown in FIG. 3, when the ratio of the screw 2 was 1.5, the length of the glass fiber was 399 μm, which was substantially the same as the length of the glass fiber in the virgin pellet (about 413 μm). When the ratio of the screw 2 was 1.8, the length of the glass fiber was 330 μm, which was about 80% of the length of the glass fiber in the virgin pellet. Further, if the ratio is less than 1.2, the fiber-reinforced resin composition cannot be sufficiently melted, so that extrusion molding cannot be performed. If the ratio is 1.95 or more, about 25% or more glass fibers are formed. It was broken. From the above, it was shown that glass fiber breakage was prevented when the ratio was 1.2 or more and 1.95.

(Example 2)
A plurality of screws 2 having different ratios L2 / L3 of the length L2 of the compressing unit 25 to the length L3 of the measuring unit 26 are prepared, and these screws 2 are used in the resin molding machine 1 having the above-described configuration. The pellets were repelletized. The ratio of the fiber reinforced resin composition melted in the compression part 25 during the re-pelletizing process was measured.

  The screw 2 is located between the outer peripheral surface 21a of the shaft portion 21 of the supply portion 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. The ratio D1 / D3 of the distance D1 is 1.8, and (the length L1 of the supply unit 24, the length L2 of the compression unit 25, the lengths L3 and L2 / L3 of the measuring unit 26) are respectively ( 200 mm, 200 mm, 120 mm, 1.7), (200 mm, 240 mm, 80 mm, 3), (200 mm, 260 mm, 60 mm, 4.3) are prepared in total, and other experimental conditions are the same as in Example 1. Went to.

  The results of Example 2 (each average value of N = 5) are shown in FIG. In FIG. 4, the horizontal axis indicates the ratio L2 / L3 of the length L2 of the compression unit 25 to the length L3 of the measuring unit 26, and the vertical axis indicates the ratio (%) of the melted fiber reinforced resin composition. As shown in FIG. 4, when the ratio is less than 2, the fiber reinforced resin composition is not sufficiently melted, and when the ratio is 2 or more and 4 or less, the fiber reinforced resin composition is about 98% or more. Was melted, indicating that the fiber-reinforced resin composition was sufficiently melted.

(Example 3)
A plurality of screws 2 having different ratios L1 / L3 between the length L3 of the measuring unit 26 and the length L1 of the supply unit 24 are prepared, and the screws 2 are used in the resin molding machine 1 having the above-described configuration to produce a fiber reinforced resin composition. Re-pelletization of the end material of the product was performed. The temperature of the fiber reinforced resin composition preheated by the supply unit 24 during the re-pelletizing process was measured.

  The screw 2 is located between the outer peripheral surface 21a of the shaft portion 21 of the supply portion 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. The ratio D1 / D3 of the distance D1 is 1.8, and (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 L1 / L3) are respectively ( 240 mm, 200 mm, 80 mm, 3), (180 mm, 200 mm, 140 mm, 1.29) and (170 mm, 200 mm, 150 mm, 1.13) were prepared in total, and the other experimental conditions were the same as in Example 1. Went to.

  The results of Example 3 (each average value of N = 5) are shown in FIG. In FIG. 5, the horizontal axis indicates the ratio L1 / L3 of the length L1 of the supply unit 24 to the length L3 of the measuring unit 26, and the vertical axis indicates the temperature (° C.) of the fiber reinforced resin composition. As shown in FIG. 5, when the ratio is smaller than 1.33, the fiber reinforced resin composition is not sufficiently preheated, and when the ratio is 1.33 or more and 5 or less, the fiber reinforced resin composition The temperature was about 198 ° C. to about 200 ° C., indicating that the fiber reinforced resin composition was sufficiently preheated.

Example 4
In the resin molding machine 1 having the above-described configuration, the temperature of the heater 71 that supplies heat to the portion where the supply unit 24 in the cylinder 3 is arranged is changed to re-pelletize the end material of the fiber reinforced resin composition. It was. The temperature of the fiber reinforced resin composition preheated by the supply unit 24 during the re-pelletizing process was measured.

