阅读说明：本技术 宝特瓶制造装置 (PET bottle manufacturing device ) 是由 藏田广明 于 2019-09-11 设计创作，主要内容包括：提供一种即使包含耐热宝特瓶的任何种类的宝特瓶,也可效率良好地制造,同时整体大小不会大型化,可设置于被限制的空间的宝特瓶制造装置。一种宝特瓶制造装置(1),其具有：搬运线(200),其将作为宝特瓶而被吹塑成型的瓶坯以规定之间隔依次搬运；瓶坯投入部(300),其将瓶坯投入到搬运线；宝特瓶取出部(700),其取出被制成的宝特瓶；吹塑成型部(600)；瓶坯加热部(400),其在搬运线的规定区间内进行为以吹塑成型部吹塑成型瓶坯所需的加热；以及瓶坯吹风部(500),其在瓶坯被瓶坯加热部加热的过程中吹风到瓶坯。(Provided is a PET bottle manufacturing device which can manufacture PET bottles efficiently even in any type of PET bottles including heat-resistant PET bottles, and can be installed in a limited space without increasing the overall size. A PET bottle manufacturing apparatus (1) comprising: a conveying line (200) for sequentially conveying bottle preforms blow-molded as PET bottles at predetermined intervals; a preform input unit (300) for inputting preforms into the conveying line; a PET bottle take-out section (700) for taking out the produced PET bottle; a blow molding section (600); a preform heating section (400) for heating the preform in a predetermined section of the transfer line, the preform being blow molded by the blow molding section; and a preform blowing section (500) that blows air to the preform in the process in which the preform is heated by the preform heating section.)

1. A PET bottle manufacturing apparatus for manufacturing PET bottles by blow molding, the PET bottle manufacturing apparatus being characterized in that,

the PET bottle manufacturing apparatus comprises:

a conveying line for sequentially conveying bottle blanks to be blow molded as PET bottles at a predetermined interval;

a preform loading section provided upstream of the conveying line and configured to load the preforms into the conveying line;

a PET bottle take-out section provided downstream of the transport line and configured to take out PET bottles produced by the PET bottle producing apparatus;

a blow molding section provided upstream of the transfer line from the PET bottle take-out section;

a preform heating section provided between the preform loading section and the blow molding section in the transfer line, the preform heating section heating the preform in a predetermined section of the transfer line to blow mold the preform by the blow molding section;

a preform blowing section that blows air to the preform at a predetermined position from the preform heating section to the blow molding section; and

and a rotating device which rotates the bottle preform around the axis thereof during the period of heating the bottle preform and the period of blowing air in a predetermined section of the conveying line.

2. The PET bottle manufacturing apparatus of claim 1,

the bottle blank blowing portion is configured to: blowing air to the preform during at least a portion of the process of heating the preform by the preform heating section.

3. The PET bottle manufacturing apparatus of claim 2,

the preform blowing section includes a blowing slit guide for causing air to be intensively blown to a predetermined portion of the preform.

4. The PET bottle manufacturing apparatus of claim 1,

the preform blowing section is provided at a predetermined position between the time when the preform is heated by the preform heating section and the time when the preform enters the blow molding section.

5. The PET bottle manufacturing apparatus as set forth in any one of claims 1 to 4,

the PET bottle manufacturing apparatus can put a preform, which can be blow molded into a PET gallon bottle for a drinking water dispenser, into the preform putting section.

6. The PET bottle manufacturing apparatus as set forth in any one of claims 1 to 4,

the PET bottle manufacturing apparatus is capable of feeding a preform of a PET bottle, which can be blow molded into a particular shape having a different shape from that of a PET bottle having a substantially constant diameter, into the preform feeding section.

7. The PET bottle manufacturing apparatus according to any one of claims 1 to 6,

in order to mass-produce pet bottles by the pet bottle manufacturing apparatus, the blow molding unit is configured to blow mold a plurality of pet bottles at a time.

8. The PET bottle manufacturing apparatus according to any one of claims 1 to 7, wherein the PET bottle manufacturing apparatus is capable of manufacturing a heat-resistant PET bottle.

9. The PET bottle manufacturing apparatus according to any one of claims 1 to 8,

instead of the preform made of polyethylene terephthalate, a preform, which may be crystallized during heating, may be introduced into the preform introduction portion.

Technical Field

The present invention relates to a pet bottle (pet bottle) manufacturing apparatus that manufactures a pet bottle by taking out a bottle preform after molding the bottle preform by an injection molding machine and reheating the bottle preform by a blow molding machine.

Background

A pet bottle manufacturing apparatus has been known which manufactures a pet bottle by taking out a bottle preform after molding the preform by an injection molding machine and reheating the preform by a blow molding machine (for example, see patent document 1).

As described in paragraph (0024) of this patent document 1, the blow molding apparatus includes a tray horizontal circulation path through which a plurality of disc-shaped trays are circulated while the bottle preforms are inverted. Further, in the tray horizontal circulation path, it includes: a bottle preform supply unit for putting bottle preforms into the trays; a heating unit that heats the bottle preform carried by the tray; a blow molding section for blow molding the preform carried by the tray and heated by the heating section; and an article recovery section that recovers an article blow-molded by the blow-molding section from the tray.

Prior patent literature

Patent document

[ patent document 1] Japanese patent application laid-open No. 2004-284016

Disclosure of Invention

Problems to be solved by the invention

The material of the bottle preform described in patent document 1 is polyester, polystyrene, polypropylene, polyethylene naphthalate, or polyethylene terephthalate. Here, when a bottle preform made of polyethylene terephthalate (PET) which is a material of a PET bottle is blow molded, for example, a whitening phenomenon (crystallization phenomenon) occurs when the bottle preform is heated abruptly or at a high temperature exceeding a certain temperature in a heating process of the bottle preform by a heating device before blow molding, and the portion does not expand well in the subsequent blow molding, resulting in a PET bottle which is a defective product.

In particular, when blow molding a preform for producing a pet gallon bottle for a drinking machine which is much larger than a normal pet bottle, a preform having a much larger wall thickness than that of the preform for producing the normal pet bottle is used, and therefore, the amount of heat increases in accordance with the preform.

Therefore, when the heating is rapidly performed to improve the production efficiency, the above-mentioned problem occurs, and when the heating is slowly performed to suppress the occurrence of the whitening phenomenon, a lot of time is required for the heating process, and the production efficiency is lowered. In order to suppress the occurrence of the whitening phenomenon and heat simultaneously, it takes a long time to heat and the heat penetrates from the outside to the inside of the preform, so that the entire length of the heating portion becomes long, and as a result, the size of the pet bottle manufacturing apparatus itself becomes large. In addition, it also becomes time consuming to manufacture the bottle body.

