JP6200930B2 - Secondary molding method and secondary molding apparatus for primary molded product - Google Patents

Description

  The present invention relates to a secondary molding method and a secondary molding apparatus of a primary molded product for secondary molding of a primary molded product molded with a synthetic resin material or a glass material.

  Such a primary molded product is formed by melting a synthetic resin as a material and injecting the molten synthetic resin into a mold at a predetermined pressure (Patent Document 1), or in a tube-like shape inside the mold. The parison is positioned and blown into the parison by blowing in pressure air, thereby pressing the parison against the molding surface of the mold (Patent Document 2).

JP-A-6-297468 Japanese Utility Model Publication No. 6-53127

  In any of the above-described injection molding and blow molding methods, the container can be formed into a shape having some uneven portions, but if it is intended to have a shape having more uneven portions than that, it is molded. The mold must consist of multiple split molds. In this way, the parting line protrudes at the part corresponding to the joint (joint) between the divided molds on the surface of the molded product that is molded by pressing with a mold composed of a plurality of divided molds. It is formed. The molded product in which such a parting line is formed has a poor appearance, reduces the commercial value, and an early improvement is desired.

  Therefore, the present invention has been made in view of such circumstances, and a secondary molding method and a secondary molding apparatus for a primary molded product that can be formed into a variety of shapes without forming a parting line. It is an issue to provide.

A secondary molding method of a primary molded product according to the present invention is a secondary molding method of a primary molded product that secondary molds a primary molded product having a cylindrical side wall portion molded of a synthetic resin material or a glass material. Deformation in which the side wall of the primary molded product is deformed along the molding surface of the mold by placing the primary molded product inside the mold and heating the primary molded product while rotating the primary molded product. And the primary molded product comprises a bottomed cylindrical container having the side wall and a bottom that closes one end of the side wall, and the opening side end of the container is the bottom during the deformation process. The method further includes a pressing step of pressing to the side .

According to the present invention, by placing the primary molded product inside the mold and heating the primary molded product while rotating it, the side wall portion of the softened primary molded product is subjected to centrifugal force due to rotation. Receive and deform outward. By deforming the deformed primary molded product so as to follow the molding surface of the mold, the side wall portion can be changed to a secondary molded product having a desired shape. And since the primary molded product in a softened state is deformed by receiving centrifugal force, even if the mold is composed of a plurality of split molds, the joints (joints) between the split molds are connected. Since it is not pressed with a strong force, the parting line does not protrude from the portion corresponding to the joint (joint) between the split molds on the surface of the secondary molded product. Further, due to the occurrence of a variation in thickness (uneven thickness) in which the thin part and the thick part of the secondary molded product are mixed due to the deformation, a secondary molded product with further changes can be obtained. .
Further, as described above, by pressing the opening side end of the container to the bottom side in the pressing step during the deformation step, the deformation to the outside of the side wall portion can be performed quickly, and the secondary molding is performed. Time can be shortened.

  Moreover, it is preferable that the secondary shaping | molding method of the primary molded article which concerns on this invention is the structure which heats the said primary molded article so that it may become the temperature below melting | fusing point more than a softening point.

  As described above, the primary molded product can be reliably softened and deformed by heating the primary molded product so as to have a temperature not lower than the melting point but not lower than the softening point.

Moreover, the secondary molding apparatus of the primary molded product according to the present invention is a secondary molding apparatus of a primary molded product for secondary molding of a primary molded product having a cylindrical side wall portion molded of a synthetic resin material or a glass material. A heating unit that heats the primary molded product, a rotating unit that rotates the primary molded product that is heated by the heating unit, and the primary molded product that is deformed outward by being rotated by the rotating unit. A molding die having a molding surface for molding into a predetermined shape, and wherein the primary molded product comprises a bottomed cylindrical container having the side wall portion and a bottom portion that closes one end of the side wall portion, It is further characterized by further comprising a pressing part that presses the opening side end of the container that is heated and deformed by the heating part to the bottom side .

