Patent Description:
In blow molding of a resin container, a configuration has been proposed in which a resin preform released from an injection mold is forcibly cooled using a cooling mold different from the injection mold (for example, see Patent Literature <NUM>).

Regarding this type of cooling mold, there is also known a mold that sucks air between a mold and a preform to bring the preform into close contact with a surface of the mold (for example, see Patent Literatures <NUM> and <NUM>).

<CIT> discloses a multi-layer porous member for a post-molding molded article conditioning apparatus.

<CIT> discloses a method and device for processing preforms. In particular <CIT> discloses a cooling mold for cooling a resin preform that has a gate portion protruding outward from a center of a bottom portion, wherein an accommodating space that accommodates the preform is formed in the cooling mold, in the accommodating space, a region facing a body portion of the preform and a bottom region facing the bottom portion of the preform are formed as a single member , a surface of the bottom region shaped following an outer shape of the bottom portion of the preform is disposed to face the gate portion , and air sucking holes for sucking air from between the cooling mold and the preform are formed in the bottom region at positions shifted from the center of the bottom portion of the preform.

<CIT> discloses an apparatus for manufacturing plastic bottles from molded hollow preforms.

<CIT> discloses a method and apparatus for crystallizing a preform port for molding a bottle.

In a bottom portion of an injection-molded preform, a gate portion that becomes a resin introduction mark from a hot runner into an injection mold is formed in a manufacturing process. When blow-molding a container from a preform, it is preferred, in terms of appearance and quality of a container after molding, to completely eliminate a gate portion of a preform from a bottom portion thereof. However, it is actually difficult to mechanically cut off a gate portion of a preform with high accuracy due to restrictions such as molding conditions of a preform and the like and apparatus configurations.

On the other hand, in a blow molding manufacturing cycle, it is desired to further shorten molding cycle time of a container. For example, when a process of mechanically cutting off a gate portion of a preform is added, molding cycle time of a container is lengthened by time of the added cutting process.

Thus, the present invention has been made in view of such problems, and an object thereof is to remove a gate portion of a preform with high accuracy without extending molding cycle time of a container.

One aspect of the present invention is a cooling mold as specified in claim <NUM>.

According to one aspect of the present invention, a gate portion of a preform can be removed with high accuracy without extending molding cycle time of a container.

In the embodiments, for easy understanding, structures and elements other than a main part of the present invention will be described in a simplified or an omitted manner. In the drawings, identical elements are denoted by identical reference numerals. Note that shapes, dimensions, and the like of respective elements illustrated in the drawings are schematically illustrated, and do not indicate actual shapes, dimensions, and the like.

First, a blow molding apparatus <NUM>, an example of a manufacturing apparatus for manufacturing a resin container, will be described with reference to <FIG> is a plan view schematically illustrating a configuration of a blow molding apparatus. <FIG> is a view schematically illustrating conveyance of a preform in an injection molding unit and a cooling unit.

The blow molding apparatus <NUM> according to the present embodiment performs a blow molding method called a <NUM> stage method having advantages of both a hot parison method and a cold parison method. In the blow molding method in the <NUM> stage method, basically similarly to the hot parison method (one stage method), a preform having heat from injection molding is blow-molded to manufacture a container. However, a cycle of blow molding in the <NUM> stage method is set to be shorter than a cycle of injection molding of a preform. A plurality of preforms molded in one injection molding cycle is blow-molded in a plurality of blow molding cycles. Although not particularly limited, a ratio (N : M) of the number (N) of preforms simultaneously injection-molded and the number (M) of containers simultaneously blow-molded is set to <NUM> : <NUM>, for example.

As illustrated in <FIG>, the blow molding apparatus <NUM> includes an injection molding unit <NUM>, a cooling unit <NUM>, a heating unit <NUM>, and a blow molding unit <NUM>.

