JP4606196B2 - Mold apparatus for molding plastic containers and molding method thereof - Google Patents

Description

In the present invention, for example, liquid contents (internal solutions) such as shampoos, rinses, body soaps, hand soaps, kitchen detergents, hair styling agents, and liquid cosmetics are stored, and the solutions can be pumped up and used. as it used as a bottle, mainly molding die apparatus of the plastic container having an extrusion pump dispenser on the upper opening side, to a method of molding.

  Conventionally, plastic containers are manufactured by, for example, injection molding or blow molding. In the case of injection molding, a plastic product as a bottle container is obtained by injecting a heat-plasticized plastic material into a cavity of a closed mold at high pressure and solidifying it. The mold used for this is strong so that it can withstand a large injection pressure, and the mold clamping force of the closed mold is sufficiently secured. In addition, as the mold, a plurality of inner molds for forming the inner wall surface of the plastic container and outer molds for forming the outer wall surface are used. However, in the case of this injection molding, in order to form a container having a smaller opening than the inner and outer diameters of the container main body in one piece, the inner mold after the molding cannot be pulled out, so there are multiple processes, It is extremely troublesome because it is necessary to combine the molds in a complicated manner.

  On the other hand, blow molding is the most important one in the production of plastic hollow products such as plastic bottles that do not require an inner mold as in injection molding, such as direct blow molding and stretch blow molding. In the case of this blow molding method, a so-called parison which is a heat-softened bottomless cylindrical resin melt extruded downward from an annular nozzle, or a heated bottomed parison molded by injection, The mold was sandwiched between two molds with cavities shaped like the following, and then the high pressure compressed air was blown into the parison to inflate the parison itself, pressing it closely against the inner wall of the mold, and then cooling and solidifying Later, the mold is opened to take out the product.

  Also, whether plastic bottles made by direct blow, stretch blow, or other blows are raised from the vicinity of the outer periphery to the center of the bottom at the bottom, or are several dome protruding radially from the bottom? And it is made to become independent by forming so that it may become a leg part. For this reason, as long as the plastic bottle itself is placed on a horizontal plane, the inner solution is dispersed in the bottom peripheral edge or the recesses associated with the dome, and does not collect in one place. That is, for example, when the internal solution of a bottle having a capacity of 600 to 700 cc is sucked up by an extrusion pump-type dispenser while being placed in a horizontal state, only about 10 cc is finally left. In this case, the average value of the remaining amount measurement data in various containers of this type is obtained.

  On the other hand, when the inner solution is gathered at a certain location, the portion becomes the lowest portion at the bottom of the plastic bottle and has a protruding shape, and the presence of the protruding portion makes it impossible to maintain self-supporting stability. That is, in order to pump out all the internal solution accumulated in the bottom of the bottle by using an extrusion pump dispenser or the like attached to the plastic bottle top opening side, the internal solution is placed in one central portion of the bottle bottom. It is only necessary to form a dent for collecting the liquid and to allow the conduit of the extrusion pump to face the dent, but in order to form such a dent on the bottom of the bottle and make it stable and self-supporting. Needs to be higher at the outer peripheral edge than the depth of the depression at the center of the inner bottom of the bottle. However, it is difficult to form a part of such a bottom part thicker or higher than other parts by a blow molding method in which it is fatal to make the entire container wall constant, It is impossible to increase the amount of the synthetic resin only in a specific portion and to make it partially thick or high.

  For this reason, conventionally, as disclosed in Patent Document 1, the bottom part bulges downward in the axial direction of the bottle to form a curved surface, and a part of the bottom part is folded back through the folded part. A technique by a molding method is proposed that includes a first step using a mold and a second step of forming a leg portion by welding and sealing the folded upper end portion with an ultrasonic vibration mold after taking out from the mold. ing.

In addition, as disclosed in Patent Document 2, when left and right molds are formed so that the bottom part is inclined toward the center when they abut each other, when the air blow is performed with the parison between the left and right molds, The wing leg part recessed in the abutting surface of the inner bottom part of the left and right molds is filled with softening resin to form a wing leg part (first step), and is formed at right angles to this wing leg part. When the softened resin layer is molded in the concave groove, the pressing plates waiting to close the left and right opening side surfaces of the concave groove advance in the proximity to each other and crush the softened resin layer in the concave groove. Thus, a technique based on a molding method has been proposed which includes forming orthogonal leg portions orthogonal to the wing-shaped leg portions (second step).
JP-A-8-244749 JP 2002-192602 A

  However, in the above-mentioned conventional example, since the secondary process is required in Patent Document 1, the molding cycle for manufacturing the container is longer and larger than the conventional one, and the manufacturing cost of the mold itself is also increased. In addition, it is not versatile for mounting on existing molding machines. Moreover, in this patent document 1, it aims at improving the pressure | voltage resistance in a bottom part, and does not consider using an extrusion pump. On the other hand, in Patent Document 2, in the second step, the necessary resin amount cannot be concentrated on the leg portion to be thickened, so that it becomes insufficient and pores are generated in the periphery of the leg molding portion, resulting in strength. May not be maintained. Further, when air is blown, the radius of curvature of the shape of the concave groove arranged at right angles to the wing leg portion may be small, and the portion may puncture when blown.

  Therefore, the present invention has been created in view of the conventional circumstances as described above, and the contained liquid content (inner solution) can be collected in the center of the inner bottom, which is the center of the bottom. In this way, it is possible to draw out the lifting capacity of the pumping conduit located in the center of the inner bottom of the container body 100% without leaving the inner solution, and to place it in a self-supporting and stable state. Another object of the present invention is to provide a plastic container which can be manufactured by a blow molding method which is an inexpensive molding method.

