JP2006137057A - Resin characteristic measuring instrument and resin characteristic measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain fine resin characteristics of high precision on the basis of sufficient data even in a case that the amount of a resin is little and to evaluate a novel material or the like on the basis of wide data with high reliability. <P>SOLUTION: The resin characteristic measuring instrument is equipped with a mold part 2 provided with a resin circuit 3, which has a cavity 4 capable of molding a molded product, a first resin passage 5 capable of supplying a molten resin R to be measured supplied from the outside to the cavity 4, the second resin passage 6 branched from the midway position of the first resin passage 5, the plunger unit 7 connected to the leading end of the second resin passage 6 and a changeover device 8 for changing over the connection state of the branch part of the first resin passage 5, and a measuring part 9 having one, two or more physical quantity detectors 9at, 9ap, etc. for detecting the physical quantity at the time of supply of the molten resin R to be measured to the resin circuit 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a resin characteristic measuring apparatus and a resin characteristic measuring method suitable for use in measuring resin characteristics and the like.

  In general, the setting of molding conditions in an injection molding machine has a side that greatly depends on the know-how and experience of the operator, and various physical quantities affect each other, so that a lot of trial driving and setting work time are required. For this reason, virtual molding (simulation) is performed by injection molding CAE (injection molding computer support technology), and molding conditions and the like are set based on this virtual molding.

  By the way, in the injection molding CAE, accurately grasping the flow state (resin characteristics) of the molten resin injected and filled into the mold is the key to realizing good virtual molding. In general, in injection molding CAE, PVT characteristics and viscosity characteristics including resin pressure P, specific volume V and resin temperature T are used as the resin characteristics of the molten resin, and the flow state of the molten resin in the mold is predicted. Uses the flow rate of the molten resin flowing into the mold from the injection nozzle.

  Conventionally, as a means for measuring such resin characteristics such as PVT characteristics and viscosity characteristics, a dedicated measuring machine such as a capillary rheometer disclosed in Japanese Patent Application Laid-Open No. 7-63663 is known. However, in the case of an injection molding machine, molecular weight distribution changes due to thermal history or strong shear stress occur, so the resin characteristics measured with a dedicated measuring machine do not match the resin characteristics of an actual injection molding machine. There are many. Eventually, even if a dedicated measuring machine is used, it is not possible to obtain resin characteristics desirable for an injection molding machine, and accurate and accurate injection molding CAE cannot be realized.

For this reason, a resin characteristic detection method for an injection molding machine in which the resin characteristic is detected by an injection molding machine is also known. For example, Japanese Patent No. 2507148 discloses a flow path opening / closing mechanism that prevents the flow of molten resin between the inside of the cylinder and the cavity between the inside of the cylinder of the injection molding machine and the cavity of the molding die. The position value of the screw at the reference stop position where the screw is moved in equilibrium by applying a pressing force of the reference pressing value to the screw and moving the screw in an equilibrium state. To obtain a screw position value at a stop position where the screw stops the balanced movement by applying a pressing force with a pressing value different from the reference pressing value to the screw and moving the screw in equilibrium. The second step of obtaining the screw movement distance from the reference stop position is sequentially performed under a predetermined molten state of the molten resin, and the relationship between the extrusion value and the movement distance is determined by a predetermined function equation. Resin characteristic detecting method of obtaining a relational expression of the molten resin pressure value and the molten resin volume value by approximating Te have been disclosed. Japanese Patent Application Laid-Open No. 6-166068 discloses a runner in which a resin temperature sensor and a resin pressure sensor are embedded, a nozzle touch surface provided at one end of the runner to be in pressure contact with the molding machine nozzle, and the nozzle touch surface. An apparatus for evaluating characteristics of a molding machine cylinder having a capillary provided in communication with the other end of the runner on the opposite side and a mounting portion for attaching the runner to a platen of the molding machine or a mold attached to the molding machine is disclosed. Yes.
JP-A-7-63663 Patent No. 2507148 JP-A-6-166068

  However, the conventional resin characteristic measuring apparatus (resin characteristic measuring method) described above has the following problems.

  First, in the case of new materials, the amount of resin that can be secured is a laboratory-level amount that has not shifted to the production stage, so conventional measuring equipment that requires a considerable amount of resin for measurement is dense and accurate. High resin characteristics cannot be obtained.

  Secondly, since the data related to the obtained resin characteristics is limited to the physical characteristics of the resin itself, what molding characteristics can be obtained when the molding process is actually performed based on the obtained resin characteristics. It is impossible to obtain a wide range of data including evaluation of final molded products such as these, and it is impossible to perform highly reliable evaluation for new materials.

  Third, when measuring various resin characteristics, it is necessary to add measurement functions corresponding to the resin characteristics. However, since conventional measurement devices are configured as dedicated measuring machines for limited resin characteristics, they are necessary. When measuring data comprehensively, the cost increases and the size increases in terms of equipment.

  An object of the present invention is to provide a resin characteristic measuring apparatus and a resin characteristic measuring method that solve the problems existing in the background art.

