JP5610816B2 - In-mold molding method and in-mold mold - Google Patents

Description

The present invention relates to a mold for producing a resin molded product.
Specifically, an in-mold film transfer foil (hereinafter referred to as an in-mold transfer foil) on which various patterns are printed is mounted in the mold, and resin is injected onto the surface of the in-mold transfer foil, The present invention relates to an in-mold molding method in which a transfer foil and a resin are integrally molded.

  In recent years, it has become difficult to claim the superiority of products in terms of functionality and cost alone in electronic devices, and as a result, the number of companies that have come up with strategies to enhance the design capabilities of products is rapidly increasing. Among them, products that require high-quality and diversity in design are the current trend, and the response by conventional painting has become a limit. Accordingly, an in-mold molding method is promising, in which a film on which a pattern is printed is mounted in a mold and molded integrally with a personal computer or portable device.

FIG. 11 shows an in-mold molding apparatus using a general plastic injection molding machine.
The mold is composed of a movable mold 104 and a fixed mold 106. In a state where the mold is opened, the in-mold transfer foil 103 drawn out from the upper foil feeder 112 passes between the movable mold 104 and the fixed mold 106 and is passed to the lower foil feeder 113. ing.

In the molding process, the in-mold transfer foil 103 sent from the foil feeding device 112 to the foil feeding device 113 is fixed on the movable mold 104.
Thereafter, the foil holding frame 105 presses the in-mold transfer foil 103 by the protruding mechanism of the molding machine, and the movable mold 104 performs the mold closing operation in the direction of the fixed mold 106 to perform the mold clamping, and then from the molding machine nozzle 108. The molten resin 102 is injected into the mold (cavity 107).

  Thus, after cooling and solidifying the molded product in which only the pattern of the in-mold transfer foil 103 fixed on the movable mold 104 side is transferred to the surface, the molded product is taken out from the cavity 107 by the mold opening operation.

  At that time, the used part of the in-mold transfer foil 103 is in a state having no pattern. When the next molding is performed, the foil feeding device 112 and the lower foil feeding device 113 are rotationally driven, and the in-mold transfer foil 103 on which the pattern is printed is sent to the movable mold 104 to prepare for the next molding. It becomes a state.

This will be described in more detail.
FIGS. 14A to 14E show an in-mold molding process for the molded product 101 having a flat plate shape.

  First, in the foil setting step of FIG. 14A, the in-mold transfer foil 103 is placed on the part surface 104 a of the movable mold 104. At that time, the foil holding frame 105 is still positioned above the surface of the in-mold transfer foil 103 and the surface of the cavity 107 is not touching the in-mold transfer foil 103.

  In the foil adsorbing / mold closing / clamping process of FIG. 14B, the air is sucked from the suction groove 104 b, thereby bringing the in-mold transfer foil 103 into close contact with the surface of the cavity 107 of the movable mold 104. Do not. While maintaining this tight contact state, the foil pressing frame 105 connected to the protruding mechanism of the molding machine moves, and the in-mold transfer foil 103 is moved to the movable mold 104 by returning the protruding portion provided on the foil pressing frame 105. While being fixed to the part surface 104a, the movable mold 104 is closed to the fixed mold 106 and clamped with a predetermined clamping force.

  In the injection / cooling step of FIG. 14C, the molten resin 102 is injected and filled from the resin flow path (sprue) 109 in the mold into the cavity 107 where the in-mold transfer foil 103 is in close contact. . Then, it cools in this state.

  14D, the movable mold 104 is opened and the molded product 101 is taken out. At that time, the pattern of the in-mold transfer foil 103 is in close contact with the surface of the removed molded product 101 as an integral molded product.

  FIG. 12 shows an in-mold molded product 101 obtained in this way. Molding in which the pattern 110 is transferred to the surface of the molded product 101 is called in-mold molding.