  In addition, a pipe of an extrusion pump type dispenser that is operated so as to suck up the inner solution without passing through a secondary process to be further processed after taking out from the left and right molds by existing blow molding such as direct blow / stretch blow, etc. A mold device for molding a plastic container that can easily produce a plastic container that does not cause residual liquid even by a conduit attached to a special lid due to fluctuations in internal pressure caused by pressing the container body itself An object of the present invention is to provide a molding method thereof.

In order to solve the above-described problems, the plastic container according to the present invention is manufactured by blow molding, and is provided with a conduit R, for example, an extrusion pump type dispenser, a conduit attached to an extrusion type special lid due to fluctuations in internal pressure of the container body, etc. Rib P which is a plastic container in which the inner solution can be lifted via R or the like, and which is formed so that the bottom peripheral edge is folded and further crushed so as to be doubled so as to be able to stand by itself. And an inclined bottom surface portion Q which is inclined in a bowl shape from the upper end of the rib portion P toward the center of the bottom surface and formed shallower than the height of the rib portion P, and is a conduit R of an extrusion pump dispenser (not shown) Is characterized in that it faces the lowest center portion of the inclined bottom surface portion Q.
In the plastic container molding die device 1 according to the present invention, the heat-softened resin melt 15 pushed downward from the annular nozzle 14 is sandwiched from both the left and right sides, and the resin melt 15 by blowing compressed air into it pressed against the contact shape to the inner wall surface inflating the resin melt 15 itself, the two having a cavity in which the bottom peripheral edge for forming molded article having a shape and a rib portion P for autonomous ground A mold apparatus 1 for molding a plastic container by blow molding comprising a split mold , and an opening 12 that is open at an outer peripheral edge position of a rib portion P formed on a bottom peripheral edge of the plastic container. There have been formed in the bottom, the left and right of the body forming mold 2 to be butted, it is fitted disposed in the vertically movable along the opening 12 of the body portion forming mold 2 Plastic A pair of left and right rib part forming molds 3 provided with annular pressing ribs 11A and 11B arranged at the rib part P position of the vessel, and along the inner peripheral edges of the pressing ribs 11A and 11B in the rib part forming mold 3 A pair of left and right inclined bottom surface forming molds 4 provided with semi-cylindrical pressing dies 6A and 6B which are slab-shaped and located on the lower surface of a mortar-shaped inclined bottom surface portion Q of a plastic container. The raising and lowering of the rib forming die 3 and the inclined bottom forming die 4 are moved up and down in conjunction with each other in a restrained state within the barrel forming die 2 with respect to the barrel forming die 2. Means 5, and the raising / lowering means 5 is configured to raise and lower the movement amount of the inclined bottom surface forming mold 4 larger than the movement amount of the rib forming metal mold 3. And
The inclined bottom surface forming mold 4 includes pressing dies 6A and 6B having a semi-cylindrical shape on one end of the upper surface of a rectangular block and an inclined surface whose upper surface gradually decreases toward the center of the semicircle, and a pair of left and right inclined bottom surfaces. In a state where the part forming dies 4 are abutted against each other, it can be configured to be a columnar pressing die 6 whose upper surface has a bowl shape.
The rib part forming mold 3 includes pressing ribs 11A and 11B each having a semicylindrical shape on one end side of the upper surface of the rectangular block and a groove part having a substantially semicircular cross section along the semicircular surface on the upper surface . The pressing rib 11 can be configured in a cylindrical shape in a state in which the pair of left and right rib portion forming molds 3 face each other.
A rib portion forming die 3 and an inclined bottom surface portion forming die 4 are disposed on the lower surface of the body portion forming die 2, and guide rods 17 protruding from the left and right positions of the lower surface of the body portion forming die 2 are provided. In addition, the rib part forming mold 3 and the inclined bottom surface part forming mold 4 can be configured to be inserted through the guide through holes 9.
The elevating means 5 connects the driving cylinder 21 that moves the inclined bottom surface forming mold 4 up and down to the inclined bottom surface forming mold 4, and also forms the rib portion forming mold 3 and the inclined bottom surface forming metal mold. type 4, respectively in a state where the vertically movable in the opening 12 of the body portion forming mold 2, a first link pin 8A protruding formed inclined oblique bottom surface portion forming mold 4, rib portions formed a second link pin 8 B protruding formed in the mold 3, by arranging the third link pin 8 C which is protruded barrel forming mold 2 substantially horizontally to each other in tandem, respectively at the link arm 22 The second link pin 8B can be configured to move within a range smaller than the movement amount of the first link pin 8A with the third link pin 8C as a fulcrum .
Furthermore, in the plastic container molding method according to the present invention, the heat-softened resin melt 15 extruded downward from the annular nozzle 14 is divided into two parts having cavities in the shape of a molded product. A rib part P for self-supporting grounding is provided on the peripheral edge of the bottom by sandwiching it with a mold and blowing compressed air into the resin melt 15 to inflate the resin melt 15 itself and press it in close contact with the inner wall surface of the mold. and are molded product a method of molding a plastic container according to the blow molding of formed shapes, as to close the opening 12 formed in the bottom of the barrel forming mold 2 of the left and right that are butted, the plastic container A pair of left and right rib part forming molds 3 provided with annular pressing ribs 11A and 11B arranged at the position of the rib part P, and along the inner peripheral edges of the pressing ribs 11A and 11B in the rib part forming mold 3 A pair of left and right inclined bottom surface forming dies 4 having semi-cylindrical pressing dies 6A and 6B which are located on the lower surface of the mortar-shaped inclined bottom surface portion Q of the plastic container are movable in the vertical direction. fitted should be placed in, blowing compressed air into the tree butter melt 15 extruded into the barrel forming mold 2, after the tree fat 15 are in close contact with the inner wall surface of each mold 2,3,4, tree fat 15 Li blanking portion forming mold 3 while a molten state, each inclined bottom surface portion forming mold 4 by the lifting means 5, the rib portion the amount of movement of the inclined bottom surface portion forming mold 4 increase compared to the amount of movement of the forming mold 3, the rib portion forming mold 3, the inclined bottom surface portion forming mold 4 raised press in conjunction with the original constrained state a predetermined time compressed air continued blowing, then, to release the internal compressed air after cooling the curing of the resin 15, the rib portion forming mold 3, inclined By the bottom surface portion forming mold 4 lifting means 5 respectively and returning to the lowered position.
The rib forming die 3 and the inclined bottom surface forming die 4 are moved up and down by the link arm 22 having the position of the barrel forming die 2 as an outer fulcrum and the opening of the barrel forming die 2. The rib forming die 3 and the inclined bottom surface forming die 4 which are sequentially fitted and arranged inside the portion 12 are sequentially connected via the link pins 8A, 8B and 8C to form the inclined bottom surface portion. It is constructed by moving to increase than the amount of movement of the inclined swash bottom portion forming mold 4 to the amount of movement of Li blanking portion forming die 3 by the drive cylinder 21 for the mold 4 and lowering movement Can do.

