JP2014240150A - Apparatus and method for production of resin product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin product production apparatus which can mold a thermoplastic resin product inexpensively in a short delivery period.SOLUTION: A resin product production apparatus includes a resin mold (210) which has an upper mold and a lower mold forming a cavity when superimposed together, with at least the inner surface forming the cavity being composed of a resin mixed with a metal powder, a discharge tool which injects a molten thermoplastic resin into the cavity of the resin mold under a pressure of 10.0 MPa, piping (231, 234, 237) which is provided within the resin in the resin mold and causes a fluid of a controlled temperature to flow through and a temperature-controlled fluid delivery part which causes a fluid of a temperature higher than the temperature of the resin mold to flow into the piping so as to prevent hardening of the molten thermoplastic resin.

Description

  The present invention relates to a resin product manufacturing apparatus and a resin product manufacturing method, and more particularly to a thermoplastic resin product manufacturing apparatus and a thermoplastic resin product manufacturing method.

  Resins used for outer plates of industrial products are mainly classified into thermoplastic resins and thermosetting resins. Thermoplastic resins generally require high-cost equipment such as molds and injection machines for molding, but are suitable for mass production due to the short molding cycle. On the other hand, the molding of thermosetting resin does not generally require a mold of a material having high heat resistance and high pressure resistance such as a mold, but is not suitable for mass production because of a long molding cycle.

  Patent document 1 is disclosing about suppressing the fall of the intensity | strength and precision of a resin mold by letting the cooled gas pass through the through-hole in a resin mold, and cooling a mold surface efficiently. Patent Document 2 discloses a molded resin mold in which a cooling pipe is arranged and a steel ball is included in the resin mold to improve heat conduction. Patent Document 3 discloses a heat insulating mold having a resin layer in which metal powder and resin are mixed in order to suppress weld lines and transfer unevenness.

JP 2002-001788 A JP 2000-351124 A JP-A-10-225962 Japanese Patent Application Laid-Open No. 08-108444 Japanese Patent Laid-Open No. 07-266340 JP 07-124953 A Japanese Patent Laid-Open No. 05-124044

  The mold as described above is suitable for mass production of thermoplastic resin products. On the other hand, in prototypes such as mock-ups that are not supposed to be used as actual products, there is a demand for molding only the shape for perceiving the appearance at a low cost with a short delivery time. For such prototypes, lower durability than the product is sufficient, and mass production is not assumed. Here, it is conceivable to manufacture such products using thermosetting resins suitable for low-volume production, but if mass production is premised, the product is molded with the same material and the appearance texture is mass-produced. There is also a demand to keep it like.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resin product manufacturing apparatus that can form a thermoplastic resin product at a low cost with a short delivery time, and a method for manufacturing the resin product. .

  The resin product manufacturing apparatus of the present invention has an upper mold and a lower mold that form a void by being overlapped with each other, and at least an inner surface that forms the void is a resin mold made of a resin mixed with metal powder. A discharger for injecting molten thermoplastic resin into the gap of the resin mold at a pressure of 10.0 MPa or less; a pipe provided in the resin mold resin for flowing a temperature-controlled fluid; and the pipe In addition, in order to prevent the molten thermoplastic resin from being cured, a resin product manufacturing apparatus including a temperature control fluid feeding section that feeds a fluid having a temperature higher than the temperature of the resin mold.

  Moreover, in the resin product manufacturing apparatus of the present invention, the temperature control fluid feed section flows a fluid having a temperature higher than the temperature of the resin mold through the pipe, and then cures the thermoplastic resin. A cooling fluid in a temperature range from the temperature of the resin mold to 50 degrees below the temperature of the resin mold may be allowed to flow. Further, in this case, the temperature control fluid feeding section may cause the cooling fluid to flow through the pipe during a period in which the discharger holds the thermoplastic resin at a pressure of 10.0 MPa or less. Good.

  Moreover, in the resin product manufacturing apparatus of the present invention, the temperature control fluid feed section causes the cooling fluid to flow from the inlet / outlet farther from the thermoplastic resin inlet out of the two inlets / outlets of the pipe. It is good as well.

  In the resin product manufacturing apparatus of the present invention, the upper surface of the upper mold that faces the inner surface of the upper mold that forms the void is a shape that follows the shape of the inner surface of the upper mold, and the void in the lower mold The lower surface facing the inner surface of the lower mold forming the shape may be a shape along the shape of the inner surface of the lower mold. In this case, the pipe provided in the resin of the resin mold may be provided at a position including a center of the thickness of the resin determined in a direction perpendicular to the inner surface of the resin mold.

