Method for setting molding condition

Abstract

To provide a technique for determining an optimal molding condition under an environmental condition at a place where a molded article is produced.SOLUTION: A method for setting a molding condition for an injection molding machine that molds a molded article comprises the steps of: (a) adjusting temperature and humidity around the injection molding machine; (b) acquiring moisture content of a material used for molding of the molded article; (c) setting a plurality of molding conditions for the molded article by the injection molding machine; (d) molding the molded article under the plurality of molding conditions by injecting a plasticized material obtained by plasticizing the material by the injection molding machine, into a mold under the environmental condition including the temperature and the humidity adjusted in the step (a), and the moisture content acquired in the step (b); and (e) determining an optimal condition of molding condition under the above environmental condition on the basis of the quality of the molded article molded in the step (d). In the step (a), the temperature is adjusted to a temperature of the place where the molded article is produced, and the humidity is adjusted to a humidity of the place where the molded article is produced.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to a method for setting molding conditions.

Background Art

[0002] Patent Document 1 discloses a method for optimizing molding conditions of an injection molding machine, in which a trial shot test is carried out under good product molding conditions to measure the variation range of molding variables resulting from environmental changes, and updated molding conditions for correcting the molding variables are created based on the measured variation range.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Optimal molding conditions for molding a molded product vary depending on environmental conditions including the temperature and humidity around the injection molding machine. Therefore, a technique for determining the optimal molding conditions under the environmental conditions at the location where the molded product is produced is desired.

Means for Solving the Problems

[0005] According to a first aspect of the present disclosure, there is provided a method for setting molding conditions of an injection molding machine for molding a molded product. This method for setting molding conditions includes: (a) a step of adjusting the temperature and humidity around the injection molding machine; (b) a step of obtaining the moisture content of the material used for molding the molded product; (c) a step of setting a plurality of molding conditions for molding the molded product by the injection molding machine; (d) a step of molding the molded product under a plurality of the molding conditions by injecting a plasticized material obtained by plasticizing the material by the injection molding machine into a mold under environmental conditions including the temperature and humidity adjusted in the step (a) and the moisture content obtained in the step (b); and (e) a step of determining an optimal condition of the molding conditions under the environmental conditions based on the quality of the molded product molded in the step (d). In the step (a), the temperature is adjusted to the temperature of the place where the molded product is produced, and the humidity is adjusted to the humidity of the place where the molded product is produced.

Brief Description of the Drawings

[0006]

Figure 1

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Figure 10

Embodiments for Carrying Out the Invention

[0007] A. First Embodiment: FIG. 1 is an explanatory diagram showing a schematic configuration of a molding condition setting system 100. In FIG. 1, arrows indicating the X, Y, and Z directions orthogonal to each other are shown. The X direction and the Y direction are directions parallel to the horizontal plane. The Z direction is a direction parallel to the vertical direction. The X, Y, and Z directions in FIG. 1 indicate the same directions as the X, Y, and Z directions in other figures. When specifying a direction, the positive direction, which is the direction indicated by the arrow, is denoted as "+", and the negative direction, which is the direction opposite to the direction indicated by the arrow, is denoted as "-", and positive and negative signs are used in combination in the direction notation. The molding condition setting system 100 includes an injection molding system 10, a control device 80, and a thermo-hygrostat 90.

[0008] The injection molding system 10 includes a material supply unit 20, an injection molding unit 30, an inspection and storage unit 40, and a controller 50. The material supply unit 20, the injection molding unit 30, and the inspection and storage unit 40 are arranged in this order side by side from the -X direction to the +X direction. Each unit is detachably connected to another adjacent unit. Each unit includes a box-shaped housing, and one or more devices, members, etc. are integrated inside the housing to form one unit. Hereinafter, the housing of the material supply unit 20 is also referred to as the first housing 21, the housing of the injection molding unit 30 is also referred to as the second housing 31, and the housing of the inspection and storage unit 40 is also referred to as the third housing 41. The first housing 21 includes a first base 22 and a first cover 23 that covers the upper surface of the first base 22. The second housing 31 includes a second base 32 and a second cover 33 that covers the upper surface of the second base 32. The third housing 41 includes a third base 42 and a third cover 43 that covers the upper surface of the third base 42. The first cover 23, the second cover 33, and the third cover 43 are provided such that the spaces inside the respective covers communicate with each other. Hereinafter, the first cover 23, the second cover 33, and the third cover 43 are collectively simply referred to as the cover.

[0009] The controller 50 is provided inside the second base 32. The controller 50 is constituted by a PLC (Programmable Logic Controller). The controller 50 controls the coordinated operation of various devices provided in each unit by being programmed in a language such as ladder language. The controller 50 is connected to the control device 80.