In the plastic container according to the present invention configured as described above, the inclined bottom surface portion Q causes the inner solution remaining in the plastic container after use to be collected at one place in the lowest central portion and faced there. For example, the residual solution is pumped up by the conduit R of the extrusion pump dispenser. And the rib part P formed in the circumference | surroundings in the bottom part of a plastic container makes the plastic container itself stand by itself in the stable state in the state which the lowest center part lower surface of the inclined bottom face part Q floated from the floor surface, the shelf surface, etc.
Further, in the molding device 1 for plastic container, the annular rib portion forming die 3 and the mortar-shaped inclined bottom surface portion forming die 4 are fitted in the opening 12 inside. Guide rods 17, it is the state which is movably constrained along the vertical direction by the guide through-hole 9 and Ai俟Chi, lift, which is configured with at the link arm 22 linked with each to each other physician and the drive cylinder 21 By means 5 , the moving amount of the inclined bottom surface forming mold 4 becomes larger than the moving amount of the rib forming metal mold 3 and is moved up and down. By this, with the molding of the body of the plastic container by the two split of the barrel forming mold 2 having a cavity in the shape of the molded article, the rib P at the bottom of the plastic container, the inclined bottom surface portion Q, respectively Allows simultaneous molding.
Further, in the molding method of the plastic container, while the resin is in a molten state, the rib portion forming die 3 and the inclined bottom surface portion forming die 4 are respectively formed in the opening portion 12 of the trunk portion forming die 2. By raising and lowering means 5, the amount of movement of rib portion forming mold 3 is made smaller than the amount of movement of inclined bottom surface portion forming mold 4 and pushed up at a different rate, and the blowing of compressed air is continued for a predetermined time. The rib portion P and the inclined bottom surface portion Q at the bottom of the plastic container are respectively formed simultaneously with the forming of the body portion of the plastic container by the split body portion forming mold 2 having the shape of the molded product. At this time, the rib portion P is formed into a double wall thickness by the inclined bottom surface portion forming die 4 that moves largely as compared with the moving amount of the rib portion forming die 3.

  According to the present invention, it is possible to place the solution in a self-supporting and stable manner, and to collect the inner solution at the center of the inner bottom of the bottom. If the suction port such as the conduit R attached to the special lid is made to face the center of the inner bottom, all of the inner solution can be pumped up without remaining. In addition, by the existing blow molding method, the inner bottom portion that is shallower than the height of the rib portion P so as to face the conduit R can be formed as one place without passing through the secondary process even after taking out from the left and right molds. It is possible to easily manufacture a plastic container that can draw out the sucking capacity of an extrusion pump dispenser or the like 100%.

  That is, the plastic container according to the present invention has a rib part P formed so that the peripheral edge of the bottom part can be folded back so that it can stand on its own, and is inclined in a bowl shape from the upper end of the rib part P toward the center of the bottom surface. This is because it has an inclined bottom surface portion Q formed shallower than the height of the portion P, and the conduit R for lifting the inner solution faces the lowest center portion of the inclined bottom surface portion Q. Can be stably supported by the rib part P, and at the same time, the extrusion pump type dispenser can be operated in this self-supported state, or the internal pressure of the extrusion type special lid can be changed by pressing the container body. For example, the inner solution can be pumped up without remaining through the conduit R facing the lowest central portion of the inclined bottom surface portion Q. Moreover, it is easy to make a plastic container that will please consumers without any restrictions on the design of plastic containers that contain various liquid contents such as shampoos, rinses, body soaps, hand soaps, liquid detergents for kitchens, and hair conditioners. Can be manufactured.

  In addition, the molding device 1 for plastic container according to the present invention is fitted into the left and right barrel forming molds 2 and the opening 12 formed at the bottom of the barrel forming die 2. It has an annular rib portion forming mold 3 and a mortar-shaped inclined bottom surface forming die 4 that are inserted and arranged, and the rib portion forming die 3 and the inclined bottom surface forming die 4 move relative to each other. Since it includes elevating means 5 that can be moved up and down in conjunction with each other under a fixed restraint movement that regulates the strokes to be different, there is no need for a secondary process after removal from the left and right molds. The molding cycle during production can be made substantially the same as the conventional one. Moreover, the manufacturing cost of the entire molding die apparatus 1 can be made much cheaper than that provided with another mold apparatus required for the conventional secondary process, and can be attached to an existing molding machine. It is also versatile.