  Moreover, in the resin product manufacturing apparatus of the present invention, the pipe provided in the resin of the resin mold is provided at a position including a center of the thickness of the resin defined by the overlapping direction of the resin mold. It's good.

  The method for producing a resin product according to the present invention is such that at least the surface of the mold has a resin mold made of a resin mixed with metal powder in a pipe formed in the resin of the resin mold at a temperature higher than the temperature of the resin mold. A mold heating step of heating the resin mold by flowing a fluid of the above, and a heat that is melted at a pressure of 10 MPa or less in the void of the resin mold while flowing a fluid having a temperature higher than the temperature of the resin mold through the pipe A resin injection step of filling a plastic resin, and maintaining the holding pressure of 10 MPa or less with respect to the filled thermoplastic resin, the pipe is provided with a temperature of 50 degrees below the temperature of the resin mold from the temperature of the resin mold. And a cooling step of cooling the resin mold by flowing a cooling fluid in a temperature range up to a temperature range.

  In the cooling step, the cooling fluid may flow from the inlet / outlet farther from the thermoplastic resin inlet out of the two inlets / outlets of the pipe.

It is a figure showing roughly about a resin product manufacture device concerning one embodiment of the present invention. It is a perspective view shown about the structure of the type | mold assembly of FIG. It is a perspective view shown about the resin type | mold of FIG. FIG. 4 is a top view of the resin mold of FIG. 3, showing a molded mold shape and piping path. It is a flowchart of the resin molding process using the resin product manufacturing apparatus of FIG. It is a graph shown about the temperature of the air which flows into piping in a resin molding process, the pressure of a thermoplastic resin, and the change of the temperature of a resin mold.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a diagram schematically showing a resin product manufacturing apparatus 100 according to an embodiment of the present invention. As shown in this figure, a resin product manufacturing apparatus 100 includes a mold assembly 200 that is molded into a mold shape by pouring molten thermoplastic resin into a gap, and a mold assembly 200 that uses molten thermoplastic resin. And a temperature-controlled fluid feeder 400 for flowing temperature-controlled air to the piping in the mold assembly 200 in order to control the temperature inside the mold assembly 200. Here, the mold assembly 200 and the discharger 300 are connected by a resin injection hose 510, and the mold assembly 200 and the temperature control fluid feeder 400 are connected by a fluid injection hose 520. The temperature-controlled fluid flow device 400 can heat or cool the air and send it to the mold assembly 200, and can switch the flow direction of the fluid (inlet and outlet of piping) as appropriate.

  FIG. 2 is a perspective view showing the configuration of the mold assembly 200 of FIG. As shown in this figure, the mold assembly 200 is arranged such that a resin mold 210 made of a resin such as an epoxy resin mixed with a metal powder such as Al, and a resin, sandwiching the upper and lower sides of the resin mold 210. The upper backup plate 251 and the lower backup plate 252, the upper press plate 255 and the lower press plate 257 made of metal disposed so as to sandwich the upper backup member 251 and the lower backup member 252 from the outside, the upper press plate The upper backup material 251, the resin mold 210, and the mold clamping mechanism 261 that fixes the lower backup material 252 with the holes formed in the lower press plate 257 are configured.

  Here, the backup material composed of the upper backup material 251 and the lower backup material 252 is not limited to resin, and metal or other materials can be used. Further, the press plate composed of the upper press plate 255 and the lower press plate 257 is not limited to metal, and other materials such as resin can be used. FIG. 2 shows the mold clamping mechanism 261 that is fixed with bolts and nuts. However, it can be appropriately changed as long as it is a mold-clamping mechanism or other fixture used in known injection molding or the like and can close the resin mold 210 with sufficient pressure.

  FIG. 3 is a perspective view showing the resin mold 210 of FIG. As shown in this figure, in the resin mold 210, an upper mold 230 and a lower mold 240 are overlapped to form a mold-shaped gap 220 (described later) inside. In the present embodiment, a resin mold 210 for one of interior parts of an automobile is shown, but the present embodiment can be applied to molding any resin product. FIG. 4 is a top view of the resin mold 210 of FIG. 3 and shows the outer shape of the molded mold and the route of the piping. In the following description, the lower end of FIG. 4 is referred to as the front, the right end as the right side, and the left end as the left side.

