JPH0622877B2 - Preform crystallization method and apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a preform crystallization method and apparatus for crystallizing an arbitrary part of a preform, particularly a bottom part.

[Prior Art] A stretched polyester container molded by biaxial stretch blow molding is currently widely used as a container for various contents because of its excellent transparency, impact resistance, lightness, and the like.

However, in this stretched polyester container, the neck portion and the bottom portion were not stretched or were insufficiently stretched.

That is, since the neck portion is originally a portion that is not blow-molded, it is non-stretched. Therefore, the neck portion is heat-treated and crystallized at the stage of preform to impart mechanical strength and heat resistance.

On the other hand, in the case of molding into a container, there is a problem in that the vicinity of the gate at the bottom of the preform is not sufficiently biaxially stretched even by blow molding, resulting in poor mechanical strength and heat resistance. Therefore, in order to strengthen the bottom of the container, a method has been proposed in which the bottom is heated and crystallized at the stage of preform in advance (Japanese Patent Laid-Open Nos. 62-39443 and 62-193938, etc.).

[Problems to be solved] In this way, the bottom part is crystallized at the stage of preform,
The container obtained by blow molding then can enhance the mechanical strength and heat resistance of the central region of the bottom of the container, while enabling the thickness of the bottom to be reduced, and the reduction of materials and the weight reduction of the container. .

However, also in the method of preliminarily crystallizing the bottom portion at the stage of preform, even if the bottom portion is simply crystallized, uniform stretching is not performed during blow molding, and a container having the above-described excellent properties cannot be obtained. However, the current situation is that it has not been put to practical use. In order to solve the above problems, the inventors of the present invention have conducted extensive research and found that in order to obtain a container having excellent properties by blow-molding a preform having a crystallized bottom, the preform bottom has a perfect circular shape. It has been found that crystallization must be performed uniformly and uniform heating must be performed.

The present invention was made on the basis of the above findings, and crystallizes the bottom of the preform in a perfect circle state, and a stretching container having a crystallized bottom so that uniform crystallization can be performed by uniform heating. The purpose of the present invention is to provide a preform crystallization method and an apparatus therefor that enable the practical use and mass production of the above.

It is another object of the present invention to provide a preform crystallization method and an apparatus for the preform, which can crystallize any part other than the bottom of the preform.

[Means for Solving the Problems] In order to achieve the above object, the preform crystallization method of the first invention covers a preform with a heat shield member in a state where only an arbitrary portion is exposed, and the outside of the heat shield member. It is heated more to crystallize only the exposed part of the preform.

Further, the preform crystallizing device of the second invention is a heat shield member which accommodates the preform and is provided with a through hole for exposing a part of the preform, and which is located in the vicinity of the heat shield member. The heating means is configured to apply heat toward the through hole. Furthermore, the preform crystallizing device bends the heater of the heating means so that both ends of the heater are bent at a substantially right angle,
By taking out the lead terminal from the bent portion, a plurality of heaters can be arranged in a state of being closely adjoined in the longitudinal direction.

[Operation] According to the preform crystallization method as described above, it is possible to easily crystallize an arbitrary portion of the preform, particularly the bottom portion. Further, by using the preform crystallizing apparatus configured as described above, any part of the preform,
In particular, the bottom can be crystallized quickly and continuously.

[Examples] Examples of the present invention will be described below.

First, one embodiment of the preform crystallization apparatus will be described with reference to the drawings.

FIG. 1 is an overall schematic view of a preform crystallizing apparatus according to an embodiment, FIG. 2 is a plan view of a main part of a preform supply unit, FIG. 3 is an explanatory view of a friction joint in a separation turret, and FIG. FIG. 5 is a layout view of the detector, and FIG. 5 is a view showing a mounting state of the heater rod.

In FIG. 1, 1 is a preform supply part, 2 is a heating part, 3 is a rotation chain, and 4 is a delivery turret.

As shown in FIGS. 1 and 2, the preform supply unit 1 includes a shooter 110, a separation turret 120, a carry-in turret 130, and a charging turret 140. The injection molding machine or the pre-blow molding machine is not shown. The preform W in a high temperature state continuously sent from the above through the shooter 110 is separated in the separation turret 120, and is supplied to the holder 216 of the heating unit 2 from the input turret 140 through the carry-in turret 130.