  The inclined bottom surface forming mold 4 includes pressing dies 6A and 6B having a semi-cylindrical shape on one end of the upper surface of a rectangular block and an inclined surface whose upper surface gradually decreases toward the center of the semicircle, and a pair of left and right inclined bottom surfaces. Since it is configured to be a columnar pressing die 6 whose upper surface is shaped like a bowl in a state where the part forming dies 4 are in contact with each other, an opening formed at the bottom of the body forming mold 2 The inclined bottom surface forming mold 4 can be easily installed on the 12 side, and the inclined bottom surface portion Q of the plastic container to be molded can be reliably and inexpensively formed.

  The rib portion forming mold 3 includes pressing ribs 11A and 11B each having a semicylindrical shape on one end of the upper surface of the rectangular block and a groove portion having a substantially semicircular cross section along the semicircular surface. Since the rib forming die 3 is configured to be a cylindrical pressing rib 11 having a groove portion with a substantially semicircular cross section on the upper surface in a state where the rib forming die 3 are abutted with each other, The rib forming die 3 can be easily installed on the opening 12 side formed at the bottom, and the rib portion P of the plastic container to be molded can be formed in a so-called double-thick shape. It is possible to secure sufficient strength for maintaining independence.

The elevating means 5 includes a driving cylinder 21 for moving the inclined bottom surface forming mold 4 up and down, a rib forming metal mold 3, and an inclined bottom surface forming metal mold 4 respectively at the bottom of the body forming metal mold 2. A first link pin 8A of the inclined bottom surface forming mold 4 and a second link pin 8B of the rib forming metal mold 3 which are arranged substantially horizontally with each other in a state of being freely movable in the vertical direction in the opening 12 of The rib forming die 3 in the opening 12 at the bottom of the body forming die 2, the inclined bottom surface, because the link arm 22 that connects the third link pins 8 </ b> C of the body forming die 2 is connected. The part forming dies 4 can be easily moved up and down at different rates. Moreover, in the production of each mold 2,3,4, each link pins 8A that is cooperative with the link arm 22, 8B, by pre-setting the different proportions arrangement interval of 8C mutual funds rib portion formed type 3, can be preliminarily restricted sets the movement amount of the up and down strokes of the respective inclined bottom surface portion forming mold 4, the rib portion P itself, can you to correspond to the difference in height of the respective inclined bottom surface portion Q.

  Furthermore, the plastic container molding method according to the present invention includes an annular rib via an elevating means 5 that can be moved up and down in conjunction with each other under a fixed restraining motion that regulates the movement strokes to be different from each other. The part forming mold 3 and the mortar-shaped inclined bottom surface forming mold 4 are fitted and arranged so as to close the opening 12 formed in the bottom of the left and right body forming molds 2 At the same time, after the compressed air is blown into the resin melt 15 and the resin is in close contact with the inner wall surfaces of the molds 2, 3, 4, the rib forming mold 3 is inclined while the resin is in a molten state. Each of the bottom surface forming molds 4 is pushed up by the lifting means 5 at a different rate, and the blowing of compressed air is continued for a predetermined time. After cooling and hardening of the resin, the internal compressed air is discharged, Inclined bottom surface formation Since each of the dies 4 is returned to the lowered position by the elevating means 5, the plastic container is molded together with the molding of the plastic container body by the split body forming mold 2 having the cavity of the shape of the molded product. The rib portion P and the inclined bottom surface portion Q at the bottom of each can be simultaneously formed by a single process.

  Note that the reference numerals added in the means for solving the above-described problems and the effects of the invention are given for easy reference to the parts showing the components shown in the drawings. The present invention is not limited to the structure / shape indicated by the reference numeral.

  The best mode for carrying out the present invention will be described below with reference to the drawings. Reference numeral 1 shown in the figure denotes, for example, shampoo, rinse, body soap, hand soap, liquid detergent for kitchens, hair conditioner, liquid cosmetics. For example, it is a molding die apparatus for manufacturing a bottle-shaped plastic container based on a blow molding method such as direct blow so as to accommodate a liquid content (inner solution) such as a liquid. As shown in FIG. 1, the molding die apparatus 1 is formed of a bifurcated block that is symmetrical to each other, and a cylinder having a shape of a molded product is formed in a state where the left and right are combined. Part forming mold 2, rib part forming mold 3, inclined bottom surface part forming mold 4, and openings which will be described later, formed at the bottom of a pair of left and right body part forming molds 2 that face each other 12, a lifting / lowering means 5 for moving up and down under a fixed restraining motion that restricts the movement strokes of the rib portion forming die 3 and the inclined bottom surface forming die 4 to be different from each other. Has been.

  The structure of each of the pair of left and right barrel forming molds 2, rib forming molds 3, and inclined bottom surface forming molds 4 will be described on one of the left and right sides, and the other side will be described on one side. This description is omitted because it has a symmetrical structure. Further, when assembling the molding die apparatus 1, the pair of left and right molds 2, 3, and 4 are fixed by a fastening device (not shown) while being abutted against each other, and are removed after the molding is completed. The molds 2, 3 and 4 can be separated from each other.