The blow molding apparatus <NUM> also includes a continuous conveying unit <NUM> that conveys preforms <NUM> carried out from the cooling unit <NUM> to the blow molding unit <NUM> via the heating unit <NUM>. The continuous conveying unit <NUM> is a conveying device that continuously conveys conveying jigs <NUM> holding the preforms <NUM> along a loop-shaped conveying line <NUM> that has a plurality of curved portions. In other words, the continuous conveying unit <NUM> can repeatedly convey the conveying jigs <NUM> each along the loop-shaped conveying line <NUM>.

The injection molding unit <NUM> injection-molds the bottomed tubular preforms <NUM> that are resin molded articles.

As illustrated in <FIG>, the injection molding unit <NUM> includes core molds <NUM> disposed above, cavity molds <NUM> disposed below, and a mold clamping mechanism <NUM> that clamps the core molds <NUM> and the cavity molds <NUM> with tie bars <NUM>. The injection molding unit <NUM> injection-molds the preforms <NUM> by filling injection spaces formed by the core molds <NUM> and the cavity molds <NUM> with a resin material (raw material) from an injection device (not illustrated).

The injection molding unit <NUM> according to the present embodiment simultaneously molds, for example, <NUM> rows × <NUM> (N = <NUM>) preforms <NUM>. In addition, the preforms <NUM> are molded in an upright state with neck portions facing upward in the injection molding unit <NUM>, and the preforms <NUM> are conveyed in the upright state in the injection molding unit <NUM>.

As illustrated in <FIG>, the injection molding unit <NUM> includes a receiving unit <NUM> that takes out injection-molded preforms to the outside of the injection molding unit <NUM>.

The receiving unit <NUM> can move in a horizontal direction (X direction in the drawing) from a receiving position on a lower side of the core molds <NUM> to a delivery position outside a space surrounded by the tie bars <NUM>.

The receiving unit <NUM> holds <NUM> cooling pots <NUM> that respectively accommodate <NUM> rows × <NUM> preforms molded in the injection molding unit <NUM>.

Each cooling pot <NUM> is an example of a cooling mold, and has an accommodating space for each preform <NUM>, corresponding to an outer shape of the preform <NUM>. The cooling pot <NUM> of the receiving unit <NUM> has a function of cooling the preform by contacting the accommodated preform <NUM>. The cooling pot <NUM> also has a function of removing a gate portion of the preform <NUM>. A configuration of the cooling pot <NUM> will be described later.

Further, the receiving unit <NUM> includes a mechanism (not illustrated) that adjusts an interval (an interval in the X direction in the drawing) between rows of the cooling pots <NUM> while moving from the receiving position to the delivery position. As a result, the receiving unit <NUM> converts the interval between the rows of the preforms <NUM> from a wide pitch state of the receiving position to a narrow pitch state of the delivery position.

Here, an example of the preform <NUM> applied in the present embodiment will be described with reference to <FIG> is a longitudinal sectional view of the preform <NUM> in the upright state as viewed from a front direction, and <FIG> is a plan view of the preform <NUM>. Fig. <NUM>(C) is a longitudinal sectional view illustrating the preform <NUM> in a state where the gate portion is removed by the injection molding unit <NUM> or the cooling unit <NUM> according to the present embodiment.

An entire shape of the preform <NUM> is a bottomed cylindrical shape in which one end side is opened and the other end side is closed. The preform <NUM> includes a body portion <NUM> formed in a cylindrical shape, a bottom portion <NUM> that closes the other end side of the body portion <NUM>, a gate portion <NUM> formed in the bottom portion <NUM>, and a neck portion <NUM> formed in an opening on one end side of the body portion <NUM>.

The gate portion <NUM> is a resin introduction mark from a hot runner, and is formed so as to protrude outside the bottom portion <NUM> at a center of the bottom portion <NUM>.

A raw material of the preform <NUM> is a thermoplastic synthetic resin, and can be appropriately selected according to uses of containers. Specific types of materials include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycyclohexanedimethylene terephthalate (PCTA), Tritan (registered trademark: copolyester manufactured by Eastman Chemical Co. ), polypropylene (PP), polyethylene (PE), polycarbonate (PC), polyethersulfone (PES), polyphenylsulfone (PPSU), polystyrene (PS), cyclic olefin polymer (COP/COC), polymethylmethacrylate (PMMA: acrylic), polylactic acid (PLA), and the like.