As shown in FIG. 3, the separating turret 120 receives the rotational force received from the carry-in turret 130 via the belt 122 via the friction joint 123.
I'm telling 1. Accordingly, when the preform W is clogged between the separating turret 120 and the carry-in turret 130, the friction joint 123 slips to prevent the turret 121 from rotating, and the feeding of the preform W is stopped.

Further, in the vicinity of the charging turret 140, there are provided a gate defect detector 141, an ejector 142 which is activated by a signal from the detector 141, and a heater rod 143 which burns off thread-shaped resin scraps.

As shown in FIG. 4, the gate defect detector 141 arranges the light emitting element 141a and the light receiving element 141b across the passage of the preform W, and inspects the state of the gate protruding from the bottom of the preform W. ing. Then, when the amount of residual resin in the gate exceeds a certain amount, or when the gate is deformed, a signal is sent to the ejector 142 to operate the ejector 142 so that the gate is in a defective state. Put reform W into pocket 144 of turret 140
Discharge from.

As shown in FIG. 5, the heater 143 bar is provided so as to be located slightly below the bottom of the preform W supported by the charging turret 140. Then, if there is a thin thread-like resin scrap that is sometimes generated due to abrasion of the cutter when the gate is removed and cannot be detected by the detector 141,
The protruding portion is burnt off by the heater rod 143.

In this way, the inspection and discharge of the defective gate and the treatment of the resin waste protruding by a predetermined amount or more before the supply to the heating unit 2 are performed by the heater 233 when heating is performed in the heating unit 2 described later. This is for preventing the resin from being melted and falling on the top, and for enabling good crystallization treatment.

The rotation chain 3 is stretched over the entire outer circumference of the heating unit 2, one end of which is fixed via a spring 31 having a large tension, and the other end of which is fixed via a spring 32 having a small tension. The spring 31 having a large tension causes the rollers of the rotation chain 3 to sprocket 218 when the rotation chain 3 and a sprocket 218 described later bite.
The spring 32 with a small tension is for adjusting the tension of the rotation chain 3 when the tip of the tooth does not bite well (cushion).

FIG. 6 is an overall longitudinal sectional view of the heating section 2, FIG. 7 is an enlarged view of an essential part of FIG. 6, and FIG. 8 is a plan view of FIG.

In these drawings, 210 is a turret rotatably supported by a central shaft 211, and a support 212 is provided in a ring shape on the outer peripheral edge thereof. A large number of holes 213 are provided in this ring-shaped support 212 in the vertical direction at appropriate intervals, and an oilless metal 214 is attached to the inner peripheral surface thereof. A water passage 215 is provided inside the ring-shaped support 212 so as to surround the hole 213, and cooling water is caused to flow through the water passage 215 to prevent a temperature rise of a holder 216 described later.

A holder 216 having a sprocket 218 mounted on the outer periphery is rotatably loosely fitted in a hole 213 provided in the support 212. The holder 216 functions as a heat shield member, and is made of a material that does not easily absorb heat, such as aluminum,
The preform W is formed into a cylindrical shape having a hollow having an inner diameter slightly larger than the outer diameter, and a through hole 2 having a perfect circular shape is formed at the center of the bottom.
17 is provided. The sprocket 218 fixed to the outer circumference of the holder 216 meshes with the above-described rotation chain 3 provided on the outer circumference of the turret 210. Therefore,
When the support body 212 rotates along with the rotation of the turret 210, the holder 216 revolves together with the support body 212 and, at the same time, rotates inside the hole 213 (oilless metal 214) of the support body 212.

In addition, the guide 2 is provided in the outer peripheral lengthwise direction of the turret 210.
A sliding rod 221 is provided which is guided by 22 and moves up and down. The sliding rod 221 is provided corresponding to each holder 216, has a pocket 223 for holding the preform W in the lower portion, and has a cam roller 224 in the upper portion.