Further, in order to manufacture a bottle having a deformed shape which three-dimensionally imitates a popular cartoon character or a famous building as a sightseeing place, for example, unlike a general bottle having a substantially constant diameter, the same problem occurs when a bottle preform is blow molded.

Specifically, when producing a pet bottle having a deformed shape, a bottle preform having a wall thickness thicker than that of a bottle preform used in producing a normal pet bottle is used in many cases. Since a large number of irregularly shaped pet bottles are stretched in a vertically and horizontally complicated manner, they are thicker than simple-shaped pet bottles, and in the case of irregularly shaped pet bottles, a bottle blank having a larger thickness than that of ordinary pet bottles is often used in order to give a higher quality feeling than other pet bottles, with a high emphasis on appearance. Therefore, in order to sufficiently heat the thick portion, a large amount of heat must be added to the thick portion in accordance with the thickness of the thick portion, as compared with the conventional preform.

In comparison with a preform used for producing such a normal pet bottle, since a preform having a large thickness is heated rapidly, the above-described whitening phenomenon (crystallization phenomenon) occurs immediately, and therefore, it is necessary to heat the thick portion in the same manner as in the case of heating a normal preform.

As a result, the heating unit that heats the tray while moving the conveying line must be long in overall length and must be heated gradually. Namely, it represents: the length occupied by the heating portion in the conveying line becomes correspondingly long. Therefore, the size of the PET bottle manufacturing apparatus itself is also increased.

In many cases, a space-saving design of the apparatus is more desirable than a mainframe if a pet bottle manufacturing apparatus is installed in a limited space in terms of the size of the apparatus. In addition, the number of the apparatus is often increased in order to increase the production amount, but since the space is limited, only a small number of the pet bottle manufacturing apparatuses can be provided.

Further, since the time required for heating the preform or the time required for blow molding the preform into a pet bottle from the preform is constant, the number of sets of the pet bottle manufacturing apparatus is reduced, which means that the throughput of the pet bottle is reduced, and as a result, there is a possibility that a delivery situation in which a large number of pet bottles must be manufactured in a short period of time cannot be dealt with.

When a large number of pet bottles must be manufactured for delivery in a short period of time, that is, when mass production is required, it is necessary to increase the number of products per unit time. Therefore, there are many types of mass production machines using a large number of molds and having a high production speed, and in the case of a general mass production machine, the total length of the heating section is increased to increase the production speed, and the machine is increased in size.

In addition, generally, when the production rate is increased, the preform is whitened (crystallized) by a method of heating at a higher temperature than usual, and cannot be blown and expanded into a pet bottle shape. Therefore, the heating temperature cannot be changed greatly from the ordinary one, and the heating portion passing speed of the preform must be increased, and the apparatus for extending the entire length of the heating portion in order to allow heat to permeate from the outside to the inside becomes large in size.

Further, a problem also arises with respect to a heat-resistant pet bottle as one form of pet bottle. The heat-resistant PET bottle is a PET bottle which can resist high-temperature liquid filling. The heat-resistant PET bottle is different from a normal ordinary-temperature bottle in that it is not deformed even when a high-temperature filler is injected.

The process for producing a heat-resistant PET bottle is roughly the same as that of a normal-temperature bottle, but the heating temperature of the preform needs to be raised to just before whitening (crystallization). Further, the blow mold in the blow molding section is different in that the blow mold for a normal-temperature bottle is cooled, and the blow mold for a heat-resistant bottle needs to be heated by a temperature regulator or the like.

For example, a crystallized resin of a preform (polyethylene terephthalate) of a PET bottle material becomes soft and stretchable when heat is applied, but becomes whitened (crystallized) and is not stretchable when a certain temperature is exceeded.

In the production of a heat-resistant bottle, it is necessary to blow-mold a bottle body before the bottle preform is completely whitened, taking advantage of the above characteristics. The reason why the blow molding is performed before the complete whitening is that, when the whitening is complete, the blow molding does not stretch even if air is blown, and thus a PET bottle product cannot be produced.

In order to increase the heat-resistant temperature, the heating temperature of the preform and the mold temperature during blow molding are preferably higher. When the resultant heat-resistant PET bottle is nearly whitened (crystallized), the resin itself becomes hard, and therefore, even when a high-temperature liquid is injected, the bottle is not deformed much. For this reason, the heat-resistant pet bottle is more whitish in appearance than a pet bottle used at normal temperature.

However, since high-temperature heat hardly permeates from the outside to the inside of the preform, conventionally, the outside of the preform begins to whiten before the heat is transferred to the inside, and the preform cannot be expanded into a pet bottle shape by blow molding, or if the preform cannot be heated until just before whitening in order to avoid whitening on the outside of the preform, there is a problem that only a bottle having a low heat-resistant temperature can be molded.

Because of such problems, conventionally, in the production of heat-resistant bottles, a relatively complicated production process different from the production of normal-temperature bottles has been required, and this process has been required to be simplified.

The invention aims to provide a PET bottle manufacturing device, which can efficiently and stably manufacture a good PET bottle without wasting redundant time by enabling a heating part to reach the necessary minimum length even for any PET bottle, and can save space design even if the whole size is not large and the installation space is limited. Further, there is provided a PET bottle manufacturing apparatus capable of manufacturing a PET bottle without performing a complicated process when the PET bottle is a heat-resistant PET bottle.

Means for solving the problems

In order to solve the above problem, a pet bottle manufacturing apparatus according to claim 1 of the present invention is a pet bottle manufacturing apparatus for manufacturing a pet bottle by blow molding, the apparatus comprising:

the PET bottle manufacturing apparatus comprises:

a conveying line for sequentially conveying bottle blanks to be blow molded as PET bottles at a predetermined interval;

a preform loading section provided upstream of the conveying line and configured to load the preforms into the conveying line;

a PET bottle take-out section provided downstream of the transport line and configured to take out PET bottles produced by the PET bottle producing apparatus;

a blow molding section provided upstream of the transfer line from the PET bottle take-out section;

a preform heating section provided between the preform loading section and the blow molding section in the transfer line, the preform heating section heating the preform in a predetermined section of the transfer line to blow mold the preform by the blow molding section;

a preform blowing section that blows air to the preform at a predetermined position from the preform heating section to the blow molding section; and

and a rotating device which rotates the bottle preform around the axis thereof during the period of heating the bottle preform and the period of blowing air in a predetermined section of the conveying line.

Further, the PET bottle manufacturing apparatus according to claim 2 of the present invention is the PET bottle manufacturing apparatus according to claim 1,

the bottle blank blowing portion is configured to: blowing air to the preform during at least a portion of the process of heating the preform by the preform heating section.

