JP5403252B2 - Molding method - Google Patents

Description

  The present invention relates to a molding method, and more particularly, enables recycle of a burr portion generated during molding when repeatedly blow-molding two thermoplastic resin sheets having different colors and / or materials. Thus, the present invention relates to a molding method capable of suppressing a decrease in yield.

Conventionally, according to the blow molding method using two thermoplastic resin sheets, the sheet-like molten parison protruding from the mold around the pinch-off portion is cut as burrs, the burrs are crushed and mixed with pellets, and molded It was reused as a material.
In particular, when the molded product is not a straight tube but a curved tube, such as a duct for automobiles, for example, a U-shape, two horizontal pipe parts parallel to each other and a vertical straight pipe connecting these horizontal pipe parts. When the blow molding is performed, a sheet-like parison having a rectangular width or more constituted by the horizontal length of the horizontal pipe portion and the vertical length of the vertical pipe portion is required for blow molding. The resin part on the side of the vertical pipe part between them was a burr, and a corresponding part of the rectangular parison sheet had to be excluded from the molding target.

Patent Document 1 discloses a technique in which two sheets having different colors are pasted together and blow-molded. More specifically, one sheet is extruded from each of at least two dies connected to an extruder, and immediately after this. Each sheet is sandwiched between a pair of sandwiching rollers, at least the surface of each sheet is heated, the wrinkles are widened, and the gloss is produced. Disclosed is a point in which the material is supplied into a mold, the blow molding die is closed, two sheets are bonded together, and blow molding is performed.
According to such a blow molding technique, the blow molding dies are closed, and the annular pinch-off portions provided in the cavities of the respective dies are brought into contact with each other by welding the peripheral edges of the two sheets. Although they can be combined and blow-molded, due to the use of two sheets having different colors, the following technical problems are associated with the reuse of burrs.

That is, out of each sheet-like parison, the outer part of the annular pinch-off part provided in the mold cavity corresponds to a burr, and when the mold is clamped, the outer parts of the pinch-off part of each sheet-like parison are It is welded in the form of surface adhesion, and it becomes particularly difficult to separate after cooling.
In a state where burrs of two sheets having different colors are mixed, it is difficult to recycle, and a considerable part of the sheet-like parison has to be discarded, resulting in a decrease in yield.
This point causes similar problems when blow molding is performed using two sheets of the same color but different materials.
JP-A-11-5248

  In view of the above technical problems, an object of the present invention is to enable recycling of a burr portion caused by molding when repeatedly blow-molding using two thermoplastic resin sheets having different colors and / or materials. Thus, an object of the present invention is to provide a molding method capable of suppressing a decrease in yield.

In order to achieve the above object, the molding method according to the present invention comprises:
A molding method using two sheets of different colors and / or materials,
An annular pinch-off portion provided at the peripheral edge of a pair of split mold cavities in a state where the melted sheet parisons of two thermoplastic resin materials having different colors and / or materials are separated from each other Positioning between a pair of split molds in a form that protrudes around,
By moving the annular outer frame fitted around the outer peripheral surface of each of the pair of divided molds toward the opposing mold until they contact the opposing surface of the corresponding sheet-like parison, the mold cavity and the corresponding sheet Forming a sealed space with the opposing surface of the parison and the inner peripheral surface of the annular outer frame part;
A step of pressing the sheet-like parison against the cavity of the corresponding mold by sucking the corresponding sheet-like parison including the portion located outside the annular pinch-off portion through the sealed space;
A pair of divided molds are clamped and the annular pinch-off portions are brought into contact with each other to weld two sheet-like parisons.

  According to the molding method having the above configuration, when molding using two sheets of different colors and / or materials, before clamping a pair of split molds, the outer side of the annular pinch-off portion By sucking each sheet-shaped parison including the part (burr) positioned toward the corresponding mold cavity, it is possible to prevent the burrs from welding in a butted form before clamping. As a result, burrs of different colors and / or materials can be independently collected and recycled, so that a decrease in yield can be suppressed.