The cam roller 224 is engaged with the cam groove 226 formed in the upper fixed body 225 of the heating unit 2. The cam groove 226 with which the cam roller 224 engages is in a low position between the arrows in FIG. 1 and in a high position between the arrows. Therefore, the preform W is accommodated in the holder 216 between the air and space, and the preform W is extracted by the holder 216 between the air and space. As a result, in the position of C in FIG. 1, the pocket 223 of the sliding rod 221 and the charging turret 1 are inserted.
40 enables the transfer of preforms to and from the pockets 144 of 40, and, in the position of D in FIG. 1, the preforms W between the pockets 223 of the sliding rod 221 and the pockets 411 of the delivery turret 4 are provided. It is possible to give and receive.

Reference numeral 230 denotes a heater unit in the heating unit 2, which is the support 2
It is formed in a substantially ring shape having the same diameter as that of 12, and is disposed below the support body 212 with a slight gap over the space between the edges of FIG. This heater unit 23
In No. 0, the groove 232 is formed in the circumferential direction of the upper surface of the base body 231, and the heater 223 is attached to the groove 232 via the heater holder 234. The heater holder 234 is formed of a thin plate material, and is in a state of being floated from the bottom of the groove 232 and the base 231.
It is fixed to. This prevents the heat of the heater 233 from being transferred to the base body 231 via the heater holder 234. Further, the surface of the groove 232 for mounting the heater 233 is formed of a metal having a high heat reflectance. This prevents conduction of heat generated from the heater 233 to the base 231.

As the heater 233, an infrared heater of the near infrared party is used, and its shape is, as shown in FIG. 9, bent at both ends of a long heater 233 which is curved, and the bent tip end portion is bent. The lead terminal 233a is taken out from the shape. The heater unit 230 arranges some of the curved heaters 233 in series,
As a whole, a substantially ring-shaped heater is configured.

In this case, the lead terminals 233a are taken out from the side portions as described above, and when the heaters and the end portions of the heaters are continuously arranged in a state of closely adjoining each other, the unheated zone existing between the heaters is not formed. Can be minimized, and uneven heating can be effectively prevented. In this way, the heater 233 configured in a substantially ring shape is arranged so as to be located immediately below the through hole 217 provided in the bottom portion of the holder 216.

An air passage 235 is formed in the lower circumferential direction of the base 231. The air passage 235 receives supply of air from the supply duct 237, communicates with the bottom of the groove 232 through the ventilation narrow groove 236, and sends air to the heater 233 side. Therefore, the air sent from the air passage 235 to the heater 233 side through the ventilation narrow groove 236 is heated by the heater 233 and then blown onto the bottom portion of the holder 216.

Further, water channels 238 are provided on both sides of the base body 231. By flowing cooling water through the water channels 238,
The temperature rise due to heat from the heater 233 is prevented.

The above-mentioned base 231 and the duct 237 fixed to the lower part of the base 231 can be moved up and down by the cylinder 239 so that they can be easily lowered when the heater unit 230 is inspected.

In FIG. 1, reference numeral 219 denotes a suction nozzle, which is disposed below the support body 212 so that the support body 21
Soak up the water droplets attached to 2. Since the support 212 is cooled by the cooling water, the water droplets are generated by condensation of water in the air on the surface thereof. In this way, by removing the water droplets from the support 212 above the heating unit 2, the water droplets are prevented from falling onto the heater and the heater is prevented from being damaged.

The delivery turret 4 delivers the preform W heated in the heating unit 2 to an apparatus (not shown) for the next step.

Next, a method of crystallizing a preform using the preform crystallizing apparatus having the above-described structure will be described.

The preform W sent through the shooter 110, the separation turret 120, and the carry-in turret 130 of the fliform supply unit 1 is located at a position where it crosses the turret 210 of the heating unit 2 by the input turret 140 (position C in FIG. 1). Will be sent to.

While the preform W is transferred by the input turret 140, the gate defect detector 141 inspects the quality of the gate, and if it is defective, the ejector 142 removes the preform W from the pocket 144 of the input turret 140. Further, when the thread-shaped resin scraps are projected beyond a certain amount, they are burned off by the heater rod 143. As a result, the preform W fed from the charging turret 140 to the heating unit 2 has only the normal gate portion.

The preform W is fed into the pocket 223 of the sliding rod 221 from the pocket 144 of the charging turret 140 at the position C in FIG. In this way pocket 2
The preform W held by 23 is transferred in the direction of the arrow in FIG. 1 by the rotation of the turret 210 of the heating unit 2. When the sliding rod 221 reaches the position (a) in FIG. 1, the sliding rod 221 is guided by the cam groove 226 and descends to insert the preform W held in the pocket 223 into the holder 216. The preform W thus stored in the holder 216 is held by the holder 216 and moves in the same manner as the holder 216.