JP-A-1-241416

  However, in the plate-shaped or box-shaped molded product 101 obtained by such a method, as shown in FIG. 13, the corners where the three surfaces, the top surface 101a and the side surfaces 101b and 101c intersect, In the side portion where the two surfaces of the surface 101a and the side surface 101b intersect at right angles, the in-mold transfer foil break 110a and the in-mold transfer foil wrinkles 110b often occur.

  This is because the in-mold transfer foil 103 is pulled too much or the in-mold transfer foil 103 does not move (displace) and an excessive shear stress is generated. On the other hand, since the pulling force of the in-mold transfer foil 103 is small, the amount of deviation of the in-mold transfer foil 103 increases, and wrinkles 110b may occur.

  An object of the present invention is to provide an in-mold forming method and an in-mold forming mold that can uniformly apply a pattern of an in-mold transfer foil.

In the in-mold molding method of the present invention, an in-mold transfer foil is brought into contact with a cavity surface of a first mold, and a resin is injected into a cavity formed by clamping the first mold and the second mold. An in-mold molding method comprising: a concave portion provided in an outer peripheral contour portion of the cavity on a plane of the first mold; and a thin portion and a thick portion of an elastic body. The first mold and the second mold using the first mold including a foil pressing frame provided with a foil pressing elastic body pressed against the part surface of the mold so as to face the in-mold transfer foil. An in-mold transfer foil is disposed between the in-mold transfer foil, and when the in-mold transfer foil is brought into contact with the part surface of the first mold and pressed by the foil holding frame, the in-mold transfer foil is moved by the foil pressing elastic body. From the pulling force in the first direction to send the foil A state having an increased tensile strength of the perpendicular second direction to said first direction, characterized by molding a resin by injection in-mold molded article in a cavity constituted by the mold clamping.
Further, when the in-mold transfer foil is brought into contact with the part surface of the first mold and pressed by the foil holding frame, the in-mold transfer foil is formed between the part surface of the first mold and the thin part. The thick portion is sandwiched, and the in-mold transfer foil is pulled and pushed into a recess provided in an outer peripheral contour portion of the cavity.

  Further, the concave portion of the first mold plane is arranged in the first direction at a position facing a foil pressing elastic body that presses the in-mold transfer foil, and the in-mold transfer foil is used as the foil pressing elastic body. In this case, a tensile force in the second direction is made larger than a tensile force in the first direction with respect to the in-mold transfer foil.

  Further, by a pressure variable mechanism that varies the pressure of the foil pressing elastic body that presses the in-mold transfer foil, it is arranged in the entire outer peripheral contour portion of the cavity or in an arbitrary region, and the in-mold transfer foil at the time of in-mold molding In other words, the pressure of the foil pressing elastic body in a place where breakage is likely to occur is variably controlled.

Further, the pressure variable mechanism variably controls the pressure of the foil pressing elastic body by a biasing means such as a spring or a leaf spring.
Further, the pressure variable mechanism variably controls the pressure of the foil pressing elastic body by a pressure adjusting means using fluid pressure such as air pressure, water pressure, and hydraulic pressure.

The pressure variable mechanism may variably control the pressure of the foil pressing elastic body by an electrical biasing means using an electromagnetic solenoid, a piezoelectric element, or the like.
In the in-mold molding die of the present invention, an in-mold transfer foil is brought into contact with the cavity surface of the first die, and the resin is injected into the cavity formed by clamping the first die and the second die. An in-mold molding mold to be molded, the first mold is provided with a foil pressing frame provided to face the in-mold transfer foil, and the foil pressing frame has a plane in the plane of the first mold. A concave portion provided in the outer peripheral contour portion of the cavity; and a foil pressing elastic body configured to hold the in-mold transfer foil against the part surface of the first mold, which is configured by a thin portion and a thick portion of the elastic body, and the in-mold transfer foil Is in contact with the part surface of the first mold and pressed by the foil pressing frame, the in-mold transfer foil is sandwiched between the part surface of the first mold and the thin part, and the thick part The outer ring of the cavity Push pull in a recess provided in a portion, characterized in that the than the tensile force of the first direction to send the in-mold transfer foil was increased pulling force of the perpendicular second direction to the first direction .