The positioning step may include a step of hanging a continuous sheet-like melted parison extruded above the pair of split molds between the pair of split molds.
Further, in the mold clamping step, it is preferable to perform mold clamping in a state where the portion of the sheet-like parison located outside the annular pinch-off portion is sucked and held.
Furthermore, in the mold clamping step, the contact position in the mold clamping direction between the annular pinch-off portions may be provided between the sheet-like parisons that are separated from each other.
Furthermore, at least one of the annular pinch-off portions is provided so as to protrude toward the opposing mold,
The mold clamping step corresponds to a mold corresponding to the at least one annular pinch-off portion protruding from the corresponding annular outer frame in a state where the annular outer frame abutting against the opposing surface of the sheet-like parison is held in its position. It is good to move.

In addition, each of the annular pinch-off portions is provided so as to protrude toward the opposing mold,
In the mold clamping step, the two molds are brought close to each other until the annular pinch-off portions protrude from the corresponding annular outer frames, with the annular outer frame abutting against the opposing surface of the sheet-shaped parison held in the same position. It may be moved in the direction.
Further, in the mold clamping step, in a state where the annular pinch-off portions are in contact with each other, an opposing surface of each annular outer frame to the opposing annular outer frame and an opposing surface of the corresponding mold to the opposing mold are provided. It is preferable to have a step of moving and adjusting the annular outer frame and / or the mold in the mold clamping direction so as to be flush with each other.
Furthermore, in the suction stage of the sheet-like parison, a portion of the sheet-like parison located outside the annular pinch-off part may be sucked through a vacuum suction port provided along the outer periphery of the pinch-off part.

Embodiments according to the present invention will be described below in detail with reference to the drawings.
In this embodiment, the resin molded product is completed by integrally molding two thermoplastic resins as the casing cover of the game machine, using the same material and different colors for the front cover and the back cover. A case will be described as an example.
First, the shaping | molding apparatus for enforcing the shaping | molding method of this invention is demonstrated below.
As shown in FIG. 1, a molding device 10 for a resin molded product has an extrusion device 12 and a mold clamping device 14 disposed below the extrusion device 12, and is a molten sheet extruded from the extrusion device 12. The parison P is fed to the mold clamping device 14, and the mold-like clamping device 14 forms the molten sheet parison P. Here, since the apparatuses for extruding each of the two thermoplastic resins and sending them to the mold clamping device 14 are the same, only one of them will be described, and the other will be given the same reference number for the description. Omitted.

  The extruding device 12 is a conventionally known type, and a detailed description thereof is omitted. However, a cylinder 18 provided with a hopper 16, a screw (not shown) provided in the cylinder 18, and a screw are connected to the screw 18. A hydraulic motor 20, an accumulator 22 that communicates with the inside of the cylinder 18, and a plunger 24 provided in the accumulator 22. The molten resin is melted and kneaded by the rotation of the resin, and the molten resin is transferred to the accumulator 22 chamber and stored in a certain amount. The plunger 24 is driven to feed the molten resin toward the T die 28, A pair of rollers 30 in which the parison P is extruded and spaced apart Thus it is suspended between the split mold 32 while being pinched sent out downward. Thereby, as will be described in detail later, the sheet-like parison P is disposed between the split molds 32 in a state having a uniform thickness in the vertical direction (extrusion direction).

The extrusion capability of the extrusion device 12 is appropriately selected from the viewpoint of the size of the resin molded product to be molded, the draw-down of the sheet parison P, or the prevention of neck-in occurrence. More specifically, from a practical point of view, the extrusion amount of one shot in intermittent extrusion is preferably 1 to 10 kg, and the extrusion rate of the resin from the extrusion slit 34 is several hundred kg / hour or more, more preferably 700 kg / hour or more. Further, from the viewpoint of preventing the draw-down or neck-in of the sheet-like parison P, the extrusion process of the sheet-like parison P is preferably as short as possible and generally depends on the type of resin, MFR value, and melt tension value. The extrusion process should be completed within 40 seconds, more preferably within 10 to 20 seconds. For this reason, the unit area and the amount of extrusion per unit time from the extrusion slit 34 of the thermoplastic resin are 50 kg / hour cm ² or more, more preferably 150 kg / hour cm ² or more.