That is, the holder 216 revolves by the rotation of the turret 210, and at the same time, is spun by the meshing of the sprocket 218 and the chain 3 to rotate, so that the preform W also revolves in the direction of the arrow described above.

On the other hand, the heater unit 230 heats the bottom portion of the preform W housed in the holder 216 via the through hole 217 having a perfect circle shape. At this time, since the preform W is rotating, the preform W receives the heat from the heater 233 while rotating, and the heating unevenness does not occur even when the heat generated from the heater is not uniform. It should be noted that although the heating unevenness can be surely prevented by rotating the preform W as described above, when a heater that generates heat substantially uniformly is used,
The method can be carried out even if the preform is heated without rotating it.

In this way, the preform W is uniformly heated at the bottom between the portions shown in FIG. Then, when it reaches the position b in FIG. 1, the sliding rod 221 is guided by the cam groove 226 and ascends, and the preform W is held in the holder 2.
Pull out from 16. Next, when the sliding rod 221 reaches the position D in FIG. 1, the preform W supported by the pocket 223 is transferred to the pocket 411 of the delivery turret 4, and the rotation of the delivery turret 4 causes the next step. It is sent to the device.

The preform W pulled out from the holder 216 and fed by the feed turret 4 is naturally cooled, and the heat-treated portion at the bottom crystallizes as shown in FIG.

Although the method and the apparatus for crystallizing the bottom of the preform W have been described in the above embodiments, according to the preform crystallization method and the crystallization apparatus of the present invention, a part of the body of the preform W is removed. It can also be crystallized.

For example, as shown in FIG. 11, a through hole 217 having an arbitrary shape is formed on a side portion of the holder 216, and the through hole 21 is formed.
Heating is performed by the heater unit 230 arranged so as to face the unit 7. In this case, the heater units 230 can be arranged on both sides so that the holder 216 is sandwiched. As described above, when a part (or a plurality of parts) of the body is heated to an arbitrary pattern and shape to be crystallized, it is possible to directly form the pattern on the body of the container.

[Effects of the Invention] As described above, according to the preform crystallization method of the first invention, it is possible to easily crystallize an arbitrary part of the preform, particularly a low part.

Further, according to the present preform crystallizing device of the second invention, any part of the preform, particularly the bottom part, can be rapidly and continuously crystallized by a device having a simple structure.

[Brief description of drawings]

FIG. 1 is an overall schematic view of a preform crystallizing apparatus according to an embodiment, FIG. 2 is a plan view of a main part of a preform supply unit, FIG. 3 is an explanatory view of a friction joint in a separation turret, and FIG. Fig. 5 is a layout view of the detector, Fig. 5 is a mounting state diagram of the heater rod, Fig. 6 is an overall vertical cross-sectional view of the heating section, and Fig. 7 is Fig. 6
8 is an enlarged plan view of an essential part of FIG. 7, FIG. 9 is a partial plan view of a heater unit, and FIG. 10 is a sectional view of a preform whose bottom is crystallized. The figure shows a cross-sectional view of an essential part of an apparatus for crystallizing a part of a preform body. 1: Preform supply part, 2: Heating part 3: Rotation chain, 4: Delivery turret 120: Separation turret 130: Carry-in turret 140: Input turret 210: Turret, 212: Support 213: Hole, 215: Water channel 216: Holder 217: Through hole 218: Sprocket, 221: Sliding rod 223: Pocket, 224: Cam roller 226: Cam groove 230: Heater unit, 232: Groove 233: Heater, 234: Heater holder 235: Air path, 236: Aeration thin Groove 238: waterway

Claims (2)

[Claims] 1. A heat shield member, which covers a preform in a state where only an arbitrary portion is exposed, and which is heated from the outside of the heat shield member to crystallize only the exposed portion of the preform. A method for crystallizing a preform characterized by: 2. A heat shield member for accommodating a preform and having a through hole for exposing a part of the preform; and a heat shield member located near the heat shield member and applying heat toward the through hole. A preform crystallization apparatus comprising a heating means.