  In addition, in order to increase the pulling force in the second direction relative to the pulling force in the first direction with respect to the in-mold transfer foil, the concave portion is opposed to a foil pressing elastic body that holds the in-mold transfer foil. The thickness difference larger than the thickness of the in-mold transfer foil is formed in the foil pressing elastic body.

  According to this configuration, the foil retainer includes a foil retainer elastic body that is formed from an elastic body or a tube whose elasticity changes according to the amount of fluid supplied, and that presses the in-mold transfer foil against the part surface of the first mold. By using the frame, the pulling force and movement amount of the in-mold transfer foil can be adjusted to prevent the in-mold transfer foil from being wrinkled or broken in the in-mold molded product.

Sectional drawing of the in-mold mold in Embodiment 1 of this invention Front view of movable mold and foil retainer frame in the same embodiment Sectional view of the foil presser short side part showing the arrangement of the foil clamp elastic body in the same embodiment Molding process diagram using in-mold mold in the same embodiment Sectional view of the foil presser long side part showing the foil presser state in the same embodiment Sectional drawing of the foil presser short side part which shows the foil pressing state in the same embodiment Partial sectional view of a foil retainer frame provided in the movable mold according to Embodiment 2 of the present invention Partial sectional view of a foil presser frame provided in the movable mold in Embodiment 3 of the present invention Partial sectional view of a foil presser frame provided in the movable mold according to Embodiment 4 of the present invention. Partial sectional view of a foil retainer frame provided in the movable mold in the fifth embodiment of the present invention Schematic configuration diagram of a conventional in-mold mold Perspective view of a conventional in-mold molded product The perspective view which shows the defect location of the molded product which carried out the conventional in-mold molding Molding process diagram using conventional mold for in-mold molding

Hereinafter, the in-mold molding method of the present invention will be described based on specific embodiments.
(Embodiment 1)
1 to 6 show Embodiment 1 of the present invention.

  In addition, the same code | symbol is attached | subjected and shown to the thing of an equivalent function corresponding to the structural member demonstrated in FIG. 11 which shows the said prior art example. In addition, an embodiment will be described mainly with a movable mold based on FIG. 11 showing a conventional in-mold molding apparatus.

FIG. 1 shows a cross-sectional view of a movable mold 104 before molding on which an in-mold transfer foil 103 is installed. FIG. 2 shows an arrangement state of the movable mold 104 and the foil holding frame 105 as the first mold.
As shown in FIGS. 1 and 2, a foil retainer frame 105 of an in-mold transfer foil 103 is disposed on the upper part of the movable mold 104, and a foil retainer elastic body 135 is disposed between the movable mold 104 and the foil retainer frame 105. Is arranged.

  As shown in FIG. 2, the in-mold transfer foil 103 is sent out from the foil feeding device 112 attached to the upper part of the movable die 104 by the movable die 104. The movable mold 104 is provided with a foil holding frame 105 that presses the in-mold transfer foil 103 in a state of protruding from the part surface 104a of the movable mold 104 by using a protruding mechanism of the molding machine. The in-mold transfer foil 103 after the transfer of the pattern is wound around the foil feeding device 113 through the gap between the opened part surface 104a (see FIG. 1) of the movable mold 104 and the foil pressing frame 105.

  On the surface of the foil retainer frame 105 facing the part surface 104a of the movable mold 104 through the in-mold transfer foil 103, the foil retainer elasticity is located at a position corresponding to the periphery of the cavity 107 as shown in FIG. A body 135 is provided. More specifically, the foil presser elasticity is respectively applied to the long side portion 115 along the feeding direction of the in-mold transfer foil 103 of the foil presser frame 105 and the short side portion 125 of the foil presser frame 105 in the width direction of the in-mold transfer foil 103. A body 135 is arranged. The foil retainer elastic body 135 is formed of a material having a smaller elastic modulus than the foil retainer frame 105. Specifically, the foil retainer frame 105 is made of the same material as the movable mold 104 or the fixed mold 105 or an iron material softer than that, and the foil retainer elastic body 135 is made of, for example, a rubber plate.