  As shown in FIGS. 3 and 4, the resin mold 210 includes a gap 220 in which a mold shape is formed, and a resin injection port that is provided near the center of the front surface of the resin mold 210 and is an opening for injecting resin into the gap 220. 222, and a right side air vent hole 223 and a left side air vent hole 224 for discharging air pushed out by the resin injected from the resin inlet 222.

  Further, the upper mold 230 is arranged so as to cross the upper side of the gap 220 in the resin, and has three pipes 231, 234, and 237 that are provided outside the upper mold 230, and the lower mold 240 is made of resin. It has three pipes 241, 244 and 247 provided across the lower side of the gap 220 in the same path as the upper mold 230 in a top view.

  In FIG. 4, description of the pipes 241, 244 and 247 is omitted and only the pipes 231, 234 and 237 are shown so as not to complicate the drawing. In this embodiment, each pipe is formed by embedding a metal pipe in the resin of the resin mold 210. However, the present invention is not limited to this, and the pipe is formed in the resin mold 210 and allows fluid to pass therethrough. Other holes that can be formed. Also, the number of pipes can be appropriately changed depending on the size of the resin mold.

  Hereinafter, the pipes 231, 234, and 237 arranged in the upper mold 230 will be described, but the same applies to the pipes 241, 244, and 247. The pipe 234 is a pipe that extends from the inlet / outlet 235 near the air vent hole 224 to the inlet / outlet 236 so as to approach the resin inlet 222 while crossing the upper side of the gap 220. The pipe 237 is a pipe extending from the inlet / outlet 238 near the air vent hole 223 to the inlet / outlet 239 so as to approach the resin inlet 222 while crossing the upper side of the gap 220. The pipe 231 extends in a straight line from the inlet / outlet port 232 on the left side of the resin inlet port 222 to the back side opposite to the front surface, and from the resin inlet port 222 so as to approach the resin inlet port 222 while meandering the upper portion of the gap 220. It extends to the right entrance 233.

  In this way, the piping through which the temperature control fluid flows is generally routed from the air vent hole toward the resin inlet, and is disposed so as to cover the entire gap 220. Each pipe can flow a fluid in any direction, and a desired direction can be selected according to the temperature control method.

  As shown by the curved irregularities on the upper surface of the upper mold 230 in FIG. 3, the upper surface of the upper mold 220 is the upper mold 230 that forms the gap 220 so that the resin thickness of the upper mold 220 is uniform. It is formed along the shape of the inner surface. Although not shown in the figure, the lower mold 240 also has a shape along the inner surface of the lower mold 240 that forms the gap 220 so that the thickness of the resin is uniform. Yes. Thus, by forming the upper mold 230 and the lower mold 240 so that the thicknesses thereof are substantially uniform, the temperature distribution in the thickness direction is substantially uniform at any position of the resin mold 210. It can be a distribution. Thereby, the temperature on the upper surface can be made uniform, and for example, deformation of the resin mold caused by local expansion or contraction on the upper surface can be suppressed.

  Further, the pipes 231, 234 and 237 of the upper mold 230 are arranged so as to pass through almost the center in the thickness direction of the upper mold 230, and the pipes 241, 244 and 247 of the lower mold 240 are arranged in the thickness direction of the lower mold 240. It is arranged to pass through almost the center of the. With such an arrangement, when each temperature control fluid is flowed, the temperature can be uniform in the thickness direction. For this reason, deformation such as warpage due to the difference in expansion and contraction between the inner surface and the outer surface of the resin mold 210 can be suppressed. In this case, the thickness direction can be determined appropriately depending on the shape of the resin product to be molded, regardless of whether the thickness direction is perpendicular to the inner surface or the direction in which the upper mold 230 and the lower mold 240 are overlapped. The effect of can be obtained.

  In the present embodiment, the shape of the upper surface of the upper mold 220 and the lower surface of the lower mold 240 are formed in accordance with the shape in which the gap is formed, and the pipe is arranged at the approximate center in the resin thickness direction. However, especially when there is no fear of deformation of the resin mold 210, it is not necessary to adopt such a shape and piping arrangement, even if the resin thickness of the resin mold 210 varies depending on the position. Even if the arrangement of the pipes is not at the center in the thickness direction, the present invention can be applied.

  Next, a resin molding process of a thermoplastic resin using the resin product manufacturing apparatus 100 of the present embodiment will be described. FIG. 5 shows a flowchart of the resin molding step S100. FIG. 6 shows the temperature of the air flowing through the piping in the resin molding step S100, the pressure applied to the thermoplastic resin, and the measured resin mold 210. A graph showing the change in temperature is shown.