  By feeding the sheet-like parison P sandwiched between the pair of rollers 30 by the rotation of the pair of rollers 30 downward, the sheet-like parison P can be stretched and thinned, and the extruded sheet-like parison P is extruded. By adjusting the relationship between the speed and the delivery speed of the sheet-like parison P by the pair of rollers 30, it is possible to prevent the occurrence of drawdown or neck-in, so the type of resin, particularly the MFR value and melt tension. It is possible to reduce the restriction on the value or the extrusion amount per unit time.

  As shown in FIG. 1, the extrusion slit 34 provided in the T die 28 is arranged vertically downward, and the continuous sheet-like parison P extruded from the extrusion slit 34 is suspended vertically from the extrusion slit 34 in the vertical downward direction. To be sent to. The extrusion slit 34 can change the thickness of the continuous sheet parison P by making the interval variable.

The pair of rollers 30 will be described. In the pair of rollers 30, the rotation axes of the pair of rollers 30 are arranged substantially horizontally in parallel with each other, one is the rotation drive roller 30A, and the other is driven to rotate. The roller 30B. More specifically, as shown in FIG. 1, the pair of rollers 30 are arranged so as to be line-symmetric with respect to the sheet-like parison P extruded in a form that hangs downward from the extrusion slit 34.
The diameter of each roller and the axial length of the roller may be appropriately set according to the extrusion speed of the sheet-like parison P to be molded, the length and width of the sheet in the extrusion direction, and the type of resin. As will be described, from the viewpoint of smoothly feeding the sheet-like parison P downward by rotation of the roller with the sheet-like parison P sandwiched between the pair of rollers 30, the diameter of the rotation drive roller 30A is the rotation-driven roller. It is preferably slightly larger than the diameter of 30B. The diameter of the roller is preferably in the range of 50 to 300 mm. If the curvature of the roller is too large or too small in contact with the sheet-like parison P, the sheet-like parison P may be wound around the roller. Become.

  On the other hand, the mold clamping device 14 is also a conventionally known type like the extrusion device 12, and detailed description thereof will be omitted, but the two divided molds 32A and 32B and the molds 32A and 32B are melted. A mold driving device that moves between an open position and a closed position in a direction substantially orthogonal to the supply direction of the sheet-like parison P.

As shown in FIG. 1, the two divided molds 32 </ b> A and 32 </ b> B are arranged with the cavities 116 facing each other, and the cavities 116 are arranged so as to face substantially vertically. The surface of each cavity 116 is provided with a concavo-convex portion according to the outer shape and surface shape of a molded product molded based on the melted sheet-like parison P.
In each of the two divided molds 32A and 32B, a pinch-off part 118 is formed around the cavity 116. The pinch-off part 118 is formed in an annular shape around the cavity 116, and the opposing molds 32A and 32B are formed. Protrusively toward. As a result, when the two divided molds 32A and 32B are clamped, the tip portions of the pinch-off portions 118 come into contact with each other so that the parting line PL is formed at the periphery of the melted sheet-like parison P. I have to.

  The molds 33A and B are slidably fitted to the outer peripheral portions of the two divided molds 32A and B in a sealed state, and the molds 33A and B are respectively fitted by a mold moving device (not shown). It can be moved relative to the molds 32A and 32B. More specifically, the mold 33A protrudes toward the mold 32B with respect to the mold 32A, thereby being able to contact the side surface of the sheet-like parison P disposed between the molds 32A and 32B. The mold frame 33B can be brought into contact with the side surface of another sheet-like parison P disposed between the molds 32A and 32B by projecting toward the mold 32A with respect to the mold 32B.