  As shown in FIG. 1, the foil pressing elastic body 135 has a difference in thickness between the inner thin portion 145 and the outer thick portion 155. The difference in thickness between the thin part 145 and the outer thick part 155 is set to be larger than the thickness of the in-mold transfer foil 103, and the thin part 145 is arranged on the inner side (cavity 107 side).

  On the part surface 104 a of the movable mold 104, as shown in FIGS. 1 and 2, a concave portion 114 that becomes a concave step corresponding to the long side portion 115 is long along the feeding direction of the in-mold transfer foil 103. Is provided. The foil retainer elastic body 135 provided on the long side portion 115 has the thick portion 155 inserted into the concave portion 114, and the end portion of the in-mold transfer foil 103 is between the thin portion 145 and the concave portion 114 due to the wedge effect. The in-mold transfer foil 103 is clamped more strongly than the part surface 104a.

  On the other hand, FIG. 3 is a sectional view of the short side portion 125 showing the arrangement of the foil pressing elastic body. The short side portion 125 is the side that always receives a pulling force on the in-mold transfer foil 103 by the foil feeding device, and the concave surface corresponding to the foil pressing elastic body 135 is not formed on the part surface 104a. The in-mold transfer foil 103 is sandwiched by the plane of the surface 104a, and the pressing force of the in-mold transfer foil 103 is generated by the pressing force of the thick portion 155 of the foil pressing elastic body 135 that is thicker than the thickness of the in-mold transfer foil 103. It is configured.

This in-mold mold performs the in-mold molding method in the steps of FIGS.
First, in the foil setting step shown in FIG. 4A, the in-mold transfer foil 103 is placed on the part surface 104 a of the movable mold 104. At that time, the foil holding frame 105 is still in a state of being located at the upper part of the surface of the in-mold transfer foil 103 and is not touching the in-mold transfer foil 103.

  4B, the air in the cavity 107 is removed by sucking the in-mold transfer foil 103 from the suction groove 104b, and the in-mold transfer foil 103 serves as the surface of the cavity 107 of the movable mold 104. Keep in line with the shape. While maintaining this state, the in-mold transfer foil 103 is sandwiched between the foil pressing elastic body 135 which is the protruding portion of the foil pressing frame 105 connected to the protruding mechanism of the molding machine and the part surface 104a of the movable mold 104. The Further, the movable mold 104 is closed by a fixed mold 106 as a second mold, and is clamped with a predetermined clamping force.

In the injection process, the molten resin 102 is injected through the resin flow path (sprue) 109 in the mold.
In the cooling step of FIG. 4C, the in-mold transfer foil 103 and the resin 102 are integrally formed by cooling.

  4D, the movable mold 104 is opened and the molded product 101 is taken out. At that time, the pattern of the in-mold transfer foil 103 is in close contact with the surface of the removed molded product 101 as an integral molded product.

The adjustment operation of the pressing force of the in-mold transfer foil 103 at the long side portion and the short side portion of the foil pressing elastic body 135 having the above-described configuration will be specifically described.
The foil setting process of FIG. 4A described above will be described.

  At this time, the in-mold transfer foil 103 is sandwiched between the part surface 104 a of the movable mold 104 and the thin portion 145 of the foil retainer elastic body 135 at the long side portion 115 of the foil retainer frame 105. Further, the thick part 155 of the foil pressing elastic body 135 pulls and pushes the end of the in-mold transfer foil 103 into the concave part 114 provided on the part surface 104 a of the movable mold 104.