  As shown in FIG. 2, the inclined bottom surface forming mold 4 includes pressing dies 6 </ b> A and 6 </ b> B having a semi-cylindrical shape on one end of the upper surface of the rectangular block and an inclined surface whose upper surface gradually decreases toward the center of the semicircle. In the state where the left and right pair of inclined bottom surface forming molds 4 are abutted with each other, a cylindrical pressing die 6 whose upper surface has a bowl shape is formed. In addition, a pair of left and right first link pins 8A protrudes from the other end on the upper surface opposite to the pressing dies 6A and 6B via a small block 7 which is erected sideways to constitute the lifting means 5. It is. Guide through-holes 9 are formed in the left and right positions of the upper surface sandwiched between the pressing dies 6A and 6B and the small block 7, respectively, and project from the left and right positions of the lower surface of the body portion forming die 2 as will be described later. A guide rod 17 is inserted.

  As shown in FIG. 3, the rib forming die 3 has a pressing rib 11A having a semicylindrical groove on one end of the upper surface of the rectangular block and a groove having a substantially semicircular cross section along the semicircular surface. 11B is formed, and the pair of left and right rib forming molds 3 are in abutment with each other, so that a cylindrical pressing rib 11 having a groove portion with a substantially semicircular cross section on the upper surface is formed. In addition, second link pins 8B that are horizontal to each other are provided in a symmetrical manner on the other side of the other end that is opposite to the pressing ribs 11A and 11B in order to form the elevating means 5. Guide through-holes 9 are formed in the left and right positions of the upper surface, respectively, and guide rods 17 (described later) projecting from the left and right positions of the lower surface of the body forming mold 2 are inserted therethrough.

  As shown in FIG. 4, the barrel forming mold 2 is formed with a groove 2 </ b> A corresponding to a half-shaped barrel portion of a molded product on one side surface of a vertically long rectangular block. The bottle-shaped cavities of the molded product are formed in a state where the molds 2 are abutted against each other. Further, a semicircular opening 12 is formed at a position substantially corresponding to the bottom peripheral edge molding portion of the plastic container on the block bottom side, and the whole is substantially U-shaped downward from the left and right sides of the lower surface so as to sandwich the opening 12. Guide frame portions 13A and 13B are formed so as to form a mold. The guide frame portions 13A and 13B are partially cut out from the side surfaces, and third link pins 8C that are horizontal to project from each other in order to form the lifting / lowering means 5. In addition, on the upper side of the pair of left and right barrel forming molds 2 that face each other, heat-softened extruded downward from the annular nozzle 14, for example, polyethylene, vinyl chloride resin, polyethylene terephthalate, polypropylene, polycarbonate, etc. A hole 16 for insertion for inserting, for example, a parison which is a resin melt 15 made of various synthetic resin materials is formed (see FIG. 8).

  In addition, a pair of left and right guide rods 17 project from the inside of the left and right guide frame portions 13A and 13B, and guide ribs 9 in the rib portion forming mold 3 and the inclined bottom surface portion forming die 4 described above. It is supposed to be inserted into the. That is, when the molding die apparatus 1 is assembled, a pair of left and right rib portion forming molds 3 butted against each other are mounted on a pair of left and right inclined bottom surface forming molds 4 butted against each other. The cylindrical pressing die 6 of the inclined bottom surface forming mold 4 is fitted into the cylindrical pressing rib 11. At this time, the guide through-holes 9 are in a state of being matched with each other, and at the same time, the first link pin 8A and the second link pin 8B are in a state of being arranged in parallel with each other.

Then, the guide rod 17 of the barrel forming die 2 is inserted into the guide through-holes 9 of the rib portion forming die 3 and the inclined bottom portion forming die 4 assembled with each other to form the barrel portion. The rib 2 forming mold 3 and the inclined bottom surface forming mold 4 are assembled into the guide frame portions 13A and 13B of the mold 2 for use, and the guide rod 17 and the guide frame portion 13A of the body forming mold 2 are used. , 13B so as to be movable in the vertical direction. At this time, the first link pin 8A, the second link pin 8B, and the third link pin 8C are in a state of being arranged substantially horizontally . By doing so, each of the rib part forming mold 3 and the inclined bottom part forming mold 4 is movable along the vertical direction under a certain restraining state with respect to the body part forming mold 2, By moving the link arm 22 that links the link pins 8A, 8B, and 8C, the movement amounts of the rib portion forming mold 3 and the inclined bottom surface portion forming mold 4 can be reliably adjusted and set in advance.

  Next, the concrete raising / lowering means 5 in the molding die apparatus 1 which concerns on this form is demonstrated. In addition, one side of each of the pair of left and right body part forming molds 2, rib part forming molds 3, and inclined bottom surface part forming molds 4 will be described, and the other side is symmetrical with the one on one side. This explanation is therefore omitted. As shown in FIG. 5, the elevating means 5 includes a drive cylinder 21 that allows the inclined bottom surface forming die 4 itself to move up and down, a first link pin 8A, a second link pin 8B, and a third link pin 8C. It is comprised by the link arm 22 which connects each. However, only one set is shown in FIG. 1 in order to avoid the complexity of drawing and inspection.

  That is, as shown in FIGS. 1 and 3, the link arm 22 is provided with a hole 23 near the center of the band plate member, and the second link pin 8B of the rib forming die 3 is provided in the hole 23. For example, it is inserted through a bearing 24 such as a bearing or a bush, and U-shaped groove-like recesses 25 are provided at both left and right (front and rear) ends of the band plate member. Each of the link pin 8C and the first link pin 8A of the inclined bottom surface forming mold 4 is inserted through a bearing 24 such as a bearing or a bush. By doing so, it is assumed that the body forming mold 2, the rib forming mold 3, and the inclined bottom surface forming mold 4 are connected to each other. The annular rib forming mold 3 and the mortar-shaped inclined bottom surface forming mold 4 are arranged so as to close the opening 12 formed at the bottom of the mold 2, respectively. It is designed to be able to move up and down in conjunction with each other under a certain restraining motion that regulates the difference. That is, as shown in FIG. 9, when the first link pin 8A is moved up and down with the third link pin 8C as a fulcrum, the second link pin 8B can be moved within a range smaller than the movement amount of the first link pin 8A. The movement amount ratio can be set based on the distance between the link pins 8A, 8B, and 8C.