[0010] Figure 2 is an explanatory diagram showing the schematic configuration of the control device 80. The control device 80 is constituted by a computer including a processing unit 81, a storage unit 82, and a communication unit 83. The processing unit 81 includes one or more processors. The processing unit 81 controls the operation of each part of the injection molding system 10 by executing the program stored in the storage unit 82. The storage unit 82 is constituted by a main storage device such as a RAM and an auxiliary storage device such as a hard disk drive. Note that the control device 80 may be realized by a configuration in which a plurality of circuits for realizing at least a part of each function are combined instead of being constituted by a computer. An input device 84 such as a keyboard and a mouse and a display device 85 such as a liquid crystal display are connected to the control device 80. Note that the input device 84 and the display device 85 may be integrated as a touch panel. The control device 80 may be a server. Also, the control device 80 may be constituted by a plurality of computers. The control device 80 may be constituted by, for example, one computer and a plurality of servers.

[0011] The thermo-hygrostat 90 is connected by the inside of the cover and the duct 91. The thermo-hygrostat 90 adjusts the temperature and humidity inside the cover.

[0012] Figure 3 is a perspective view of each unit with the cover removed.

[0013] The material supply unit 20 includes a material dryer 24 and a material supply section 25. The material dryer 24 stores the material used for molding the molded product. The material stored in the material dryer 24 is dehumidified and dried within the material dryer 24. As the material, for example, thermoplastic resins such as polypropylene resin (PP), polyethylene resin (PE), and polyacetal resin (POM) are used. The material supply section 25 is a loader equipped with a conveyor for transporting the material. The material in the material dryer 24 is supplied by the material supply section 25 to the hopper 111 of the injection molding machine 110 provided in the injection molding unit 30.

[0014] The injection molding unit 30 includes an injection molding machine 110, a spectrometer 120, a mold temperature controller 130, a take-out device 140, a transport device 150, and a gate cutting device 160. The injection molding machine 110, the spectrometer 120, the take-out device 140, the transport device 150, and the gate cutting device 160 are installed on the second base 32. The mold temperature controller 130 is housed inside the second base 32.

[0015] The injection molding machine 110 is configured to be able to mount a mold. The injection molding machine 110 includes a hopper 111, an injection section 112, and a mold clamping section 113. The hopper 111 stores the material supplied from the material supply section 25. The hopper 111 is preferably formed of a material that transmits infrared rays. The injection section 112 plasticizes the material supplied from the hopper 111 to generate a plasticized material, and injects the generated plasticized material into the cavity of the mold. The mold clamping section 113 opens and closes the mold mounted on the injection molding machine 110. The injection section 112 and the mold clamping section 113 are arranged side by side in the horizontal direction.

[0016] Figure 4 is a cross-sectional view showing the schematic configuration of the injection molding machine 110. The injection section 112 includes a plasticizing section 201, a suction and delivery section 202, and a nozzle 203.

[0017] The plasticizing unit 201 plasticizes at least a part of the material supplied from the hopper 111 to generate a plasticized material. Here, "plasticizing" is a concept that includes melting and means changing from a solid state to a state with fluidity. Specifically, in the case of a material that undergoes a glass transition, plasticizing means raising the temperature of the material above the glass transition point. In the case of a material that does not undergo a glass transition, plasticizing means raising the temperature of the material above the melting point. The plasticizing unit 201 includes a screw 210, a barrel 220, and a heater 230.

[0018] The screw 210 is housed in a screw case 211. The screw 210 is connected to a drive motor 212 and rotates within the screw case 211 by the rotational driving force generated by the drive motor 212. The axial direction of the rotation axis RX of the screw 210 is a direction along the X direction. The rotation speed of the screw 210 is controlled by the controller 50 controlling the rotation speed of the drive motor 212. Note that the screw 210 may be driven by the drive motor 212 via a speed reducer. The screw 210 is also called a rotor or a flat screw.

[0019] The barrel 220 is installed on the +X direction side of the screw 210. A communication hole 221 is formed at the center of the barrel 220. The communication hole 221 forms at least a part of a flow path 240 through which the plasticized material flows. An injection cylinder 251, which will be described later, is connected to the communication hole 221. A check valve 222 is provided in the communication hole 221 upstream of the injection cylinder 251. A heater 230 is provided inside the barrel 220. The temperature of the heater 230 is controlled by the controller 50.