  A resin characteristic measuring apparatus 1 according to the present invention is a measuring apparatus for measuring at least a resin characteristic related to a resin material in order to solve the above-described problems, and is supplied from a cavity 4 capable of molding a molded product and from the outside. Connected to the first resin passage 5 capable of supplying the measured molten resin R to the cavity 4, the second resin passage 6 branched from the middle position of the first resin passage 5, and the tip of the second resin passage 6 The mold unit 2 provided with the resin circuit 3 having the plunger unit 7 and the switch 8 for switching the connection state of the branch portion in the first resin passage 5 is provided, and the measured molten resin R is supplied to the resin circuit 3. The measurement unit 9 includes one or more physical quantity detectors 9at, 9ap, 9bt,.

  In this case, according to a preferred aspect of the invention, the switch 8 is configured such that the front first resin passage 5f in the first resin passage 5 located in front of the branch portion and the rear side in the first resin passage 5 located behind the branch portion. A three-way switching valve 8v that selectively connects or blocks the first resin passage 5r and the second resin passage 6 can be used. The physical quantity can include at least the resin temperature Ta ..., the resin pressure Pa ..., and the plunger position X1. Further, the resin characteristic measuring apparatus 1 can be provided with an injection molding machine M that supplies the measured molten resin R to the first resin passage 5 by nozzle-touching the injection nozzle Min to the mold part 2. As the machine M, a pre-plastic injection molding machine Mp can be used. Further, the injection molding machine M can also be provided with a molding machine measuring section 10 having one or more physical quantity detectors 10nt, 10np, 10it... For detecting the physical quantity of the measured molten resin R accommodated therein. In addition, at least the resin temperature Tn, the resin pressure Pn, and the plunger position Xo can be included in the physical quantity.

  On the other hand, the resin characteristic measuring method according to the present invention solves the above-described problems, and at least when measuring the resin characteristics related to the resin material, the cavity 4 capable of molding a molded product and the measured melt supplied from the outside. A first resin passage 5 capable of supplying the resin R to the cavity 4, a second resin passage 6 branched from a midway position of the first resin passage 5, and a plunger unit 7 connected to the tip of the second resin passage 6. Using the mold part 2 provided with the resin circuit 3 having the switch 8 for switching the connection state of the branch part in the first resin passage 5, the switch 8 is switched to the predetermined switching positions C1, C2, C3. By supplying the measured molten resin R to the resin circuit 3 and detecting one or more physical quantities related to the supplied measured molten resin R, at least the resin characteristics related to the resin material are measured. And it said that there was Unishi.

  In this case, according to a preferred aspect of the invention, the injection nozzle Min of the injection molding machine M can be touched on the mold part 2 and the measured molten resin R can be supplied from the injection molding machine M to the resin circuit 3. The three-way switching valve 8v is used as the switch 8 and the first first resin passage 5f of the first resin passage 5 located in front of the branch portion and the first rear side of the first resin passage 5 located behind the branch portion. The resin passage 5r and the second resin passage 6 can be selectively connected or disconnected.

  As a result, the three-way switching valve 8v is switched to the first switching position C1 that blocks the rear first resin passage 5r with respect to the front first resin passage 5f and the second resin passage 6, and the measured molten resin R is By supplying the rear first resin passage 5r, the PVT (resin pressure-specific volume-resin temperature) characteristic of the measured molten resin R can be measured.

Further, the three-way switching valve 8v connects the second resin passage 6 and the rear first resin passage 5r, and shuts off the front first resin passage 5f from the second resin passage 6 and the rear first resin passage 5r. The viscosity characteristics of the measured molten resin R are measured by switching to the second switching position C2 and supplying the measured molten resin R to the plunger unit 7 through the rear first resin passage 5r and the second resin passage 6. it can. At this time, the viscosity characteristic of the measured molten resin R can be measured by feeding back the measured molten resin R supplied to the plunger unit 7 to the supply side through the second resin passage 6 and the rear first resin passage 5r. In addition, a process for supplying the measured molten resin R to the plunger unit 7 through the rear first resin passage 5r and the second resin passage 6 and measuring the viscosity characteristics of the measured molten resin R, and the plunger unit The measurement molten resin R supplied to 7 is reversely fed to the supply side through the second resin passage 6 and the rear first resin passage 5r, thereby repeatedly measuring the viscosity characteristics of the measurement molten resin R. It can be carried out. In this viscosity characteristic, g is the acceleration of gravity, r is the resin passage radius, L is the length of the resin passage from point a to point b, Q is the flow rate, Pa is the resin at the rear position (point a) of resin passage 6. Pressure, Pb is the resin pressure at the front position (point b) of the resin passage 6, the resin viscosity η is η = {πgr ⁴ / 8LQ} (Pa−Pb), the resin shear rate ν is ν = 4Q / Πr ³ , which can be determined from the resin viscosity η and the resin shear rate ν.

  Further, the three-way switching valve 8v is connected to the front first resin passage 5f and the rear first resin passage 5r, and the second resin passage 6 is connected to the front first resin passage 5f and the rear first resin passage 5r. By switching to the third switching position C3 to be shut off and supplying the measured molten resin R to the cavity through the first resin passage 5, molding characteristics of the measured molten resin R can be obtained.

