JP4656567B2 - Preliminary temperature control die used for preliminary temperature control in blow molding molding process - Google Patents

Description

The present invention requires a wall thickness in the circumferential direction, such as making the wall thickness in the circumferential direction of the hollow molded product uniform, or making the desired range in the circumferential direction different from others. pre備温tone mold about that used in the manufacturing method of manufacturing by blow molding the modified or adjusted hollow molded article according. More specifically, the present invention relates to a thickness adjusting method or a thickness adjusting technique capable of freely adjusting the thickness in the circumferential direction of a hollow molded product in blow molding.

  Conventional blow molding methods include the cold parison method in which parison formation is completely separated from blow molding and the cooled and solidified parison is heated and temperature-controlled before blow molding, and temperature control is continued following parison formation and blow molding is continued. The hot parison method is known.

  In the hot parison method, replace the preform (bottomed parison) in the injection mold with a temperature control pot while keeping the temperature high, and blow the air into the preform to make the outer surface of the preform the cavity of the temperature control pot. It has been proposed to adjust the cooling temperature by bringing it into close contact with the inner wall surface constituting the material to shorten the cooling time (see, for example, Patent Document 1). At that time, in order to partially cool the preform to be cooled by the temperature control pot, a part contacting the application part by partially applying a heat insulating paint to the inner wall surface of the temperature control pot In this patent document, it has been proposed that the cooling should be made weaker than the part that contacts the part other than the application part.

  In addition, the inner wall surface constituting the cavity of the temperature control pot is partially made large in diameter with respect to the vertical direction of the preform or conversely made small in diameter, and air is blown into the preform placed in the temperature control pot. It is also proposed in Patent Document 2 that the preform before blow molding is partially thinned or thickened by bringing it into close contact with the inner wall surface.

  Furthermore, the present applicant uses the cold parison method to heat and regulate the preform (cold parison) after cooling and solidification, in particular, in order to achieve uniform wall thickness in the circumferential direction of the flat bottle. Patent Document 3 proposes heating the portion of the flat shape that extends in the minor axis direction to a higher temperature than the portion that extends in the major axis direction.

JP-A-57-103821 JP 59-115816 A JP 2000-127230 A

  By the way, the injection molded preform or the extrusion molded parison has a circular cross section. Therefore, when a flat bottle (a cross section in the plane direction is oval, elliptical, or rectangular) is formed by blow molding, the flat shape is flat. The blow ratio (expansion ratio) differs between the minor axis direction and the major axis direction of the shape, and the blow ratio in the major axis direction is larger than the minor axis direction. As a result, the wall thickness of the major axis side part after blow molding is The wall thickness of the thin and short diameter side portion becomes thick, resulting in uneven thickness. Such uneven thickness hinders weight reduction, loss of material consumption, insufficient strength of the long diameter side portion, or deterioration of squeeze performance particularly in the case of eye drops bottles. There is a demand for uniform thickness. In particular, there is an extremely strong demand for uniformization in flat bottles having a major axis / minor axis ratio of 1.6 to more than 4.

  Alternatively, when a circular cross-section bottle is manufactured by blow molding using the above-mentioned circular cross-section preform or parison, the wall thickness in the circumferential direction should normally be uniform. Depending on the form of use, purpose of use, etc., there may be a request from the bottle designer at the manufacturing site that the wall thickness of a specific part in the circumferential direction should be intentionally made thicker than other parts.

  However, in response to these demands, even if the above-described conventional method is used, the following disadvantages are caused. In other words, considering the application of the proposed technique in Patent Document 1, the partial formation of a heat insulating layer on the inner wall surface of the temperature control pot means that the outer surface of the preform is partially cooled due to the presence of the heat insulating layer. Cooling that is the original purpose because it is necessary to wait until the part that is difficult to be cooled is cooled to the minimum that it can be released from the mold. It becomes impossible to shorten the time. Or, there is an extreme difference in thermal conductivity between the heat-insulating layer formed by application of the heat-insulating paint and the temperature control pod that is a metal mold, so that it is cooled to the extent that it can be released. In order to secure the function that the temperature control pot should perform, the above heat insulating layer must be made extremely thin. When the heat insulating layer is set to an extremely thin wall, it is not durable because it is formed by application of a heat insulating paint, which makes it difficult to apply to stable mass production. In addition, as a result of the outer surface of the preform or the like being in close contact with the application surface of the heat insulating paint, the pattern of the application surface is transferred to the outer surface of the preform, leading to deterioration of the appearance quality.

  Considering the application of the proposed technique in Patent Document 2, when a bottle with a flat shape such as an eye drop bottle with a very small inner diameter of the mouth and a very small blow ratio of the short diameter side portion is targeted, There is a possibility that the partial unevenness itself that needs to be formed in the temperature control pot due to restrictions cannot be formed, and it is not possible to adopt a means for uneven thickness by preliminary blow molding using the temperature control pot in the proposed technique. . Furthermore, even if unevenness is formed in the temperature control pot, the temperature is uniform throughout, and the cooling rate at the time of preliminary blow molding is also uniform throughout the preform, so the above-mentioned wall thickness change itself cannot be obtained. There is a fear.

  Furthermore, considering the application of the proposed technique in Patent Document 3, the cold parison method is such that the injection-molded preform is cooled to room temperature and then heated again to the blow molding temperature. In addition, equipment for parison storage is required between the parison forming process and the blow molding process. For this reason, there is room for improvement from the viewpoint of the efficiency of stable mass production.

The present invention has been made in view of such circumstances, and an object of the present invention is to blow a hollow molded product whose wall thickness in the circumferential direction of the hollow molded product is freely corrected or adjusted as required. Another object of the present invention is to provide a preliminary temperature control mold that can be manufactured by molding and used for preliminary temperature control in order to realize a manufacturing method suitable for more stable mass production. The adjustment of the wall thickness of the above, more specifically, is to equalize the wall thickness in the circumferential direction of the hollow molded article of a flat shape.

