Temperature control apparatus for preform, temperature control method for preform, resin container and method for producing resin container

Abstract

The outer circumferential surface of a bottom 4 of a preform 1 and a lower site 3a of a trunk 3 continuous with the bottom 4 is mechanically brought into intimate contact with a cooling pot 16 to undergo reliable cooling. The trunk 3, excluding the lower site 3a of the trunk 3 continuous with the bottom 4, is heated to a predetermined temperature by a heating block 17. When blow-molded, the so treated preform 1 can provide a container having a bottom of a desired thickness and having a uniformly stretched thin-walled trunk.

Claims

1. A blow molding method for a resin container, comprising: an injection molding step of forming a bottomed preform having a mouth/head, a bottom, and a trunk continuous with the bottom, and having a wall thickness of the bottom increased relative to a wall thickness of the trunk; a temperature control step of cooling an outer surface and an inner surface of the bottom of the bottomed preform and a lower site of the trunk continuous with the bottom, and simultaneously heating a site of the trunk of the bottomed preform, excluding the lower site of the trunk, to a predetermined temperature; and a blow molding step of stretching the bottomed preform, which has been temperature-controlled in the temperature control step, such that a longitudinal axis length of the bottomed preform does not change substantially, thereby forming the resin container.

2. The blow molding method for a resin container according to claim 1, wherein in the temperature control step, the bottomed preform is disposed within a temperature control pot, with the mouth/head being held by a neck mold provided on a rotary table, cooling of the outer surface of the bottom and the lower site of the trunk is performed by a cooling pot which is provided below the bottom so as to be raised and lowered and which is located in a lowermost part of the temperature control pot, cooling of the inner surface of the bottom and the lower site of the trunk is performed by a cooling core which is provided above the mouth/head so as to be raised and lowered and which is inserted into the bottomed preform through the mouth/head, and heating of the site of the trunk of the bottomed preform, excluding the lower site of the trunk, is performed by a heating block located above the cooling pot in the temperature control pot.

3. The blow molding method for a resin container according to claim 2, wherein in the temperature control step, the bottom and the lower site of the trunk in the bottomed preform are disposed between the cooling pot and the cooling core, and the bottom and the lower site of the trunk in the bottomed preform are cooled, with the cooling core being lowered to contact an inner surface of the bottom and the lower site of the trunk in the bottomed preform.

4. The blow molding method for a resin container according to claim 3, wherein in the temperature control step, the bottom and the lower site of the trunk in the bottomed preform are cooled, with the cooling pot being separated from an outer surface of the bottom and the lower site of the trunk in the bottomed preform.

5. The blow molding method for a resin container according to claim 4, wherein in the temperature control step, the cooling pot is raised to become close to the outer surface of the bottom and the lower site of the trunk in the bottomed preform, and thereafter the cooling core is lowered to contact the inner surface of the bottom and the lower site of the trunk in the bottomed preform.

6. The blow molding method for a resin container according to claim 4, wherein in the temperature control step, the cooling pot is raised to contact the outer surface of the bottom and the lower site of the trunk in the bottomed preform, and then the cooling pot is lowered to be separated from the outer surface of the bottom and the lower site of the trunk in the bottomed preform, with the cooling core being lowered to contact the inner surface of the bottom and the lower site of the trunk in the bottomed preform.

7. The blow molding method for a resin container according to claim 3, wherein in the temperature control step, the bottom and the lower site of the trunk in the bottomed preform are cooled, with the cooling pot being in contact with the outer surface of the bottom and the lower site of the trunk in the bottomed preform.

8. The blow molding method for a resin container according to claim 7, wherein in the temperature control step, the bottom and the lower site of the trunk in the bottomed preform are cooled, with the bottom and the lower site of the trunk in the bottomed preform being held between the cooling pot and the cooling core, and with the bottom and the lower site of the trunk in the bottomed preform being slightly increased in diameter in imitation of a shape of an inner wall surface of the cooling pot.