  According to the resin characteristic measuring apparatus 1 and the resin characteristic measuring method according to the present invention as described above, the following remarkable effects can be obtained.

  (1) Since the plunger unit 7 can be driven to return the measured molten resin R to the supply side (reverse feed), the amount of resin that can be secured is small, such as a new material, that is, the production stage. Even if the amount is not in the laboratory level, sufficient data can be obtained by repeatedly using the measured molten resin R, and a dense and highly accurate resin characteristic can be obtained.

  (2) Including the evaluation of the final molded product, including not only the physical characteristics of the measured molten resin R itself but also the molding characteristics when the molding process is actually performed based on the resin characteristics obtained. In addition, since a wide range of data can be obtained, highly reliable evaluation of new materials can be performed.

  (3) Since various resin characteristics and molding characteristics can be measured with a single measuring device, even when necessary data are comprehensively measured, it is possible to contribute to cost reduction and downsizing in terms of equipment.

  (4) According to a preferred embodiment, as the switch 8, the front first resin passage 5f in the first resin passage 5 located in front of the branch portion, the rear first in the first resin passage 5 located in the rear of the branch portion. If the three-way switching valve 8v that selectively connects or blocks the resin passage 5r and the second resin passage 6 is used, it is possible to easily and smoothly switch to the predetermined switching positions C1, C2, and C3.

  (5) According to a preferred embodiment, if at least resin temperature Ta ..., resin pressure Pa ... and plunger position X1 ... are included as physical quantities, at least both PVT characteristics and viscosity characteristics that are important in injection molding are measured simultaneously. Is possible.

  (6) If an injection molding machine M for supplying the molten resin R to be measured to the first resin passage 5 is provided by touching the injection nozzle Min to the mold part 2 according to a preferred embodiment, general injection molding is possible. The machine M can be used directly, and if the pre-plastic injection molding machine Mp is used as the injection molding machine M, stabilization when measuring the measured molten resin R can be achieved.

  Next, the best embodiment according to the present invention will be given and described in detail with reference to the drawings.

  First, the structure of the resin characteristic measuring apparatus 1 according to the present embodiment will be described with reference to FIGS.

  The resin characteristic measuring device 1 includes a cavity 4 in which a molded product can be molded, a first resin passage 5 that can supply the measured molten resin R supplied from the outside to the cavity 4, and an intermediate position of the first resin passage 5. A resin circuit 3 having a second resin passage 6 branched from the first resin passage 6, a plunger unit 7 connected to the tip of the second resin passage 6, and a switch 8 for switching the connection state of the branch portion in the first resin passage 5. A mold part 2 is provided.

  In this case, the basic form of the mold part 2 is the same as that of a general mold used for injection molding, and includes a movable mold 2m and a fixed mold 2c, which can be attached to a mold clamping device (not shown). it can. Therefore, mold opening, mold closing and mold clamping can be performed by the mold clamping device. In addition, a heater (not shown) is attached to the mold part 2 and can be controlled to be heated to the same temperature as that of an injection cylinder 44 described later.

  On the other hand, the specific form of the mold part 2 is as follows. First, the cavity 4 is formed on the parting surfaces of the movable mold 2m and the fixed mold 2c. The volume of the cavity 4 is taken into consideration so as to ensure a necessary minimum size and not to increase unnecessarily. Further, a nozzle touch surface 21 on which the tip of an injection nozzle Min of an injection molding machine M described later is nozzle-touched is provided on the end surface of the fixed mold 2c. Then, the first resin passage 5 is formed between the nozzle touch surface 21 and the cavity 4. The formation direction of the first resin passage 5 is made to coincide with the injection direction of the injection nozzle Min. Further, the second resin passage 6 is branched from the midway position of the first resin passage 5 in the direction perpendicular to the upper surface (side surface) 22 of the fixed mold 2c. In this case, the inner diameters of the first resin passage 5 and the second resin passage 6 are made to coincide with the inner diameter of the injection nozzle Min in order to suppress the occurrence of shearing.

  The plunger unit 7 is attached to the upper surface 22 of the fixed mold 2 c and connected to the tip of the second resin passage 6. The plunger unit 7 includes a barrel portion 23 whose tip is fixed to the upper surface 22 and whose inside communicates with the tip of the second resin passage 6, a reverse plunger portion 24 accommodated in the barrel portion 23, and the reverse plunger portion A plunger drive unit 25 is provided to drive 24 forward and backward. The plunger drive unit 25 may use a hydraulic drive system or an electric drive system. Further, the switching device 8 uses a three-way switching valve 8v disposed in the middle position of the first resin passage 5, that is, at a branch portion where the second resin passage 6 branches from the first resin passage 5. As a result, the first resin passage 5 forward from the three-way switching valve 8v becomes the front first resin passage 5f, and the first resin passage 5 rearward from the three-way switching valve 8v becomes the rear first resin passage 5r.