  As shown in these drawings, in the resin molding step S100 of the present embodiment, first, in the mold heating step S110, air heated to a temperature higher than the temperature of the resin mold 210 in the temperature control fluid feeder 400 is piped. 231, 234, 237, 241, 244 and 247, and the resin mold is heated. Here, the temperature of the heated air in this embodiment is 200 ° C. and the flow rate is 200 L / min, but the temperature and flow rate of the heated air are the material of the thermoplastic resin used, the molding shape, and the material and size of the resin mold 210. It can be determined as appropriate in consideration of the position of the piping. When the heated air is flowed in only one direction with respect to each pipe, the upstream side is heated from the downstream side, so the flow direction is switched in the middle. In the present embodiment, the process is performed for 45 minutes per direction for a total of 90 minutes. By this step, the temperature of the resin mold 210 is about 175 ° C.

  Next, in the resin injection step S <b> 120, the thermoplastic resin heated and melted is injected from the resin injection port 222 using the discharger 300. Filling is completed when the pressure reaches about 2.6 MPa, and then the holding pressure of 2.0 MPa is maintained. In the present embodiment, even during the resin injection step S120, the same conditions as the mold heating step S110, that is, heated air having a temperature of 200 ° C. and a flow rate of 200 L / min is caused to flow through each pipe. Thus, the thermoplastic resin does not start to cure in the middle until the gap 220 is completely filled, and is filled while maintaining the viscosity at the time of inflow. In the resin injection step S120 of the present embodiment, the air flowing through the piping is set to the same temperature and flow rate as the mold heating step S110, but is for maintaining the temperature of the resin mold 210 and is different from the mold heating step S110. Also, the flow rate may be used.

  Next, in the cooling step S130, heated air lower than the temperature of the resin mold is caused to flow through the pipe while maintaining a predetermined filling pressure. In the resin molding method of the present embodiment, since the pressure for filling the resin is considerably lower than that in normal injection molding, it is considered that so-called “shrinkage” occurs when the resin is rapidly cooled. In this embodiment, by flowing heated air that is slightly lower than the temperature of the resin mold through the piping, the resin mold is cooled with a gentle temperature gradient, and the predetermined filling pressure is maintained in the discharger 300, so that “shrinkage” occurs. The portion that is about to be produced is further filled with resin. In this embodiment, as cooling air, cooling is performed over 100 minutes at 125 ° C. for 100 minutes at 100 ° C. for 30 minutes, and further at 100 ° C. for 30 minutes at 50 ° C. for 60 minutes, and the filling pressure is maintained at 2.0 MPa. To do. Generally, it is desirable to flow air within 50 degrees below the temperature of the resin mold 210, and more preferably, after flowing air within 30 degrees below the temperature of the resin mold 210, 50 degrees below the temperature of the resin mold 210. It is desirable to flow air within.

  In order to sufficiently fill the “shrinkage” in curing the injected thermoplastic resin, it is desirable that the thermoplastic resin is cured from the side far from the resin injection port 222. For this reason, the heated air that flows in the cooling process is allowed to flow from the inlet / outlet on the side far from the resin inlet 222, specifically, the outlets 235, 232, and 238 in FIG. This is because the air flowing through the pipe is warmed as it goes downstream, so that the cooling efficiency is low on the downstream side and the cooling efficiency is high on the upstream side. Thereafter, in the product extraction step S140, the resin mold 210 is opened, and after a predetermined time has elapsed, the mold is released by protrusion or the like. Thereby, the thermoplastic resin product which has the same surface finish as injection molding can be manufactured.

  In this embodiment, the filling pressure and the holding pressure are 2.6 MPa and 2.0 Pa, respectively, but the upper limit of these pressures is determined by the capacity of the discharger 300 and the pressure resistance of the resin mold 210, and the product size and The minimum pressure required is determined by the shape. Considering the pressure resistance of the resin mold, it should be used at 10.0 MPa or less, and when considering the shape and production number, it is preferably used at 6.0 MPa or less. Moreover, even if it is 3.0 Mpa or less like this embodiment, the product which has sufficient surface finish can be shape | molded. On the other hand, the lower limit of the filling pressure is preferably 1.0 MPa or more in consideration of surface roughness and shrinkage.

  As described above, in the present embodiment, since the thermoplastic resin can be molded at a low pressure, it can be molded using a resin mold having a lower pressure resistance than the mold. For this reason, it is not necessary to use an injection molding machine and a metal mold | die, and it can shape | mold at low cost. Further, by performing temperature control using a pipe capable of performing temperature management, a smooth surface can be formed as in the case of molding at high pressure.