9. The blow molding method for a resin container according to claim 7, wherein in the temperature control step, the cooling pot is raised to contact the outer surface of the bottom and the lower site of the trunk in the bottomed preform, and thereafter the cooling core is lowered to contact the inner surface of the bottom and the lower site of the trunk in the bottomed preform.

10. The blow molding method for a resin container according to claim 8, wherein in the temperature control step, the cooling core is lowered to contact the inner surface of the bottom and the lower site of the trunk in the bottomed preform, and thereafter the cooling pot is raised to contact the outer surface of the bottom and the lower site of the trunk in the bottomed preform, and at least one of the cooling core and the cooling pot is moved toward the other of them.

11. The blow molding method for a resin container according to claim 2, wherein in the temperature control step, temperature control of the bottomed preform is exercised, with the cooling pot and the cooling core being controlled beforehand to a predetermined temperature necessary for the cooling, and with the heating block being controlled beforehand to a predetermined temperature necessary for the heating.

12. The blow molding method for a resin container according to claim 1, wherein in the injection molding step, the bottomed preform is formed using polyethylene terephthalate so that the wall thickness of the trunk is 2.5 to 5.0 mm, and the wall thickness of the bottom is 2.5 to 15.0 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a sectional view representing the appearance of an injection molded preform.

(2) FIG. 2 is a sectional view of a temperature control apparatus according to an embodiment of the present invention.

(3) FIG. 3 is an appearance drawing of a temperature control pot.

(4) FIG. 4 is an appearance drawing of a temperature control core.

(5) FIGS. 5(a) to 5(c) are a process chart of temperature control actions.

(6) FIGS. 6(a), 6(b) are sectional views of the preform and a container.

(7) FIG. 7 is an appearance drawing of the container.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

(8) Mode for Carrying Out the Invention

(9) A temperature control apparatus for a preform will now be described based on FIGS. 1 to 4.

(10) FIG. 1 shows a section representing the appearance of an injection molded preform. FIG. 2 shows a section of a temperature control apparatus according to an embodiment of the present invention. FIG. 3 shows the appearance of a temperature control pot equipped with a cooling pot and a heating block. FIG. 4 shows the appearance of a temperature control core.

(11) The temperature control apparatus for a preform according to the present invention is an apparatus for adjusting the temperature of a resin-made bottomed preform and the wall thickness of its bottom to a desired state, the preform having been injection molded. The preform adjusted to the desired temperature and wall thickness is blow-molded to form a container. In order that a container having a peripheral portion (trunk) free from a uneven wall thickness distribution, having a bottom locally increased in wall thickness, and having the degree of transparency and the degree of gloss maintained in a uniform state is obtained by blow molding, the temperature and wall thickness of the preform are adjusted by the temperature control apparatus of the present invention. The resulting container is used, for example, as a container for a cosmetic or the like, which has an aesthetic appearance fitting consumers' image of containers and whose look is important.

(12) A device for producing a container from a preform is equipped with at least an injection molding device for injection molding a bottomed preform; a temperature control apparatus for adjusting the temperature and wall thickness of the injection-molded bottomed preform to a desired state; and a blow molding device for blow molding the temperature-controlled bottomed preform to form a hollow container. The bottomed preform is sequentially transported to the injection molding device, the temperature control apparatus, and the blow molding device, for example, by a neck mold of a rotary table rotatably held on the blow molding device.

(13) With the injection molding device, a bottomed preform (preform) 1 as shown in FIG. 1 is injection-molded. The preform 1 has a mouth/head 2 having a thread groove formed therein, a trunk 3 disposed below the mouth/head 2, and a bottom 4 which becomes a bottom surface portion of a hollow container after blow molding. That is, the preform 1 has the trunk 3 disposed as a peripheral portion continuous with the bottom 4. In the preform 1, relative to the wall thickness t1 of the trunk 3, the wall thickness t2 of the bottom 4 is rendered equal to or larger than the wall thickness t1 of the trunk 3. In an embodiment, t1 is set at 2.5 mm to 5.0 mm, t2 is set at 2.5 mm to 15.0 mm, and t2/t1=1 to 3. The injection-molded preform 1 is supplied to the temperature control apparatus.