  Therefore, the three-way switching valve 8v selectively connects or blocks the front first resin passage 5f, the rear first resin passage 5r, and the second resin passage 6, specifically, the first switching position shown in FIG. It is possible to switch to C1, a second switching position C2 shown in FIG. 5, and a third switching position C3 shown in FIG. In this case, the rear first resin passage 5r is blocked from the front first resin passage 5f and the second resin passage 6 at the first switching position C1. In the second switching position C2, the second resin passage 6 and the rear first resin passage 5r are connected, and the front first resin passage 5f is blocked from the second resin passage 6 and the rear first resin passage 5r. The At the third switching position C3, the front first resin passage 5f and the rear first resin passage 5r are connected, and the second resin passage 6 is blocked from the front first resin passage 5f and the rear first resin passage 5r. Is done. In addition, although the same switching can be performed by disposing each on-off valve in each of the resin passages 5f, 5r, 6, it is easy to move to each switching position C1, C2, C3 by using the three-way switching valve 8v. It can be switched smoothly. The cavity 4, the first resin passage 5, the second resin passage 6, the plunger unit 7 and the three-way switching valve 8v constitute the resin circuit 3.

  Further, the resin characteristic measuring apparatus 1 includes a measuring unit 9 having one or more physical quantity detectors 9at, 9ap... For detecting a physical quantity when the measured molten resin R is supplied to the resin circuit 3. In this case, as shown in FIGS. 1 and 3, the temperature (resin temperature) Ta of the molten resin R to be measured is detected at the lower side (three-way switching valve 8v side) position of the second resin passage 6 at the point a. And a pressure detector 9ap for detecting the pressure (resin pressure) Pa of the molten resin R to be measured. Further, a temperature detector 9bt for detecting the temperature (resin temperature) Tb of the measured molten resin R and the pressure of the measured molten resin R are positioned above the second resin passage 6 (plunger unit 7 side) as the point b. (Resin pressure) A pressure detector 9bp for detecting Pb is provided. Further, a position detector 9c for detecting the positions (reverse feed plunger positions) X1, X2 of the reverse feed plunger portion 24 in the plunger unit 7 is provided. The detectors 9at, 9ap, 9bt, 9bp, and 9c are connected to the measurement processing unit 31, and the measurement processing unit 31 is connected to a processing computer 32 that executes various processes.

  On the other hand, Mp is a pre-plastic injection molding machine (injection molding machine M), and the measured molten resin R is supplied to the first resin passage 5 by nozzle-touching the injection nozzle Min on the nozzle touch surface 21 of the mold part 2. can do. As a means for supplying the measured molten resin R to the first resin passage 5, a dedicated supply device can be used, but in this embodiment, a general injection molding machine M can be directly used. In particular, since the pre-plastic injection molding machine Mp is used, stabilization when the measured molten resin R is measured can be achieved.

  The pre-plastic injection molding machine Mp includes a plasticizing device Mm that plasticizes and melts a resin material, and an injection device Mi that supplies (injects) a measured molten resin (measured molten resin) R to the mold part 2. The plasticizing apparatus Mm includes a plasticizing cylinder 41. The plasticizing cylinder 41 includes a screw 42 and a hopper 43 that supplies a resin material to the plasticizing cylinder 41 at the rear. In addition, the screw drive part which does not appear in the figure which rotates the screw 42 is provided in the rear end of the plasticizing cylinder 41. FIG. The injection device Mi includes an injection cylinder 44. The injection cylinder 44 incorporates an injection plunger 45, and includes an injection nozzle Min at the front end and further moves the injection plunger 45 forward and backward. A plunger driving unit 46 is provided. The injection device Mi is supported by a moving device (not shown), and the injection nozzle Min touches the nozzle touch surface 21 of the mold unit 2. The nozzle touch position shown in FIG. 2 or the injection nozzle Min is separated from the nozzle touch surface 21. 1 can be moved to the nozzle touch release position. The injection nozzle Min communicates with the tip of the injection cylinder 44 through the resin passage 47, and the tip of the plasticizing cylinder 41 communicates with the resin passage 47 through the resin passage 48. The resin path 48 is provided with a backflow prevention valve 49 that opens by the forward flow of the molten resin and closes by the backflow. As the pre-plastic injection molding machine Mp, it is desirable to use a small machine as much as possible. The example pre-plastic injection molding machine Mp has a maximum injection capacity of 1.4 [cc].

  On the other hand, the pre-plastic injection molding machine Mp also includes a molding machine measuring unit 10 having one or more physical quantity detectors 10nt, 10np,... For detecting the physical quantity of the measured molten resin R accommodated therein. In this case, as shown in FIG. 1, a temperature detector 10nt for detecting the temperature (resin temperature) Tn of the measured molten resin R in the injection nozzle Min and the pressure (resin of the measured molten resin R) The pressure detector 10np for detecting the pressure (Pn) and the temperature detector 10it for detecting the temperature (resin temperature) Ti of the measured molten resin R in the injection cylinder 44 and the measured melt A pressure detector 10ip for detecting the pressure (resin pressure) Pi of the resin R is provided. Further, a position detector 10c for detecting the positions (injection plunger positions) Xo and Xm of the injection plunger 45 is provided. The detectors 10 nt, 10 np, 10 it, 10 ip, and 10 c are connected to the measurement processing unit 31.