Further, the PET bottle manufacturing apparatus according to the 3 rd aspect of the present invention, in the PET bottle manufacturing apparatus according to the 2 nd aspect,

the preform blowing section includes a blowing slit guide for causing air to be intensively blown to a predetermined portion of the preform.

Further, the PET bottle manufacturing apparatus according to the 4 th aspect of the present invention is the PET bottle manufacturing apparatus according to the 1 st aspect,

the preform blowing section is provided at a predetermined position between the time when the preform is heated by the preform heating section and the time when the preform enters the blow molding section.

The PET bottle manufacturing apparatus according to claim 5 of the present invention is the PET bottle manufacturing apparatus according to any one of claims 1 to 4,

the PET bottle manufacturing apparatus can put a preform, which can be blow molded into a PET gallon bottle for a drinking water dispenser, into the preform putting section.

The PET bottle manufacturing apparatus according to claim 6 of the present invention is the PET bottle manufacturing apparatus according to any one of claims 1 to 4,

the PET bottle manufacturing apparatus is capable of feeding a preform of a PET bottle, which can be blow molded into a particular shape having a different shape from that of a PET bottle having a substantially constant diameter, into the preform feeding section.

The PET bottle manufacturing apparatus according to claim 7 of the present invention is the PET bottle manufacturing apparatus according to any one of claims 1 to 6,

in order to mass-produce pet bottles by the pet bottle manufacturing apparatus, the blow molding unit is configured to blow mold a plurality of pet bottles at a time.

The PET bottle manufacturing apparatus according to claim 8 of the present invention is the PET bottle manufacturing apparatus according to any one of claims 1 to 7,

the PET bottle manufacturing apparatus can manufacture heat-resistant PET bottles.

The PET bottle manufacturing apparatus according to claim 9 of the present invention is the PET bottle manufacturing apparatus according to any one of claims 1 to 8,

instead of the preform made of polyethylene terephthalate, a preform, which may be crystallized during heating, may be introduced into the preform introduction portion.

Effects of the invention

According to the present invention, there is provided a pet bottle manufacturing apparatus capable of efficiently and stably manufacturing a good quality pet bottle without spending an extra time even if a heating portion has a required minimum length for any kind of pet bottle, and capable of saving a space design even if an installation space is limited without increasing the size of the whole apparatus. Further, there is provided a PET bottle manufacturing apparatus capable of manufacturing a PET bottle without performing a complicated process when the PET bottle is a heat-resistant PET bottle.

Drawings

Fig. 1 is a plan view schematically showing the structure of a pet bottle manufacturing apparatus according to embodiment 1 of the present invention.

Fig. 2 is a schematic view of the bottle preform and the mandrel passing between the heating section and the blowing section of the pet bottle manufacturing apparatus shown in fig. 1, as viewed from the upstream side of the conveying line.

Fig. 3 is an explanatory view showing a heated state from the heating unit and a blown state from the blowing unit with respect to the bottle preform in fig. 2.

Fig. 4 is an explanatory view corresponding to fig. 2 showing a heated state from the heating section and a blown state from the blowing section with respect to the bottle preforms in fig. 3.

Fig. 5 is a plan view schematically showing the structure of a pet bottle manufacturing apparatus according to embodiment 2 of the present invention.

Detailed Description

Next, the configuration of the pet bottle manufacturing apparatus 1 according to embodiment 1 of the present invention will be described. The pet bottle manufacturing apparatus 1 is a manufacturing apparatus of the following type: the preform molded by the injection molding machine and taken out is reheated by the blow molding machine to manufacture a PET bottle.

Hereinafter, a baote bottle manufacturing apparatus 1 according to embodiment 1 of the present invention (hereinafter, simply referred to as "the present embodiment" or "the embodiment" as appropriate) will be described in detail with reference to the drawings. Fig. l is a plan view schematically showing the structure of a pet bottle manufacturing apparatus 1 according to embodiment 1 of the present invention. Fig. 2 is a schematic view of the preform 20 and the mandrel 100 passing between the heating section and the blowing section of the pet bottle manufacturing apparatus 1 shown in fig. 1, as viewed from the upstream side of the conveying line 200. Fig. 3 is an explanatory view showing a heated state from the heating unit and a blown state from the blowing unit with respect to the preform 20 in fig. 2. Fig. 4 is an explanatory view showing a heated state from the heating section and a blown state from the blowing section with respect to the preform 20 shown in fig. 3, corresponding to fig. 2. In fig. 1, the number of mandrels 100 is shown in a small number for simplifying the illustration for easy understanding of the invention, but in reality, although the number of mandrels 100 is larger than the number shown in the figure, the mandrels 100 are conveyed at a predetermined interval through a conveying line 200, depending on the size of the pet bottle manufacturing apparatus 1.

The pet bottle manufacturing apparatus 1 of the present embodiment (hereinafter, simply referred to as "pet bottle manufacturing apparatus l") is a pet bottle manufacturing apparatus for manufacturing a pet bottle 30 by blow molding, and includes: a base 11 whose upper surface is horizontal in a set state; a conveying line 200 provided on the upper surface of the base 11, for sequentially conveying the preforms 20 carried by the mandrels 100 at predetermined intervals; a preform loading unit 300 for sequentially loading preforms 20 onto the mandrels 100 of the conveying line 200; a preform heating section 400 that sequentially heats preforms 20 that are introduced into the preform introduction section 300 and transported through the transport line 200; a preform blowing section 500 disposed opposite to the preform heating section 400; a blow molding unit 600 that sequentially blow molds the preforms 20 that are heated by the preform heating unit 400 and conveyed through the conveying line 200; and a pet bottle take-out unit 700 for sequentially taking out the pet bottles 30 which are blow molded by the blow molding unit 600, manufactured as products from the preforms 20, and transported by the transport line 200.

The portion where preform heating section 400 and preform blowing section 500 are arranged includes a heated air exhaust section 800. Further, an intermediate blowing section 900 is provided in the vicinity of the transfer line 200 between the preform heating section 400 and the blow molding section 600.

In the following description, the preform loading section 300 and a part of the transfer line 200 corresponding thereto are referred to as a preform loading station, the preform heating section 400 and the preform blowing section 500 and a part of the transfer line 200 sandwiched therebetween are referred to as a preform heating/blowing station, the blow molding section 600 for blow molding the preform 20 and a part of the transfer line 200 corresponding thereto are referred to as a preform blow molding station, and the transfer blowing section 900 and a part of the transfer line 200 corresponding thereto are referred to as a transfer station, as appropriate.