Thus, since each of the first link pin 8A, the second link pin 8B, and the third link pin 8C is connected by the link arm 22, the rib portion forming mold 3 and the inclined bottom surface portion forming mold 4 movement certain constraint movements of the upright direction of the molded article, i.e. is performed in a state where the upper and lower movement is constrained in the opening 12 of the body portion forming mold 2, along the vertical direction, the inclination It has become possible by moving cylinder 21 driving that tandem on the bottom portion forming mold 4. For example, when the movement of the inclined bottom surface portion forming mold 4 is 10 (see symbol H1 of the white arrow in FIG. 12), the movement of the rib portion forming mold 3 is 3 by the ratio. In the present embodiment, the movement of the rib portion forming mold 3 is performed at the ratio by making the positional interval between the hole portion 23 of the link arm 22 and the left and right concave portions 25 the same. 5 (see symbol H2 of the white arrow in FIG. 12) . In this way, the amount of movement of the inclined bottom portion forming mold 4 is made larger than the amount of movement of the rib portion forming mold 3. This depends on the distance of movement of the part forming mold 4 and the capacity / weight / design of the plastic container.

  In the present embodiment, the bottle-shaped plastic container is molded not only in a circular cross section (see FIG. 6) but also in an ellipse (see FIG. 7) or a rectangle, or the deformation of the bottle itself. If possible, the molding die apparatus 1 having the above-described characteristics can be manufactured.

  And at the time of plastic container molding, as shown in FIG. 8, the left and right barrel forming molds are formed so as to surround the parison or the like, which is a heat-softened resin melt 15 extruded downward from the annular nozzle 14. 2, and the opening 12 formed at the bottom of the body forming die 2 is closed with a rib forming die 3 and an inclined bottom forming die 4 that can be moved up and down together. Then, high-pressure compressed air is blown into the resin melt 15 to inflate the resin melt 15 itself, whereby the barrel portion forming die 2, the rib portion forming die 3, and the inclined bottom surface portion forming die 4, respectively. A bottle-shaped plastic container is formed by pressing in close contact with the inner wall surface.

  That is, the molding die apparatus 1 includes a pair of left and right rib portion forming molds 3 that are abutted with each other simultaneously with the formation of the body portion of the plastic container by the pair of left and right body portion forming dies 2 that abut each other. As a result of the slight upward movement, the peripheral edge portion of the bottom portion is folded back into a double shape to form an annular rib portion P that can be independently grounded, thereby forming a plateau called a bowl in the bottom portion of the plastic container. In addition, the slant bottom surface forming die 4 that moves in conjunction with the rib portion forming die 3 and moves upward with a larger stroke than the rib portion forming die 3 itself, and moves toward the center of the bottom surface from the upper end of the rib portion P. By forming the inclined bottom surface portion Q that is inclined in a shape and is shallower than the height of the rib portion P, a tea pot called a teacup is formed. The rib portion P and the inclined bottom surface portion Q are molded by a single process when compressed air is blown into the resin melt 15 in blow molding, and after the plastic container is molded, the bottle upper opening side is not shown. The pump-type dispenser is closed and the conduit R of the extrusion pump-type dispenser faces the lowest center of the inclined bottom surface. Moreover, the container body itself in the plastic container is pressed and closed with a special lid provided with a pumping mechanism that pumps up the internal solution by fluctuation of internal pressure, and the conduit R attached to this special lid is the lowest center of the inclined bottom surface portion. I try to face the club.

  Next, a method for molding a bottle-shaped plastic container by the molding die apparatus 1 in this configuration will be described with reference to FIGS. As shown in FIG. 8, first, the body portion forming die 2, the rib portion forming die 3, and the inclined bottom surface portion forming die 4 are combined and fixed to each other by a fastening device (not shown). At this time, the guide rod 17 of the barrel forming die 2 is inserted into the guide through-holes 9 of the rib portion forming die 3 and the inclined bottom surface forming die 4 so that the barrel forming die is concerned. The rib portion forming mold 3 is inclined by connecting the first link pin 8A, the second link pin 8B, and the third link pin 8C with the link arm 22 in the guide frame portions 13A and 13B. Each of the bottom surface forming dies 4 is disposed so as to be movable up and down along the guide rod 17 and the guide frame portions 13A and 13B of the body forming die 2. Then, the driving cylinder 21 is driven downward, and each of the rib portion forming die 3 and the inclined bottom surface portion forming die 4 is kept at the lowest position.

  Further, a parison or the like, which is a heat-softened resin melt 15 extruded downward from the annular nozzle 14, is inserted from the insertion hole 16 on the upper side of the body forming die 2, and the shape of the molded product is changed. It is arranged so as to be surrounded by the body forming die 2 having the cavity. Then, high-pressure compressed air is blown into the resin melt 15 of the parison to inflate the resin melt 15 itself and press it against the inner wall surfaces of the molds 2, 3, 4 to form a plastic container. At this time, each of the rib part forming mold 3 and the inclined bottom surface forming mold 4 is in a lowered position as shown in FIG. This is to realize uniform elongation of the resin when the compressed air is blown, and for this purpose, the molding surfaces of the rib portion forming mold 3 and the inclined bottom surface forming die 4 are made to be as far as possible from each other. The reason for this is that the radius of curvature of the molding surface should be as large as possible.