[0020] FIG. 5 is a perspective view showing a schematic configuration of the screw 210. The screw 210 has a substantially cylindrical shape in which the length in the direction along the rotation axis RX is smaller than the length in the direction perpendicular to the rotation axis RX. On the groove forming surface 213 of the screw 210 facing the barrel 220, a spiral groove 215 is formed around the central portion 214. The groove 215 communicates with a material inlet 216 formed on the side surface of the screw 210. The material supplied from the hopper 111 is supplied to the groove 215 through the material inlet 216. The groove 215 is formed by being separated by the rib portion 217. FIG. 5 shows an example in which three grooves 215 are formed, but the number of grooves 215 may be one or two or more. Note that the groove 215 is not limited to a spiral shape, and may be a helical shape or an involute curve shape, or may be a shape extending in an arc from the central portion 214 toward the outer periphery.

[0021] FIG. 6 is a schematic plan view of the barrel 220. The barrel 220 has a facing surface 223 facing the groove forming surface 213 of the screw 210. A communication hole 221 is formed at the center of the facing surface 223. A plurality of guide grooves 224 are formed on the facing surface 223, which are connected to the communication hole 221 and extend spirally from the communication hole 221 toward the outer periphery. The material supplied to the groove 215 of the screw 210 is plasticized between the screw 210 and the barrel 220 by the rotation of the screw 210 and the heating of the heater 230, and flows along the groove 215 and the guide groove 224 by the rotation of the screw 210, and is guided to the central portion 214 of the screw 210. The material flowing into the central portion 214 flows out from the communication hole 221 provided at the center of the barrel 220 to the suction and delivery portion 202. Note that the barrel 220 may not be provided with the guide groove 224. Also, the guide groove 224 may not be connected to the communication hole 221.

[0022] The suction and delivery unit 202 includes an injection cylinder 251, a plunger 252, and a plunger drive unit 253. The suction and delivery unit 202 has a function of injecting and injecting the plasticized material in the injection cylinder 251 into the cavity of the mold 900. The suction and delivery unit 202 controls the injection amount, injection speed, and injection pressure of the plasticized material from the nozzle 203 under the control of the controller 50. The injection cylinder 251 is a substantially cylindrical member connected to the communication hole 221 of the barrel 220, and is provided with a plunger 252 inside. The plunger 252 slides inside the injection cylinder 251 and pumps the plasticized material in the injection cylinder 251 to the nozzle 203. The plunger 252 is driven by a plunger drive unit 253 constituted by a motor.

[0023] A flow path 240 is formed in the nozzle 203. When the plunger 252 pumps the plasticized material in the injection cylinder 251 to the nozzle 203, the plasticized material is injected from the nozzle 203 into the mold 900.

[0024] The mold clamping unit 113 opens and closes the mold 900 mounted on the injection molding machine 110. The mold clamping unit 113 rotates the ball screw 262 by driving the motor 261 under the control of the controller 50, and moves the movable mold 901 coupled to the ball screw 262 relative to the fixed mold 902 to open and close the mold 900.

[0025] The spectrometer 120 shown in FIG. 3 is provided in the hopper 111. The spectrometer 120 measures the moisture content of the material stored in the hopper 111. The spectrometer 120 measures the moisture content of the material, for example, by irradiating the material in the hopper 111 with near-infrared light and measuring the light reflected without being absorbed by the material.

[0026] The mold temperature regulator 130 circulates a heat medium through the cooling pipes provided in the mold 900 to adjust the temperature of the mold 900.

[0027] The take-out device 140 is a device that takes out the molded product molded by the injection molding machine 110 from the injection molding machine 110. The take-out device 140 is arranged on the -Y direction side of the injection molding machine 110. The take-out device 140 is composed of a hand for gripping the molded product and a linear actuator for moving the hand along the X direction and the Y direction. The take-out device 140 takes out the molded product from the injection molding machine 110 with the hand, and moves the molded product taken out from the injection molding machine 110 to the end on the -X direction side of the conveying device 150 by the linear actuator and places it on the conveying device 150.

[0028] The conveying device 150 is a device that conveys the molded product taken out by the take-out device 140. The conveying device 150 is arranged on the -Y direction side of the injection molding machine 110 and on the +X direction side of the take-out device 140. The conveying device 150 is composed of a linear actuator capable of moving the molded product along the X direction. The conveying device 150 moves the molded product placed on the conveying device 150 by the take-out device 140 from the end on the -X direction side to the end on the +X direction side. On the conveying device 150, a gate cutting device 160 for cutting the gate portion and the runner remaining on the molded product is arranged. The molded product being conveyed on the conveying device 150 has the gate portion and the runner cut during conveyance by the gate cutting device 160.

[0029] The inspection and storage unit 40 includes a robot 310, an inspection device 320, and a stacking mechanism 330.