(14) The temperature control apparatus will be described based on FIGS. 2 to 4.

(15) As shown in FIG. 2, the preform 1 has the mouth/head 2 held by a neck mold 7 provided on a rotary table 6, and is supplied in this state to a temperature control apparatus 11. The temperature control apparatus 11 is equipped with a temperature control pot 12 surrounding an outside part of the preform 1, and a temperature control core 13 inserted into an inside part of the preform 1.

(16) As shown in FIGS. 2 and 3, a plurality of the temperature control pots 12 as a set are fixed to a pot base 15. The temperature control pot 12 is composed of a cooling pot 16, as a temperature control pot, and two heating blocks 17, as temperature control blocks, which are integrated via a coupling stand 18 and fixed to the pot base 15.

(17) The cooling pot 16 has an inner wall surface 16a holding an outer circumferential surface portion of the bottom 4 of the preform 1 and a lower site (a part of a peripheral portion) 3a of the trunk 3 continuous with the bottom 4. The heating block 17 has an inner wall surface 17a opposed in a noncontact manner to the outer circumferential surface of a site of the trunk 3 of the preform 1, except the lower site 3a. In the drawings, two of the heating blocks 17 stacked are illustrated, but there may be the single heating block 17 or a stack of three of the heating blocks 17. Each heating block can be independently temperature-controlled and, for example, its temperature can be set, as appropriate, in the range of 100 to 450 C. Similarly, the temperature of the cooling pot 16 can be controlled, for example, in the range of 10 to 90 C.

(18) The pot base 15 is furnished with a raising/lowering device 19 as a pressing drive means, and a plurality of the temperature control pots 12 are raised or lowered by the raising/lowering device 19 via the pot base 15.

(19) As shown in FIGS. 2 and 4, a plurality of the temperature control cores 13 provided as a set are fixed to a core base 21. The temperature control core 13 has a core 22 to be inserted into the preform 1, and the leading end site of the core 22 constitutes a cooling core portion 23 as a leading end part which contacts and holds an inner circumferential surface portion of the bottom 4 of the preform 1 and the lower site 3a of the trunk 3 continuous with the bottom 4. In the core 22, the diameter of the cooling core portion 23 as the leading end part is large, and the site other than the cooling core portion 23 is inserted into the preform 1 without contacting the inner wall surface of the trunk 3.

(20) If the site other than the cooling core portion 23 (i.e., core 22) makes no contact, a uniform temperature distribution can be imparted (in a sectional direction) to the trunk of the preform 1. Thus, satisfactory results are obtained by molding which enables the trunk of a container to be equally stretched (in the sectional direction) (for example, for formation of a circular container). In the case of the trunk of a container of a quadrilateral shape or the like having corners (as a sectional shape), however, the trunk is evenly stretched in the absence of contact. Thus, the cornered parts are necessarily subjected to a high stretch ratio, and tend to be thin-walled. In this case, the core 22 is brought into substantial contact with the portions of the preform 1 having a high stretch ratio (the portions corresponding to the corners) (the substantial contact including the state of approach to a degree to which the core 22 is deemed to contact), thereby lowering the temperature of those portions. By so doing, the corners of the container can be inhibited from becoming thin-walled. This is because stretching begins in the noncontact portion with higher residual heat, and stretching minimally takes place at the contact portion decreased in residual heat. In producing a quadrilateral container, for example, a quadrilateral core 22 is used, and substantially contacted with the portions of the preform 1 which will become the corners of the resulting container. By this measure, a quadrilateral container having sufficient wall thickness at the corners can be produced.