According to the present invention, when the primary molded product heated by the heating unit is rotated by the rotating unit, the side wall portion of the softened primary molded product receives the centrifugal force due to the rotation and deforms to the outside. By receiving the side wall portion of the deformed primary molded product on the molding surface of the molding die and deforming it into a predetermined shape, the side wall portion can be made into a secondary molded product having a desired shape rich in change. And since the primary molded product in a softened state is deformed by receiving centrifugal force, even if the mold is composed of a plurality of split molds, the joints (joints) between the split molds are connected. Since it is not pressed with a strong force, the parting line does not protrude from the portion corresponding to the joint (joint) between the split molds on the surface of the secondary molded product. Further, due to the occurrence of a variation in thickness (uneven thickness) in which the thin part and the thick part of the secondary molded product are mixed due to the deformation, a secondary molded product with further changes can be obtained. .
In addition, as described above, by pressing the opening side end of the container that has been heated and deformed by the heating unit to the bottom side, deformation to the outside of the side wall portion can be performed quickly, and secondary molding is performed. It is possible to reduce the time required for

  In the secondary molding apparatus for a primary molded product according to the present invention, it is desirable that the heating unit is configured to heat the primary molded product so as to have a temperature equal to or higher than a softening point and lower than a melting point. .

  As described above, the heating unit heats the primary molded product so as to have a temperature equal to or higher than the softening point and lower than the melting point, so that the primary molded product can be reliably softened and deformed.

  As described above, according to the present invention, by heating the primary molded product while rotating, the side wall portion of the primary molded product that has been softened by receiving the centrifugal force due to the rotation is desired along the molding surface of the mold. Therefore, it is possible to provide a secondary molding method and a secondary molding apparatus for a primary molded product that can be formed into a variety of shapes without forming a parting line.

(A) is a vertical side view of the secondary forming apparatus of the present invention, and (b) is a vertical side view of a secondary molded product formed by the apparatus of (a). It is a front view of the secondary forming apparatus. It is a cross-sectional top view of the principal part of the secondary shaping | molding apparatus. (A) is a front view of a primary molded product, (b) is a front view of a secondary molded product obtained by secondary molding of the primary molded product of (a) with a secondary molding device. (A), (b) is a front view of the secondary molded product which secondary-molded the primary molded product of another shape with the secondary molding apparatus. It is a front view of the primary molded product of another shape.

  In FIG. 1, the secondary shaping | molding apparatus S of this invention is shown. This secondary molding apparatus S is an apparatus for secondary molding of a primary molded product 1 having a cylindrical side wall portion 1A molded of a synthetic resin material or a glass material. As shown in FIG. 1 (a), the primary molded product 1 has a cylindrical side wall 1A and a substantially circular bottom 1B that closes one end (the lower end in the figure) of the side wall 1A. Although it is a bottom cylindrical container (cup), the cylindrical body which consists only of a cylindrical side wall part may be sufficient. The side wall portion 1A has a tapered shape whose diameter increases toward the upper end side. In FIG. 1A, the left side is the front, the right side is the rear, the left side is the left, the right side is the right, and in FIG. 3, the left side is the left, the right side is the right, and the lower side is the front. Each will be described with the upper side as the rear.

  The secondary molding apparatus includes a heating unit 2 that heats the primary molded product 1, a rotating unit 3 that rotates the primary molded product 1 that is heated by the heating unit 2, and a primary that is deformed outward by being rotated by the rotating unit 3. A molding die 4 having molding surfaces 411 and 421 for receiving and molding the molded product 1 into a predetermined shape is provided on the base frame 5.

  The heating unit 2 is configured so that the heating temperature of the primary molded product 1 can be set so that the temperature is higher than the softening point and lower than the melting point. Specifically, the heating unit 2 includes a heat gun that is a gun-like radiator, and includes a main body 2A and a nozzle portion 2B provided at the tip (lower end in FIG. 1) of the main body 2A. Hot air blows downward from the tip.