As shown in fig. 1, the conveying line 200 has a rail shape in a plan view, and the mandrels 100 are arranged at predetermined intervals and moved counterclockwise in the drawing at a predetermined moving speed, and the mandrels 100 are moved while holding the bottle preforms 20 and the pet bottles 30 in the inverted state, respectively. The shape of the conveyance line and the moving direction of the mandrel in the present embodiment are only examples of the present invention, and the conveyance line in fig. 1 is merely an example. That is, the conveying line may have a shape other than the rail shape in plan view, and similarly, the moving direction of the mandrel may be clockwise in the drawing.

The transfer line 200 is composed of three sections, namely, a preform transfer line section 210 from the preform loading section 300 to the blow molding section 600 (a section in which hatching is applied only to a circle representing the inside of the double circle of the mandrel 100 in the drawing), a pet bottle transfer line section 220 from the blow molding section 600 to the pet bottle removing section 700 (a section in which hatching is applied to the whole of the double circle representing the mandrel 100 in the drawing), and an empty mandrel transfer line section 230 from the pet bottle removing section 700 to the preform loading section 300 (a section in which hatching is not applied to the whole of the double circle representing the mandrel 100 in the drawing).

The rotating device 250 is provided below the conveying line 200 defined between the preform heating section 400 and the preform blowing section 500 and below the conveying line 200 in the vicinity of the intermediate blowing section.

The rotating device 250 rotates the mandrel 100 and rotates the preforms 20 around the mandrels while the preforms 20 are heated in a predetermined section of the conveying line 200 in the preform heating/blowing station and the transfer station.

As shown in fig. 2, the mandrel 100 includes a housing 110 and a mouth portion assembling portion 120 detachably fixed to the housing 110.

The mouth portion assembling portion 120 is inserted into the mouth portion 21 of the preform 20 and firmly fitted to the same, and is held on the mandrel 100 while the preform 20 and the blow-molded pet bottle 30 are held in a vertically inverted state.

The lower side of the mandrel 100 includes a rotary joint 130 that rotates the mandrel 100 itself in conjunction with a rotating device provided in the heating/blowing station and the transfer station.

The preform input portion 300 functions as follows: when the hollow mandrel 100 on the conveying line reaches the preform loading station, the mouth portion 21 of the preform 20 is fitted into the mouth portion assembling portion 120 of the hollow mandrel 100, and the plurality of preforms 20 are sequentially supplied to the next heating/blowing station while the preform 20 is held in an inverted state by the mandrel 100. In addition, various known devices such as a dedicated loading device and an orthogonal coordinate type robot are used in the preform loading unit 300.

The preform heating section 400 is provided on one side of the conveying line 200 of the heating/blowing station occupying a predetermined section of the conveying line 200. The preform heating section 400 has the following structure: in fig. 1, a plurality of heaters 411,412,413,414,415,416(410) having a predetermined length extending in the horizontal direction on the front side of the conveyance line 200 are arranged at predetermined intervals in the vertical direction as shown by the solid line in fig. 2 (in the present embodiment, a small number of 6 heaters are shown for the purpose of understanding the invention and facilitating the illustration). Further, the heater 411 at the lowermost stage is disposed at a height suitable for applying a heating amount for expanding the vicinity of the preform 20, except the mouth portion 21, of the mandrel 100, which is carried through the heating/blowing station by blow molding. In practice, the number of heaters varies depending on the model of the pet bottle manufacturing apparatus, and a larger number of heaters than the present embodiment, for example, 10 or more heaters, are generally arranged at predetermined intervals to cope with heating of bottle preforms having different heights.

Further, a heating-section internal blowing section 420 is provided on the back side of each heater 410. The heating-section internal blowing section 420 is constituted by a fan or a blower, and functions as follows: in each heater 410, the heated air is not trapped in the heater, and the preforms 20 in the heating/blowing station are efficiently heated (see the arrow of the right-to-left wavy line in fig. 4).

The amount of heat to be applied to each preform 20 by the preform heating section 400 can be set high by adjusting the heater. The heating amount was set as follows: at least a part of preform 20 is whitened (crystallized) when preform blowing section 500 is not activated, but such whitening (crystallization) does not occur even when heated at high temperature when preform blowing section 500 is activated. That is, compared to the conventional pet bottle manufacturing apparatus not having the preform blowing section 500, the amount of heat per preform 20 can be increased in the conveying line 200 in the heating/blowing station.

The preform blowing section 500 is provided on the other side of the preform heating section 400 with respect to the conveying line 200 of the heating/blowing station occupying a certain section of the conveying line 200. The preform blowing section 500 is not shown in detail, but includes a blower 510 such as a fan, a blower, or an air compressor, and a blowing slit guide 520 for locally blowing the air flow sent by the blower 510 to the entire preform.

As shown in FIG. 3, the blowing slit guide 520 is disposed so that the partition plates 521 to 527 face in the same direction at predetermined intervals. The air sent from the air blower 510 is rectified by passing through the partition plates 521-527 constituting the blowing slit guides 520, and is blown locally from the slit guides to the entire preform (see the white arrows between the blowing slit guides 520 in fig. 3 and the white arrows from the left side to the right side of the blowing slit guides 520 in fig. 4).

In the present embodiment, the number of the blowing slits is reduced so that the interval between the blowing slits is wide for the purpose of understanding the invention and facilitating the illustration, but in practice, the present invention is not limited to this form, and a large number of blowing slit guides are provided in consideration of the blowing effect on the bottle preforms.

That is, the air blown toward the respective preforms 20 by the air blowing slit guides 520 is heated by the heater and blown to the entire preform 20 moving on the conveying line 200 while rotating around the axis. This suppresses the occurrence of whitening (crystallization) due to a rapid temperature rise on the surface of preform 20 heated by heaters 410, and also reduces the temperature difference between the inner and outer surfaces of the preform, thereby achieving an optimum preform state for bottle molding.

The blowing amount of each bottle preform 20 by the bottle preform blowing portion 500 can be adjusted as follows: when the preform blowing section 500 is not activated, at least a part of the preform 20 is whitened (crystallized) by the high-temperature heating from the preform heating section 400, but when the preform blowing section 500 is activated, such whitening (crystallization) is not generated even by the high-temperature heating.

In the present embodiment, the preform blowing section 500 does not perform automatic frequency conversion control. The reason for this is that: when the automatic frequency conversion control is performed, the motor is automatically controlled depending on the temperature in the preform heating section 400, and the air volume changes, so that the surface temperature of the heated preform 20 also varies. Therefore, in the present embodiment, the following conditions are set: the intensity of the air blown to the preforms 20 may be manually adjusted so that the same amount of air is always blown while heating the preforms 20 of the same batch. However, the blow may be performed to the bottle preform 20 being heated by a control method other than this embodiment, if it is within a range that the operation of the present invention can be sufficiently exerted.