The preform <NUM> injection-molded by the injection molding unit <NUM> is supplied from the injection molding unit <NUM> to the cooling unit <NUM>. The cooling unit <NUM> forcibly cools the preform <NUM> molded by the injection molding unit <NUM>. The preform <NUM> is carried out from the cooling unit <NUM> in a state of being cooled to a predetermined temperature, and is continuously conveyed along the conveying line <NUM>.

As illustrated in <FIG>, a conveying device <NUM> that conveys the preform <NUM> in the upright state from the receiving unit <NUM> to the cooling unit is provided between the injection molding unit <NUM> and the cooling unit <NUM>. The conveying device <NUM> includes a holding unit <NUM> that holds the neck portion of the preform <NUM> in the upright state, and can move the holding unit <NUM> in a vertical direction (Z direction in the drawing) and the horizontal direction (X direction in the drawing) by an air cylinder (not illustrated).

As illustrated in <FIG>, the cooling unit <NUM> includes an inverting unit <NUM>. The inverting unit <NUM> is invertible around a shaft <NUM> extending in the X direction in the drawing as a rotation axis, and is movable up and down in the Z direction (vertical direction) in the drawing. On a first surface 121a illustrated on an upper side in the drawing of the inverting unit <NUM> and a second surface 121b facing the first surface 121a, <NUM> cooling pots <NUM> are disposed on each of the surfaces in order to accommodate <NUM> rows × <NUM> preforms <NUM>.

In the present embodiment, the cooling pots <NUM> disposed on the first surface 121a and the second surface 121b in the inverting unit <NUM> have a configuration similar to the configuration of the cooling pots <NUM> of the receiving unit <NUM>. The cooling pots <NUM> in the inverting unit <NUM> are cooled by a refrigerant circulating through a refrigerant passage (not illustrated) provided in the inverting unit <NUM>. The cooling pots <NUM> each in the inverting unit <NUM> have a function of sucking and holding the accommodated preform <NUM> and a function of removing the gate portion of the preform.

In the following description, the cooling pots <NUM> disposed on the first surface 121a in the inverting unit <NUM> are also referred to as first cooling pots 300a, and the cooling pots <NUM> disposed on the second surface 121b in the inverting unit <NUM> are also referred to as second cooling pots 300b.

In addition, the inverting unit <NUM> reverses the preforms <NUM> in the upright state received from the conveying device <NUM> to an inverted state in which the neck portions face downward during cooldown time. Then, the preforms <NUM> in the inverted state are delivered to the conveying jigs <NUM> of the continuous conveying unit <NUM>, disposed in a plurality of rows below the cooling unit <NUM>. The conveying jigs <NUM> holding the preforms <NUM> are sequentially conveyed along the conveying line <NUM> by driving forces of sprockets <NUM> or the like.

The heating unit <NUM> heats the preforms <NUM> in the inverted state continuously conveyed by the continuous conveying unit <NUM> to an appropriate stretching temperature. The heating unit <NUM> includes a plurality of heaters (not illustrated) disposed at predetermined intervals along the conveying line <NUM> on both sides of the conveying line <NUM>. In the heating unit <NUM>, the preforms <NUM> in the inverted state are heated while rotating about axial directions of the preforms <NUM>, and the entire preforms <NUM> are uniformly heated.

Further, the blow molding apparatus <NUM> includes an intermittent conveying unit <NUM> and a delivery unit <NUM> on a downstream side of the heating unit <NUM> in the conveying line <NUM>.

The intermittent conveying unit <NUM> holds a plurality of (M, e.g., four) preforms <NUM> heated by the heating unit <NUM> and intermittently conveys the preforms <NUM> to the blow molding unit <NUM>. The delivery unit <NUM> delivers the preforms <NUM> continuously conveyed by the continuous conveying unit <NUM> from the conveying line <NUM> to the intermittent conveying unit <NUM>.