  In the present embodiment, the piping is provided in the resin mold 210. However, particularly when the resin mold 210 containing metal powder is formed thin, the backup material 251 and the lower backup material 252 and the like. It is good also as forming inside. In this case, the meaning of the resin mold includes backup materials 251 and 253 in addition to the resin mold 210 of the present embodiment.

  Moreover, in this embodiment, although heated air was used also in the cooling process, it is good also as using cooled air depending on environments, such as room temperature. In the present embodiment, air is used as a fluid to control the temperature, but a gas other than air or a liquid such as water may be used.

  100 resin product manufacturing apparatus, 200 mold assembly, 210 resin mold, 220 gap, 222 resin inlet, 223 air vent hole, 224 air vent hole, 230 upper mold, 231, 234, 237 piping, 232, 233, 235, 236 238, 239 Entrance / exit, 240 Lower mold, 241, 244, 247 Piping, 251 Upper backup material, 252 Lower backup material, 255 Upper press plate, 257 Lower press plate, 261 Mold clamping mechanism, 300 Discharger, 400 Temperature control Fluid feeder, 510 Resin injection hose, 520 Fluid injection hose.

Claims (9)

Having an upper mold and a lower mold that form voids by being overlapped with each other, and at least an inner surface that forms the voids is made of a resin mixed with metal powder; and
A dispenser for injecting a molten thermoplastic resin into the gap of the resin mold at a pressure of 10.0 MPa or less;
A pipe that is provided in the resin of the resin mold and flows a fluid whose temperature is controlled;
In order to prevent hardening of the molten thermoplastic resin in the pipe, a resin product manufacturing apparatus comprising: a temperature control fluid feed section for flowing a fluid having a temperature higher than the temperature of the resin mold. In the resin product manufacturing apparatus according to claim 1,
The temperature control fluid flow section flows a fluid having a temperature higher than the temperature of the resin mold through the pipe, and then cures the thermoplastic resin from the temperature of the resin mold to the temperature of the resin mold. An apparatus for producing a resin product, characterized by flowing a cooling fluid in a temperature range of up to 50 degrees. In the resin product manufacturing apparatus according to claim 2,
Resin product manufacturing characterized in that the temperature control fluid flow section causes the cooling fluid to flow through the pipe during a period in which the discharger holds the thermoplastic resin at a pressure of 10.0 MPa or less. apparatus. In the resin product manufacturing apparatus according to claim 2 or 3,
The temperature control fluid flow section feeds the cooling fluid from the inlet / outlet farther from the thermoplastic resin inlet out of the two inlets / outlets of the pipe. In the resin product manufacturing apparatus according to any one of claims 1 to 4,
In the upper mold, the upper surface facing the upper mold inner surface forming the gap is a shape along the shape of the upper mold inner surface,
In the lower mold, a lower surface facing the inner surface of the lower mold that forms the gap is a shape that conforms to the shape of the inner surface of the lower mold. In the resin product manufacturing apparatus according to claim 5,
The resin product manufacturing apparatus, wherein the pipe provided in the resin of the resin mold is provided at a position including a center of the thickness of the resin defined in a direction perpendicular to the inner side surface of the resin mold. . In the resin product manufacturing apparatus according to any one of claims 1 to 5,
The resin product manufacturing apparatus, wherein the pipe provided in the resin of the resin mold is provided at a position including a center of the thickness of the resin defined by the overlapping direction of the resin mold. At least the surface of the mold is made of a resin mold made of a resin mixed with metal powder, and a fluid having a temperature higher than the temperature of the resin mold is allowed to flow through a pipe formed in the resin of the resin mold. A mold heating step for heating;
A resin injection step of filling a molten thermoplastic resin with a pressure of 10 MPa or less into the voids of the resin mold while flowing a fluid having a temperature higher than the temperature of the resin mold to the pipe;
While maintaining a holding pressure of 10 MPa or less with respect to the filled thermoplastic resin, a cooling fluid in a temperature range from the temperature of the resin mold to 50 degrees below the temperature of the resin mold is caused to flow through the pipe. And a cooling step for cooling the resin mold. In the manufacturing method of the resin product of Claim 8,
In the cooling step, the cooling fluid is caused to flow from the inlet / outlet farther from the thermoplastic resin inlet out of the two inlets / outlets of the pipe.

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