(21) Inside the temperature control core 13, a circuit for flowing a temperature control medium such as water or an oil is provided (not shown), and the temperature can be set, for example, in the range of 10 to 90 C.

(22) The core base 21 is equipped with a raising/lowering device as a pressing drive means (not shown), and a plurality of the temperature control cores 13 are raised or lowered by the raising/lowering device via the core base 21.

(23) Since the preform 1 is supplied to the temperature control pot 12, the outer circumferential surface of the bottom 4 and the lower site 3a of the trunk 3 continuous with the bottom 4 becomes holdable by the inner wall surface 16a of the cooling pot 16 (a waiting state). Also, the temperature control core 13 is inserted into the preform 1, whereupon the inner circumferential surface of the bottom 4 and the lower site 3a of the trunk 3 continuous with the bottom 4 becomes holdable by the cooling core portion 23.

(24) By the action of the raising/lowering device 19 of the pot base 15 and the raising/lowering device of the core base 21 (or one of these raising/lowering devices), the temperature control pot 12 and the temperature control core 13 are brought close to each other, whereby the bottom 4 of the preform 1 and the lower site 3a of the trunk 3 continuous with the bottom 4, disposed between the temperature control pot 12 and the temperature control core 13, are brought into intimate contact with, and held by, the inner wall surface of the temperature control pot 12 (or both of the inner wall surface of the temperature control pot 12 and the leading end part of the temperature control core 13).

(25) In this state, the bottom 4 of the preform 1 and the lower site 3a of the trunk 3 continuous with the bottom 4 (i.e., the bottom wall surface) contact the inner wall surface 16a of the cooling pot 16 (or both the inner wall surface 16a of the cooling pot 16 and the cooling core portion 23 of the core 22), and get cooled thereby. Simultaneously, portions of the trunk 3, other than the bottom 4 of the preform 1 and the lower site 3a of the trunk 3 continuous with the bottom 4, are heated in a noncontact manner by the inner wall surfaces 17a of the heating blocks 17 (or between the inner wall surfaces 17a of the heating blocks 17 and sites of the core 22 other than the cooling core portion 23). When the preform 1 and the site other than the cooling core portion 23 (i.e., core 22) are partly contacted, the area of contact of the inner circumferential surface of the preform 1 is cooled and, at the same time, the outer circumferential surface of the preform 1 is heated in a noncontact manner. Furthermore, the bottom 4 of the preform 1 and the lower site 3a of the trunk 3 continuous with the bottom 4 can be mechanically pressed between the inner wall surface 16a of the cooling pot 16 and the cooling core portion 23, and thereby compressed and deformed into a shape more similar to the bottom of the final container. In this case, the material on the part of the bottom 4 is partially flowed to the trunk 3. By adjusting the bottom 4 of the preform 1 and the lower site 3a of the trunk 3 continuous with the bottom 4 to a wall thickness distribution and a shape closer to those of the final container, it becomes possible to impart the bottom shape of the final container which cannot be attained merely by cooling upon intimate contact.

(26) By the above procedure, the temperature of the preform 1 and the shape (wall thickness) of the bottom are adjusted to a desired state. For example, cooling can be performed, with the wall thickness of portions of the preform 1 in the neighborhood of the bottom 4 being secured. Also, heating can be performed, with the wall thickness of the trunk of the preform 1 being relatively decreased. By so doing, stretchability during blow molding in a subsequent step is ensured. By adjusting the temperature and wall thickness of the preform 1 to the desired state, a container thick-walled at the bottom, having a proper wall thickness distribution in the peripheral portion (trunk), and uniform in the degree of transparency and the degree of gloss is obtained by blow molding. The resulting container can be used, for example, as a container for a cosmetic or the like, which has an aesthetic appearance fitting consumers' image of containers and whose look is important.

(27) By using the temperature control apparatus 11 of the present invention, an appropriate temperature distribution and an appropriate shape (wall thickness) change can be provided to the preform 1 which is required to yield a container improved in look.