In the present embodiment, a plurality of (for example, eight) conveying jigs <NUM> continuous in a conveying direction is connected by a connecting member (not illustrated). Then, the continuous conveying unit <NUM> repeats driving and stopping by sprockets 154a on the conveying line <NUM> on a downstream side of a curved conveying unit <NUM> curved at a predetermined radius, thereby supplying the (M, e.g., four) preforms <NUM> to the delivery unit <NUM> at a time.

The delivery unit <NUM> includes a reversing device (not illustrated) at a delivery position P0. The preforms <NUM> conveyed in the inverted state along the conveying line <NUM> are inverted by the reversing device disposed on the upper side of the preforms <NUM> at the delivery position P0 to be in the upright state. In addition, the delivery unit <NUM> includes, for example, a lifting device (not illustrated) that lifts and lowers the reversing device, and delivers the preforms <NUM> in the upright state to the intermittent conveying unit <NUM> in a state of being lifted to a predetermined position (delivery position P1).

The intermittent conveying unit <NUM> grips the neck portion of each of the preforms <NUM> in the upright state by an openable and closable blow conveying chuck member (not illustrated) provided in the intermittent conveying unit <NUM>. Then, the chuck member (not illustrated) of the intermittent conveying unit <NUM> grips the neck portion of the preform <NUM> at the delivery position P1 located above the delivery position P0, and moves the preform <NUM> from the delivery position P1 to a blow molding position P2. As a result, the preforms <NUM> are conveyed to the blow molding unit <NUM> at predetermined intervals.

The blow molding unit <NUM> includes a pair of blow cavity molds <NUM> that are split molds corresponding to shapes of containers and an air introduction member (not illustrated) that also serves as a stretching rod. In the blow molding unit <NUM>, predetermined number of the preforms <NUM> received from the delivery unit <NUM> are conveyed to the blow cavity molds <NUM>, and the preforms <NUM> are subjected to stretch blow molding by the blow cavity molds <NUM> to manufacture containers.

The containers manufactured by the blow molding unit <NUM> are conveyed to a taking-out position P3 outside the blow molding unit <NUM> by the intermittent conveying unit <NUM>.

Next, configuration examples of the cooling pots <NUM> of the injection molding unit <NUM> and the cooling unit <NUM> will be described with reference to <FIG> and <FIG>.

As described above, the first cooling pots 300a and the second cooling pots 300b of the cooling unit <NUM> are similar to the cooling pots <NUM> of the receiving unit <NUM>. Therefore, here, the configuration of the cooling pots <NUM> of the receiving unit <NUM> will be described, and redundant description will be omitted.

<FIG> is a plan view of each of the cooling pots <NUM>, and <FIG> is a sectional view taken along a line Vb-Vb in <FIG>.

The cooling pot <NUM> has a bottomed cylindrical shape as a whole, and is a cooling mold into which the preform <NUM> can be inserted from an upper surface side. The cooling pot <NUM> has an accommodating space <NUM> capable of accommodating the body portion <NUM> and the bottom portion <NUM> of the preform <NUM> and having an open upper surface side. An internal shape of the accommodating space <NUM> is a shape following outer shapes of the body portion <NUM> and the bottom portion <NUM> of the preform <NUM>.

In the accommodating space <NUM> of the cooling pot <NUM>, air sucking holes <NUM> for sucking air between the mold and the preform <NUM> are formed in a bottom region 301a facing the bottom portion <NUM> of the preform <NUM>. Each of the air sucking holes <NUM> is connected to an air sucking pump (not illustrated) via an air flow path <NUM> formed in the cooling pot <NUM>.