  Furthermore, the mold is closed in the foil adsorption / injection process of FIG. 4B and is clamped with a predetermined clamping force, so that the movable mold 104 is pressed against the fixed mold 106 via the foil pressing frame 105. The in-mold transfer foil 103 is engaged with a concave recess 114 of the part surface 104a provided at the end surface position in the width direction, and the in-mold transfer foil 103 is bent at the slope portion 135b of the part surface 104a and the recess 114. Is formed, and the tensile force is increased at the long side portion where the wrinkles of the in-mold transfer foil 103 are generated, and the movement of the in-mold transfer foil 103 due to the pull to the cavity 107 is suppressed.

  Further, the in-mold transfer foil 103 is pressed by the thin portion 145 of the foil clamp elastic body 135 and the tensile force is maintained by increasing the holding force. As a result, the mold is bent by the molding pressure at the time of injection, and the in-mold transfer foil 103 Even if the pressing force against the pressure decreases, the pulling force of the in-mold transfer foil 103 and wrinkles due to the foil movement can be prevented.

  Further, even when the melted resin 102 is injected and filled into the cavity 107, the in-mold transfer foil 103 is strongly pressed by the thin portion 145 so that there is no displacement of the foil. Since it follows the shape of the cavity 107, no foil wrinkles occur.

  FIG. 6 is a sectional view of the in-mold transfer foil 103 in the direction along the feeding direction. A constant tension is applied to the in-mold transfer foil 103 by the foil-feed device 112 (not shown in FIG. 6) on the in-mold transfer foil 103 provided on the movable mold 104 and the foil-feed device 113 on the take-up side. It depends. Therefore, the in-mold transfer foil 103 holds a constant tensile force, and the in-mold transfer foil 103 can be held between the thick portion 155 of the foil pressing elastic body 135 and the part surface 104 a of the movable mold 104.

  Furthermore, the in-mold transfer foil 103 is hardly lifted by the injection pressure at the end corner portion 107 a filled with the resin 102, and the foil pressing frame 105 is surrounded by three sides, and the in-mold is formed by the filling pressure of the injected resin 102. Since the transfer foil 103 is stretched, the part surface 104a in the feeding direction of the movable mold 104 corresponding to the short side portion 125 of the foil holding frame 105 is not provided with the recess 114 seen in the long side portion 115, and the foil The in-mold transfer foil 103 is sandwiched between the thick portion 155 of the presser elastic body 135 and the flat part surface 104a.

  Therefore, a slack portion 135 a is formed in the in-mold transfer foil 103 in the direction along the feeding direction of the in-mold transfer foil 103 due to the step between the thick portion 155 and the thin portion 145 of the foil pressing elastic body 135. The slack portion 135a provides an allowance for the elongation of the in-mold transfer foil 103, and the in-mold transfer foil 103 adjusts the amount of movement of the in-mold transfer foil 103 with respect to the tensile force caused by the injection filling pressure of the resin 102. Is prevented from breaking at the end corner portion 107a filled with.

  Thus, when the molten resin 102 is injected with the in-mold transfer foil 103 uniformly stretched on the movable mold 104, the pulling force of the in-mold transfer foil 103 and the movement amount of the in-mold transfer foil 103 are automatically set. It is possible to obtain a molded article 101 that is adjusted and in-mold molded without any breakage on the in-mold transfer foil 103.

  Further, the in-mold transfer foil 103 is thermally expanded by the heat of the injected resin 102 when the resin 102 is injected into the cavity 107. If the elongation of the in-mold transfer foil 103 generated by this thermal expansion remains within the cavity 107, it will become wrinkles. In particular, when the cavity 107 is shallow, the wrinkles are conspicuous. In the first embodiment, since the material of the foil holding elastic body 135 that holds the in-mold transfer foil 103 is formed of an elastic body, the amount of thermal expansion of the in-mold transfer foil 103 due to the heat of the injected resin 102. The elongation of the foil retainer elastic body 135 itself is elastically deformed by the elongation, and the expansion of the thermal expansion of the in-mold transfer foil 103 can be released to the outside of the cavity 107, and the wrinkles of the in-mold transfer foil 103 remaining in the cavity 107 can be surely secured. Can be reduced. Therefore, it is very effective when the cavity 107 is formed with a shallow depth.