  The heating unit 2 is held at the tip (lower end) of the arm 6 that extends obliquely downward and is located downward as it goes down. The base end portion of the arm 6 is attached to a single-axis robot 7 attached so that the longitudinal direction thereof is along the vertical direction, so that the heating unit 2 can be moved in the vertical direction via the arm 6. It has become. Accordingly, when the arm 6 moves downward, as shown by the solid line in FIG. 1, the nozzle 2B of the heating unit 2 is positioned in the mold 4 and the arm 6 moves upward. As indicated by a two-dot chain line 1, the heating unit 2 can be repositioned to the retreat position where the nozzle unit 2 </ b> B of the heating unit 2 is retreated above the mold 4. In addition, a disc-shaped heat protection plate 8 that closes the opening 4 </ b> K at the upper end of the mold 4 at the heating position is attached to the tip side portion of the heating unit 2. The single-axis robot 7 is attached to a support body 10 attached to an upper end of a vertically long fixed frame 9 erected on the base frame 5 so that the position of the single-axis robot 7 can be adjusted in the front-rear direction. When the primary molded product 1 is formed of, for example, a glass material, the heating temperature of the heating unit 2 is set so as to be an arbitrary temperature between 700 ° C. and 750 ° C. that is a deformation temperature. When the primary molded product 1 is polypropylene, the deformation temperature is 128 ° C. to 167 ° C., and when it is polystyrene, the deformation temperature is 90 ° C. to 104 ° C. It depends on the material. Examples of the thermoplastic resin for molding the primary molded product 1 include polyolefin resins, polyester resins (for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate), polycarbonate resins, and polylactic acid resins. .

  The rotating unit 3 includes a disk-shaped disk member 3A on which the molding die 4 is placed, an electric motor 3B, and a transmission mechanism 3C for transmitting the rotational force of the electric motor 3B to the disk member 3A. ing. The rotational speed of the disc member 3A can be set to an arbitrary rotational speed between about 600 rpm and 1200 rpm in consideration of the size and weight of the primary molded product 1. Here, since the rotational speed when the primary molded product 1 is a cup is shown, when the primary molded product 1 is something other than a cup, the rotational speed suitable for the primary molded product 1 is set. It will be.

  1 and 2, the transmission mechanism 3C includes a first roller chain coupling 11, a gear box 12, and a second roller chain coupling 13 that transmit power from the electric motor 3B. The power is transmitted to the three-jaw scroll chuck 14 via the ring 13 to rotate the disc member 3A. The three-jaw scroll chuck 14 includes a chuck operation handle 15. By operating the chuck operation handle 15, the primary molded product 1 is fastened and fixed to the disk member 3 </ b> A by the three-jaw scroll chuck 14. be able to. 2 shown in FIG. 2 is an electromagnetic brake used when the electric motor 3B is stopped.

  The mold 4 is composed of two semicircular split molds 41 and 42 made of wood (which may be made of metal), and the other split mold 42 is swung around the vertical axis X with respect to one split mold 41. It is configured to freely open and close. A molding surface 411 or 421 is formed on the inner surface of each split mold 41 or 42. Each molding surface 411 or 421 has an arc-shaped upper molding surface 411a or 421a that protrudes in an arc shape outward from the upper end to the lower side, and a linear shape that hangs substantially vertically from the lower end of the upper molding surface 411a or 421a. A lower molding surface 411b or 421b.

  On the front side of the mold 4, a guard member 17 for guarding an operator is provided at the upper end of a vertically long fixed wall 18 erected on the base frame 5. The two split molds 41 and 42 are screwed to metal outer frames 19 and 20, respectively.

  The guard member 17 is attached to a fixed frame 21 fixed to the upper end of the fixed wall 18 via a pair of upper and lower roller slide rails 22 and 22 so as to be movable in the left-right direction. Therefore, the guard member 17 is positioned in front of the mold 4 to guard the operator by holding the U-shaped handle 23 attached to the guard member 17 and moving it in the left-right direction (see FIG. 3). A solid position) and a retracted position (see a two-dot chain line in FIG. 3) that moves from the front of the mold 4 in the left-right direction and allows the other split mold 42 to swing open and close around the vertical axis X. It is configured so that it can be made.