The heated air exhaust unit 800 is provided above the space between the preform heating unit 400 and the preform blowing unit 500. The heated air exhaust portion 800 functions as follows: the air generated in the heating/blowing station after heating the preforms 20 is sucked in as a whole to be discharged to the outside (refer to an upward arrow bent toward the heated air discharge part 800 in fig. 4).

In the present embodiment, since the mouth portion 21 of the preform 20 (the drinking mouth portion of the blow-molded pet bottle 30) faces downward as described above, the heated air exhaust portion 800 is provided above the space between the preform heating portion 400 and the preform blowing portion 500. However, when the mouth portion 21 of the preform 20 (the drinking mouth portion of the bottle 30 after blow molding) is directed upward according to the structure of the pet bottle manufacturing apparatus 1, the heated air exhaust portion 800 may be provided in the heating/blowing station to exhaust the heated air to the lower side so that the heated air is not blown to the mouth portion 21 of the preform 20.

The transfer blowing section 900 is provided at a standby position from the heating/blowing station to the blow molding station, that is, at a transfer station staying at a position of each mandrel 100 during a period in which the preforms 20 mounted on the mandrels 100 are blow molded by the blow molding section 600, and functions to further blow the preforms 20 immediately before the molds 611,612, (610) heated by the heating/blowing station and fed into the blow molding section 600. In addition, as in the bottle preform blowing section 500, an appropriate blowing device such as a fan, a blower, an air compressor, or the like is used.

In the transfer station, since heat penetrates into the preforms 20 and a whitening phenomenon (crystallization phenomenon) may progress, whether or not to perform blowing in the transfer blowing section 900 is determined according to the crystallization state of the preforms 20 immediately before blow molding. That is, when it is clear that the preform 20 is not whitened (crystallized) in the transfer station, the transfer blower unit 900 does not need to be activated.

In fig. 1, the intermediate blowing section 900 is provided at a position which is a part of the vicinity of the conveying line 200 between the preform heating section 400 and the preform blowing section 500 and the blow molding section 600 and which is temporarily on standby before the blow molding of the preform 20, but may be provided entirely in the vicinity along the conveying line 200.

The blow molding portion 600 is provided across the conveying line 200. When the preform 20 before blow molding is attached to the mandrel 100 from the upstream side of the transfer line 200 and moved, as shown in fig. 1, the halves 611 and 612 of the mold 610 are separated from each other and opened, and the mandrel 100 and the preform 20 fitted thereto are positioned and stopped at the pet bottle molding station as desired. After these stops, the half portions 611 and 612 of the mold 610 come into contact with each other to be closed, thereby forming the mold 610 for blow molding. Then, in this state, after blow molding is performed to mold the pet bottle 30 from the bottle preform 20, the half parts 611 and 612 of the mold 610 are separated from each other again to be opened, and the blow molded pet bottle 30 is moved to the pet bottle taking-out portion 700 for each mandrel 100.

The pet bottle taking-out unit 700 functions as follows, in contrast to the preform loading unit 300: the pet bottle 30 is molded in the blow molding unit 600, and the pet bottle 30 moved in the conveying line 200 while being attached to the mandrel 100 is taken out as a product at a pet bottle take-out station. In the pet bottle taking-out section 700, as in the case of the preform loading section 300, various known devices such as a dedicated taking-out device and an orthogonal coordinate type robot are used.

The base 11 includes a control device (not shown in the drawings) for operating the respective components of the pet bottle manufacturing apparatus 1 of the present embodiment in synchronization with each other at predetermined operation timings, and an input device and a display device (not shown in the drawings) for an operator to operate the apparatus or for checking the start-up state of the apparatus in the pet bottle manufacturing apparatus 1.

Next, a method for manufacturing the pet bottle 30 using the pet bottle manufacturing apparatus 1 of the present embodiment will be described. First, in the preform loading section 300, the preforms 20 are inserted into the mouth assembling sections 120 of the respective mandrels 100 one by one in sequence. Then, the preform is conveyed to a heating/blowing station along the preform conveying line section. In the stage near the heating/blowing station, each mandrel 100 is rotated by a rotation device 250. Accordingly, the preform 20 fitted into each mouth portion assembling portion 120 also rotates around its axis together with each mouth portion assembling portion 120.

The preforms 20 pass between the preform heating section 400 and the preform blowing section 500 of the heating/blowing station while rotating. During the passage of the heating/blowing station, a greater than usual degree of heating is applied by each heater 410: when there is no local blowing from the preform blowing portion, at least the surface of the preform 20 is whitened (crystallized).

That is, such heating amount is applied from the preform heating section 400, and the preforms 20 sequentially pass through the heating/blowing station while preventing the whitening phenomenon (crystallization phenomenon) of the preforms 20 by local blowing from the preform blowing section 500.

In this way, the air heated to the preforms 20 in the heating/blowing station is always discharged through the heated air discharging unit 800, and the amount of heating and the amount of blowing of the preform heating unit 400, which maximally suppresses the occurrence of the whitening phenomenon (crystallization phenomenon) of the preforms 20 in the preforms 20 passing through the heating/blowing station, are always supplied to the preforms 20 in a well-balanced manner. Further, since the heated air is discharged to the opposite side of the mouth portion 21 of the preform 20, only the portion of the preform 20 to be heated can be heated.

Since the preform heating section 400 constituting the heating/blowing station, which is a characteristic part of the present invention, has a shorter length than that of the conventional pet bottle manufacturing apparatus, the preform 20 passing therethrough is efficiently heated to such an extent that the blow molding can be performed without causing a whitening phenomenon (crystallization phenomenon) in a short time.

The preform 20 heated by the heating/blowing station is on standby in a state of being mounted on the mouth portion assembling portion 120 of the mandrel 100 until the preform 20 conveyed in front of the transfer station is blow-molded by blow molding. At this time, the mandrel 100 is rotated by the rotating device 250, whereby the preform 20 is also rotated together with the mouth assembling portion 120. Further, the air is blown to the entire circumference of the axial center of the preform 20 by the intermediate blowing unit 900 provided in the intermediate transfer station, thereby preventing the occurrence of whitening (crystallization) at the intermediate transfer station.

After the blow molding of the preform 20 is completed, the blow mold 610 of the blow molding station is opened, and the continuously heated preform 20 is moved to the blow molding station for each mandrel 100 and stopped in a state of being mounted on the mouth portion assembling portion 120. Then, the blow mold 610 is closed, and the preform 20 is blow molded to the size of the pet bottle 30.

The blow molded pet bottle 30 moves for each mandrel 100 in the pet bottle conveying line section of the conveying line 200 until the pet bottle takeout station in a state where the drinking spout is fitted to the spout assembling portion 120. In the pet bottle takeout station, the pet bottles 30 are sequentially taken out as products from the mouth assembling portion 120 of the mandrel 100 by the pet bottle takeout portion 700 in a state where the mandrel 100 is stopped.