[0030] The robot 310 is a device that moves the molded product conveyed by the conveying device 150. The robot 310 is configured as a scalar robot. The robot 310 holds the molded product conveyed to the end on the +X direction side of the conveying device 150 by the conveying device 150 and moves it to the inspection device 320. Also, the robot 310 moves the molded product for which the inspection by the inspection device 320 has been completed to the pallet PL of the stacking mechanism 330. Note that the robot 310 is not limited to a scalar robot and may be configured by a vertical articulated robot having a plurality of axes.

[0031] The inspection device 320 inspects the molded products molded by the injection molding machine 110. The inspection device 320 includes an inspection table 321 on which the molded products are placed, an imaging unit 322 that captures images of the molded products placed on the inspection table 321, and a weight measurement unit 323 that measures the weight of the molded products.

[0032] The imaging unit 322 is a camera equipped with an image sensor such as a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor) sensor, and also has an attached lighting unit. The inspection device 320 captures an image of the molded product on the inspection table 321 by the imaging unit 322, analyzes the captured image, and performs an appearance inspection including the shape of the molded product. After the appearance inspection is completed, the molded product is moved to the weight measurement unit 323 by the robot 310.

[0033] The weight measurement unit 323 is composed of a weight sensor such as a load cell. The inspection device 320 measures the weight of the molded product placed on the weight measurement unit 323. After the inspection is completed, the molded product is moved to the pallet PL by the robot 310. Note that the molded products determined to be defective by the inspection device 320 are discharged by the robot 310 to a defective product discharge area (not shown).

[0034] The stacking mechanism 330 is a mechanism for stacking pallets PL on which molded products are placed. The stacking mechanism 330 includes a first placement part 331 and a second placement part 332. The pallet PL is placed on each of the first placement part 331 and the second placement part 332. The first placement part 331 mounts the pallet PL on which a plurality of molded products inspected by the inspection device 320 are placed. The robot 310 transports the molded products to the pallet PL mounted on the first placement part 331. When a predetermined number of molded products are placed on the pallet PL, the first placement part 331 lowers the pallet PL into the interior of the second housing 31. The second placement part 332 slides and moves the pallet PL mounted on the top of the lowered first placement part 331. A plurality of pallets PL are stacked in the vertical direction on the second placement part 332. When the topmost pallet PL moves to the first placement part 331, the second placement part 332 raises the remaining pallets PL.

[0035] Figure 7 is a process diagram of the molding condition setting process. The molding condition setting process realizes a method for setting the molding conditions of the injection molding machine 110 for molding molded products. In the molding condition setting process, first, the optimum condition determination process is executed in step S1, and then the molded product production process is executed in step S2.

[0036] Figure 8 is a process diagram of the optimum condition determination process. First, in step S10, the thermo-hygrostat 90 adjusts the temperature inside the cover to the temperature of the location where the molded product is produced, and adjusts the humidity inside the cover to the humidity of the location where the molded product is produced. That is, the thermo-hygrostat 90 adjusts the temperature around the injection molding machine 110 to the temperature of the location where the molded product is produced, and adjusts the humidity around the injection molding machine 110 to the humidity of the location where the molded product is produced. Here, the location where the molded product is produced is, for example, a factory where the molded product is produced using the injection molding machine, the shipping destination or rental destination of the injection molding machine.

[0037] In step S20, the spectrometer 120 obtains the moisture content of the material stored in the hopper 111. Hereinafter, the temperature around the injection molding machine 110, the humidity around the injection molding machine 110, and the moisture content of the material are collectively referred to as environmental conditions.

[0038] In step S30, the control device 80 sets the set value of the factors related to the molding of the molded product. The factors include the temperature of the mold 900, the temperature of the plasticized material, the pressure of the plasticized material, the injection speed of the plasticized material, and the cooling time of the mold 900. Here, the cooling time of the mold 900 is the time required for cooling the mold 900 after the plasticized material is filled into the mold 900. The control device 80 may set the value input by the user to the control device 80 via the input device 84 as the set value of the factor, or may set a predetermined value as the set value of the factor. Hereinafter, the set value of the factor is simply referred to as the set value.