  Further, the secondary molding method for secondary molding of the primary molded product according to the present invention has a cylindrical side wall portion 1A (cylindrical in FIG. 1A) molded from a synthetic resin material or a glass material. A method for secondary molding of the primary molded product 1, wherein the primary molded product 1 is disposed inside the mold 4, and the primary molded product 1 is heated while rotating in this state. 1A is provided with a deformation process for deforming 1A along the molding surfaces 411 and 421 of the mold 4.

  The primary molded product 1 is molded by melting a synthetic resin or glass as a material and injecting the molten synthetic resin or glass into a mold at a predetermined pressure, or a tube-shaped parison inside the mold. Is placed, and pressure air is blown into the inside of the parison to inflate it so that the parison is pressed against the molding surface of the mold. The primary molded product thus molded is molded into a secondary molded product using the secondary molding apparatus, and the molding process will be described.

  First, the primary molded product 1 is set (arranged) inside the mold 4 and the heat gun 2 is positioned at the heating position. Then, the upper end of the mold 4 is closed by the heat protection plate 8. In this state, the heat gun 2 is operated to start heating, and the electric motor 3B is driven to rotate the disk member 3A to rotate the primary molded product 1. When the primary molded product 1 is in a softened state, the side wall portion 1A of the primary molded product 1 is subjected to centrifugal force due to rotation and deformed outward. The side wall portion 1A of the deformed primary molded product 1 is received by the molding surfaces 411 and 421 of the mold 4 and deformed into a predetermined shape, so that the side wall portion 1A has a desired shape with various changes (the upper portion is circular on the outside). It is possible to obtain a secondary molded product 24 (see FIG. 1B) having an arc shape that is curved so as to be convex in an arc shape. And since the primary molded product 1 in a softened state is deformed by receiving centrifugal force, even if the mold 4 is composed of a plurality of split molds 41, 42, the split molds 41, 42 Since it is not pressed against the joint part (joint) of the secondary molding product 24 with a strong force, a parting line is formed on the surface corresponding to the joint part (joint) between the split molds 41 and 42 on the surface of the secondary molded product 24. Is not formed protruding. In addition, the variation in thickness (unevenness) in which the thin portion and the thick portion of the secondary molded product 24 are mixed due to the deformation occurs, so that the secondary molded product 24 with further changes can be obtained. Can do.

  The secondary molded product 24 shown in FIG. 1 (b), which is formed by deforming the primary molded product 1 shown in FIG. 1 (a) outward, is deformed and molded so as to expand outward by receiving centrifugal force due to rotation. Is done. Therefore, the diameter of the side wall portion 24A and the bottom portion 24B of the secondary molded product 24 is larger than the diameter of the side wall portion 1A and the bottom portion 1B of the primary molded product 1, and the height of the secondary molded product 24 is the primary molded product 1. It is lower than the height. In addition, when the secondary molded product 24 is subjected to secondary molding, a variation in thickness (uneven thickness) due to deformation occurs as described above. However, the variation in thickness was anticipated when the primary molded product 1 was molded. If the thickness of the primary molded product 1 is set so that the thickness, that is, the thin portion of the molded secondary molded product 24 becomes the minimum required thickness, the strength is disadvantageous. There is no.

  Although not shown, a pressing portion (not shown) that presses the opening side end of the upper end of the container (primary molded product) 1 heated and deformed by the heat gun 2 (heating portion) toward the bottom 1B side. If the secondary forming apparatus is provided, it is possible to quickly deform the side wall portion 1A of the container 1 that is heated and deformable, and the time required for the secondary molding can be shortened. In addition, the said press part becomes a press process in the secondary shaping | molding method, and if the press process is provided, the same effect as the above will be produced.