The hollow core shaft 100 after the pet bottle 30 is taken out from the mouth assembling unit 120 passes through the hollow core shaft conveying line section of the conveying line 200, moves again to the preform loading station, and repeats the above-described series of steps again.

In this way, the heating station which becomes the bottleneck of the production efficiency and miniaturization of the PET bottle manufacturing apparatus is changed to a heating/blowing station different from the conventional heating/blowing station, thereby greatly improving the production efficiency and realizing the miniaturization of the PET bottle manufacturing apparatus.

Next, the reason why the bottle preform blowing unit or the intermediate blowing unit is specially provided to actively blow the bottle preforms in the pet bottle manufacturing apparatus of the present invention, which is an example of the above-described embodiment, is described in more detail.

As a problem of applying heat to a bottle preform made of polyethylene terephthalate (PET), when the preform is rapidly heated at a temperature exceeding a certain temperature in a heating step, the surface thereof is crystallized (whitened), and in a subsequent blow molding step, it becomes impossible to re-stretch the preform. That is, in the blow molding step, the crystallized portion becomes a non-stretched bottle preform, and is blow molded into a pet bottle having no defective product of a predetermined shape. Therefore, there is a limit to the method of raising the temperature of the heater in the heating step, and it is necessary to provide a heating station that is long to some extent along the conveyance line.

In particular, in the case of a thick preform, it is necessary to rotate the mandrel so as to sufficiently heat a portion having a large thickness from the surface of the preform itself in the thickness direction to the inner surface thereof by the heater. Therefore, when heated from the surface portion of the bottle preform at a high temperature by the heater so as to be sufficiently heated to the inside surface, a temperature difference is generated between the surface and the inside surface of the bottle preform. That is, the slope of the temperature change from the surface to the inside becomes large.

In a state where the inner surface of the preform is heated to a predetermined temperature, a temperature gradient occurs in the thickness direction in relation to heating from only the surface of the preform, and the temperature of the surface of the preform becomes high, and only the surface may be whitened (crystallized).

Even if a portion of the preform is whitened (crystallized) and cannot expand as intended, the preform is not formed into a desired pet bottle shape, but is formed into a defective product, and is discarded in this state or cut again into a sheet shape and recovered, so that the yield of the product is lowered.

Therefore, conventionally, when heating a thick preform or increasing the production speed, it is necessary to increase the length of the heating station along the conveying line by a large amount. As a result, the size of the pet bottle manufacturing apparatus itself is increased, and the length of the heating station is also limited to increase the production speed, so that the production efficiency of the pet bottles is limited.

However, according to the present invention, when the preform is heated by the heater in the heating/blowing station, the preform is blown locally from the blowing slit guide of the preform blowing portion at the same time, and even if the preform has a thick wall, for example, the temperature difference between the inner and outer surfaces is reduced, and the preform can reach the predetermined temperature of the inner surface without whitening (crystallization) without taking extra time.

Further, since the blow is performed in a predetermined intermediate (standby) period until the preform fed from the heating/blowing station enters the mold for blow molding, the effect can be improved.

That is, in the present invention, the inventors have paid attention to the fact that the surface of the preforms is forcibly cooled by forming the blowing portions in the heating/blowing station and the transfer station by the preform blowing portion as described above, and thereby the whitening phenomenon (crystallization phenomenon) can be prevented from occurring on the surface of the preforms even if the heater temperature of the heating device is increased, which is technically significant.

Further, in this blowing, the preforms are rotated by the rotating device all the time, so that the heat of the heater is uniformly applied to the outer peripheral surfaces of the preforms, and at the same time, the air blown out from the guide slits of the blowing portion is uniformly blown out.

As a result, the heat of the heater is blown from the surface to the preform, and the whitening (crystallization) caused by the high temperature of the surface of the preform in the process of penetrating into the inside of the preform can be prevented as in the conventional case.

Further, by blowing air to the surface of the preform, even if the preform is heated at a higher temperature than in the conventional case, whitening (crystallization) of the surface is suppressed, and heat is immediately transferred to the inside of the preform than in the conventional case, so that the temperature difference between the surface and the inner surface is reduced. As a result, the bottle preform can be heated at a high temperature in which the slope of the entire temperature change is slow from the surface to the inner surface without causing whitening (crystallization) on the surface of the preform.

Therefore, even if the preform is thick, the preform can be heated stably at a high temperature in its entirety, and the subsequent blow molding is facilitated.

Further, according to the blowing technique specific to the present invention, since whitening (crystallization) caused by the high temperature of the surface of the preform can be prevented as in the conventional technique, it is not necessary to take a measure of penetrating heat by slowly heating the preform at a temperature at which whitening does not occur, and therefore, the heater can be set to a high temperature, and the heating time can be shortened. As a result, the heating zone can be shortened, and therefore, the power consumption of the heating device can be reduced.

Further, according to the present invention, the space saving of the pet bottle manufacturing apparatus is achieved, which brings about a great advantage. That is, according to the conventional pet bottle manufacturing apparatus, particularly when a thick preform or the like is made into a pet bottle, the heater time needs to be made long, and accordingly, a long heating station is required, but in the case of the present invention, the heating time can be shortened in the heating process of the preform, and therefore, the heating/blowing station can be made short.

Further, according to the pet bottle manufacturing apparatus of the present invention, stable blow molding can be performed even if the bottle preform has a large wall thickness, and thus, a pet bottle can be manufactured with high yield. As a result, various types of bottle preforms for producing pet bottles can be introduced into the pet bottle producing apparatus. Specifically, a bottle preform with a large wall thickness, which is blow molded into a pet gallon bottle for a drinking machine, is exemplified. Further, the bottle preform having a thick wall can be used also for a pet bottle blow molded into a deformed shape different from a general pet bottle having a substantially constant diameter, that is, for example, a bottle preform having a deformed shape three-dimensionally imitating a popular cartoon character or a building having famous sites.

In addition, in the case of the pet bottle manufacturing apparatus of the present invention, when it is desired to install the pet bottle manufacturing apparatus in a limited space, it can be designed to save space compared with a mainframe.