(28) Based on FIGS. 5(a) to 5(c) to FIG. 7, the actions of the temperature control apparatus 11 of the above-mentioned configuration will be described to explain the temperature control method for a preform according to the present invention.

(29) FIG. 5(a) shows a section of a state in which the preform 1 is supplied to the temperature control pot 12 (i.e., a waiting state). FIG. 5(b) shows a section of a state in which the wall surface of the bottom of the preform 1 is intimately contacted with the cooling pot 16 and cooled thereby. FIG. 5(c) shows a section of a state in which the bottom 4 of the preform 1 is pressed and held between the cooling pot 16 of the temperature control pot 12 and the cooling core portion 23 of the temperature control core 13. FIG. 6(a) shows a section of the preform 1 temperature-controlled to a desired state, while FIG. 6(b) shows a section of a container after blow molding. FIG. 7 shows the appearance status of the container.

(30) The cooling pot 16 of the temperature control pot 12 is adjusted to a necessary temperature for predetermined cooling, whereas the heating block 17 is adjusted to a necessary temperature for predetermined heating. Moreover, the cooling core portion 23 of the temperature control core 13 is adjusted to a necessary temperature for predetermined cooling.

(31) As shown in FIG. 5(a), a plurality of the temperature control pots 12 are positioned at predetermined positions (caused to wait) by the raising/lowering device 19 via the pot base 15. Then, the temperature control pot 12 is raised by a desired height (M) (FIG. 5(b)) so that the bottom 4 of the preform 1 and the lower site 3a of the trunk 3 continuous with the bottom 4 can intimately contact the inner wall surface 16a of the cooling pot 16. In this state, the bottom 4 of the preform 1 and a part of the peripheral portion 3 continuous with the bottom 4 are slightly increased in diameter while following the shape of the inner wall surface 16a of the cooling pot 16. Thus, their lengths become somewhat shorter, and the thickness of the bottom 4 is slightly decreased relative to FIG. 5(a). At this time, the inner wall surfaces 17a of the heating blocks 17 are opposed, in a noncontact manner, to the outer circumferential surface of a site of the trunk 3 of the preform 1, excluding the lower site 3a. By the actions and method described above, the bottom 4 and the part of the peripheral portion 3 continuous with the bottom 4 are cooled overall and rendered lower in temperature than the trunk 3. As a result, the wall thickness of the resin can easily remain in the bottom of the container after blowing.

(32) Furthermore, the temperature control core 13 is lowered via the pressing drive means of the core base 21, whereby the core 22 can be inserted into the preform 1. At this time, the lower-limit position of the cooling core portion 23 serving as the leading end of the temperature control core 13 is defined as the position where the cooling core portion 23 can lightly contact the inner circumferential surface of the bottom 4 of the preform 1 and the lower site 3a of the trunk 3 continuous with the bottom 4. The shapes of the bottom 4 of the preform 1 and the part of the peripheral portion 3 continuous with the bottom 4 remain substantially unchanged, from the point in time of FIG. 5(b) onwards. Because of the above-described actions and method, it becomes possible to cool the bottom 4 of the preform 1 and the part of the peripheral portion 3 continuous with the bottom 4 from inside and outside simultaneously, while maintaining their wall thicknesses. By this procedure, whitening of the bottom 4 due to slow cooling can be considerably suppressed. The front end shape of the cooling core portion 23 is desirably flat rather than pointed, so that the area of contact with the inner surface of the bottom 4 of the preform 1 is increased to raise the efficiency of cooling.