  Next, a resin characteristic measuring method according to this embodiment using such a resin characteristic measuring apparatus 1 will be described with reference to FIGS.

  In the resin characteristic measuring apparatus 1 according to the present embodiment, the PVT (resin pressure-specific volume-resin temperature) characteristic of the measured molten resin R is obtained by switching the three-way switching valve 8v to the first switching position C1 shown in FIG. Can be measured. First, a method for measuring the PVT characteristic will be described according to the flowchart shown in FIG.

  First, as a measurement preparation, the injection nozzle Min is made to touch the nozzle touch surface 21 and a resin material is put into the hopper 43. Further, the rear first resin passage 5r is vented (step S1). There are a plurality of air venting methods. For example, the air can be vented by switching the three-way switching valve 8v to the third switching position C3 shown in FIG. 6 and operating the pre-plastic injection molding machine Mp. . In this case, since the molten resin R is supplied to the first resin passage 5 by the operation of the pre-plastic injection molding machine Mp, the molten resin R passes through at least the three-way switching valve 8v and enters the front first resin passage 5f. If supplied, air can be vented as much as the molten resin R enters. If the molten resin R has entered the front first resin passage 5f, the three-way switching valve 8v is switched to the first switching position C1 shown in FIG. 4 (step S2). As a result, the rear first resin passage 5r is blocked from the front first resin passage 5f and the second resin passage 6, and the measured molten resin R is introduced into the rear first resin passage 5r from the three-way switching valve 8v. Is filled.

  In this state, a required amount for the measured molten resin R required for measurement is measured (step S3). At the time of weighing, the resin material supplied from the hopper 43 is plasticized and melted by the rotation of the screw 42 and enters the resin path 47 through the resin path 48. At this time, since the rear first resin passage 5r side is blocked by the three-way switching valve 8v, the measured molten resin R that has entered the resin passage 47 is accumulated in the injection cylinder 44, and the injection plunger 45 moves backward. Then, weighing is performed. When the metering is completed, the plunger driving unit 46 is controlled to perform pressure relief, and the pressure applied to the measured molten resin R is released to the atmospheric pressure (step S4).

  Then, the injection plunger position Xo at this time is detected by the position detector 10c (step S5). Further, the plunger drive unit 46 is driven and controlled, and the measured molten resin R is pressurized with a predetermined pressure by the injection plunger 45, and measurement processing is performed in this state (steps S6 and S7). That is, the resin temperature Tn and / or Ti is detected by one or both of the temperature detectors 10nt and 10it, and the resin pressure Pn and / or Pi is detected by one or both of the pressure detectors 10np and 10ip. Further, the specific volume V is calculated using a known specific volume calculation method by detecting the injection plunger position Xm by the position detector 10c and obtaining the movement amount of the injection plunger 45 (step S8). When the above measurement processing is completed, the plunger driving unit 46 is controlled to perform pressure relief, and the pressure applied to the measured molten resin R is released to atmospheric pressure (steps S9 and S10).

  Next, the resin temperature and the resin pressure are sequentially changed, and the processes from Steps S5 to S10 are similarly performed (Steps S11, S12, S5... S10). On the other hand, when the set number of measurements is reached, the measurement for the measured molten resin R subjected to the measurement is terminated (step S11). In this case, the number of times of measurement is set in consideration of deterioration of the measured molten resin R due to repeated measurement performed on the measured molten resin R, and can be set in advance depending on the properties of the measured molten resin R. . When the set number of measurements is reached, the three-way switching valve 8v is switched to the third switching position C3 shown in FIG. 6 (step S13).

  Accordingly, the front first resin passage 5f and the rear first resin passage 5r are connected, and the second resin passage 6 is blocked from the front first resin passage 5f and the rear first resin passage 5r. In other words, the injection device Mi is connected to the cavity 4 through the first resin passage 5 and can perform a normal injection molding process for injecting and filling the measured molten resin R into the cavity 4 to form a molded product. A molded product using the measured molten resin R can be obtained (step S14). Therefore, it is possible to collect not only the physical characteristics of the measured molten resin R itself but also the molding characteristics when the molding process is actually performed based on the obtained resin characteristics (PVT characteristics). A wide range of data including evaluation can be obtained, and highly reliable evaluation for new materials can be performed. In this case, the obtained molding characteristics (evaluation items) include injection load pressure, metering torque, plasticizing ability, molding temperature range, dimensional stability, mechanical strength, residual strain, molded product structure (molecular structure), water absorption , Chemical resistance, weather resistance, etc.

  On the other hand, if the target number of measurements remains, the three-way switching valve 8v is switched to the first switching position C1 and a new measurement is performed, so that a new measured molten resin R is used as in steps S2 to S12. The process is performed to collect data (steps S16, S2 to S12). When the preset number of measurements is reached, injection molding processing similar to steps S13 to S15 is performed to collect molding characteristics (steps S11 to S15). The above processing is performed up to the target number of measurements (step S16). By plotting the data collected in this way, the PVT characteristic shown in FIG. 10, that is, the specific volume characteristic with respect to the resin temperature using the resin pressure as a parameter can be obtained.