(Embodiment 2)
FIG. 7 shows a partial cross-sectional view of the foil retainer frame provided in the movable mold 104 according to the second embodiment of the present invention. Components having the same functions corresponding to the components described with reference to FIG.

  In the first embodiment, the foil holder elastic body 135 is directly attached to the foil holder frame 105, but in this second embodiment, the foil holder elastic body 135 is attached to the foil holder frame 105 via a pressure variable mechanism. The only difference is that

  As shown in FIG. 7, a coil spring 137 is interposed as a variable pressure mechanism between the entire area of the long side 115 and the short side 125 of the foil retainer frame 105 or between arbitrary positions and the foil retainer elastic body 135. . The guide pin 136 located inside the coil spring 137 is provided on the foil retainer elastic body 135.

The coil spring 137 varies the pressing pressure of the in-mold transfer foil 103 at the long side portion 115 and the short side portion 125 by setting the spring force.
By adjusting the pulling force partially on the in-mold transfer foil 103, the compression force of the spring 137 is increased in order to increase the foil pressing force on the long side portion where the wrinkles of the in-mold transfer foil 103 are generated during molding. In addition, an effect of suppressing the amount of movement of the in-mold transfer foil 103 toward the molded product 101 is provided.

  On the other hand, since the foil retainer frame 105 is hardly lifted by the molding pressure at the end corner portion where the short side resin is fluid-filled and is surrounded by the three sides of the foil retainer frame 105, the in-mold is caused by the injection pressure of the molten resin. In order to stretch the transfer foil 103, the compression force of the spring 137 of the foil pressing elastic body 135 is lowered, and a step slack portion 135a is provided in the pressing portion of the in-mold transfer foil 103 to reduce the pressing force. Adjusts the step of the slack portion 135a and the force of the spring 137 to such a level that the in-mold transfer foil 103 can move with respect to the pulling force due to the injection pressure of the molten resin. Eventually, the molded product 101 is prevented from breaking at the corners, and the same effect as in the first embodiment is obtained.

The variable pressure mechanism according to the second embodiment uses a coil spring as an example, but is not limited to this as long as an urging force such as a leaf spring can be obtained and a similar action can be obtained.
(Embodiment 3)
FIG. 8 shows a partial cross-sectional view of the foil retainer frame provided in the movable mold 104 according to Embodiment 2 of the present invention. Components having the same functions corresponding to the components described with reference to FIG.

  In Embodiment 1, the foil holder elastic body 135 is directly attached to the foil holder frame 105. However, in Embodiment 3, the foil holder elastic body 135 is attached to the foil holder frame 105 via a pressure variable mechanism. The only difference is that

  As shown in FIG. 8, the foil pressing frame is provided as a variable pressure mechanism via a cylinder driving unit 138 between the entire region of the long side 115 and the short side 125 of the foil pressing frame 105 or an arbitrary position and the foil pressing elastic body 135. The only difference is that it is attached to 105.

  The cylinder driving unit 138 can adjust the pressing force with a driving source such as air pressure, hydraulic pressure, water pressure, etc., and can control the pressing pressure with the pressure adjusting valve 139 according to the part of the molded product. By adjusting the tensile force and the amount of movement of the in-mold transfer foil 103 partially on the long side portion, the short side portion, and the like on the foil 103, and adjusting the tensile force of the in-mold transfer foil 103 and adjusting the amount of movement of the foil. An in-mold molded product having no wrinkles or breakage can be obtained.

(Embodiment 4)
FIG. 9 shows a partial cross-sectional view of the foil retainer frame provided in the movable mold 104 according to Embodiment 4 of the present invention. Components having the same functions corresponding to the components described with reference to FIG.