That is, it is not necessary to increase the entire length of the heating section more than necessary to increase the production speed, as in a general mass production machine, and as a result, the machine does not become large. Specifically, in the case of a conventional general manufacturing apparatus, in a method of raising the heating temperature to a higher temperature than usual in order to increase the production rate, the preform is whitened (crystallized) and it is difficult to blow-expand the preform into a PET bottle shape. In order to prevent this, the heating temperature does not change much compared with the usual temperature, and it is necessary to increase the speed of passing the heating portion of the preform, and in order to allow heat to permeate from the outside to the inside, it is necessary to provide a device for extending the entire length of the heating portion, which leads to an increase in the size of the machine. However, in the case of the present invention, since the bottle preform can be heated at a high temperature by the blowing device and the heating zone is shortened, there is a characteristic corresponding to a space-saving design that a large number of bottle preforms can be heated in a shorter time than in the conventional art, and blow molding can be performed by placing them in a mold having a large number of modules for mass production, and therefore, a large number of pet bottles can be produced in a shorter time than in the conventional art.

Further, the pet bottle manufacturing apparatus according to the present invention is also suitable for manufacturing heat-resistant pet bottles. Specifically, the problem of the heat-resistant pet bottle having a pet bottle form described in detail as a problem to be solved can be solved. That is, according to the present invention, since high-temperature heat can permeate from the outside to the inside of the preform, unlike the conventional art, the problem that the preform cannot be blow-molded and expanded to a pet bottle shape because whitening on the outside progresses before heat on the outside is transferred to the inside, or only a bottle body having a low heat-resistant temperature cannot be molded because the preform cannot be heated to be whitened in order to avoid whitening on the outside of the preform can be solved. As a result, in the case of the present invention, when manufacturing the heat-resistant bottle, it is not necessary to perform a complicated manufacturing process different from the conventional normal-temperature bottle manufacturing process, and this process can be simplified.

Next, the extent of the application of the pet bottle manufacturing apparatus of the present invention described above will be described. First, the advantages that can be applied to a large-capacity bottle such as a drinking fountain will be described. The water dispenser (3 gallon/5 gallon, etc.) is manufactured by largely stretching a bottle body.

When a large capacity bottle is expanded like a gallon bottle, since a bottle preform is thermoformed at a high temperature when a corner portion is formed, the corner portion is often wrinkled or whitened, and it is difficult to achieve a desired molding condition in the past.

Further, it is also advantageous for the application of a PET bottle having a high elongation (PET bottle requiring a large stretch of a bottle preform). Since it takes time for the thick bottle preform used in the manufacture of a complicated PET bottle to be thermally infiltrated into the inside, the air blowing technique is used to shorten the time for infiltrating into the bottle preform, so that a PET bottle having a constant surface and inner surface temperature can be formed from a high-temperature bottle preform.

Moreover, the scope of the present invention is not limited to the above-described embodiments. That is, the present invention is not limited to the material of the preform in the above embodiment, and for example, instead of the preform made of polyethylene terephthalate, a preform made of polypropylene (PP), for example, which may be crystallized during heating, may be introduced into the preform introducing part of the pet bottle manufacturing apparatus of the present invention.

The scope of the present invention is not limited to the shapes and the number of components illustrated in the above embodiments. For example, the present invention can be applied to a pet bottle manufacturing apparatus in which the entire conveying line is provided above the pet bottle manufacturing apparatus, and the preform or pet bottle is suspended while moving the bottle bodies along the conveying line by providing the mandrel to which the preform or pet bottle is attached downward at a predetermined interval on the conveying line. In this case, the heated air exhaust portion of the heating/blowing station may be located on the opposite side of the mouth portion of the preform.

Further, in the preform blowing portion, it is not necessary to provide the blow guide slit, but it is preferable to provide the blow guide slit, whereby the preform can be efficiently blown.

In fig. 1, the preform blowing section 500 is formed to have a length substantially equal to that of the heater 410 of the preform heating section 400 along the conveying direction of the mandrel, but the length is not necessarily equal to that of the preform blowing section 500.

Further, in the heating/blowing station, if the bottle preform blowing section is provided, the intermediate blowing section is not necessarily provided between the heating/blowing station and the blow molding station. However, the above-described operation of the present invention can be more effectively achieved by providing the intermediate blowing portion in a part or all of the vicinity of the conveyance line therebetween.

Further, in order to make it more likely to mass-produce pet bottles by the pet bottle manufacturing apparatus of the present invention, the blow molding portion may be configured to blow mold a plurality of pet bottles at a time. Specifically, for example, a plurality of molds are arranged in series and side by side in the blow molding section, and a bottle preform is simultaneously blow molded in each mold to form a pet bottle. Since the preform heating section is shorter than conventional mass production machines, it is possible to cope with mass production even if it is a manufacturing apparatus designed to save space compared with the conventional apparatus.

Further, according to the pet bottle manufacturing apparatus of the present invention, instead of the above-described bottle preform made of polyethylene terephthalate, a bottle preform, which may be crystallized during heating, may be put into the bottle preform putting portion. Specifically, for example, a preform made of a thermoplastic resin such as polypropylene (PP) is introduced into a preform introduction portion, and thereby pet bottles made of polypropylene and usable as containers for beverages or containers for foods can be mass-produced by a small pet bottle production apparatus.

Finally, embodiment 2 that can exhibit the effects of the present invention will be described. Fig. 5 is a plan view schematically showing the structure of a pet bottle manufacturing apparatus according to embodiment 2 of the present invention. Since the pet bottle manufacturing apparatus according to embodiment 2 basically has a structure equivalent to that of the pet bottle manufacturing apparatus according to embodiment 1, only the characteristic portions of embodiment 2 that are different from each other will be described, and the same reference numerals are given to the other structures, and detailed description thereof will be omitted.

In fig. 5, a smaller number of mandrels 100 are depicted for the purpose of facilitating understanding of the invention and simplifying the illustration, but in practice, the number of mandrels 100 is larger than the illustrated number, although it differs depending on the size of the pet bottle manufacturing apparatus 2, and the mandrels 100 are conveyed by the conveying line 200 at shorter intervals.

In the pet bottle manufacturing apparatus 1 according to embodiment 1, the preform blowing section 500 is configured to blow air to the preforms 20 while the preforms 20 are being heated by the preform heating section 400. The intermediate blowing unit 900 is provided as an auxiliary blowing means at a predetermined position in an intermediate transfer zone from the heating of the preforms 20 to the entry into the blow molding unit 600. It should be noted that the intermediate transfer blowing unit 900 merely performs an auxiliary blowing function, and if the main preform blowing unit 500 is provided at a position facing the preform heating unit 400, the auxiliary transfer blowing unit 900 is not necessarily required.

In the case of the pet bottle manufacturing apparatus 2 according to embodiment 2, as shown in fig. 5, a reflection plate 550 for heating promotion is provided in the preform heating section 400 instead of the preform blowing section 500 according to embodiment 1, and a transition zone blowing section 950, which is a main blowing section in the present embodiment, is provided at a position where the transition blowing section 900 that performs an auxiliary function in embodiment 1 is provided.