The air sucking hole <NUM> is formed at a position shifted from a center of the bottom portion of the preform <NUM> in the bottom region 301a of the accommodating space <NUM>. In other words, there is no air sucking hole <NUM> at a position facing the gate portion <NUM> of the preform <NUM> in the cooling pot <NUM> (center of an axial direction of the cooling pot <NUM>), and a surface of the bottom region 301a following the outer shape of the bottom portion <NUM> of the preform <NUM> faces the gate portion <NUM>.

The air sucking holes <NUM> are formed in the bottom region 301a of the accommodating space <NUM> so as to be rotationally symmetric with respect to the center of the bottom portion of the preform <NUM>. <FIG> illustrates an example in which four of the air sucking holes <NUM> are disposed at intervals of <NUM> degrees in a circumferential direction of an inner peripheral surface of the bottom region 301a so as to be point-symmetric with respect to the center of the bottom region 301a (position faced by the center of the bottom portion of preform <NUM>, the center of the axial direction of the cooling pot <NUM>). Note that the number of the air sucking holes <NUM> provided may be a number other than four (two, three, or more integers) as long as disposition is rotationally symmetric with respect to the center of the bottom portion of the preform <NUM>. Further, an annular air sucking hole (not illustrated) concentric with the center of the bottom portion of the preform <NUM> may be formed.

<FIG> is a schematic view illustrating a state before air between the cooling pot <NUM> and the preform <NUM> is sucked, and <FIG> is a schematic view illustrating a state after air between the cooling pot <NUM> and the preform <NUM> is sucked.

When air is sucked from the air sucking holes <NUM> in a state where the preform <NUM> is disposed in the accommodating space <NUM> of the cooling pot <NUM> (see <FIG>), the preform <NUM> is drawn inward into the accommodating space <NUM> and comes into close contact with the cooling pot <NUM> (see <FIG>).

As a result, the body portion <NUM> and the bottom portion <NUM> of the preform <NUM> come into surface contact with a surface of the accommodating space <NUM>, and the preform <NUM> is efficiently cooled by heat exchange with the cooling pot <NUM>. Since a shape of the accommodating space <NUM> of the cooling pot <NUM> follows the outer shape of the preform <NUM>, the shape of the preform <NUM> is maintained by the cooling pot <NUM> at a time of cooling.

Here, since the preform <NUM> has residual heat from injection molding, the gate portion <NUM> is easily deformed. Therefore, when the preform <NUM> is drawn inward into the accommodating space <NUM> as described above, the gate portion <NUM> located at the center of the bottom portion of the preform <NUM> is collapsed on the surface of the opposing bottom region 301a. As a result, as illustrated in <FIG>, the shape of the bottom portion of the preform becomes a curved surface following the bottom region 301a of the accommodating space <NUM>.

As described above, in the present embodiment, the gate portion <NUM> is removed from the bottom portion <NUM> of the preform <NUM> with high accuracy in a process of cooling the preform <NUM> with the cooling pot <NUM>.

Further, the air sucking holes <NUM> are located at the positions shifted from the center of the bottom portion of the preform <NUM>, but are disposed so as to be rotationally symmetric. Therefore, sucking power when the preform <NUM> is drawn substantially uniformly acts on the bottom portion <NUM> of the preform <NUM>. Thus, it is possible to suppress distortion from occurring in the bottom portion <NUM> of the preform <NUM> when the preform <NUM> is drawn inward into the accommodating space <NUM>.

The first cooling pot 300a and the second cooling pot 300b of the cooling unit <NUM> also function similarly to the cooling pot <NUM> described above. Although the cooling unit <NUM> inverts the preform <NUM> received in the upright state to the inverted state, the cooling unit <NUM> can adsorb and hold the preform <NUM> in the inverted state by sucking air from the air sucking holes <NUM>.

Next, a blow molding method by the blow molding apparatus <NUM> according to the present embodiment will be described.

<FIG> is a diagram for explaining temperature changes of the preform <NUM> in the blow-molding method according to the present embodiment. In <FIG>, a vertical axis represents a temperature of the preform <NUM>, and a horizontal axis represents time. In <FIG>, examples of temperature changes of the preform according to the present embodiment are indicated by (A) in <FIG>. Examples of temperature changes of the preform in a comparative example (conventional method) described later are indicated by (B) in <FIG>.