The mold driving device is the same as the conventional one, and the description thereof is omitted. However, the two divided molds 32A and 32B are respectively driven by the mold driving device and are divided into two in the open position. Two melted continuous sheet parisons P can be arranged between the molds 32A and 32B, and the pinch-off portions 118 of the two split molds 32A and 32B are in contact with each other in the closed position. The pinch-off portions 118 are in contact with each other so that a sealed space is formed in the two divided molds 32A and 32B. Regarding the movement of the molds 32A and 32B from the open position to the closed position, the closed position, that is, the position where the pinch-off portions 118 are in contact with each other is between the two continuous sheet-like parisons P in the molten state. The positions are equidistant from the parison P, and the molds 32A and 32B are driven by the mold driving device to move toward the positions.
Note that the extrusion device and the pair of rollers for one continuous sheet-like parison P and the extrusion device and the pair of rollers for the other continuous sheet-like parison P are arranged symmetrically with respect to this closed position.

As shown in FIG. 4 (only shown for one mold), a vacuum suction chamber 120 is provided inside the split mold 32, and the vacuum suction chamber 120 communicates with the cavity 116 through the suction hole 122. By sucking from the vacuum suction chamber 120 through the suction hole 122, the sheet-like parison P is adsorbed toward the cavity 116 and shaped into a shape along the outer surface of the cavity 116.
In this case, as shown in FIG. 3, a vacuum suction port 124 communicating with the vacuum suction chamber 120 is provided between the outer periphery of the pinch-off portion 118, more precisely, between the pinch-off portion 118 and the inner peripheral surface 102 of the mold 33. Thus, the portion (burr portion) of the sheet-like parison P located outside the pinch-off portion 118 can be sucked. As a result, when the divided mold 32 is clamped, it is possible to prevent a situation where burrs are stuck together and cannot be separated.
The vacuum suction port 124 may be provided in an annular shape around the pinch-off portion 118, or may be provided in a plurality of tubular shapes distributed around the pinch-off portion 118.
The protrusion D in the mold clamping direction of the mold 33 with respect to the mold 32 and the distance L between the inner peripheral surface 102 of the mold 33 and the vacuum suction port 124 can surely attract the burr part in relation to the suction pressure. From the viewpoint of making it.
Such a vacuum suction port 124 is preferably provided in each of the molds 32A and 32B, but one of the two molten resin sheets is sucked and held by suction in the corresponding mold 32. As long as it is possible to prevent the burrs of the two molten resin sheets from sticking to each other when the mold is clamped, the vacuum suction port 124 may be provided in only one mold 32. Good.

  The sheet-like parison P is made of a sheet formed from polypropylene, engineering plastics, olefin resin, or the like. More specifically, the sheet-like parison P is preferably made of a resin material having a high melt tension from the viewpoint of preventing the occurrence of thickness variations due to drawdown, neck-in, etc., while being transferred to a mold. It is preferable to use a resin material with high fluidity in order to improve the property and followability. The two sheet-like parisons P are made of the same kind of resin and different colors by changing the colorant.

A molding method using the molding apparatus 10 for a resin molded product having the above configuration will be described below with reference to the drawings.
First, a predetermined amount of the melted and kneaded thermoplastic resin is stored in the accumulator 22, and the stored thermoplastic resin is intermittently discharged at a predetermined extrusion amount per unit time from the extrusion slits 34 provided in the T die 28. By extruding, the thermoplastic resin swells and is extruded at a predetermined extrusion speed with a predetermined thickness so as to hang downward into a molten sheet.

  Next, the pair of rollers 30 is moved to the open position, and the gap between the pair of rollers 30 disposed below the extrusion slit 34 is widened from the thickness of the sheet-like parison P, so that the molten sheet is pushed downward. The lowermost part of the parison P is smoothly supplied between the pair of rollers 30. In addition, the timing which makes the space | interval of the rollers 30 wider than the thickness of the sheet-like parison P may be performed after the end of the secondary molding for each one shot, not after the start of extrusion.

  Next, the pair of rollers 30 are moved closer to each other and moved to the closed position, the sheet-like parison P is sandwiched by narrowing the interval between the pair of rollers 30, and the sheet-like parison P is sent downward by the rotation of the rollers.