Before describing the means for solving the problem, the first reference invention related to the manufacturing method, which is not included in the claims, will be described. In the first reference invention , a thermoplastic resin is used as a resin molding material, a starting molded body that is a cylindrical resin melt is molded by extrusion molding or injection molding, and a preliminary temperature control is performed on the starting molded body following this molding. Next, a hollow molded product manufacturing method for obtaining a final molded body by accommodating the blow molded mold having a cavity surface corresponding to the outer surface shape of the final molded body and performing the final blow molding will be described below. It is equipped with the specific matter. That is, as the preliminary temperature control, the starting molded body is accommodated in a predetermined preliminary temperature control mold, subjected to preliminary blow molding, and the outer surface is brought into contact with the cavity surface to perform heat exchange so that the temperature is kept in a deviated temperature state. Mold into a prepared preform. At that time, of the cavity surface of the preliminary temperature control die, the peripheral wall portion to be made thinner than the original thickness in the final molded body and the first specific peripheral wall portion of the corresponding preformed body in the circumferential direction are in contact with each other. While forming a thin skin solidified layer on the outer surface of the first specific peripheral wall portion of the preform, by reducing the amount of heat absorbed by contact heat exchange of the first mold wall portion constituting the cavity surface to become Preliminary temperature control is performed so that the resin molding material of the remaining meat portion excluding the thinned solidified layer is maintained in a molten state having a high temperature and low viscosity to such an extent that it can flow in the circumferential direction when subjected to the internal pressure by the main blow molding. On the other hand, in the final molded body, a second mold that forms a cavity surface in which the peripheral wall portion that is originally desired to be thicker than the wall thickness and the second specific peripheral wall portion of the preform corresponding to the circumferential direction are in contact with each other. Wall part contact heat By heat exploitation amount of conversion in a large set shall be the be pre temperature control to cool the resin molding material constituting the second specific peripheral wall portion of the preform to a molten state of high viscosity at low temperatures Is .

In the case of the first reference invention, the first specific peripheral wall portion of the preform after the preliminary temperature adjustment is in a molten state having a low viscosity at a high temperature except for the thinned solidified layer, and the second specific peripheral wall portion is a high viscosity at a low temperature. Since it is in a molten state, the resin molding material constituting the first specific peripheral wall portion is stretched while flowing in the circumferential direction, that is, on the second specific peripheral wall portion side during the blow molding. As a result, the peripheral wall portion of the final molded body corresponding to the first specific peripheral wall portion is formed relatively thin, and the peripheral wall portion of the final molded body corresponding to the second specific peripheral wall portion is formed relatively thick. It will be. Thereby, even if the outer peripheral surface of the final molded body is a perfect circle, the thickness distribution of the peripheral wall can be freely corrected or adjusted in the circumferential direction.

Also, the second reference onset bright according to the manufacturing method, by extrusion or injection molding using a thermoplastic resin is a cylindrical resin melt molding the starting molded body as the resin molding material, the starting molded Following this molding Preliminary temperature control is applied to the body, and then stored in a blow mold having a cavity surface corresponding to the outer shape of the final molded body and subjected to the blow molding, so that the cross section is shorter and longer. When those having the following specific features as an object a hollow molded article manufacturing method of obtaining a more becomes final form of flat shape. That is, as the preliminary temperature control, the starting molded body is accommodated in a predetermined preliminary temperature control mold having a cavity surface corresponding to the outer surface shape of the preliminary molded body having an intermediate shape between the starting molded body and the final molded body. Then, preliminary blow molding is performed, and the outer surface is brought into contact with the cavity surface to perform heat exchange, thereby forming a preform that is temperature-controlled so that the temperature is deviated between the short diameter side and the long diameter side. In that case, the cavity surface which contacts the short diameter side peripheral wall part of the preformed body corresponding to the peripheral wall part which becomes a short diameter side in the final molded body among the cavity surfaces of the preliminary temperature control mold is constituted. By reducing the amount of heat absorbed by heat exchange of the first mold wall portion, a thin skin solidified layer is formed on the outer surface of the short-diameter side peripheral wall portion of the preform, and the rest of the thin mold solidified layer is removed. While the temperature of the resin molding material of the meat part is preliminarily adjusted so as to be able to flow in the circumferential direction when subjected to the internal pressure by the main blow molding, it is preliminarily adjusted while the long diameter of the final molded body is By setting a large amount of heat absorption by heat exchange of the second mold wall portion that constitutes the cavity surface that contacts the long-diameter side peripheral wall portion of the preform corresponding to the peripheral wall portion that becomes the side, Long diameter side circumference of preform The resin molding material constituting the site in which it was decided to reserve temperature control to cool at low temperature to a molten state of high viscosity.

In the case of the second reference invention, if the blow molding is performed as it is without performing the preliminary temperature control, the short diameter side peripheral wall portion of the final molded body becomes thick due to the flat shape, and the long diameter It is possible to avoid the occurrence of inconvenience that the side peripheral wall portion is thinned so that it becomes thin, and the final molded body is obtained by performing the preliminary temperature control as described above and then performing the main blow molding. Even if it is flat, the thickness of the short-diameter side peripheral wall portion is suppressed, and at the same time, the thinning of the long-diameter side peripheral wall portion is suppressed, so that the thickness is uniform in the circumferential direction. That is, when the preliminary blow is blown into the starting molded body, the peripheral wall expands to the outer peripheral side, and the short diameter side peripheral wall part contacts the cavity surface of the preliminary temperature control mold, the outer surface of the short diameter side peripheral wall part is cooled by contact heat exchange. Although it tends to solidify, since the amount of heat absorbed is small, heat equilibrium is reached early and further cooling capacity is lost. For this reason, although a thin solidified layer is formed on the outer surface side of the short diameter side peripheral wall portion of the preform, the remainder is maintained in a low viscosity molten state at a high temperature close to the molten state of the starting molded body. Become. On the other hand, the long-diameter side peripheral wall portion of the preform, which is still stretched even if the short-diameter side peripheral wall portion contacts the cavity surface, tends to be thin, and finally has a large amount of heat absorbed from the contacted cavity surface. Upon being cooled by contact heat exchange, the resin molding material is in a molten state having a high viscosity at a low temperature. When this blow molding is applied to such a preform, it is bulged toward the outer periphery under pressure from the inside, and when the short-diameter side peripheral wall portion contacts the cavity surface of the blow molding die, a high-viscosity resin molding is performed. The material starts to flow to both sides in the circumferential direction, that is, to the side of the long-diameter side peripheral wall portion, and is supplied as a resin molding material for the long-diameter side peripheral wall portion. Thereby, the thickness in the circumferential direction is made uniform. Further, since the cavity surface is formed by the first mold wall portion or the second mold wall portion, if the mold surface forming the wall portion is polished to smooth the cavity surface, mirror transfer is also possible. It is possible to secure the production of a hollow molded article having a transparent and smooth surface.

In the above manufacturing method, the magnitude of the amount of heat absorbed by the contact heat exchange between the first mold wall part and the second mold wall part is set to the size of the preform that is in contact with the first mold wall part. Set so that the temperature difference between the two resin molding materials in the molten state after the preliminary temperature adjustment between the specific peripheral wall portion and the specific peripheral wall portion of the preform that is in contact with the second mold wall portion is 10 ° C. or more. it is Ru can be. Thereby, the condition setting of the first and second mold wall portions that can realize the fluidization of the resin molding material from the short diameter side peripheral wall portion to the long diameter side peripheral wall portion at the time of the main blow molding is set more specifically. Will be able to.