In the present embodiment, the injection molding unit <NUM> is opened immediately after completion of resin filling or after minimum cooldown time provided after resin filling, and the preforms <NUM> are released from the core molds <NUM> and the cavity molds <NUM> in a high temperature state in which the outer shapes of the preforms <NUM> can be maintained. In short, in the present embodiment, when the resin material is injected at a temperature equal to or higher than a melting point of the resin material, only minimum cooling of the preforms <NUM> after injection molding is performed in the injection molding unit <NUM>, and the preforms <NUM> are cooled in the cooling pots <NUM> of the receiving unit <NUM> or the first cooling pots 300a or the second cooling pots 300b in the cooling unit <NUM>.

In the present embodiment, time (cooldown time) for cooling the resin material by the injection molding unit <NUM> after completion of injection of the resin material is preferably <NUM>/<NUM> or less with respect to time (injection time) for injecting the resin material. The time for cooling the resin material can be made shorter than the time for injecting the resin material depending on weight of the resin material. The time for cooling the resin material is more preferably <NUM>/<NUM> or less, still more preferably <NUM>/<NUM> or less, and particularly preferably <NUM>/<NUM> or less with respect to the time for injecting the resin material. Since the cooldown time is significantly shortened as compared with the comparative example described later, a skin layer (surface layer in a solidified state) of a preform is formed to be thinner than before, and a core layer (inner layer in a softened or molten state) is formed to be thicker than before. In other words, as compared with the comparative example, a preform having a large heat gradient between the skin layer and the core layer and having high residual heat at a high temperature is molded.

On the other hand, as a comparative example, when the preforms <NUM> are cooled in the core molds <NUM> and the cavity molds <NUM>, examples of temperature changes of the preforms ((B) in <FIG>) will be described.

In the comparative example, each of the preforms <NUM> is cooled to a temperature lower than one in the present embodiment in the molds of the injection molding unit <NUM>. Therefore, in the comparative example, the molding cycle time of a preform becomes longer than that in the present embodiment, and as a result, the molding cycle time of a container also becomes longer.

In the first cooling pots 300a and the second cooling pots 300b in the cooling unit <NUM>, the preforms <NUM> are cooled. At this time, in the first cooling pots 300a and the second cooling pots 300b, the preforms <NUM> are sucked and held by air suction, and the gate portions <NUM> are further removed. The gate portions <NUM> are removed twice, that is, in the cooling pots <NUM> of the receiving unit <NUM> and the first cooling pots 300a or the second cooling pots 300b of the cooling unit <NUM>, so that the gate portions <NUM> of the preforms <NUM> can be removed with higher accuracy.

Furthermore, in the present embodiment, for example, the N preforms <NUM> in the upright state, injection-molded in the m-th cycle are held by the first cooling pots 300a, then inverted by the inverting unit <NUM>, and cooled in the inverted state. During this period, the N preforms <NUM> in the upright state, injection-molded in a cycle following the m-th cycle (m + <NUM>-th cycle) are held and cooled in the second cooling pots 300b. In short, the cooling unit <NUM> can simultaneously cool the preforms <NUM> in different cycles on the first surface 121a and the second surface 121b.

As described above, the cooling unit <NUM> can forcibly cool the preforms <NUM> for a time equal to or longer than the cycle time of injection molding when the injection molding unit <NUM> injection-molds the N preforms <NUM>.

Since the preforms <NUM> forcibly cooled in the cooling unit <NUM> do not need to be cooled to a room temperature and the preforms <NUM> have heat from injection molding, it is possible in the present embodiment as well to share advantages of energy efficiency in the one stage method.

Although the N preforms <NUM> immediately before heating have residual heat from injection molding, clear temperature differences may occur among the cycles of blow molding described later, depending on natural cooling time due to time differences among the cycles of blow molding. The forced cooling in the cooling unit <NUM> is effective, when the N preforms <NUM> simultaneously injection-molded are heated at different heating start timings, in suppressing temperature differences of the preforms <NUM> immediately before heating in each cycle of blow molding.