Next, as shown in FIG. 1, the sheet-like parison P having a uniform thickness in the extrusion direction is disposed between the divided molds 32 disposed below the pair of rollers 30. Thereby, the sheet-like parison P is positioned in a form that protrudes around the pinch-off portion 118.
The above process is performed for each of the two sheet-like parisons P having different colors.

Next, as shown in FIG. 2, the mold frame 33 is moved toward the sheet-shaped parison P with respect to the mold 32 until it hits the surface of the sheet-shaped parison P facing the mold 32.
Next, as shown in FIG. 3, the vacuum is passed through the first sealed space 200 constituted by the cavity 116 of the mold 32, the inner peripheral surface 102 of the mold frame 33, and the surface of the sheet-like parison P facing the mold 32. By sucking from the suction chamber 120 through the suction holes 122 and 124, the sheet-like parison P is pressed against the cavity 116, and the sheet-like parison P is shaped into a shape along the uneven surface of the cavity 116. Thereby, the sheet-like parison P can be blended to some extent along the concavo-convex surface of the cavity 116 as a preliminary shaping for the final shaping after the mold clamping of the mold 32 described later.
In this case, as shown in FIG. 3, the sheet-like parison P including the portion located outside the pinch-off portion 118 is sucked by the vacuum suction port 124, thereby adsorbing the surface of the corresponding mold 32 including the burr portion. It is possible to hold.
The above process is performed for each of the two sheet-like parisons P having different colors. In addition, it is preferable that the process up to the mold clamping of the mold 32 so far is preferably performed for the two sheet-like parisons P substantially at the same time, but a substantial waiting time is generated at the start of the mold clamping process of the mold 32. Unless otherwise, it need not be done exactly at the same time.

Next, as shown in FIG. 4, the sheet 33 including the portion positioned outside the pinch-off portion 118 by the vacuum suction port 124 in a state in which the formwork 33 that contacts the surface of each sheet-shaped parison P is held in that position. While holding the parison P by suction, the molds 32 are moved toward each other until the respective annular pinch-off portions 118 come into contact with each other. In this case, the abutting position in the mold clamping direction between the pinch-off portions 118 is between two sheet-like parisons P that are separated from each other. As shown in FIG. Although the two sheet-like parisons P are welded and fixed to each other, the burrs of each of the two sheet-like parisons P are adsorbed and held on the surface of the corresponding mold. These portions are prevented from adhering to each other while being separated from each other.
In this case, as shown in FIG. 5, in a state where the annular pinch-off portions 118 are in contact with each other, the opposing surface 208 of each mold 33 to the opposite mold and the corresponding mold of the corresponding mold 32 are opposed to each other. It is preferable to move and adjust the mold 33 and / or the mold 32 in the mold clamping direction so that the opposing surface 206 is flush with the opposing surface 206.

Next, the sheet-shaped parison P is pressurized through the second sealed space 204 formed inside by the mold 32A and the mold 32B, and the sheet-shaped parison P is sucked from the mold 32 side through the first sealed space 200. .
Thereby, it is possible to shape a fine texture pattern or the like on the surface of the sheet-like parison P facing the mold 32.

Next, as shown in FIG. 6, the split mold 32 is opened, the molded resin molded product is taken out, the burr portion B outside the pinch-off portion 118 is cut, and the molding is completed. In this case, since the burr portions B of the two sheet-like parisons P are not welded to each other and separated, they can be easily collected separately, and are each crushed after cooling to form a molding material as a pellet Used for reuse. It is also possible to put the collected burr portion into the cylinder 18 from the hopper 16 and use it for a subsequent shot in the same molding process.
As described above, each time the molten resin is intermittently extruded in the primary molding, it is possible to form a sheet-shaped resin molded product one after another by repeating the above-described steps, and the primary molding (extrusion molding) ), The thermoplastic resin is intermittently extruded as a melted sheet-like parison P, and the sheet-like parison P extruded by secondary molding (blow molding or vacuum molding) can be molded using a mold. .