As a means for solving the problem, in order to achieve the above object, in the present invention, a thermoplastic resin is used as a resin molding material, and a starting molded body that is a cylindrical resin melt is formed by extrusion molding or injection molding. After the molding, the starting molded body is preliminarily adjusted, and then stored in a blow mold having a cavity surface corresponding to the outer surface shape of the final molded body, and then subjected to the blow molding. The following specific matters were provided for a preliminary temperature control die used for preliminary temperature control in a manufacturing method of a hollow molded product that obtains a flat shaped final molded body having a short diameter side and a long diameter side. That is, it is a cavity surface formed in a shape corresponding to the outer surface shape of a preformed body having an intermediate shape between the starting molded body and the final molded body, and is molded by pre-blowing into the starting molded body. With a cavity surface that causes the pre-molded body to deviate to a different temperature control state on the short-diameter side and the long-diameter side by contacting the outer surface of the pre-molded body and taking heat away from the resin molding material by heat exchange And Of the cavity surfaces, the first mold wall portion constituting the cavity surface that comes into contact with the short-diameter side peripheral wall portion of the preform corresponding to the short-wall side peripheral wall portion in the final molded body. As the amount of heat absorbed by contact heat exchange, the resin molding material of the remaining meat portion excluding this thin skin solidified layer is formed while the thin skin solidified layer is formed on the outer surface of the short peripheral side wall portion of the preform by the contact heat exchange. Corresponding to the peripheral wall portion on the long diameter side in the final molded body while maintaining a low-viscosity molten state at a high temperature so that it can flow in the circumferential direction when subjected to internal pressure by the blow molding As the amount of heat absorbed by the contact heat exchange of the second mold wall portion that constitutes the cavity surface that comes into contact with the long-diameter side peripheral wall portion of the preform, the long diameter of the preform by the contact heat exchange Resin molding material constituting the wall site with a large set to be cooled to a molten state of a high viscosity at low temperatures, the temperature control state of polarization Yutakaka different temperature control states to each other in the minor axis and the major axis side By performing the main blow molding on the preform, the thickness of the short-diameter side peripheral wall portion is suppressed, and at the same time, the thinning of the long-diameter side peripheral wall portion is suppressed to achieve a uniform thickness in the circumferential direction. .

In the case of the above invention specific matters , the starting molded body is included in the preliminary temperature control mold according to the present invention having a cavity surface corresponding to the outer surface shape of the preformed body having an intermediate shape between the starting molded body and the final molded body. Is preliminarily blow molded, and the outer surface is brought into contact with the cavity surface and heat exchange is performed, so that the preform is temperature-controlled in a state where the temperature is deviated between the short diameter side and the long diameter side. By performing preliminary temperature control, if it is blow molded as it is without such preliminary temperature control, the short diameter side peripheral wall part of the final molded body becomes thick due to the flat shape, and the long diameter It is possible to avoid the occurrence of inconvenience that the side wall portion becomes thin as the side wall portion becomes thin, and after the preliminary temperature control is performed using the preliminary temperature control mold as described above, the main blow is performed. By molding, the final molded body is flattened. A shape also suppress thinning of long diameter side wall portion and simultaneously suppress the thickening of the short diameter side wall portion, so that the uniformity of the thickness in the circumferential direction can be achieved. That is, when the preliminary blow is blown into the starting molded body, the peripheral wall expands to the outer peripheral side, and the short diameter side peripheral wall part contacts the cavity surface of the preliminary temperature control mold, the outer surface of the short diameter side peripheral wall part is cooled by contact heat exchange. Although it tends to solidify, since the amount of heat absorbed is small, heat equilibrium is reached early and further cooling capacity is lost. For this reason, although a thin solidified layer is formed on the outer surface side of the short diameter side peripheral wall portion of the preform, the remainder is maintained in a low viscosity molten state at a high temperature close to the molten state of the starting molded body. Become. On the other hand, the long-diameter side peripheral wall portion of the preform, which is still stretched even if the short-diameter side peripheral wall portion contacts the cavity surface, tends to be thin, and finally has a large amount of heat absorbed from the contacted cavity surface. Upon being cooled by contact heat exchange, the resin molding material is in a molten state having a high viscosity at a low temperature. When this blow molding is applied to such a preform, it is bulged toward the outer periphery under pressure from the inside, and when the short-diameter side peripheral wall portion contacts the cavity surface of the blow molding die, a high-viscosity resin molding is performed. The material starts to flow to both sides in the circumferential direction, that is, to the side of the long-diameter side peripheral wall portion, and is supplied as a resin molding material for the long-diameter side peripheral wall portion. Thereby, the thickness in the circumferential direction is made uniform. Further, since the cavity surface is formed by the first mold wall portion or the second mold wall portion, if the mold surface forming the wall portion is polished to smooth the cavity surface, mirror transfer is also possible. It is possible to secure the production of a hollow molded article having a transparent and smooth surface.

In addition to the above subject matter, in the present invention, with integrally formed using the same mold-forming material to each other as a first mold wall part and a second mold wall portion constituting the cavity surface, the upper Symbol a first mold wall portion thinner so as to correspond to the setting of the thermal exploitation amount of heat exchange, and forming the second mold wall portion thicker. Ing to be the magnitude set of heat exploitation amount according to the above contact heat exchange is achieved by the magnitude of the wall thickness.

Furthermore, in addition to the above-mentioned invention specific matters, the magnitude setting of the amount of heat absorbed by the heat exchange between the first mold wall part and the second mold wall part can be set by the pre-molded body in contact with the first mold wall part. The temperature difference between the two resin molding materials in the molten state after the preliminary temperature control between the short-diameter side peripheral wall portion and the long-diameter side peripheral wall portion of the preform that is in contact with the second mold wall portion is 10 ° C. or more. It was set to (claim 1). Ri by the so doing, at the time of the blow molding capable of realizing a flow of the resin molding material to the major axis side wall portion from the short diameter side wall portion, the condition setting of the first and second mold wall portion , will be capable of setting more specifically, the resin molding material portion except for the thin skin solidified layer of short diameter side wall portion of the preform which has been subjected to pre備温tone can reliably flow if Ukere this blow It becomes possible to be in a state.

And by setting the wall thickness of the first mold wall part to be less than 0.5 cm, the flow can be reliably realized at a high temperature and a low viscosity, and the temperature difference of 10 ° C. or more can be achieved. Realization is achieved (Claim 2 ).

Furthermore, a reinforcing member that is formed of a heat-insulating material and reinforces the first mold wall portion from the back side may be integrally provided on the opposite side of the cavity surface of the first mold wall portion. Item 3 ). As a result, it is possible to realize a preliminary temperature adjustment die that can withstand the air pressure of the preliminary blow and is suitable for mass production over a long period of time.