  The temperature of the heater 71 was changed to 200 ° C., 230 ° C., and 260 ° C. The screw 2 is located between the outer peripheral surface 21a of the shaft portion 21 of the supply portion 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. The ratio of the distance D1 was 1.8, and the other experimental conditions were the same as in Example 1.

  The results of Example 4 (each average value of N = 5) are shown in FIG. In FIG. 6, the horizontal axis indicates the temperature (° C.) of the heater 71, and the vertical axis indicates the temperature (° C.) of the fiber reinforced resin composition. As shown in FIG. 6, when the temperature of the heater 71 is 200 ° C., the temperature of the fiber reinforced resin composition is about 195 ° C., and when the temperature of the heater 71 is 225 ° C., the temperature of the fiber reinforced resin composition is about It was 220 ° C. Further, when the temperature of the heater 71 is lower than 200 ° C., the fiber reinforced resin composition is not sufficiently preheated, and when the temperature of the heater 71 is higher than 225 ° C., the fiber reinforced resin composition starts to melt. From the above, it was shown that the fiber reinforced resin composition was sufficiently preheated when the temperature of the heater 71 was about 200 ° C. or higher and about 225 ° C. or lower.

  In the above-described embodiment, the resin molding machine 1 includes one screw 2. However, in this invention, the resin molding machine 1 provided with the some screw 2 may be sufficient. The axes of the plurality of screws 2 may be parallel or oblique.

  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 a lineblock diagram showing the outline of the resin molding machine concerning one embodiment of the present invention. It is a side view which expands and shows the screw shown by FIG. The relationship between the ratio of the distance between the outer peripheral surface of the shaft part of the supply unit and the tip of the flight to the distance between the outer peripheral surface of the shaft part of the measuring unit and the tip of the flight, and the length of the glass fiber in the repellet It is a graph which shows. It is a graph which shows the relationship between the ratio of the length of the compression part with respect to the length of a measurement part, and the ratio of the molten fiber reinforced resin composition. It is a graph which shows the relationship between the ratio of the length of a supply part with respect to the length of a measurement part, and the temperature of the preheated fiber reinforced resin composition. It is a graph which shows the relationship between the temperature of the heater which supplies heat to the part by which a supply part is arranged, and the temperature of the preheated fiber reinforced resin composition.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin molding machine 2 Screw 3 Cylinder 3a Base end part 3b Tip part 4 Hopper port (1st opening)
5 Discharge port (second opening)
7, 71, 72, 73, 74 Heater 21 Shaft portion 21a Outer peripheral surface 22 Flight 22a Tip 24 Supply portion 25 Compression portion 26 Weighing portion D1 Distance between the outer peripheral surface of the shaft portion of the supply portion and the front end of the flight D3 Measuring portion Distance between the outer peripheral surface of the shaft part and the tip of the flight L1 Length of the supply part L2 Length of the compression part L3 Length of the measurement part

Claims (5)

A screw having a shaft portion and a flight erected from the outer peripheral surface of the shaft portion; a cylinder containing the screw therein; a base resin and a fiber provided in the base end portion of the cylinder; And a second opening through which the fiber reinforced resin composition provided at the tip of the cylinder and melted and kneaded in the cylinder is discharged. In a resin molding machine provided with an opening,
A supply portion in which the screw is arranged on the first opening side and the outer diameter of the shaft portion is formed constant in the longitudinal direction; and the outer diameter of the shaft portion is connected to the supply portion and the supply portion A compression portion that is formed to be gradually larger as it is separated from, and a measuring portion that is continuous with the compression portion and has a constant outer diameter of the shaft portion in the longitudinal direction,
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 1.2 or more. And the resin molding machine characterized by being 1.95 or less.   The resin molding machine according to claim 1, wherein each of the supply unit and the compression unit is provided longer than the weighing unit.   3. 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 or more and 4 or less.   The resin molding according to any one of claims 1 to 3, wherein a ratio of the length of the supply unit to the length of the measuring unit is 1.33 or more and 5 or less. Machine. A heater for supplying heat into the cylinder;
The temperature of the heater that supplies heat to a portion of the cylinder where the supply unit is disposed is -25 ° C or higher and lower than the melting point of the base resin with respect to the melting point of the base resin. The resin molding machine as described in any one of Claims 1 thru | or 4.

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