  In this case, when molding using two sheets of different colors and / or materials, a part (burr) located outside the annular pinch-off part is also included before clamping the pair of split molds. By sucking each sheet-like parison P toward the cavity of the corresponding mold, it is possible to prevent the burrs from being welded together in a butting manner at the time of mold clamping, whereby the color and / or material can be prevented. It is possible to suppress a decrease in yield by independently collecting and recycling burrs having different sizes.

  Although the embodiments of the present invention have been described in detail above, various modifications and alterations can be made by those skilled in the art without departing from the scope of the present invention. For example, in this embodiment, each split mold is provided with an annular pinch-off portion that protrudes toward the opposing mold, and both molds are moved toward each other until the annular pinch-off portions come into contact with each other. However, the present invention is not limited thereto, and at least one of the molds is provided with an annular pinch-off part that protrudes toward the opposing mold unless the respective burr parts are welded by clamping the mold. In that case, one mold may be moved toward the other mold. Further, in the present embodiment, as the two resin sheets, the case of the same material and different colors has been described. However, without limitation, for example, one is a polyolefin-based elastomer soft resin, and the other is The present invention can also be applied to polyolefin hard resins having the same color or different resin materials and colors.

  It is a side view which shows the state by which the molten resin sheet was arrange | positioned between the division molds with the shaping | molding apparatus which concerns on embodiment of this invention.   It is a schematic side view which shows the state which is making the outer frame of a division mold contact | abut to the side surface of a molten resin sheet in the shaping | molding apparatus which concerns on embodiment of this invention.   In the molding apparatus which concerns on embodiment of this invention, it is the schematic around the pinch-off part which shows the state in which the part of a burr | flash is adsorbed | sucked to the division mold.   In the molding apparatus which concerns on embodiment of this invention, it is a figure similar to FIG. 2 which shows the state which has moved the division mold to the direction which mutually approaches.   In the molding apparatus which concerns on embodiment of this invention, it is a figure similar to FIG. 2 which shows the state which clamped the division mold.   In the molding apparatus which concerns on embodiment of this invention, it is a figure similar to FIG. 2 which shows the state which open | released the split mold.

P sheet parison P
PL parting line 10 molding device 12 extrusion device 14 mold clamping device 16 hopper 18 cylinder 20 hydraulic motor 22 accumulator 24 plunger 28 T die 30 roller 32 split mold 33 mold 34 extrusion slit 102 inner peripheral surface 116 cavity 118 pinch-off part 120 Vacuum suction chamber 124 Vacuum suction port 200 First sealed space 202 Second sealed space 206 Facing surface 208 Facing surface

Claims (4)