  In Embodiment 1, the foil holder elastic body 135 is directly attached to the foil holder frame 105. However, in Embodiment 4, the foil holder elastic body 135 is attached to the foil holder frame 105 via a pressure variable mechanism. The only difference is that

  As shown in FIG. 9, an electrical solenoid such as an electromagnetic solenoid or a piezoelectric element as a pressure variable mechanism is provided in the entire area of the long side and short side of the foil holding frame 105 installed at the outer peripheral contour portion of the molded product 101 or at an arbitrary position. A mold using the foil retainer frame 105 provided with the actuator and the foil retainer elastic body 135 via the guide pin 136 is configured. An electric actuator driving unit (electromagnetic solenoid 140) and an electromagnetic solenoid 140 having a foil pressing elastic body 135 in the entire area of the long side portion and the short side portion of the foil holding frame 105 installed in the outer peripheral contour portion of the molded article 101 or at arbitrary positions. It is constituted by a foil presser frame 105 for fixing

  The electromagnetic solenoid 140 can be controlled by the electric pressure according to the part of the molded product, so that the in-mold transfer foil 103 may have a partial pulling force such as a long side or a short side. By adjusting the amount of movement of the transfer foil 103, making the tensile force of the in-mold transfer foil 103 uniform and adjusting the amount of movement of the foil, an in-mold molded product free from foil wrinkles and breakage can be obtained.

  The pressure variable mechanism of the fourth embodiment is an electromagnetic solenoid, but is limited to this as long as it can obtain the electrical urging force of the above-described piezo element and the like and can obtain the same action. is not.

(Embodiment 5)
FIG. 10 shows a partial cross-sectional view of the foil retainer frame provided in the movable mold 104 in the fifth embodiment of the present invention. Components having the same functions corresponding to the components described with reference to FIG.

  In Embodiment 1, the foil retainer elastic body 135 is formed of a rubber plate or the like, but in Embodiment 4, the foil retainer elastic body 135 is changed to a tube 141 whose elasticity changes according to the amount of fluid, The only difference is that the amount of fluid supplied to the tube 141 is adjusted.

  As shown in FIG. 10, a foil holding frame 105 that holds the in-mold transfer foil 103 is provided around the contour of the molded product 101, and the foil holding frame 105 is provided with a tube 141 as a pressure variable mechanism that comes into contact with the in-mold transfer foil 103. The foil pressing force can be controlled by providing an air pressure or hydraulic pressure supply source (not shown) and a pressure regulating valve 139 in the tube 141. At that time, in the long side portion 115 where wrinkles are likely to occur, a concave portion 114 is formed on the part surface 104a of the movable mold 104 corresponding to the tube 141 as a foil pressing elastic body, and the pressure of the tube 141 is increased. Thus, the in-mold transfer foil 103 can be prevented from wrinkling by increasing the holding force of the in-mold transfer foil 103 and increasing the pulling force of the in-mold transfer foil 103 against the flow resistance when the molten resin 102 is injected.

  On the other hand, in the short side portion, the pressure of the foil pressing tube 141 is decreased, the pressing force of the in-mold transfer foil 103 is decreased, and the in-mold transfer foil 103 moves with respect to the tensile force due to the injection pressure of the molten resin 102. The pressing force is adjusted by the pressure adjustment valve 139 to a level that can be achieved. Eventually, breakage at the terminal corner 107a is suppressed, and the same effect as in the first embodiment is obtained.

  The in-mold molding method and the in-mold molding die of the present invention can be applied to a case where a pattern of an in-mold transfer foil is transferred to a flat surface of a molded product.

101 Molded product 101a Top surface 101b, 101c Side surface 102 Resin 103 In-mold transfer foil 104 Movable mold (first mold)
104a Part surface 104b Suction groove 105 Foil presser frame 106 Fixed mold (second mold)
107 Cavity 107a End corner 108 Molding machine nozzle 109 Resin flow path (sprue)
110 Pattern 110a Break 110b Foil 112 Foil Feeder 113 Foil Feeder 114 Recess 115 Long Side 125 Short Side 135 Foil Press Elastic Body 135a Slack Part 136 Guide Pin 137 Spring 138 Cylinder Drive 139 Pressure Adjustment Valve 140 Electromagnetic Solenoid 141 Tube 145 Thin part 155 of the foil clamp elastic body Thick part of the foil clamp elastic body