  After the resin melt 15 is brought into close contact with the inner wall surfaces of the molds 2, 3 and 4, for example, 0.5 to 2 seconds after the resin remains in a molten state, the drive cylinder 21 is driven upward to form a rib portion. The rib 3 is formed by pushing the mold 3 for forming the inclined mold 3 and the mold 4 for forming the inclined bottom surface part 1 at a rate of 1 and blowing in compressed air for a predetermined time, and releasing the internal compressed air after cooling and hardening the resin. Each of the mold 3 and the inclined bottom surface forming mold 4 is returned to the lowered position. Then, the pair of left and right molds 2, 3, and 4 are separated by a fastening device, and the molded product is taken out. By repeating the above operations, bottles of plastic containers by blow molding are mass-produced.

  Next, the mechanism by which the circumferential rib portion P is created at the peripheral edge of the bottom of the plastic container will be described with reference to FIGS. 11 is an enlarged cross-sectional view of only the resin at the moment when compressed air is blown into the resin melt 15 such as a parison and the resin is in close contact with the inner wall surfaces of the molds 2, 3, and 4. FIG. 21 is an enlarged cross-sectional view of only the resin when the rib portion forming mold 3 is pushed up by 21 and the inclined bottom surface forming die 4 is pushed up by a ratio of 1. FIG.

  In FIG. 11, the resin material that has once adhered to the rib portion forming mold 3 and the inclined bottom surface forming die 4 is in a cooling process unless mechanical force is applied in a state where compressed air is continuously blown. Since there is no significant movement except for the contraction, the non-cross-section line portion is maintained as it is. Since the rib volume V8 to be created by pushing up the rib forming die 3 is a rotating body having the central axis 1 as the rotation axis, V8 = the sectional area S of the rib portion P × the circumference of the inclined bottom surface portion Q. It can be determined by the length L. Similarly, the volume of the rib volume V7 before the rib part forming mold 3 to be pushed up to the rib volume V8 can be obtained.

If the magnitude relationship between the rib volumes V7 and V8 is V7> V8, a resin sufficient for rib molding can be obtained. For this purpose, the U-shaped groove dimension β ′, which is the lateral thickness of the rib portion P, is desirably 2α> β ′, where α is the uniform thickness of the body portion of the plastic container. Under such conditions, when the inclined bottom surface forming die 4 and the rib portion forming die 3 are raised at a ratio of about 10: 3 to 7, respectively, as shown in FIG. Can be raised while being dragged by an angle γ with β of the U-shaped groove as an inversion reference, and can be changed to the shape of the rib volume V8.

  The bottom part of the plastic container can be molded in the same manner not only by the direct blow method but also by a stretch blow method having a different molding process as long as a molten state can be secured.

1 is an exploded perspective view showing the best mode of a molding die apparatus for carrying out the present invention, and only one set of link configuration of lifting means is shown. Similarly, it shows one of the two molds for forming the inclined bottom surface, wherein (a) is a plan view, (b) is a front view, (c) is a rear view, and (d) is a side view. Similarly, it shows one of the halved rib part forming molds, (a) is a plan view, (b) is a front view, (c) is a rear view, and (d) is a side view. Similarly, it shows one of the molds for splitting the barrel part, (a) is a plan view, (b) is a front view, and (c) is a side view. It is sectional drawing which similarly shows each assembly state of the inclination bottom part formation die, the rib part formation die, and the trunk | drum formation die. It is a top view which similarly shows each assembly state of the metal mold | die for inclination bottom face part formation, the metal mold | die for rib part formation, and the body part formation mold. It is a top view which shows the assembly state of each of the inclined bottom part forming mold, the rib part forming mold, and the body part forming mold for forming the bottle-shaped plastic container when the plane cross section is oval. . Describes the molding method with each of the inclined bottom surface forming die, rib portion forming die, and body portion forming die, and the parison introduced into the die is inflated with compressed air to each die inner wall. It is sectional drawing which shows the state before the shaping | molding closely attached. Similarly, it explains the molding method by each of the mold for forming the inclined bottom surface part, the mold for forming the rib part, and the mold for forming the body part, and the mold for forming the inclined bottom surface part and the mold for forming the rib part by the driving cylinder. It is sectional drawing when pushing up each type | mold and shape | molding a rib part. Similarly, it explains the molding method with the inclined bottom part forming mold, the rib part forming mold, and the body part forming mold, and the inclined bottom part forming mold and the rib part forming mold by the driving cylinder. It is sectional drawing when each is lowered | hung and a rib part is shape | molded. It is an expanded sectional view of only the resin material in the state before pushing up similarly the metal mold | die for inclined bottom face part formation. It is an expanded sectional view of only the resin material in the state after pushing up similarly the metal mold | die for inclined bottom face part formation.