[0039] In step S40, the control device 80 sets a plurality of molding conditions for the molded product by the injection molding machine 110. The molding conditions have a plurality of parameters such as barrel temperature, injection pressure, holding time, screw rotation speed, etc. The control device 80 sets the molding conditions so that the effective value of the factor in the process of molding the molded product becomes a value close to the set value set in step S30. Here, the effective value of the factor means the actual value of the factor in the process where the molded product is molded. Hereinafter, the effective value of the factor will be simply referred to as the effective value. For example, the temperature of the plasticized material varies depending on the barrel temperature. The control device 80 sets the barrel temperature so that the effective value of the temperature of the plasticized material in the process of molding the molded product becomes a value close to the set value. Also, the pressure of the plasticized material and the injection speed of the plasticized material vary depending on the injection pressure and the holding time. Here, the injection pressure is the pressure with which the plunger 252 extrudes the plasticized material toward the nozzle 203. The control device 80 sets the injection pressure and the holding time so that the effective value of the pressure of the plasticized material in the process of molding the molded product becomes a value close to the set value. Also, the control device 80 sets the injection pressure and the holding time so that the effective value of the injection speed of the plasticized material in the process of molding the molded product becomes a value close to the set value.

[0040] Also, in step S40, the control device 80 sets a first molding condition and a second molding condition in which a first parameter, which is a parameter included in the first molding condition, is different from the first molding condition. The first parameter may be a parameter determined by the control device 80 or a parameter specified by the user operating the input device 84. For example, when the first parameter is the barrel temperature and the barrel temperature in the first molding condition is 200°C, the control device 80 sets the barrel temperature in the second molding condition to 210°C. Note that the first parameter is not limited to one parameter and may be a plurality of parameters. The control device 80 may set a plurality of different molding conditions including the first molding condition and the second molding condition, not limited to the first molding condition and the second molding condition.

[0041] In step S50, the injection molding machine 110 forms a molded product under the environmental conditions including the temperature and humidity adjusted in step S10 and the moisture content of the material acquired in step S20, by injecting the plasticized material into the mold 900, under a plurality of molding conditions set in step S40. That is, the injection molding machine 110 forms a molded product under the first molding condition and the second molding condition. Hereinafter, the molded product formed under the first molding condition is referred to as the first molded product, and the molded product formed under the second molding condition is referred to as the second molded product.

[0042] In step S50, steps S51 and S52 are executed. In step S51, the control device 80 monitors the effective value of the factor during the period when the molded product is being formed. FIG. 9 is a diagram showing an example of the time change of the effective value. The horizontal axis of FIG. 9 represents the elapsed time, and the vertical axis represents the effective value of the pressure of the plasticized material. FIG. 9 shows the time change of the effective value of the pressure of the plasticized material.

[0043] In step S52, the control device 80 stores in the storage unit 82 first information associating the environmental conditions under which the molded product was formed, the molding conditions used for molding the molded product, and the effective value when the molded product was formed. In other words, the first information is information associating the environmental conditions including the temperature and humidity adjusted in step S10 and the moisture content of the material acquired in step S20, the molding conditions set in step S40, and the effective value when the molded product was formed under the above environmental conditions under the above molding conditions.

[0044] In step S60, the inspection device 320 inspects the molded product molded in step S50.

[0045] In step S70, the control device 80 determines the optimum conditions of the molding conditions under the environmental conditions including the temperature and humidity adjusted in step S10 and the moisture content of the material acquired in step S20, based on the quality of the molded product molded in step S50. The control device 80 determines, as the optimum conditions, the molding conditions under which the molded product with the best quality among the molding conditions set in step S40 is molded. The molded product with the best quality is, for example, a molded product without defects in appearance, and the dimensions and weight of the molded product are closest to the standard values of the dimensions and weight of the molded product, respectively. In other words, the control device 80 selects the optimum conditions from among the first molding conditions and the second molding conditions according to the comparison result between the first molded product and the second molded product. The control device 80 determines, as the optimum conditions, the molding conditions under which a molded product with better quality is molded among the first molding conditions and the second molding conditions. As described above, the optimum condition determination process is executed.

[0046] FIG. 10 is a process diagram of the molded product production process. The molded product production process is executed at the "location where the molded product is produced" described in step S10 of the optimum condition determination process. As described in step S10, the temperature and humidity at the location where the molded product is produced are the same as the temperature and humidity around the injection molding machine 110 adjusted in step S10, respectively. The molding condition setting system used in the molded product production process may be a system that does not include the thermo-hygrostat 90 and the cover. Also, the injection molding machine used in the molded product production process may be the same injection molding machine as the injection molding machine 110 used in the optimum condition determination process, or another injection molding machine.

[0047] In step S110, the injection molding machine 110 molds a molded product under the environmental conditions including the temperature and humidity adjusted in step S10 of the optimum condition determination process and the moisture content of the material acquired in step S20, at the optimum conditions determined in step S70. The moisture content of the material stored in the hopper 111 of the injection molding machine 110 is the same as the moisture content acquired in step S20. If the moisture content of the material stored in the hopper 111 is different from the moisture content acquired in step S20, the material is dried by the material dryer 24 so that they become equal.