The heating acceleration reflecting plate 550 is provided on the opposite side of the heating heater 410 through the conveying line 200, and reflects the heat of the heater 410 to efficiently heat the preforms 20. The heating acceleration reflecting plate 550 of the preform heating section 400 is provided temporarily in embodiment 2, and is not necessarily required depending on the heating state of the preform 20 when the present invention is implemented.

The configuration of the preform heating section 400 according to embodiment 2 is provided with a heating acceleration reflecting plate 550 instead of the preform blowing section 500, and is similar to that of embodiment 1, and therefore, descriptions of the same components are omitted.

The basic configuration of the transition zone blowing section 950 is the same as that of the transition blowing section 900 according to embodiment 1, but measures can be taken to prevent the occurrence of a whitening (crystallization) phenomenon in the transition zone where the whitening (crystallization) phenomenon does not occur when the preform passes through the preform heating section 400, reliably at low cost. In fig. 5, only one transition area blowing portion 950 is shown for convenience of explanation and easy understanding of the present invention, but the present invention is not limited to the arrangement of the mandrel 100 shown in fig. 5, since the blow may be performed to several preforms 20 depending on the type of the preform.

In this way, the preform heating section 400 is not provided with the preform blowing section 500, and the transition zone blowing section 950 is provided at a predetermined position between the time when the preform heating section 400 heats the preform 20 and the time when the preform enters the blow molding section 600, so that the operational effects unique to the present invention can be sufficiently exhibited. This point will be explained below.

The reason why only the blowing section of the transition area, which is a structure unique to embodiment 2, is effective is as follows.

(1) Although whitening (crystallization) does not occur during heating of the heating zone of the preform, whitening (crystallization) may occur in the transition zone. Specifically, the whitening (crystallization) occurs immediately after the preform is fed from the preform heating section in many cases.

(2) The inventors confirmed that: since the bottle preform is heated by the preform heating portion and the heat becomes stuffy in the bottle preform as the temperature approaches the latter half of the heating portion, the temperature becomes high in the latter half of the heating portion and in the vicinity of the portion fed from the heating portion, and whitening (crystallization) occurs. Therefore, in order to prevent such a phenomenon, a method of preventing whitening (crystallization) by blowing air only in the transit zone is a very effective means in the present situation.

(3) In order to perform ideal molding in a designed manner when a pet bottle of a bottle preform is molded, it is desirable that there is no difference (constant) in the temperature of the inner and outer surfaces of the bottle preform. That is, it is preferable that the temperature gradient from the outer peripheral surface to the inner peripheral surface of the preform (gradient toward temperature decrease) is not at all, or, in fact, in consideration of various factors affecting this, the smaller the temperature gradient, the better the temperature gradient.

Therefore, when the preform heating portion is not provided with the preform blowing portion, heat is transferred from the outside to the inside of the preform in one direction when the preform is heated by the preform heating portion, and the outside and inside temperatures may not be constant at the time after the preform is sent from the preform heating portion. This is because the thicker the wall thickness of the preform, the more pronounced the tendency becomes.

Therefore, by blowing air from the outside to bring the temperatures of the inner and outer surfaces close to each other in the transition zone immediately after the heating process in which the preforms are fed from the preform heating section, the outer temperature of the preforms is set higher than the inner temperature, and the effects of the present invention can be fully exerted for the same reason as in the case where air is blown to the preforms by the preform blowing section in the preform heating section in embodiment 1. That is, it is possible to prevent occurrence of whitening (crystallization) or occurrence of defective molding of the bottle body due to a difference in temperature between the inner and outer surfaces, which is caused in the conventional PET bottle manufacturing apparatus having no blowing portion in the preform heating portion or the subsequent transition zone.

For the above reasons, as shown in embodiment 1, the bottle preform heating section 400 may be provided with no preform blowing section 500, and instead, the transit zone may be provided with the transit zone blowing section 950, thereby sufficiently exhibiting the effects of the present invention.

As a specific structure of the staging area blowing section, the staging area blowing section 950 may be provided at the installation position of the staging area blowing section 950 representatively shown in fig. 5, and actually, the start of the installation position is provided on the exit side of the preform heating section 400, and the staging area blowing section 950 having a length sufficient to prevent whitening (crystallization) of the preform may be provided from the start to the blow molding section 600 along the conveying line 200. The length in this case may be determined by simulation, field verification, or the like, taking into account the amount of air blown by the transition area blowing unit 950, the wind speed, or the like.

According to the pet bottle manufacturing apparatus according to embodiment 2 of the present invention, the transition area blowing portion can be additionally installed in the conventional pet bottle manufacturing apparatus, that is, the manufacturing apparatus in which the preform blowing portion is not provided in the preform heating apparatus. Thus, the temperature of the heater of the conventional preform heating apparatus is increased, and the linear movement speed of the conveyance in the heating apparatus of the mandrel is increased, whereby all preforms can be passed through the heating step in a shorter time than in the conventional apparatus.

That is, in this state, although a phenomenon of whitening (crystallization) of the preform may occur immediately after the preform is fed from the preform heating apparatus in the related art, or a temperature gradient of heat distribution between the outside and the inside of the preform may be generated to a poor degree to adversely affect the blow molding in the subsequent blow molding portion, by additionally installing the transition area blowing portion as in embodiment 2 of the present invention in the related art pet bottle manufacturing apparatus, the preform can be blown to the preform in the transition area after the preform is fed from the preform heating apparatus by the transition area blowing portion, and thus a serious problem due to the whitening (crystallization) as in the related art can be avoided.

As described above, according to embodiment 2 of the present invention, the preform blowing section is additionally installed in the conventional pet bottle manufacturing apparatus, and thereby, as a further effect, the time of the heating process in the preform heating apparatus of the manufacturing apparatus can be shortened. This makes it possible to share the particular advantage of efficiently producing more PET bottles in a certain period of time.

Description of the reference symbols

1,2 Baote bottle manufacturing installation

11 base

20 bottle blank

21 mouth part

30 Baote bottle

100 core shaft

110 outer casing

120 mouth assembling part

130 swivel joint

200 conveying line

210 bottle blank conveying line interval

220 Baote bottle conveying line interval

230 empty core axis conveying line interval

250 rotating device

300 bottle blank input part

400 bottle base heating portion

411,412,413,414,415,416(410) heaters

420 heating part internal blowing part

500 bottle blank blowing part

510 blower

520 blowing slit guider

521 ~ 527 division board

550 heating promoting reflecting plate

600 blow molded part

610 (for blow molding) mold

611,612 half part (mold)

700 Baote bottle take-out part

800 heated air exhaust

900 transfer blowing part

950 a staging area blowing section.