As described above, according to the pre備温tone mold used for the preliminary temperature control in 請 Motomeko 1 to any of the manufacturing method of hollow molded articles according to the blow molding of claim 3, the forming of the starting molded body Subsequently, by performing preliminary temperature control using the preliminary temperature control mold, it becomes possible to perform the blow molding in a temperature controlled state in which the temperature is deviated, so that the final molded body has a flat shape. In addition, it is possible to suppress the increase in the thickness of the short-diameter side peripheral wall portion and at the same time to suppress the thinning of the long-diameter side peripheral wall portion, and to achieve a uniform thickness in the circumferential direction. As a result, because of the flat shape, it has hitherto been ensured that the short diameter side peripheral wall portion of the final molded body becomes thick and the long diameter side peripheral wall portion becomes thin so that the inconvenience of being unbalanced is generated. It can be avoided. In addition, a production method suitable for a stable mass production system without the occurrence of conventional inconveniences can be obtained simply by interposing a preliminary temperature adjustment process in which preliminary blow using a preliminary temperature adjustment mold is performed prior to this blow molding. Can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 and 2 show a molded body in each molding step which would cause are sequentially molded change shape in manufacturing method using the engagement Ru preliminary temperature control mold to an embodiment of the present invention. In the present embodiment, a flat eye drop bottle is manufactured by blow molding as a hollow molded article (final molded body 3 described later), and the wall thickness in the circumferential direction is uniform as the final molded body 3 The case of manufacturing is shown. In the figure, reference numeral 1 denotes a preform (bottomed parison) which is a cylindrical resin melt as a starting molded body, 2 denotes a preformed body, and 3 denotes a final molded body. The figure and the lower cross-sectional view are shown as a pair.

  The preform 1 is formed in a cylindrical shape having a perfect cross-sectional shape, and the final molded body 3 has a dimensional ratio (major axis / minor axis ratio) between the long diameter side peripheral walls 31 and 31 and the short diameter side peripheral walls 32 and 32. Is formed in an oblong flat shape of approximately 2.5, and the preform 2 is formed in an intermediate shape (intermediate cross-sectional shape) between the preform 1 and the final molded body 3, for example, an elliptical shape. Is done. In this manufacturing method, both the long-diameter side peripheral wall 31 and the short-diameter side peripheral wall 32 of the final molded body 3 can be formed with the same wall thickness, and the long-diameter side peripheral walls 21 and 21 of the preform 2 are thin. The short diameter side peripheral walls 22, 22 are formed to be thick.

  In this manufacturing method, the preform 1 is molded using the injection mold, and the preform 1 is molded into the preform 2 while the preform 1 is temperature-controlled using the preliminary temperature control mold. It consists of a preliminary temperature control step and a main blow molding step in which the preform 2 is molded into the final molded body 3 using the blow mold. Refer to the 4-station type injection blow equipment shown in each example of the injection station (FIG. 3), temperature control preliminary blow station (FIG. 4), main blow station (FIG. 5) and take-out station (FIG. 6). The above steps will be described below.

  The injection molding process is performed at the injection station shown in FIG. First, the cavity mold 101, the lip mold 102, and the core 103 constituting the injection mold are fitted together and clamped (step a). Next, the thermoplastic resin material is kneaded and melted outside the figure, and the molten resin is injected from the hot runner nozzle 104 into the cavity that is clamped to form the preform 1 (see FIGS. 1 and 2) (step) b). When the cavity mold 101, the lip mold 102, and the core 103 are opened, the preform 1 is taken out while being held by the lip mold 102 at the mouth portion 11 (see FIG. 1) (step c). The lip mold 102 can be moved between the above four stations by, for example, rotating operation. By moving the lip mold 102 while holding the mouth portion 11, the lip mold 102 can be changed from an injection molding process to a preliminary temperature control process. The blow molding process and the processes up to the final take-out can be performed continuously.

  Examples of the thermoplastic resin material include polyethylene terephthalate (PET), polypropylene (PP), low density polyethylene (PE-LD), high density polyethylene (PE-HD), polyarylate (PAR), polycarbonate (PC), polyethylene Naphthalate (PEN) or cycloolefin polymer (COP) is used.

  As shown in FIG. 4, the preliminary temperature adjustment step is performed after the preform 1 is moved to the temperature adjustment preliminary blow station by moving the lip mold 102 after completion of the injection molding step. First, the preform 1 is accommodated in the cavity of the pre-temperature regulating mold 201 that is divided into left and right and is in an opened state, and a drawing rod 202 that also serves as an air blowing tube is inserted into the preform 1 to perform mold clamping. (Steps d and e). The preliminary temperature adjustment mold 201 will be described in detail later. Next, the stretching rod 202 is lowered and the inner bottom surface of the preform 1 is pushed and preliminarily stretched downward and pressed as it is, or when the prestretching is unnecessary, the inner bottom surface of the preform 1 is pressed and held. In the state (step f), air is blown into the preform 1 from the periphery of the stretching rod 202 to perform preliminary blow molding (step g). By this preliminary blow, the peripheral wall 12 (see FIG. 1) of the preform 1 is bulged to the outer peripheral side and is brought into close contact with the cavity surface of the preliminary temperature adjustment mold 201, and a predetermined temperature control is performed. Molded. Then, the preliminary temperature control mold 201 is opened to the left and right to open the mold, and the lip mold 102 is separated from the preliminary temperature control mold 201 to release the preliminary molded body 2 (step h). In this preliminary temperature adjustment process, the preform 1 transferred at a high temperature from the injection molding process is subjected to a cooling temperature adjustment by heat exchange using the above-mentioned preliminary temperature adjustment mold 201, and in the next blow molding process of the next process. Therefore, the temperature is adjusted in a predetermined uneven temperature state.

  As shown in FIG. 5, the final blow molding step is performed after moving the preform 2 to the main blow station by moving the lip mold 102 after the completion. First, the preform 2 is accommodated in the cavity of the blow molding die 301 that is divided into left and right and is in an open state, and a drawing rod 302 that also serves as an air blowing tube is inserted into the preform 2 and clamped. (Steps i and j). The extending rod 302 is lowered to push the inner bottom surface of the preform 2 to extend the bottom wall 20 (see FIG. 1) downward and press it as it is (step k). In this state, air is blown from the periphery of the stretching rod 302 into the preform 2 to perform the main blow molding (step l). By this main blow molding, the peripheral wall portions 21 and 22 (see FIG. 1) of the preform 2 are bulged to the outer peripheral side and are brought into close contact with the cavity surface of the main blow molding die 301. Molding is performed. The final blow molded mold 301 is opened from the left and right, and the mold is opened, and the lip mold 102 is separated from the main blow mold 301, thereby releasing the final molded body 3 from the blow mold 301. (Step m).