(33) If the bottom of the container is to be formed with a larger wall thickness, it is desirable to keep the bottom 4 of the preform 1 and the cooling pot 16 in disjunction at a point in time at which the temperature control core 13 is lowered. As will be seen from FIGS. 6(a) and 6(b), there is little difference in the longitudinal-axis length between the preform 1 after temperature control (FIG. 6(a)) and the container 25 after blow molding (FIG. 6(b)). That is, longitudinal-axis stretching minimally takes place in blow molding. Thus, the shape of the bottom 26 of the final container 25 tends to be similar to the shape of the bottom 4 of the preform 1 (and the part of the peripheral portion 3 continuous with the bottom 4) after temperature control. If the cooling core portion 23 is inserted into the preform 1 without descent of the cooling pot 16, there is a possibility that the bottom 4 will be pressed and collapsed. As a result, the bottom 4, the part of contact with the cooling core portion 23, will be thin-walled, or the shape of the cooling core portion 23 will remain as a mark on the inner surface of the bottom 4.

(34) From the viewpoint of positively deforming the bottom 4 into a shape resembling the shape of the bottom of the final container at the stage of temperature control, however, it can be said that the pressing of the bottom 4 by the cooling pot 16 and the cooling core portion 23 is a method worth utilizing. In FIG. 5(c), such a method is illustrated. It should be noted, however, that the thickness of the bottom of the final container will be smaller than in the method of FIG. 5(b).

(35) The temperature control pot 12 and the temperature control core 13 are brought closer to each other than in FIG. 5(b). As a result, the inner circumferential surface of the bottom 4 of the preform 1 and the lower site 3a of the trunk 3 continuous with the bottom 4 is pressed against the cooling core portion 23 of the core 22. Also, the outer circumferential surface of the bottom 4 of the preform 1 and the lower site 3a of the trunk 3 continuous with the bottom 4 is pressed against the inner wall surface 16a of the cooling pot 16.

(36) That is, the bottom 4 of the preform 1 and the lower site 3a of the trunk 3 continuous with the bottom 4 are mechanically compressed and held between the temperature control pot 12 and the temperature control core 13.

(37) Consequently, the material of the thick-walled bottom 4 of the preform 1 flows toward the lower site 3a of the trunk 3 continuous with the bottom 4 to cause deformation. As a result, the inner circumferential surface of the bottom 4 and the lower site 3a of the trunk 3 continuous with the bottom 4 reliably makes intimate contact with the cooling core portion 23 of the core 22. On the other hand, the outer circumferential surface of the bottom 4 and the lower site 3a of the trunk 3 continuous with the bottom 4 is pressed by the inner wall surface 16a of the cooling pot 16 and reliably brought into intimate contact therewith.

(38) By performing the above-described pressing of the preform bottom, therefore, the wall thickness of the lower site 3a of the trunk 3 continuous with the bottom 4 is sufficiently ensured, and the inner circumferential surface and the outer circumferential surface of the bottom 4 and the lower site 3a of the trunk 3 continuous with the bottom 4 are simultaneously contacted with and cooled by the inner wall surface 16a of the cooling pot 16 and the cooling core portion 23, with the inner and outer circumferential surfaces maintaining the desired shape (a shape resembling the bottom shape of the final container).

(39) At the same time, the site 3b of the trunk 3, which is other than the bottom 4 of the preform 1 and the lower site 3a of the trunk 3 continuous with the bottom 4, is heated in a noncontact manner between the inner wall surfaces 17a of the heating blocks 17 and the core 22 at the site other than the cooling core portion 23. Under these conditions, an insufficiency of the necessary internal heat quantity for blow molding can be avoided within the range of the peripheral portion and the bottom to be blow-molded.

(40) In the manner described above, the bottom 4 of the preform 1 is cooled, the lower site 3a of the trunk 3 continuous with the bottom 4 is cooled, and the site 3b of the trunk 3 other than the lower site 3a of the trunk 3 is heated in a stretchable state, whereby the temperature and shape of the preform 1 (a shape resembling the bottom shape of the final container) are adjusted to the desired state.

(41) For example, cooling is performed, with the wall thicknesses at sites near the bottom 4 of the preform 1 and the lower site 3a of the trunk 3 continuous with the bottom 4 being ensured. Thus, during blow molding in the subsequent step, their shape is to be ensured. On the other hand, the wall thickness of the site 3b of the trunk 3 of the preform 1 is rendered relatively small. In this state, the site 3b can be heated such that it is uniformly stretchable during blow molding in the subsequent step.