[0048] In step S120, the control device 80 determines whether the effective value of the factor has varied outside a predetermined range. If the effective value has varied outside the predetermined range, step S130 is executed. If the effective value has not varied outside the predetermined range, step S140 is executed. Note that the control device 80 may determine whether an abnormality appears in the waveform of the graph showing the time change of the effective value as shown in FIG. 9, and execute step S130 when an abnormality appears, and execute step S140 when there is no abnormality.

[0049] In step S130, the control device 80 corrects the optimum conditions based on the first information. For example, when the temperature of the plasticized material, which is one of the factors, falls below a predetermined lower limit value, the control device 80 corrects the barrel temperature of the optimum conditions so that the temperature of the plasticized material rises. The control device 80 corrects the barrel temperature of the optimum conditions to a value obtained by multiplying the barrel temperature of the optimum conditions by a coefficient. The above-described coefficient is a value calculated from the relationship between the effective value of the temperature of the plasticized material included in the first information and the barrel temperature, and by multiplying the barrel temperature of the optimum conditions by the above-described coefficient, the temperature of the plasticized material becomes a value exceeding the predetermined lower limit value. After step S130 is executed, step S110 is executed. Thereby, a molded product is molded under the corrected optimum conditions.

[0050] In step S140, the control device 80 determines whether or not a predetermined number of molded products have been molded. If a predetermined number of molded products have been molded, the control device 80 ends the molded product production process. If a predetermined number of molded products have not been molded, the control device 80 returns the process to step S110. In the manner described above, the molded product production process is executed.

[0051] According to the first embodiment described above, molded products are molded under a plurality of molding conditions under the environmental conditions of the location where the molded products are produced, and the optimal conditions of the molding conditions are determined based on the quality of the molded products thus molded. Here, the environmental conditions of the location where the molded products are produced are reproduced by adjusting the temperature and humidity around the injection molding machine 110 to the temperature and humidity of the location where the molded products are produced, respectively. Therefore, the optimal molding conditions under the environmental conditions of the location where the molded products are produced can be determined. Also, since the optimal conditions at the location where the molded products are produced can be determined at a location where the temperature and humidity are different from those at the location where the molded products are produced, it is not necessary to investigate the optimal conditions at the location where the molded products are produced. Further, even when the temperature and humidity of the location where the molded products are produced change with the seasons, the optimal conditions corresponding to the seasons can be determined.

[0052] Also, in the present embodiment, the optimal conditions are selected from among the first molding conditions and the second molding conditions according to the comparison result between the first molded product and the second molded product. Therefore, the molding conditions under which a molded product of better quality is molded out of the first molding conditions and the second molding conditions can be determined as the optimal conditions.

[0053] Also, in the present embodiment, the moisture content of the material used for molding the molded product is measured by the spectrometer 120. Therefore, the moisture content of the material can be measured from the outside of the portion where the material is stored.

[0054] Also, in the present embodiment, the spectrometer 120 is arranged in the hopper 111 where the material is stored. Therefore, the moisture content of the material immediately before being used for molding the molded product can be measured.

[0055] In addition, in the present embodiment, the molding conditions are set such that the effective value of the factor in the process of molding the molded product is close to its set value. Therefore, compared with the case where there is no restriction on the setting of the molding conditions, the range of the molding conditions that can be set can be narrowed. As a result, the number of the molding conditions to be set can be reduced, and the time required for determining the optimum conditions can be shortened.

[0056] In addition, in the present embodiment, in the process of molding the molded product, first information including environmental conditions, molding conditions, and the effective value when the molded product is molded under the molding conditions under the environmental conditions is stored in the storage unit 82. Therefore, after the molded product is molded, the user can check the first information.

[0057] In addition, in the present embodiment, in the process of the injection molding machine 110 molding the molded product under the optimum conditions, when the effective value fluctuates outside a predetermined range, the optimum conditions are corrected based on the first information. Therefore, when the quality of the molded product deteriorates during the molding of the molded product under the optimum conditions, the quality of the molded product can be improved.

[0058] B. Other Embodiments: (B-1) In the above embodiment, the moisture content of the material used for molding is measured by the spectrometer 120. In contrast, the moisture content of the material used for molding may be measured by a device other than the spectrometer.

[0059] (B-2) In the above embodiment, the spectrometer 120 is disposed in the hopper 111 in which the material is stored. In contrast, the spectrometer 120 may be disposed not only in the hopper 111 but also at a position where the moisture content of the material can be measured.