  The lip mold 102 holding the final molded body 3 is moved to the take-out station as shown in FIG. 6, and the final molded body 3 is opened by opening the lip mold 102 to the left and right and lowering the push rod 401 at the take-out station. Is taken out as a product (steps n, p).

  In FIG. 4 or FIG. 5, the dividing direction in which the preliminary temperature adjusting mold 201 or the main blow molding mold 301 is opened is divided into directions different from the actual 90 degrees due to the illustrated relationship. Although shown so as to open, in practice, the mold is opened by being divided so as to cross the minor axis direction of the preform 2 or the final molded body 3.

  Next, the preliminary temperature adjustment mold 201 used in the preliminary temperature adjustment step will be described in detail with reference to FIGS. The preliminary temperature adjustment mold 201 includes a pair of half molds 203 and 203, and the outer surface shape of the preform 2 is formed by recesses formed in the opposing surfaces 204 and 204 of the pair of half molds 203 and 203, respectively. Cavity surface 205 is defined to define The cavity surface 205 is formed entirely of the metal material constituting the half molds 203, 203 and has a relatively good thermal conductivity. The short diameter side wall portions (first mold wall portions) 206 and 206 constituting the short diameter side region of the cavity surface 205 are formed to have a predetermined thin wall thickness (for example, t = 1.5 mm), while the long diameter .., 207,... Constituting the side region are formed thick, and temperature control circuits 208, 208,... For cooling the mold are disposed on the wall portion 207. Thus, a cooling temperature adjusting medium is passed through each temperature adjusting circuit 208. Reinforcing members 210 and 210 for reinforcing the short-diameter side wall portions 206 and 206 are fixed in close contact with the short-diameter side wall portions 206 and 206 on the side opposite to the cavity surface 205. Since the short diameter side wall portion 206 is considerably thin, the reinforcing member 210 is fixed so as to support the short diameter side wall portion 206 from the back side to supplement rigidity. If the portions 206 and 206 are rigid, the reinforcing members 210 and 210 can be omitted. Also, as will be described later, the short-diameter side wall portion 206 is set to be thin in order to suppress the amount of heat sequestration low. For this reason, when the reinforcing member 210 is installed, the presence of the reinforcing member 210 The reinforcing member 210 is preferably formed of a heat insulating material so as not to affect heat absorption.

  In short, in the preliminary temperature adjustment process, by using the preliminary temperature adjustment mold 201, the short-diameter side peripheral wall 32 whose wall thickness tends to increase in the final molded body 3 because of the flat shape, 32 (see FIG. 2A), the short-diameter side peripheral walls 22 and 22 of the preform 2 to be formed into a low-viscosity melt state while maintaining the high temperature, while the wall thickness of the final molded body 3 is The long-diameter side peripheral walls 21 and 21 of the preform 2 that will form the long-diameter peripheral walls 31 and 31 that tend to be thin are temperature-controlled to a high viscosity melt state. In order to realize this, the short-diameter side wall portions 206 and 206 constituting the cavity surface 205 for forming the short-diameter side peripheral walls 22 and 22 in the preliminary temperature adjustment mold 201 are thinned to reduce the thickness from the peripheral wall portion 12a of the preform 1. The heat sink by heat exchange is suppressed to a low level, while the long diameter side wall portions 207, 207,... Constituting the cavity surface 205 for forming the long diameter side peripheral walls 21, 21 are made thick and a temperature control circuit 208 for cooling the mold is provided. Installed to increase the heat seizure by heat exchange.

  Then, when the preform 1 subjected to the internal pressure by the preliminary blow (air blow from the stretching rod 202) is uniformly expanded toward the outer peripheral side, first, the preform on the side facing the short-diameter side wall portions 206 and 206 is firstly formed. The outer peripheral surface of 1 is brought into contact with and pressed against the wall portion 206, and the outer peripheral surface of the peripheral wall portion 12a of the preform 1 in contact with the short-diameter side wall portion 206 is cooled. Since the peripheral wall portion 12a comes into contact with the short-diameter side wall portions 206 and 206 early after the start of preliminary blow, that is, within a very small blow ratio range, the short-diameter side peripheral walls 22 and 22 of the preform 2 are the above-mentioned peripheral walls. It will remain relatively thick near 12a. On the other hand, even after the peripheral wall portion 12a comes into contact, the peripheral wall portion 12b of the preform 1 on the side facing the long diameter side wall portions 207, 207,... 207, 207,... Are pressed against and cooled by heat exchange. For this reason, since the long diameter side peripheral walls 21 and 21 of the preform 2 are extended in a considerably large blow ratio range, they are considerably thinner than the short diameter side peripheral walls 22 and 22 and are subjected to cooling temperature control. .

  On the other hand, the short-diameter side peripheral walls 22 and 22 formed by contact with the short-diameter side wall portions 206 and 206 are cooled by heat exchange by the above-described contact and solidification starts from the outer surface, but the short-diameter side wall portions 206 and 206 Since the heat absorption by heat exchange reaches saturation early, that is, the amount of heat absorption by heat exchange is small corresponding to the thin wall thickness, the cooling capacity by the short-diameter side wall portions 206 and 206 is further increased. Will no longer exist. For this reason, in the preformed body 2 molded by executing the above-described preliminary temperature adjustment mold 201, the following temperature deviation can be realized in the circumferential direction. Although the short-diameter side peripheral walls 22 and 22 remain thick with a thin solidified layer formed on their outer surfaces, the other parts of the thick wall except the thin solidified layer are the same as those described above. In this way, a high retained heat is maintained and a low-viscosity molten state is maintained. On the other hand, the long-diameter side peripheral walls 21 and 21 are considerably thinner than the short-diameter side peripheral walls 22 and 22 due to stretching, and are in a low temperature state (state where the retained heat is lowered) due to cooling temperature control. The entire thin-walled long-diameter side peripheral walls 21 and 21 are in a high-viscosity molten state.