  In addition, the secondary molding method of the primary molded product and the secondary molding apparatus of the primary molded product according to the present invention are not limited to the embodiments, and various modifications are possible without departing from the gist of the present invention. is there.

  For example, as shown in FIG. 4A, the primary molded product 1 has a bottom wall 1A having a tapered side wall portion that expands outward toward the upper end and a circular bottom portion 1B that closes one end of the side wall portion 1A. It consists of a cylindrical container (cup). On the outer surface of the side wall 1A, a large number of concave portions (patterns) 1H having a substantially elliptic shape (any shape such as a rhombus shape, a polygonal shape, or a circular shape) may be formed. FIG. 4B shows a secondary molded product 25 obtained by secondary molding of the primary molded product 1. The secondary molded product 25 shown in FIG. 4B includes a side wall portion 25A and a circular bottom portion 25B. An upper portion of the side wall portion 25A has a curved portion 25a that is curved in an arc shape so as to protrude outward. Further, the secondary molded product 25 formed by deforming the primary molded product 1 outward is deformed and molded so as to expand outward by receiving centrifugal force due to rotation. Therefore, the diameter of the side wall portion 25A and the bottom portion 25B of the secondary molded product 25 is larger than the diameter of the side wall portion 1A and the bottom portion 1B of the primary molded product 1, and the height of the secondary molded product 25 is the primary molded product 1. It is lower than the height. Further, each of the substantially elliptical concave portions (patterns) 25H formed on the outer surface is not crushed along with the deformation of the side wall portion 25A and the bottom portion 25B, and more secondary than the primary molded product 1 as described above. The molded product 25 has a lower height and a wider left-right width. In FIG. 4A, the concave portion (pattern) 1H is formed on the outer surface of the side wall portion 1A. However, the concave portion and / or the convex portion may be provided on the inner surface of the side wall portion 1A. . Also in this case, even if the primary molded product 1 is secondary molded, the pattern formed on the inner surface of the side wall portion 1A is not crushed, and the secondary molded product 25 is compared with the primary molded product 1 in the same manner as described above. However, the height is low and the width is widened. Further, the shape of the secondary molded product 25 shown in FIG. 4B can be freely changed. For example, as shown in FIG. 5 (a), it may be a secondary molded product 26 having a massive and stable shape provided with a lower portion 26U curved in an arc shape protruding outwards downward. Moreover, as shown in FIG.5 (b), the side wall part 27A may be the secondary molded product 27 of the shape provided with the recessed part 27K curved in the circular arc shape which becomes convex inside. In addition, as shown in FIG. 6, a shape having a large number of leg portions 1 </ b> R having a substantially triangular shape in a side view at the same interval may be secondarily formed at the lower end portion of the side wall portion 1 </ b> A of the primary molded product 1. Moreover, although not shown in figure, the secondary molded article of the shape provided with the convex part which becomes convex on the side wall part, and the recessed part which becomes concave inside may be sufficient. For example, in a plastic bottle having a cap that is screwed into the mouth of the upper end of the main body, the main body in which the screw portion is formed inside the mouth is primarily molded, and the mouth of the primary molded product is not heated. To. Then, the main body can be secondarily formed into various shapes by applying heat only to the main body. This makes it possible to obtain a plastic bottle having a variety of shapes having a mouth portion that is easy to drink with a flat surface on which the screw is not formed on the outside of the mouth portion.

  In the above embodiment, the primary molded product having a circular shape in plan view is subjected to secondary molding. However, the primary molded product in any shape such as an elliptical shape in plan view, a rectangular shape, or a polygonal shape may be secondary molded. Good.