(42) What temperature distribution should be imparted to the preform 1 by the temperature control apparatus 11 and the temperature control method described above is changed according to the shape or weight of the preform 1, the state of a temperature distribution present since injection molding, the shape of the final container, the required standard values, etc. In the embodiment, the temperature control pot 12 is initially raised, but this is not limitative, if the temperature control pot 12 and the temperature control core 13 are used in combination. Concretely, the length of the temperature control time, and which of the temperature control core 13 and the temperature control pot 12 should be separated first from the preform 1 (which of the cooling time and the heating time should be made longer) may be changed, as appropriate, in order to impart an appropriate temperature distribution to the preform 1.

(43) The preform 1 adjusted to a predetermined shape (wall thickness) and a predetermined temperature by the temperature control apparatus 11 is biaxially stretched by blow molding. As shown in FIG. 6(b), the preform 1 is molded into a container (resin container) in which the wall thicknesses of the bottom 4 and the lower site 3a of the trunk 3 continuous with the bottom 4, cooled in the desired state, have been maintained; the site 3b of the trunk 3 of the preform 1, heated to ensure stretchability, has been stretched uniformly with a relatively thin wall; and the degree of transparency and the degree of gloss have been maintained uniform, without an uneven wall thickness distribution in the bottom or the trunk. In order to shape the thick-walled bottom 26 satisfactorily, it is desirable to carry out a molding method for intentionally delaying the driving of a bottom mold at the time of biaxial stretching, a so-called raised bottom delay molding method. Since this method has been made publicly known, for example, by the applicant's Japanese Patent Gazette (Japanese Patent No. 2107926), its detailed explanations is omitted herein.

(44) As shown in FIG. 7, the blow-molded container 25 is the container 25 which has the strength of its bottom 26 sufficiently ensured, which is free from a wall thickness distribution in its peripheral portion (trunk) 27, and whose degree of transparency and degree of gloss are kept uniform. The container 25 can be used, for example, as a container for cosmetics, etc. whose look matters.

(45) According to the temperature control method for a preform using the above-described temperature control apparatus 11, therefore, it is possible to obtain a container 25 improved in look. It is also possible to obtain a resin container in which a thick-walled bottom and a thin-walled uniform-thickness trunk are adjacent. In addition, it becomes possible to provide a method for producing a resin container, the method being capable of yielding a resin container which has been prepared using a preform temperature-controlled by the temperature control method for a preform and whose look has been improved.

(46) Examples of the resin usable in the present apparatus and method are polyethylene terephthalate (PET) and polypropylene (PP).

INDUSTRIAL APPLICABILITY

(47) The present invention can be utilized in the industrial fields of a temperature control apparatus for a preform and a temperature control method for a preform, which apparatus and method control the temperature of an injection molded preform. The present invention can also be utilized in the industrial fields of a resin container, and a method for producing a resin container.

EXPLANATIONS OF LETTERS OR NUMERALS

(48) 1 Bottomed preform (preform)

(49) 2 Mouth/head

(50) 3 Peripheral portion (trunk)

(51) 4 Bottom

(52) 6 Rotary table

(53) 7 Neck mold

(54) 11 Temperature control apparatus

(55) 12 Temperature control pot

(56) 13 Temperature control core

(57) 15 Pot base

(58) 16 Cooling pot

(59) 17 Heating block

(60) 18 Coupling stand

(61) 19 Pressing drive means (raising/lowering device)

(62) 21 Pressing drive means (core base)

(63) 22 Core

(64) 23 Leading end portion (cooling core portion)

(65) 25 Container (final container)

(66) 26 Bottom

(67) 27 Peripheral portion (trunk).

(68) Although only some embodiments of the present invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within scope of this invention.