Explanation of symbols

P ... Rib part Q ... Inclined bottom part R ... Conduit S ... Cross-sectional area V7, V8 ... Rib volume L ... Circumference length
H1... Movement amount of the inclined bottom portion forming mold H2... Movement amount of the rib portion forming mold .alpha.. Uniform thickness of the barrel .beta., .Beta. '. Mold device 2 ... Body portion forming die 2A ... Groove portion 3 ... Rib portion forming die 4 ... Inclined bottom surface portion forming die 5 ... Elevating means 6, 6A, 6B ... Pressing die 7 ... Small block 8A ... 1st link pin 8B ... 2nd link pin 8C ... 3rd link pin 9 ... Through-hole 11 for guides, 11A, 11B ... Pressing rib 12 ... Opening part 13A, 13B ... Guide frame part 14 ... Ring-shaped nozzle 15 ... Resin melting Body 16 ... Insertion hole 17 ... Guide rod 21 ... Driving cylinder 22 ... Link arm 23 ... Hole 24 ... Bearing 25 ... Recess

Claims (7)

By sandwiching the heat-softened resin melt extruded downward from the annular nozzle from both left and right sides, blowing the compressed air into the resin melt to inflate the resin melt itself and press it closely against the inner wall surface , a molding die apparatus of the plastic container by blow molding comprising comprises a mold two split having a bottom peripheral edge to the cavity in which the formed molded article having a shape and a rib portion for autonomous ground, plastic have openings formed in the bottom portion which is open at the outer peripheral edge position of the rib portion formed in the bottom periphery of the container, and the body forming mold of the left right that is butted, gold for body portion formed A pair of left and right rib forming molds that are fitted and arranged so as to be movable in the vertical direction along the opening of the mold , and that are provided with annular pressing ribs that are arranged at rib positions of the plastic container, Rib forming mold A pair of left and right inclined bottom portion forming golds having a semi-cylindrical pressing die which is movable in the vertical direction along the inner peripheral edge of the pressing rib and which is located on the lower surface of the inclined bottom surface portion of the plastic container. A lifting and lowering means for moving the rib part forming mold and the inclined bottom part forming mold in conjunction with each other in a restraint state in the body forming mold with respect to the body forming mold; And the raising and lowering means is configured to raise and lower the moving amount of the inclined bottom surface forming mold as compared with the moving amount of the rib forming metal mold. Mold equipment. The inclined bottom surface forming mold includes a pressing die having a semi-cylindrical shape on one end of the upper surface of the rectangular block and an inclined surface whose upper surface gradually decreases toward the center of the semicircle, and a pair of left and right inclined bottom surface forming molds. in a state where the mold is butted to each other, upper surface molding die apparatus of the plastic container of claim 1 Symbol mounting configured as a cylindrical press die became conical. Rib portion forming mold has a pressing rib top surface with semi-cylindrical on the upper surface at one end of the rectangular block is e Bei on the upper surface of the groove cross-section substantially semicircular arc shape along a semicircle, a pair of left and right ribs parts forming mold from each other collision intertwined the pressing rib was claim 1 or constructed as a cylindrical shape state molding die apparatus of the plastic container 2 Symbol placement. A rib forming die and an inclined bottom surface forming die are arranged on the lower surface of the body forming die, and guide rods protruding from the left and right positions of the lower surface of the body forming die are used for rib forming. 4. The mold apparatus for molding a plastic container according to claim 1, wherein the mold apparatus is inserted into a guide through hole formed in each of the mold and the inclined bottom surface forming mold. Lifting means may be linked with each drive cylinder over which vertically moving the inclined bottom surface portion forming mold in the inclined bottom surface portion forming mold, the rib portion forming mold, the inclined bottom surface portion forming die respectively torso in the opening of the forming die in a state of being movable in the vertical direction, a first Rinkupi down protruding formed inclined oblique bottom portion forming mold, a second Rinkupi down protruding form the rib portion forming mold If, respectively by arranging the third Rinkupi down protruding formed in the body portion forming mold substantially horizontally to each other in tandem in the link arm, the ratio to the amount of movement of the first link pin of the third link pin as a fulcrum molding die apparatus of the plastic container according to claim 1乃 optimum 4 a small range and made so as to move the second link pin. A resin melt that has been heated and softened extruded downward from an annular nozzle is sandwiched between two molds having cavities in the shape of a molded product, and compressed air is blown into the resin melt to form a resin melt. by pressing inflate itself to form close contact with the inner wall surface of the mold, a molding method for a plastic container molded article has a rib portion for self-supporting ground in the bottom peripheral portion by blow molding the formed shape, butt A pair of left and right rib forming molds having annular pressing ribs arranged at the rib position of the plastic container so as to close the opening formed at the bottom of the combined left and right body forming molds And a pair of left and right inclined bottom surfaces provided with a semi-cylindrical pressing die that is located on the lower surface of the mortar-shaped inclined bottom surface of the plastic container along the inner periphery of the pressing rib in the rib-forming mold Part shape A mold leave movably fitted vertically arranged, blowing compressed air into the tree butter melt in extruded into the barrel forming mold, the resin is in close contact with the inner wall surface of the mold after, Li blanking portion formed mold while the resin is in a molten state, each inclined bottom surface portion forming mold by the lifting means, the rib portion forming mold the amount of movement of the inclined bottom surface portion forming mold of larger than the amount of movement, the rib portion forming mold, the inclined bottom surface portion forming mold with raised press in conjunction with the original constrained state continues only blowing compressed air prescribed time, then, to release the internal compressed air after cooling curing tree fat, rib forming mold, a molding method for plastic containers and returning each inclined bottom surface portion forming mold to the lowered position by the lifting means. The rib forming mold and the inclined bottom forming mold are moved up and down sequentially inwardly in the opening of the body forming mold on the link arm with the position of the body forming mold as the outer fulcrum. interpolation disposed rib portion formed mold in advance in tandem through the sequentially link pin the inclined bottom surface portion forming mold, inclined swash bottom portion formed by a drive cylinder for raising and lowering movement of the inclined bottom surface portion forming mold method of molding a plastic container according to claim 6, wherein moving by increasing than the amount of movement of the mold to the moving amount of Li blanking portion forming mold.

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