  Moreover, in the said embodiment, although comprised so that both the primary molded product 1 and the shaping | molding die 4 may rotate, you may comprise the shaping | molding die 4 as a fixed die | dye which does not rotate, and it may be comprised so that only the primary molded product 1 may rotate. . In this case, the molding die 4 may not be configured in a cylindrical shape that surrounds the entire outer peripheral surface of the primary molded product 1. That is, it can also be implemented by forming an arc-shaped partial mold in plan view so as to surround a part of the outer peripheral surface of the primary molded product 1. Thus, even if it comprises an arc-shaped partial mold, the outer peripheral surface of the primary molded product 1 can be sequentially brought into contact with the molding surface of the inner surface of the partial mold and molded into a predetermined shape by rotating the primary molded product 1. it can.

  In the above embodiment, the primary molded product 1 is heated from the inside. However, the primary molded product 1 may be heated from the outside, or the primary molded product 1 is heated from both the inside and the outside. May be added. Moreover, the specific structure of the heating part 2 can be changed freely.

  Moreover, in the said embodiment, although the shaping | molding die was comprised from the two division | segmentation shaping | molding dies 41 and 42, you may comprise from three or more division | segmentation shaping | molding dies.

DESCRIPTION OF SYMBOLS 1 ... Primary molded product (container), 1A ... Side wall part, 1B ... Bottom part, 1H ... Recessed part, 1R ... Leg part, 2 ... Heating part (heat gun), 2A ... Main part, 2B ... Nozzle part, 3 ... Rotating part, 3A ... disc member, 3B ... electric motor, 3C ... transmission mechanism, 4 ... mold, 4K ... opening, 5 ... stand frame, 6 ... arm, 7 ... single axis robot, 8 ... heat protection plate, 9 ... fixed frame DESCRIPTION OF SYMBOLS 10 ... Support body, 11 ... 1st roller chain coupling, 12 ... Gear box, 13 ... 2nd roller chain coupling, 14 ... Three-claw scroll chuck, 15 ... Chuck operation handle, 17 ... Guard member, 18 ... Fixed wall, 19, 20 ... outer frame, 21 ... fixed frame, 22, 22 ... roller slide rail, 23 ... handle, 24 ... secondary molded product, 24A ... side wall, 24B ... bottom, 25 ... secondary molded product, 25A ... side wall, 2 B ... Bottom part, 25H ... Concave part, 25a ... Curved part, 26 ... Secondary molded part, 26U ... Lower part, 27 ... Secondary molded part, 27A ... Side wall part, 27K ... Concave part, 41, 42 ... Split mold 411, 421 ... molding surface, 411a, 421a ... upper molding surface, 411b, 421b ... lower molding surface, S ... secondary molding device, X ... vertical axis

Claims (4)

A secondary molding method of a primary molded product for secondary molding of a primary molded product having a cylindrical side wall molded with a synthetic resin material or a glass material, wherein the primary molded product is disposed inside a mold, In this state, it comprises a deformation step of deforming the side wall portion of the primary molded product so as to follow the molding surface of the mold by heating the primary molded product while rotating the primary molded product, and the primary molded product includes the side wall portion and the side wall portion. And a bottomed cylindrical container having a bottom for closing one end of the side wall, and further comprising a pressing step of pressing the opening side end of the container toward the bottom during the deformation step. Secondary molding method for primary molded products.   The secondary molding method for a primary molded product according to claim 1, wherein the primary molded product is heated so as to have a temperature not lower than the melting point and not lower than the softening point. A secondary molding apparatus of a primary molded product for secondary molding of a primary molded product having a cylindrical side wall molded with a synthetic resin material or a glass material, the heating unit for heating the primary molded product, and the heating A rotating part that rotates the primary molded product heated by the part, and a mold having a molding surface for receiving the primary molded part that is deformed outward by being rotated by the rotating part and molding the primary molded product into a predetermined shape. The primary molded article comprises a bottomed cylindrical container having the side wall part and a bottom part that closes one end of the side wall part, and is heated by the heating part and is deformable. A secondary molding apparatus for a primary molded product, further comprising a pressing portion that presses the end toward the bottom side . The secondary molding apparatus for a primary molded product according to claim 3 , wherein the heating unit is configured to heat the primary molded product so as to have a temperature not lower than the melting point and not lower than the softening point. .

Images