  On the other hand, in the resin characteristic measuring apparatus 1 according to the present embodiment, the viscosity characteristic of the measured molten resin R can be measured by switching the three-way switching valve 8v to the second switching position C2 shown in FIG. Hereinafter, this viscosity characteristic measuring method will be described according to the flowchart shown in FIG.

  First, as a measurement preparation, the injection nozzle Min is made to touch the nozzle touch surface 21 and a resin material is put into the hopper 43. Further, the reverse feed plunger portion 24 of the plunger unit 7 is moved to the most advanced position. Then, the three-way switching valve 8v is switched to the second switching position C2 (step S21). Thereby, the second resin passage 6 and the rear first resin passage 5r are connected, and the front first resin passage 5f is blocked from the second resin passage 6 and the rear first resin passage 5r.

  Next, a required amount for the measured molten resin R required for measurement is measured in this state (step S22). At the time of weighing, the resin material supplied from the hopper 43 is plasticized and melted by the rotation of the screw 42 and enters the resin path 47 through the resin path 48. At this time, a predetermined back pressure is applied to the injection plunger 45. Thereby, the measured molten resin R first enters the rear first resin passage 5r and the second resin passage 6, and the measured molten resin R is accumulated up to the front of the reverse feed plunger portion 24. Thereafter, the molten resin R to be measured that has entered the resin passage 47 is accumulated in the injection cylinder 44, and the injection plunger 45 moves backward to perform measurement. When the measurement is completed, the plunger driving unit 46 is controlled to perform pressure relief, and the pressure applied to the measured molten resin R is released to atmospheric pressure. This state is shown in FIG. 9 (a) to 9 (c), symbols Ra to Rf indicate the measured molten resin R according to the state when repeatedly measured, where Ra is a holding pressure and Rb is a pre-process residence. , Rc represents the residence exclusion, Rd represents the measurement, Re represents the measurement exclusion, and Rf represents the holding pressure.

  Next, forward injection is performed by the injection device Mi (step S23). In this case, the injection plunger 45 is moved forward at a preset injection speed to perform an injection operation, and measurement processing during the injection operation is performed (step S24). That is, the temperature detector 9at at the point a detects the resin temperature Ta, the pressure detector 9ap detects the resin pressure Pa, the temperature detector 9bt at the point b detects the resin temperature Tb, and the pressure detection The resin pressure Pb is detected by the device 9bp. In this case, as shown in FIG. 9B, the detection timing is performed within a period in which the measured amount Rd in the measured molten resin R passes through the second resin passage 6. Further, the reverse feed plunger positions X1 and X2 before and after the predetermined time Δtm within this period are detected by the position detector 9c. The flow rate Q of the measured molten resin R is obtained by the predetermined time Δtm and the reverse feed plunger positions X1, X2.

And from the obtained detection results, the resin viscosity η and the resin shear rate ν are
η = {πgr ⁴ / 8LQ} (Pa−Pb) (01)
ν = 4Q / πr ³ (02)
Where g: acceleration of gravity
r: Resin passage radius
L: Calculated from the length of the resin passage from point a to point b (step S25).

  When the above measurement process is completed, injection in the reverse direction is performed by the plunger unit 7 (steps S26 and S27). FIG. 9C shows a state where the injection operation by the injection device Mi has been completed. In this case, since the measured amount Rd of the measured molten resin R on the injection device Mi side is moved to the plunger unit 7 side, the plunger drive unit 25 in the plunger unit 7 is driven and controlled by a preset injection speed. The backward feeding plunger portion 24 is advanced to perform the injection operation, and the measurement process during the injection operation is performed (step S28). That is, the temperature detector 9at at the point a detects the resin temperature Ta, the pressure detector 9ap detects the resin pressure Pa, the temperature detector 9bt at the point b detects the resin temperature Tb, and the pressure detection The resin pressure Pb is detected by the device 9bp. In this case, as shown in FIG. 9B, the detection timing is performed within a period in which the measured amount Rd in the measured molten resin R passes through the second resin passage 6. Further, the reverse feed plunger positions X1 and X2 before and after the predetermined time Δtm within this period are detected by the position detector 9c. The flow rate Q of the measured molten resin R is obtained by the predetermined time Δtm and the reverse feed plunger positions X1, X2. Then, the resin viscosity η and the resin shear rate ν are calculated from the obtained detection results by the above-described equations (01) and (02) (step S29). When the above measurement processing is completed, the plunger driving unit 46 is controlled to perform depressurization, and the pressure applied to the measured molten resin R is released to atmospheric pressure.

  Next, the resin temperature and the injection speed are sequentially changed, and the processing from step S23 to S30 is performed similarly (steps S31, S32, S23... S30). On the other hand, when the set number of measurements is reached, the measurement for the measured molten resin R subjected to the measurement is terminated (step S31). In this case, the number of times of measurement is set in consideration of deterioration of the measured molten resin R due to repeated measurement performed on the measured molten resin R, and can be set in advance depending on the properties of the measured molten resin R. . When the set number of measurements is reached, the three-way switching valve 8v is switched to the third switching position C3 shown in FIG. 6 (step S33).