Claims (9)

An in-mold molding method in which an in-mold transfer foil is brought into contact with a cavity surface of a first mold, and a resin is injected and molded into a cavity formed by clamping the first mold and the second mold,
Foil holding elasticity which is composed of a concave portion provided in the outer peripheral contour portion of the cavity on the plane of the first mold, and a thin part and a thick part of an elastic body , and holds the in-mold transfer foil against the part surface of the first mold. Using the first mold provided with a foil pressing frame provided to face the in-mold transfer foil,
An in-mold transfer foil is disposed between the first mold and the second mold,
When the in-mold transfer foil is brought into contact with the part surface of the first mold and pressed by the foil pressing frame, the foil pressing elastic body causes a pulling force in the first direction to send the in-mold transfer foil. An in-mold molding method in which a tensile force in a second direction perpendicular to the first direction is increased, and an in-mold molded product is molded by injecting a resin into the cavity formed by the mold clamping. When the in-mold transfer foil is brought into contact with the part surface of the first mold and pressed by the foil holding frame,
Sandwiching the in-mold transfer foil between the part surface of the first mold and the thin part,
The thick part pulls and pushes the in-mold transfer foil into a recess provided in the outer peripheral contour of the cavity.
The in-mold molding method according to claim 1. The concave portion of the first mold plane is arranged in the first direction at a position facing a foil pressing elastic body that holds the in-mold transfer foil, and the thickness of the in-mold transfer foil is used as the foil pressing elastic body. The in-mold molding method according to claim 1, wherein a tensile force in the second direction is made larger than a tensile force in the first direction with respect to the in-mold transfer foil by using a material having a larger thickness difference. By a pressure variable mechanism that varies the pressure of the foil pressing elastic body that presses the in-mold transfer foil, it is arranged in the whole area of the outer peripheral contour portion of the cavity or in an arbitrary area, and the The in-mold molding method according to claim 1, wherein the pressure of the foil pressing elastic body in a place where breakage is likely to occur is variably controlled. The pressure variable mechanism variably controls the pressure of the foil pressing elastic body by a biasing means such as a spring or a leaf spring.
The in-mold molding method according to claim 4 . The pressure variable mechanism variably controls the pressure of the foil pressing elastic body by pressure adjusting means using fluid pressure such as air pressure, water pressure, and hydraulic pressure.
The in-mold molding method according to claim 4 . The pressure variable mechanism variably controls the pressure of the foil pressing elastic body by an electrical biasing means using an electromagnetic solenoid, a piezo element or the like.
The in-mold molding method according to claim 4 . An in-mold mold for injecting resin into a cavity formed by bringing an in-mold transfer foil into contact with a cavity surface of a first mold and clamping the first mold and the second mold. ,
The first mold is provided with a foil holding frame provided to face the in-mold transfer foil,
In the foil presser frame,
A recess provided in an outer peripheral contour portion of the cavity in the plane of the first mold;
Provided with a foil pressing elastic body that is composed of a thin part and a thick part of an elastic body and presses the in-mold transfer foil against the part surface of the first mold,
In the state where the in-mold transfer foil is brought into contact with the part surface of the first mold and pressed by the foil pressing frame,
The in-mold transfer foil is sandwiched between the part surface of the first mold and the thin part, and the thick part pulls and pushes the in-mold transfer foil into a recess provided in an outer peripheral contour part of the cavity, An in-mold mold in which a pulling force in a second direction perpendicular to the first direction is larger than a pulling force in a first direction for feeding the in-mold transfer foil. In order to make the pulling force in the second direction larger than the pulling force in the first direction with respect to the in-mold transfer foil, the concave portion is positioned at a position facing a foil pressing elastic body that holds the in-mold transfer foil. A thickness difference larger than the thickness of the in-mold transfer foil was formed in the foil pressing elastic body arranged in the first direction.
The in-mold mold according to claim 8 .

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