A molding method using two sheets of different colors and / or materials,
An annular pinch-off portion provided at the peripheral edge of a pair of split mold cavities in a state where the melted sheet parisons of two thermoplastic resin materials having different colors and / or materials are separated from each other Positioning between a pair of split molds in a form that protrudes around,
By moving the annular outer frame fitted around the outer peripheral surface of each of the pair of divided molds toward the opposing mold until they contact the opposing surface of the corresponding sheet-like parison, the mold cavity and the corresponding sheet Forming a sealed space with the opposing surface of the parison and the inner peripheral surface of the annular outer frame part;
A step of pressing the sheet-like parison against the cavity of the corresponding mold by sucking the corresponding sheet-like parison including the portion located outside the annular pinch-off portion through the sealed space;
Clamping a pair of split molds and bringing the annular pinch-off parts into contact with each other to weld two sheet parisons,
The molding method according to claim 1, wherein in the mold clamping step, the mold clamping is performed in a state where a portion of the sheet-like parison located outside the annular pinch-off portion is sucked and held . A molding method using two sheets of different colors and / or materials,
An annular pinch-off portion provided at the peripheral edge of a pair of split mold cavities in a state where the melted sheet parisons of two thermoplastic resin materials having different colors and / or materials are separated from each other Positioning between a pair of split molds in a form that protrudes around,
By moving the annular outer frame fitted around the outer peripheral surface of each of the pair of divided molds toward the opposing mold until they contact the opposing surface of the corresponding sheet-like parison, the mold cavity and the corresponding sheet Forming a sealed space with the opposing surface of the parison and the inner peripheral surface of the annular outer frame part;
A step of pressing the sheet-like parison against the cavity of the corresponding mold by sucking the corresponding sheet-like parison including the portion located outside the annular pinch-off portion through the sealed space;
A pair of split molds are clamped, and the annular pinch-off portions are brought into contact with each other between the sheet-like parisons spaced apart from each other, thereby welding the two sheet-like parisons,
At least one of the annular pinch-off portions is provided so as to protrude toward the opposing mold,
The mold clamping step corresponds to a mold corresponding to the at least one annular pinch-off portion protruding from the corresponding annular outer frame in a state where the annular outer frame abutting against the opposing surface of the sheet-like parison is held in its position. Move
In the mold clamping step, the annular pinch-off portions are in contact with each other, and the opposed surfaces of the respective annular outer frames to the opposed annular outer frames and the opposed surfaces of the corresponding molds to the opposed molds are flush with each other. A step of moving and adjusting the annular outer frame and / or the mold in the mold clamping direction,
A molding method characterized by the above. A molding method using two sheets of different colors and / or materials,
An annular pinch-off portion provided at the peripheral edge of a pair of split mold cavities in a state where the melted sheet parisons of two thermoplastic resin materials having different colors and / or materials are separated from each other Positioning between a pair of split molds in a form that protrudes around,
By moving the annular outer frame fitted around the outer peripheral surface of each of the pair of divided molds toward the opposing mold until they contact the opposing surface of the corresponding sheet-like parison, the mold cavity and the corresponding sheet Forming a sealed space with the opposing surface of the parison and the inner peripheral surface of the annular outer frame part;
A step of pressing the sheet-like parison against the cavity of the corresponding mold by sucking the corresponding sheet-like parison including the portion located outside the annular pinch-off portion through the sealed space;
A pair of split molds are clamped, and the annular pinch-off portions are brought into contact with each other between the sheet-like parisons spaced apart from each other, thereby welding the two sheet-like parisons,
Each of the annular pinch-off portions is provided so as to protrude toward the opposing mold,
In the mold clamping step, the two molds are brought close to each other until the annular pinch-off portions protrude from the corresponding annular outer frames, with the annular outer frame abutting against the opposing surface of the sheet-shaped parison held in the same position. Move in the direction,
In the mold clamping step, the annular pinch-off portions are in contact with each other, and the opposed surfaces of the respective annular outer frames to the opposed annular outer frames and the opposed surfaces of the corresponding molds to the opposed molds are flush with each other. A step of moving and adjusting the annular outer frame and / or the mold in the mold clamping direction,
A molding method characterized by the above. A molding method using two sheets of different colors and / or materials,
An annular pinch-off portion provided at the peripheral edge of a pair of split mold cavities in a state where the melted sheet parisons of two thermoplastic resin materials having different colors and / or materials are separated from each other Positioning between a pair of split molds in a form that protrudes around,
By moving the annular outer frame fitted around the outer peripheral surface of each of the pair of divided molds toward the opposing mold until they contact the opposing surface of the corresponding sheet-like parison, the mold cavity and the corresponding sheet Forming a sealed space with the opposing surface of the parison and the inner peripheral surface of the annular outer frame part;
A step of pressing the sheet-like parison against the cavity of the corresponding mold by sucking the corresponding sheet-like parison including the portion located outside the annular pinch-off portion through the sealed space;
Clamping a pair of split molds and bringing the annular pinch-off parts into contact with each other to weld two sheet parisons,
The suction stage of the sheet-like parison sucks a portion of the sheet-like parison located outside the annular pinch-off part through a vacuum suction port provided along the outer periphery of the pinch-off part.
A molding method characterized by the above.

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