  And when such a preforming body 2 is accommodated in the cavity 303 of this blow molding die 301 (refer FIG.2 (b)) and this blow molding (air blow into the preforming body 2) is implemented. First, the outer surfaces of the short-diameter side peripheral walls 22, 22 come into contact with the cavity surfaces 304, 304 of the blow molding die 301, and cooling proceeds from the thinned solidified layer side to the inside, while the inner thick and thick wall is retained. The meat portion that is in a low-viscosity molten state while maintaining heat flows to the major axis on both sides. And the long diameter side peripheral walls 21 and 21 still receive air blow and are extended to the long diameter side, and the outer surfaces thereof come into contact with the long diameter side cavity surfaces 305 and 305. At this time, as shown by the solid line in FIG. 2B, the cross-sectional shape of the molded body 5 being stretched in the circumferential direction by the main blow molding is indicated by a solid line. Even though it tends to be thin (see reference numerals 501 and 501 in the figure), the material is compensated by continuously receiving the flow of the meat part from the short diameter side (see reference numerals 502, 502, ... in the figure). ). As described above, the short-diameter side peripheral walls 32 and 32 of the final molded body 3 have a thickness with the thinned solidified layer and the remaining meat portion due to the progress of cooling, while the long-diameter side peripheral walls 31 and 31 have the above-described thickness. (Resin material) compensates for the thickness so that it does not become so thin, and the difference in thickness between the short diameter side peripheral walls 32, 32 and the long diameter side peripheral walls 31, 31 is reduced as much as possible. The final molded body 3 having a substantially uniform thickness can be molded.

  Next, as the above-described mold for temperature control / pre-blow molding in the present invention and the short diameter side wall portions 206 and 206, specifications necessary for obtaining the effects of the present invention are more quantitative. Consider to get an indicator. As a study, a preliminary temperature adjustment process is performed using the preliminary temperature control mold 201 of the preliminary blow molding mold of FIG. 7 and FIG. The wall thickness of each of the wall portions 206 and 207 is changed with respect to what kind of situation the temperature difference between the short diameter side wall portions 206 and 206 and the long diameter side wall portions 207 and 207 becomes when the body 2 is formed. And simulated. Here, the above temperature difference is a difference between both temperatures that have reached equilibrium by heat exchange, and the temperature difference between the short diameter side peripheral walls 22 and 22 and the long diameter side peripheral walls 21 and 21 of the preform 2. It can be said that represents.

  As a precondition for the simulation, the resin molding material was PET (polyethylene terephthalate), and the resin molding material, the mold forming material, and the preliminary blow molding conditions were set as follows.

Resin molding material: PET (polyethylene terephthalate)
Specific heat Xp = 0.40 (cal / g · ° C.), density Yp = 1.40 (g / cm ³ )
Specific heat per unit volume XYp = Xp × Yp = 0.560 (cal / cm ³ ° C.)
Mold forming material: Fe
Specific heat Xk = 0.12 (cal / g. ° C.), density Yk = 7.85 (g / cm ³ )
Specific heat per unit volume XYk = Xk x Yk = 0.942 (cal / cm ³ · ° C)
Thermal conductivity from resin molding material (PET) to mold forming material (Fe): λ = 0.3 (J / sec)
The peripheral wall thickness of the preform 2 immediately before the preliminary blow molding: 0.25 (cm)
Preform 2 temperature just prior to preliminary blow molding: 200 (° C)
Temperature of the mold 201 immediately before preliminary blow molding: 60 (° C)
Thickness of the short-side wall portion 206 of the mold: Bs = 0.1, 0.15, 0.2, 0.3,... Thickness of the portion 207: Bc = 1.0, 1.5, 2.0, 2.5,..., Then changed to 16.0 (cm) in 0.5 increments Pre-blowing time: t = 3 (sec)
Under the above preconditions, the preform 1 is formed into the preform 2 by performing the preliminary blow molding, and the amount of heat transferred from the preform 2 after the preliminary blow to the mold 201 (taken by the mold 201). First, the amount of heat (Ht) is obtained from the thermal conductivity λ of the resin molding material and the preliminary blow time t.
Ht = λ × t = 0.3 × 3 = 0.9 (J)
Since 1 (J; Joule) = 4.2 (cal), when the unit is converted,
Ht = 0.9 × 4.2 = 3.78 (cal)
The temperature rises Zs and Zc of the short diameter side wall portion 206 and the long diameter side wall portion 207 of the mold 201 due to the movement of the heat quantity Ht are the specific heat XYk per unit unit volume and the thicknesses Bs and Bc, respectively. On the basis of the,
Zs = Ht / (XYk · Bs) (1)
Zc = Ht / (XYk · Bc) (2)
Is obtained. Here, since Bs <Bc, Zs> Zc.

For example, when Bs = 0.15 (cm) and Bc = 3.0 (cm), Zs = 26.75 (° C./cm ² ) from the equation (1), and similarly, Zc = 1 from the equation (2). .34 (° C./cm ² ), and the temperature difference is 25.41 (° C./cm 2). Since the original mold temperature is 60 ° C., the short diameter side wall portion 206 is 86.75 (° C./cm ² ), and the long diameter side wall portion 207 is 61.34 (° C./cm ² ). This is because the temperature of the short-diameter side peripheral wall 22 of the preform 2 in contact with the short-side wall portion 206 is controlled to 86.75 (° C./cm ² ) and a high-temperature molten state (high retained heat). On the other hand, it shows that the long-diameter side peripheral wall 21 in contact with the long-diameter side wall portion 207 is temperature-controlled to 61.34 (° C./cm ² ) and a low-temperature molten state (low retained heat).

Using the above equations (1) and (2), the temperature difference T between the short diameter side wall portion 206 and the long diameter side wall portion 207 is
T = Zs-Zc = (Ht / XYk). {(1 / Bs)-(1 / Bc)} (3)
It will be represented by

  In FIG. 9, using equation (3), the thickness Bc of the long-side wall portion 207 of the mold is fixed to 3.0 (cm), and the thickness Bs of the short-side wall portion 206 is changed as described above. FIG. 10 shows the change of the temperature difference T in the case where the thickness Bs of the short side wall portion 206 of the mold is fixed to 0.15 (cm) using the equation (3). The change state of the temperature difference T when the thickness Bc of 20 is changed as in the above preconditions is shown.

  Referring to FIG. 9, a large temperature difference of about 6 ° C. to 40 ° C. is caused in the range where the wall thickness Bs of the short-diameter side wall portion 206 is thinner than 1 cm, particularly, thinner than 0.5 cm, and slightly thin. Although the change to the side appears as a very large change in temperature difference, the temperature difference is less than 2.5 ° C in the range of thicker than 1 cm, and the change in temperature difference is poor. Yes. On the other hand, even if the wall thickness Bc of the long-diameter side wall portion 207 in FIG. 10 is changed greatly from 1.0 cm to 16.0 cm, the temperature difference changes in the range of approximately 23 ° C. to 26 ° C., which is more than about 3.0 cm. In the thick range, no matter how much the thickness is increased, the change in temperature difference is almost 1 ° C. and hardly changes.

  Here, in the relational diagram about the temperature dependence of the tensile yield strength of PET, which is the resin molding material of FIG. 11, 80 ° C. to 110 ° C. is adopted as the temperature at which the resin molding material flows in blow molding (stretch blow molding). Will be. Looking at such temperature dependence, for example, if there is a temperature difference of 10 ° C., the elongation characteristics (viscosity) of the resin molding material at both temperature values having the temperature difference will change, and a difference in fluidity should occur.