  Accordingly, the front first resin passage 5f and the rear first resin passage 5r are connected, and the second resin passage 6 is blocked from the front first resin passage 5f and the rear first resin passage 5r. In other words, the injection device Mi is connected to the cavity 4 through the first resin passage 5 and can perform a normal injection molding process for injecting and filling the measured molten resin R into the cavity 4 to form a molded product. A molded product using the measured molten resin R can be obtained (step S34). Therefore, it is possible to collect not only the physical characteristics of the measured molten resin R itself but also the molding characteristics when the molding process is actually performed based on the obtained resin characteristics (viscosity characteristics). Since a wide range of data including evaluation can be obtained, highly reliable evaluation for new materials and the like can be performed. In this case, the obtained molding characteristics (evaluation items) include the aforementioned injection load pressure, metering torque, plasticizing ability, molding temperature range, dimensional stability, mechanical strength, residual strain, molded product structure (molecular structure), Water absorption, chemical resistance, weather resistance, etc.

  On the other hand, if the target number of measurements remains, the three-way switching valve 8v is switched to the second switching position C2 and a new measurement is performed, so that a new measured molten resin R is used as in steps S21 to S32. The process is performed to collect data (steps S36, S21 to S32). When the preset number of measurements is reached, injection molding processing similar to steps S33 to S35 is performed to collect molding characteristics (steps S31 to S35). The above processing is performed up to the target number of measurements (step S36). By plotting the data collected in this manner, the viscosity characteristics shown in FIG. 11, that is, the viscosity characteristics with respect to the shear rate using the resin temperature as a parameter can be obtained.

  According to the resin characteristic measuring apparatus 1 and the resin characteristic measuring method according to this embodiment, the plunger unit 7 can be driven to return the measured molten resin R to the supply side (reverse feed). When the amount of resin that can be secured is small, such as a new material, that is, even if it is a laboratory level amount that has not shifted to the production stage, sufficient data can be obtained by repeatedly using the measured molten resin R Therefore, dense and highly accurate resin characteristics can be obtained. In addition, since various resin characteristics and molding characteristics can be measured with a single measuring device, it is possible to contribute to cost reduction and downsizing in terms of equipment even when necessary data is comprehensively measured. Furthermore, since the physical quantities to be detected include the resin temperature Ta, the resin pressure Pa, and the plunger position X1, it is possible to simultaneously measure at least both the PVT characteristic and the viscosity characteristic that are important in injection molding.

  As described above, the best embodiment has been described in detail, but the present invention is not limited to such an embodiment, and the detailed configuration, method, numerical value, and the like are within the scope not departing from the gist of the present invention. It can be changed, added, or deleted arbitrarily. For example, although the resin pressure, the resin temperature, and the plunger position are exemplified as the physical quantities to be detected, other arbitrary physical quantities can be included. Moreover, although the PVT characteristic and the viscosity characteristic were illustrated as a resin characteristic, other various resin characteristics, such as a compressibility characteristic and injection rate characteristic of the to-be-measured molten resin R, can be measured. Further, in the exemplary embodiment, when measuring the PVT characteristics to measure the molding characteristics, the viscosity characteristics are measured to measure the molding characteristics. However, after the PVT characteristics are measured, the viscosity characteristics are measured. Thereafter, the molding characteristics may be measured, and the combination and procedure of the measurement process are arbitrary.

The principle block diagram including the structure of the measurement system of the resin characteristic measuring apparatus according to the best embodiment of the present invention, Configuration diagram of the mechanical system in the resin characteristic measuring device, AA line sectional view in FIG. 1 of the resin characteristic measuring device, Action explanatory diagram when the three-way switching valve in the resin characteristic measuring device is switched to the first switching position, Action explanatory diagram when switching the three-way switching valve to the second switching position in the resin characteristic measuring device, Action explanatory diagram when the three-way switching valve in the resin characteristic measuring device is switched to the third switching position, The flowchart which shows the process sequence at the time of measuring a PVT characteristic and a shaping | molding characteristic using the resin characteristic measuring apparatus, A flowchart showing a processing procedure when measuring viscosity characteristics and molding characteristics using the resin characteristic measuring apparatus, Action explanatory diagram when measuring viscosity characteristics using the resin characteristic measuring device, PVT characteristic diagram showing an example measured by the resin characteristic measuring device, Viscosity characteristic diagram showing an example measured by the resin characteristic measuring device,

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin characteristic measuring apparatus 2 Mold part 3 Resin circuit 4 Cavity 5 1st resin path 5f Front side 1st resin path 5r Rear side 1st resin path 6 Second resin path 7 Plunger unit 8 Switcher 8v Three-way switching valve 9 Measuring part 9 at ... physical quantity detector 10 molding machine measuring unit 10 nt ... physical quantity detector R molten resin to be measured M injection molding machine Mp pre-plastic injection molding machine Min injection nozzle C1 switching position (first switching position)
C2 switching position (second switching position)
C3 switching position (third switching position)