[0060] (B-3) In the above embodiment, in step S30 of the optimal condition determination process, the set value of the factor is set, and in step S40, the molding conditions are set so that the effective value of the factor in the process of molding the molded product is close to the set value. In contrast, in the optimal condition determination process, the set value of the factor may not be set. That is, step S30 of the optimal condition determination process may not be executed.

[0061] (B-4) In the above embodiment, the factors include the temperature of the mold 900, the temperature of the plasticized material, the pressure of the plasticized material, the injection speed of the plasticized material, and the cooling time of the mold 900. In contrast, the factors may include at least any one of the temperature of the mold 900, the temperature of the plasticized material, the pressure of the plasticized material, the injection speed of the plasticized material, and the cooling time of the mold 900.

[0062] (B-5) In the above embodiment, in step S52 of the optimal condition determination process, the first information including the environmental conditions, the molding conditions, and the effective value when the molded product is molded under the molding conditions under the environmental conditions is stored in the storage unit 82. In contrast, in the process of molding the molded product, the first information may not be stored in the storage unit 82. That is, step S52 of the optimal condition determination process may not be executed.

[0063] (B-6) In the above embodiment, in the molding condition setting process, the molded product production process is executed. In contrast, the molded product production process may not be executed.

[0064] C. Other Forms: The present disclosure is not limited to the above-described embodiments and can be implemented in various forms without departing from the gist thereof. For example, the present disclosure can also be implemented in the following forms. The technical features in the above-described embodiments corresponding to the technical features in each of the following forms can be appropriately replaced or combined in order to solve some or all of the problems of the present disclosure or to achieve some or all of the effects of the present disclosure. Further, if the technical feature is not described as essential in this specification, it can be appropriately deleted.

[0065] (1) According to one aspect of the present disclosure, a method for setting molding conditions of an injection molding machine for molding a molded product is provided. This method for setting molding conditions includes: (a) a step of adjusting the temperature and humidity around the injection molding machine; (b) a step of obtaining the moisture content of the material used for molding the molded product; (c) a step of setting a plurality of molding conditions for molding the molded product by the injection molding machine; (d) a step of molding the molded product under a plurality of the molding conditions by injecting a plasticized material obtained by plasticizing the material by the injection molding machine into a mold under environmental conditions including the temperature and humidity adjusted in the step (a) and the moisture content obtained in the step (b); and (e) a step of determining an optimum condition of the molding conditions under the environmental conditions based on the quality of the molded product molded in the step (d). In the step (a), the temperature is adjusted to the temperature of the place where the molded product is produced, and the humidity is adjusted to the humidity of the place where the molded product is produced. According to such an aspect, an optimum molding condition under environmental conditions of the place where the molded product is produced can be determined.

[0066] (2) In the above-described embodiment, in the step (c), a first molding condition and a second molding condition in which a first parameter, which is a parameter included in the first molding condition, is different from the first molding condition are set. The step (d) includes a step in which the injection molding machine molds a first molded product under the first molding condition and a step in which the injection molding machine molds a second molded product under the second molding condition. In the step (e), the optimal condition may be selected from among the first molding condition and the second molding condition according to the comparison result between the first molded product and the second molded product. According to such a form, it is possible to determine, as the optimal condition, the molding condition under which a molded product with better quality is molded, from among the first molding condition and the second molding condition.

[0067] (3) In the above-described embodiment, in the step (b), the moisture content may be measured by a spectrometer. According to such a form, the moisture content of the material can be measured from the outside of the portion where the material is stored.

[0068] (4) In the above-described embodiment, the spectrometer may be arranged in the hopper in which the material is stored. According to such a form, the moisture content of the material immediately before being used for molding the molded product can be measured.

[0069] (5) In the above-described embodiment, (f) further includes a step of setting a set value of a factor related to the molding of the molded product, which is a factor adjusted according to the environmental conditions. In the step (c), the molding condition is set so that the effective value of the factor in the step (d) becomes a value close to the set value. The factor may include at least any one of the temperature of the mold, the temperature of the plasticized material, the pressure of the plasticized material, the injection speed of the plasticized material, and the cooling time of the mold. According to such a form, compared with the case where there is no limitation on setting the molding condition, the range of the settable molding condition can be narrowed. Thereby, the number of set molding conditions can be reduced, and the time required for determining the optimal condition can be shortened.

[0070] (6) In the above-described aspect, the step (d) may include a step of monitoring the effective value, a step of storing, in a storage unit, first information associating the environmental conditions, the molding conditions, and the effective value when the molded product is molded under the molding conditions under the environmental conditions. According to such an aspect, after the molded product is molded, the user can check the first information.