  Therefore, if the temperature can be adjusted (biased temperature adjustment) so that a temperature difference of 10 ° C. is established between the short diameter side peripheral wall 22 and the long diameter side peripheral wall 21 of the preform 2 at the end stage. In other words, if the temperature of the short diameter side peripheral wall 22 has a retained heat corresponding to a temperature difference of 10 ° C. higher than the long diameter side peripheral wall 21 and the temperature can be adjusted so that a difference in viscosity is generated, When the thin portion of the long-diameter side peripheral wall 31 of the final molded body 3 is suppressed by the flow of the meat portion from the short-diameter side peripheral wall 22 to the long-diameter side peripheral wall 21, the thickness can be made substantially uniform with the short-diameter side peripheral wall 32. Conceivable.

  As the thickness setting capable of realizing the temperature difference of 10 ° C. as described above, when the thickness of the long-side wall portion 207 of the mold is set to 3.0 cm, the thickness of the short-side wall portion 206 is almost as shown in FIG. 0.4cm. For this reason, if the thickness of the short side wall portion 206 is set to 0.4 cm or less, it can be said that a temperature difference of 10 ° C. or more can be realized, and the effects of the present invention can be obtained. Although the thickness of the short-diameter side wall portion 206 capable of realizing such a temperature difference of 10 ° C. is 0.4 cm, this is derived on the assumption of a specific resin molding material (PET). Considering including the resin molding material, the thickness of the short-diameter side wall portion 206 may be set to 0.5 cm or less.

<Other embodiments>
In addition, this invention is not limited to the said embodiment, Various other embodiments are included. Further , in the above embodiment, the present invention is applied as means for thinning the short diameter side that tends to be thick in the bottle having a flat cross-sectional shape and thickening the long diameter side that tends to be thin. Accordingly, although so as to Hitoshiniku of the peripheral wall in the bottles of flat shape (uniform in thickness), originally if example embodiment cross-sectional shape is a true circle is uneven wall thickness in the peripheral wall occurs In order to make a desired bottle in the circumferential direction thicker than other parts, or conversely, in a blow molded bottle whose thickness is essentially uniform in the circumferential direction The present invention can also be applied to.

For example, as shown in FIG. 12, as the final molded body 5 whose outer peripheral surface is a perfect circle shape, the peripheral wall portions 501 and 501 corresponding to the circumferential regions R1 and R3 are thinned, and the peripheral wall portions 502 and 502 corresponding to the regions R2 and R4 are formed. The present invention can be applied to obtain a thicker 502 .

  Moreover, in the said embodiment, although the injection-molded preform is used as the starting molded object, it is not restricted to this, You may apply this invention by using the parison formed by extrusion molding as a starting molded object.

  In the above-described embodiment, the case where the bottom wall is stretched downward by the stretching rod has been described. However, the present invention may be applied to blow molding that does not involve stretching of the bottom wall.

  Furthermore, in the said embodiment, although the elliptical thing was shown as the cavity shape of the preforming body 2 and a preliminary temperature control metal mold | die, not only this but the circular shape of the preform 1 and the flat shape of the final molding body 3 are shown. An intermediate shape between them may be used, and for example, a rectangular shape or an oval shape may be used.

  The bottle formed by the embodiment shown in FIGS. 1 to 8 (final molded body according to this embodiment) and the reinforcing member 210 are arranged instead of the preliminary temperature adjustment dies 201 and 201 shown in FIGS. A bottle made by blow molding after a simple preliminary temperature control using a short-diameter side wall portion integrated with the short-diameter side wall portions 206 and 206 (final molded body by a comparative molding method). The thickness distribution of both peripheral walls was measured and the thickness distribution was compared. As the bottle according to the present embodiment and the bottle according to the comparative molding method, five samples Nos. 1 to 5 were respectively molded and compared. Other molding conditions (preform molding, preliminary blow molding and main blow molding, mold temperature, air blow time, pressure, etc.) were set to be the same except that the preliminary temperature control mold was different. That is, a comparison was made between a bottle whose temperature was adjusted using the preliminary temperature adjustment mold according to the present invention and a bottle formed by a comparative molding method where temperature adjustment was not performed. Hereinafter, the case according to the present embodiment is also referred to as “with temperature regulation temperature control”, and the case according to the comparative molding method is also referred to as “without temperature regulation temperature control”.

  FIG. 13 (a) shows the longitudinal cross-sectional dimensions of the bottle in the short diameter region, and FIG. 13 (b) shows the positions of twelve thickness measurement points t1 to t12 in the transverse cross section. The numbers displayed in FIGS. 13 (a) and 13 (b) indicate dimensional values, and the unit is mm.

  FIG. 14 shows the thickness measurement results at the measurement points t1 to t12 in each final molded body of five specimens by the comparative molding method, and FIG. 14 shows the thickness measurement results at the measurement points t1 to t12 in each final molding body of the five specimens according to this embodiment. FIG. 15 shows the comparison of the distribution of the average thickness values at the measurement points t1 to t12 with a graph in FIG.

  As is apparent from FIG. 16, the comparison of the above wall thickness distributions shows that when the temperature control is performed using the pre-blow mold of this embodiment, the short diameter side wall thickness t1, t2, t6. Although the difference in thickness between ~ t8, t12 and the major diameter side wall thickness t3 ~ t5, t9 ~ t11 is about 0.1mm, In some cases, the difference in wall thickness was 1.0 mm or more (about 1.3 mm at the maximum). As a result, by applying the uneven temperature control of this embodiment, the occurrence of a difference in thickness between the short diameter side peripheral wall and the long diameter side peripheral wall in the flat bottle can be almost eliminated, and the thickness of the peripheral wall Can be made substantially uniform.

  Using the five specimens according to the present embodiment and the five specimens by the comparative molding method, the water vapor permeation amount permeated through the wall from the liquid filled in a sealed state and evaporated to the outside is measured and compared. It was. This is to verify the barrier performance when the bottle as the final molded body is used as, for example, an eye drop container filled with eye drops.

  FIG. 17 shows the measurement result in the case of the specimen molded according to the present embodiment to which the temperature variation is controlled, and FIG. 18 shows the measurement result in the case of the specimen molded by the comparative molding method without performing the temperature regulation. FIG. 19 is a graph showing the comparison results using the average values of both cases with and without temperature regulation. In FIG. 17 or FIG. 18, the upper half shows the initial weight of the specimen in a state filled with liquid and the weight after 1, 2, 3, 4 weeks, and the lower half shows the same period. The weight of the weight loss (transpiration weight loss), that is, the water vapor transmission amount is displayed.