(<NUM>) The preforms <NUM> in the inverted state are continuously conveyed along the conveying line <NUM> of the continuous conveying unit <NUM> and pass through the heating unit <NUM>. As a result, the preforms <NUM> are subjected to temperature equalization and removal of uneven temperature, and heated to an appropriate stretching temperature.

Here, the N preforms <NUM> simultaneously injection-molded in the m-th cycle are blow-molded a plurality of times (three times) by M preforms <NUM>. Therefore, a line indicating temperature changes in <FIG> is different for each blow molding cycle. In other words, in <FIG>, the temperature changes of the preforms until carried into the continuous conveying unit <NUM> are common regardless of the blow molding cycle. However, the temperature changes of the preforms from heating to blow molding are indicated by three lines having time differences according to the cycles of blow molding.

Thus, a series of processes of the blow molding method is completed.

Hereinafter, effects of the present embodiment will be described.

According to the present embodiment, air between the accommodating spaces <NUM> of the cooling pots <NUM> for cooling the preforms <NUM> and the preforms <NUM> is sucked, and the gate portions <NUM> of the preforms <NUM> are collapsed on the surface of the bottom regions 301a of the accommodating spaces <NUM>. As a result, since shapes of the bottom portions <NUM> of the preforms <NUM> become curved surfaces following the bottom regions 301a of the accommodating spaces <NUM>, the gate portions <NUM> can be removed from the bottom portions <NUM> of the preforms <NUM> with high accuracy, and an aesthetic appearance of containers to be manufactured can be improved.

In addition, the removal of the gate portions <NUM> is carried out simultaneously when the preforms <NUM> are accommodated in the cooling pots <NUM>, using the process of cooling the injection-molded preforms <NUM>. Therefore, in the present embodiment, since it is not necessary to newly add a process of cutting off the gate portions <NUM> of the preforms <NUM>, molding cycle time of containers is not extended by the removal of the gate portions <NUM>.

Further, in the removal of the gate portions <NUM> described above, the gate portions <NUM> are collapsed and integrated with the bottom portions <NUM> of the preforms, so that fragments are not produced with the removal of the gate portions <NUM>. Therefore, discarding or regenerating the fragments of the gate portions <NUM> is not necessary, thereby reducing costs associated with manufacturing containers.

Furthermore, the removal of the gate portions <NUM> can be performed twice, that is, in the cooling pots <NUM> of the receiving unit <NUM> and the first cooling pots 300a or the second cooling pots 300b in the cooling unit <NUM>. As described above, by removing the gate portions <NUM> twice, the gate portions <NUM> can be removed from the bottom portions <NUM> of the preforms <NUM> with higher accuracy.

The present invention is not limited to the above embodiment, and various improvements and design changes may be made without departing from the scope of the appended claims.

For example, in the above embodiment, the example in which the cooling pots <NUM> of the present invention are disposed in the receiving unit <NUM> and the cooling unit <NUM> has been described, but the cooling pots of the present invention may be disposed in only either one thereof.

In the above embodiment, as an example, the configuration in which the cooling pots <NUM> are applied to the blow molding apparatus in the <NUM> step method has been described. However, the cooling pots <NUM> according to the present embodiment may be applied to an injection molding machine without a blow molding unit to remove the gate portions.

<FIG> is a diagram schematically illustrating a configuration of an injection molding apparatus <NUM>. The injection molding apparatus <NUM> in <FIG> is a apparatus used for manufacturing the preforms <NUM> at a high speed. The injection molding apparatus <NUM> includes an injection molding unit <NUM>, a post-cooling unit <NUM>, a taking-out unit <NUM>, and a rotating plate <NUM> as a conveying mechanism.