[0071] (7) In the above-described aspect, the injection molding machine may further include a step (g) of molding the molded product under the optimum conditions under the environmental conditions. In the step (g), when the effective value fluctuates outside a predetermined range, the optimum conditions may be corrected based on the first information. According to such an aspect, when the quality of the molded product deteriorates during molding the molded product under the optimum conditions, the quality of the molded product can be improved.

Description of Reference Numerals

[0072] 10…Injection molding system, 20…Material supply unit, 21…First housing, 22…First base, 23…First cover, 24…Material dryer, 25…Material supply section, 30…Injection molding unit, 31…Second housing, 32…Second base, 33…Second cover, 40…Inspection storage unit, 41…Third housing, 42…Third base, 43…Third cover, 50…Controller, 80…Control device, 81…Processing section, 82…Memory section, 83…Communication section, 84…Input device, 85…Display device, 90…Thermostat and humidistat, 91…Duct, 100…Molding condition setting system, 110…Injection molding machine, 111…Hopper, 112…Injection section, 113…Clamping section, 120…Spectrometer, 130…Mold temperature controller, 140…Take-out device, 150…Conveyor, 160…Gate cutting device, 201…Plasticizing section, 202…Suction and delivery section, 203…Nozzle, 210…Screw, 211…Screw case, 212…Drive motor, 213…Groove forming surface, 214…Central part, 215…Groove, 216…Material inlet, 217…Ribbed part, 220…Barrel, 221…Communication hole, 222…Check valve, 223…Opposing surface, 224…Guide groove, 230…Heater, 240…Flow path, 251…Injection cylinder, 252…Plunger, 253…Plunger drive section, 261…Motor, 262…Ball screw, 310…Robot, 320…Inspection device, 321…Inspection table, 322…Imaging section, 323…Weight measurement section, 330…Stacking mechanism, 331…First placement section, 332…Second placement section, 900…Mold, 901…Movable mold, 902…Fixed mold, PL…Pallet, RX…Rotating shaft

Claims

1. A method for setting molding conditions of an injection molding machine for molding a molded product, comprising: (a) adjusting the temperature and humidity around the injection molding machine; (b) obtaining the moisture content of the material used for molding the molded product; (c) setting a plurality of molding conditions for molding the molded product by the injection molding machine; (d) injecting a plasticized material obtained by plasticizing the material by the injection molding machine into a mold under environmental conditions including the temperature and humidity adjusted in step (a) and the moisture content obtained in step (b), thereby molding the molded product under a plurality of the molding conditions; (e) determining an optimum condition of the molding conditions under the environmental conditions based on the quality of the molded product molded in step (d). In step (a), the temperature is adjusted to the temperature of the place where the molded product is produced, and the humidity is adjusted to the humidity of the place where the molded product is produced. A method for setting molding conditions.

2. The method for setting molding conditions according to claim 1, wherein in step (c), a first molding condition and a second molding condition in which a first parameter, which is a parameter included in the first molding condition, is different from the first molding condition are set; step (d) includes a step of molding a first molded product by the injection molding machine under the first molding condition, and a step of molding a second molded product by the injection molding machine under the second molding condition; and in step (e), the optimum condition is selected from the first molding condition and the second molding condition according to the comparison result between the first molded product and the second molded product. A method for setting molding conditions.

3. The method for setting molding conditions according to claim 1, wherein in step (b), the moisture content is measured by a spectrometer. A method for setting molding conditions.

4. The method for setting molding conditions according to claim 3, wherein the spectrometer is disposed in a hopper in which the material is stored. A method for setting molding conditions.

5. The method for setting molding conditions according to claim 1, further comprising: (f) setting a set value of a factor related to the molding of the molded product, which is a factor adjusted according to the environmental conditions; and in step (c), the molding conditions are set such that an effective value of the factor in step (d) is close to the set value. The factor includes at least any one of the temperature of the mold, the temperature of the plasticized material, the pressure of the plasticized material, the injection speed of the plasticized material, and the cooling time of the mold. Method for setting molding conditions.

6. The method for setting molding conditions according to claim 5, The step (d) is a step of monitoring the effective value; a step of storing in a storage unit first information associating the environmental conditions, the molding conditions, and the effective value when the molded product is molded under the molding conditions under the environmental conditions. Method for setting molding conditions.

7. The method for setting molding conditions according to claim 6, further comprising (g) a step of molding the molded product under the optimum conditions by an injection molding machine under the environmental conditions, in the step (g), when the effective value fluctuates outside a predetermined range, modifying the optimum conditions based on the first information. Method for setting molding conditions.

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