Claims (16)

  In a resin characteristic measuring apparatus for measuring at least resin characteristics related to a resin material, a cavity capable of molding a molded product, a first resin passage capable of supplying a measured molten resin supplied from the outside to the cavity, and A resin circuit having a second resin passage branched from an intermediate position of the first resin passage, a plunger unit connected to the tip of the second resin passage, and a switch for switching the connection state of the branch portion in the first resin passage. And a measuring unit having one or more physical quantity detectors for detecting a physical quantity when the molten resin to be measured is supplied to the resin circuit. measuring device.   The switch includes a front first resin passage in the first resin passage located in front of the branch portion, a rear first resin passage in the first resin passage located in the rear of the branch portion, and the second resin. 2. The resin characteristic measuring apparatus according to claim 1, wherein a three-way switching valve for selectively connecting or blocking the passage is used.   2. The resin characteristic measuring apparatus according to claim 1, wherein the physical quantity includes at least one or more of a resin temperature, a resin pressure, and a plunger position.   2. The resin characteristic measuring apparatus according to claim 1, further comprising an injection molding machine that supplies the measured molten resin to the first resin passage by touching the injection nozzle with the mold part.   The resin characteristic measuring apparatus according to claim 4, wherein the injection molding machine is a pre-plastic injection molding machine.   6. The resin according to claim 4, wherein the injection molding machine includes a molding machine measuring unit having one or more physical quantity detectors for detecting a physical quantity of a measured molten resin contained therein. Characteristic measuring device.   The resin characteristic measuring apparatus according to claim 6, wherein the physical quantity includes at least one or more of a resin temperature, a resin pressure, and a plunger position.   In a resin characteristic measurement method for measuring at least resin characteristics related to a resin material, a cavity capable of molding a molded product, a first resin passage capable of supplying a measured molten resin supplied from the outside to the cavity, and A resin circuit having a second resin passage branched from an intermediate position of the first resin passage, a plunger unit connected to the tip of the second resin passage, and a switch for switching the connection state of the branch portion in the first resin passage. The measured molten resin is supplied to the resin circuit by switching the switch to a predetermined switching position, and one or more physical quantities related to the supplied measured molten resin are obtained. A method for measuring resin characteristics, comprising: measuring at least a resin characteristic related to a resin material by detection.   9. The resin characteristic measuring method according to claim 8, wherein the mold part is touched with an injection nozzle of an injection molding machine, and the molten resin to be measured is supplied from the injection molding machine to the resin circuit.   A three-way switching valve is used as the switch, and a front first resin passage in the first resin passage located in front of the branch portion, and a rear first resin in the first resin passage located behind the branch portion. The resin characteristic measuring method according to claim 8, wherein the passage and the second resin passage are selectively connected or disconnected.   The three-way switching valve is switched to a first switching position that blocks the rear first resin passage with respect to the front first resin passage and the second resin passage, and the measured molten resin is fed to the rear first resin passage. The resin characteristic measuring method according to claim 9, wherein the PVT (resin pressure-specific volume-resin temperature) characteristic of the molten resin to be measured is measured by supplying it to the resin passage.   The three-way switching valve connects the second resin passage and the rear first resin passage, and blocks the front first resin passage from the second resin passage and the rear first resin passage. Switching to the two switching position and measuring the viscosity characteristic of the measured molten resin by supplying the measured molten resin to the plunger unit through the rear first resin passage and the second resin passage. The resin characteristic measuring method according to claim 9.   Viscosity characteristics of the measured molten resin are measured by sending the measured molten resin supplied to the plunger unit back to the supply side through the second resin passage and the rear first resin passage. The resin characteristic measuring method according to claim 12.   The three-way switching valve connects the second resin passage and the rear first resin passage, and blocks the front first resin passage from the second resin passage and the rear first resin passage. Switching to the two switching positions, supplying the measured molten resin to the plunger unit through the rear first resin passage and the second resin passage, and measuring the viscosity characteristics of the measured molten resin; and the plunger The measurement molten resin supplied to the unit is repeatedly sent to the supply side through the second resin passage and the rear first resin passage, thereby repeatedly measuring the viscosity characteristics of the measurement molten resin. The resin characteristic measuring method according to claim 9. The viscosity characteristics include resin viscosity η and resin shear rate ν,
η = {πgr ⁴ / 8LQ} (Pa−Pb)
ν = 4Q / πr ³
Where g: acceleration of gravity
r: Resin passage radius
L: Resin passage length from point a to point b
Q: Flow rate
Pa: Resin pressure at the rear position (point a) of the resin passage
The resin characteristic measuring method according to claim 12, 13 or 14, wherein Pb is obtained from a resin pressure at a front side position (point b) of the resin passage and is obtained from the resin viscosity η and the resin shear rate ν.   The three-way switching valve connects the rear first resin passage and the front first resin passage, and blocks the second resin passage from the front first resin passage and the rear first resin passage. The resin characteristic measurement according to claim 9, wherein the molding characteristic of the measured molten resin is obtained by switching to the third switching position and supplying the measured molten resin to the cavity through the first resin passage. Method.

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