The injection molding unit <NUM>, the post-cooling unit <NUM>, and the taking-out unit <NUM> are disposed at positions rotated by a predetermined angle (for example, <NUM> degrees) in a circumferential direction of the rotating plate <NUM>. In the injection molding apparatus <NUM>, rotation of the rotating plate <NUM> conveys the preforms <NUM> having the neck portions held by the rotating plate <NUM> to the injection molding unit <NUM>, the post-cooling unit <NUM>, and the taking-out unit <NUM> in this order.

The injection molding unit <NUM> includes injection cavity molds and injection core molds (both not illustrated), and manufactures the preforms <NUM> by injection molding. An injection device <NUM> that supplies a resin material, which is a raw material of the preforms <NUM>, is connected to the injection molding unit <NUM>.

The post-cooling unit <NUM> can provide cooling in a short time to such an extent that the preforms <NUM> can be discharged in a cured state by the taking-out unit <NUM>. The post-cooling unit <NUM> includes the above-described cooling pots <NUM>, accommodates the preforms <NUM> in the cooling pots <NUM> by suction of air, and simultaneously performs cooling and removal of the gates.

The removing unit <NUM> releases the neck portions of the preforms <NUM> from the rotating plate <NUM> and takes out the preforms <NUM> to outside of the injection molding apparatus <NUM>.

In the injection molding apparatus <NUM>, the post-cooling unit <NUM> is provided on a downstream side of the injection molding unit <NUM>, so that the post-cooling unit <NUM> can additionally cool the preforms <NUM>. Additional cooling of the preforms <NUM> in the post-cooling unit <NUM> can release the preforms <NUM> even in a high temperature state in the injection molding unit <NUM>, and significantly shorten the cooldown time of the preforms <NUM> in the injection molding unit <NUM>. As a result, since molding of the subsequent preforms <NUM> can be started early, molding cycle time of the preforms <NUM> in the injection molding apparatus <NUM> can be shortened.

Furthermore, in the post-cooling unit <NUM> of the injection molding apparatus <NUM>, the gate portions can be satisfactorily removed from the preforms <NUM> by using the cooling pots <NUM> described above.

In the above embodiment, the example in which the air sucking holes <NUM> of each of the cooling pots <NUM> are disposed rotationally symmetrically has been described, but the disposition of the air sucking holes <NUM> is not limited to the above. For example, in the two or more air sucking holes <NUM>, radial distances of the air sucking holes <NUM> from a central axis may be different. For example, in the bottom surface region 301a of the cooling pot <NUM>, the two or more air sucking holes <NUM> may be provided on the inner peripheral surface in a predetermined range extending in a vertical direction away from a center (the central axis of the cooling pot <NUM>) which the gate portion <NUM> of each of the preforms <NUM> abuts.

Claim 1:
A cooling mold (<NUM>) for cooling a resin preform (<NUM>) that has a gate portion (<NUM>) protruding outward from a center of a bottom portion (<NUM>), wherein
an accommodating space (<NUM>) that accommodates the preform (<NUM>) is formed in the cooling mold (<NUM>),
a bottom region (301a) facing the bottom portion (<NUM>) of the preform (<NUM>) in the accommodating space (<NUM>) has a shape following the bottom portion (<NUM>) of the preform (<NUM>), and
an air sucking hole (<NUM>) that sucks air is formed in the bottom region (301a) at a position shifted from the center of the bottom portion (<NUM>) of the preform (<NUM>),
such that there is no air sucking hole (<NUM>) at a position facing the gate portion (<NUM>) of the preform (<NUM>) in the cooling mold (<NUM>) and a surface of the bottom region (301a) following the outer shape of the bottom portion (<NUM>) of the preform (<NUM>) faces the gate portion (<NUM>),
such that the cooling mold (<NUM>) is adapted for:
sucking air from the air sucking holes (<NUM>) of the cooling mold (<NUM>) and drawing the preform (<NUM>) into the accommodating space (<NUM>); and
collapsing the gate portion (<NUM>) in the bottom region (301a) to remove the gate portion (<NUM>).