  From the above measurement results and comparison results, the water vapor permeation amount of the bottle according to the present embodiment that has been subjected to the temperature-unevening temperature adjustment at the time of the first week is 5% compared to the bottle that has not been subjected to the temperature-unevening temperature adjustment. The decrement gradually increased and decreased by more than 10% after 4 weeks. That is, the bottle according to the present embodiment that has been subjected to uneven temperature control can reduce the amount of water vapor permeated and improve the barrier performance.

FIG. 3 is an explanatory cross-sectional view showing a pair of a longitudinal cross-sectional shape and a cross-sectional shape of a preform, a preformed body, and a final molded body that are molded in each molding stage of the embodiment of the present invention. FIG. 2 (a) shows a preform, a preformed body, and a final molded body, and FIG. 2 (b) shows a preformed body. The molded body and final molded body in the middle of the blow molding are shown. It is sectional explanatory drawing which shows each step of the injection molding process in an injection station. It is sectional explanatory drawing which shows each step in a temperature control preliminary | backup blow station. It is sectional explanatory drawing which shows each step of this blow molding process in this blow station. It is sectional explanatory drawing which shows each step of the taking-out process of the final molded object in a taking-out station. It is a longitudinal cross-sectional explanatory drawing of a preliminary temperature control metal mold | die. It is an expanded sectional explanatory view in the AA line of FIG. It is a related figure of the thickness of a short diameter side wall part, and a temperature difference. It is a related figure of the thickness of a long diameter side wall part, and a temperature difference. It is a relationship figure of tensile yield strength and temperature in a resin molding material (PET). It is sectional explanatory drawing which shows the cross-sectional shape of the final molded object shape | molded by other embodiment. It is a figure which shows the bottle shape and dimension of the object which performed the comparative measurement test about thickness distribution, and a measurement position, Fig.13 (a) shows the longitudinal cross-sectional explanatory drawing of a minor axis direction, FIG.13 (b) is a cross section. An explanatory diagram is shown. It is a table | surface which shows the thickness measurement result of the final molded object by a comparative shaping | molding method. It is a table | surface which shows the thickness measurement result of the final molded object by this embodiment. It is a graph shown by contrast for every measurement point using the average value of the thickness measurement result of FIG.14 and FIG.15. It is a table | surface which shows the water-vapor-permeation amount measurement result of the final molded object (bottle) by this embodiment. It is a table | surface which shows the water-vapor-permeation amount measurement result of the last molded object (bottle) by a comparative shaping | molding method. It is a graph shown by contrast for every time passage period using the average value of the water vapor permeation amount measurement results of FIGS.

Explanation of symbols

1 Preform (starting molded body)
2 Preliminary body 3 Final molded body 21 Long-diameter side peripheral wall 22 of pre-molded body Short-diameter side peripheral wall 201 of pre-molded body Preliminary temperature control mold 205 Preliminary temperature control mold cavity surface 206 Short-diameter side wall portion (first mold) Wall part)
207 Long-diameter side wall (second mold wall)
210 Reinforcing member Bs Wall thickness of short side wall

Claims (3)

A thermoplastic resin is used as a resin molding material to form a starting molded body, which is a cylindrical resin melt, by extrusion molding or injection molding, and after this molding, the starting molded body is preliminarily adjusted and then final molded. A hollow molded product that obtains a flat shaped final molded body having a short cross section and a long diameter side by being housed in a blow mold having a cavity surface corresponding to the outer shape of the body and subjected to the blow molding A preliminary temperature control mold used for preliminary temperature control in the manufacturing method of
A cavity surface formed in a shape corresponding to the outer surface shape of a preformed body having an intermediate shape between the starting molded body and the final molded body, and being preformed by pre-blowing into the starting molded body The outer surface of the molded body is in contact and has a cavity surface that deviates the temperature of the preform from the resin molding material by heat exchange to different temperature control states on the short diameter side and the long diameter side,
Of the cavity surface, the contact heat of the first mold wall portion constituting the cavity surface that contacts the peripheral wall portion on the short diameter side of the final molded body and the short diameter side peripheral wall portion of the corresponding preform. As the amount of heat absorbed by the exchange, the resin molding material of the remaining meat portion excluding the thinned solidified layer is formed on the outer surface of the short peripheral side wall portion of the preform by the contact heat exchange. While it is set to a small size so that it can be kept in a molten state at a high temperature and low viscosity to the extent that it can flow in the circumferential direction when subjected to internal pressure due to blow molding, it corresponds to the peripheral wall portion on the long diameter side in the final molded body. As the amount of heat absorbed by the contact heat exchange of the second mold wall part constituting the cavity surface with which the long-diameter side peripheral wall portion of the preform is in contact, the long-diameter side peripheral wall of the preform is obtained by contact heat exchange. Preliminary temperature control state in which the temperature is set to be large so that the resin molding material constituting the position is cooled to a molten state with a high viscosity at a low temperature, and the temperature is shifted to different temperature control states on the short diameter side and the long diameter side. By performing the above blow molding on the molded body, the thickness of the short-diameter side peripheral wall portion is suppressed, and at the same time, the thinning of the long-diameter side peripheral wall portion is suppressed, and the thickness in the circumferential direction is made uniform. ,
The first mold wall portion and the second mold wall portion constituting the cavity surface are integrally formed using the same mold forming material, and correspond to the setting of the amount of heat absorbed by the heat exchange. The first mold wall portion is thin, the second mold wall portion is thick, and
The magnitude of the amount of heat absorbed by heat exchange between the first mold wall portion and the second mold wall portion is determined by the short diameter side peripheral wall portion of the preform that is in contact with the first mold wall portion, temperature difference of each other in both the resin molding material that is set to be equal to or greater than 10 ° C. in the melt after the preliminary temperature regulation of the major axis side wall portion of the preform in contact with the mold wall portion
Preliminary temperature control mold used for the preliminary temperature control in the method for manufacturing a hollow molded article by blanking rows molding, characterized in that. A preliminary temperature control die used for preliminary temperature control in a method for producing a hollow molded article by blow molding according to claim 1 ,
A preliminary temperature control die used for preliminary temperature control in a method of manufacturing a hollow molded product by blow molding, wherein the wall thickness of the first mold wall portion is set to be thinner than 0.5 cm. A preliminary temperature adjustment die used for preliminary temperature adjustment in the method for producing a hollow molded article by blow molding according to claim 1 or 2 ,
On the side opposite to the cavity surface of the first mold wall part, a hollow molding by blow molding is integrally provided with a reinforcing member that is formed of a heat-insulating material and reinforces the first mold wall part from behind. Preliminary temperature control mold used for preliminary temperature control in the manufacturing method of goods.

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