WO2007004811A1

WO2007004811A1 - Supporting device for a preform of polyethylene terephthalate bottle

Info

Publication number: WO2007004811A1
Application number: PCT/KR2006/002543
Authority: WO
Inventors: Ho Seon Kim
Original assignee: Pisko Engineering Co., Ltd.
Priority date: 2005-07-04
Filing date: 2006-06-29
Publication date: 2007-01-11
Also published as: CN101223020B; JP2009500192A; KR20060119825A; CN101223020A; KR100674218B1

Abstract

Disclosed herein is a supporting device for a preform of a polyethylene terephthalate bottle, which supports the preform and transfers it in a processing direction, when a neck portion of the polyethylene terephthalate bottle is heat-treated to crystallize it. According to the invention, a holder sleeve, which supports a base ring Pa of a preform P and is made of a heat insulating material for preventing heat transfer between a holder 200 and the preform P, is mounted to an upper opening 202 of the holder 200, so that heat transfer between the preform P and the holder 200 is prevented by the holder sleeve 400 made of the heat insulating material, thus rapidly and uniformly heating a neck portion of the preform P to a proper temperature without heat loss and thereby satisfactorily crystallizing the neck portion of the preform P.

Description

SUPPORTING DEVICE FOR A PREFORM OF POLYETHYLENE TEREPHTHALATE BOTTLE

Technical Field

[1] The present invention relates to a supporting device for a preform of a polyethylene terephthalate bottle, which supports the preform and transfers it in a processing direction, when a neck portion of the polyethylene terephthalate bottle is heat-treated to crystallize it. Background Art

[2] As is well-known to those skilled in the art, when material, such as a beverage or cereal, is put into a polyethylene terephthalate bottle, a hot input nozzle may contact or come near the neck portion of the bottle. In this event, the neck portion may be deformed. Thus, a polyethylene terephthalate bottle having a neck portion which has been treated to be heat resistant must be used.

[3] When the polyethylene terephthalate bottle is manufactured, the neck portion of a preform of the polyethylene terephthalate bottle is heated to a suitable temperature for a predetermined period of time, and is then cooled. In this case, particles of the neck portion are crystallized, so that the neck portion is heat resistant. The preform of the polyethylene terephthalate bottle is inserted into a supporting device, as shown in FIGS. 1 to 4, so that the preform is supported by the supporting device. The supporting device is transferred in a processing direction while being rotated by an additional transfer means. Thus, in the state where the preform of the polyethylene terephthalate bottle is inserted into and supported by the supporting device of FIGS. 1 to 4, the preform is rotated and transferred in the processing direction. Thereby, the neck portion of the polyethylene terephthalate bottle, exposed to the outside of the supporting device, is heat-treated by a heater under high temperature. Thereafter, the neck portion is cold molded by a cooling core chuck.

[4] As shown in FIGS. 1 to 4, a conventional supporting device for a preform of a polyethylene terephthalate bottle includes a base block 100, a holder 200 having the shape of a cylindrical pipe, and an elastic preform supporting unit 300. The base block 100 includes a power transmission part 110 coupled to an additional transfer means (not shown), and a holder coupling part 120 located above the power transmission part 110. An opening 201 formed in the lower end of the holder 200 is coupled to the holder coupling part 120 of the base block 100. The elastic preform supporting device 300 is installed in the base block 100, and elastically supports the preform P inserted into the holder 200 such that a base ring Pa of the preform P is spaced apart from an opening 202 formed in the upper end of the holder 200 by a predetermined interval.

[5] The structure of the elastic supporting unit 300 may be slightly changed as necessary. FIGS. 1 to 4 show a typical elastic supporting unit. Referring to the drawings, the elastic supporting unit 300 includes a nut 310, a preform supporting rod 320, and a spring 330. The nut 310 is installed in a second insert hole 100b of the base block 100 in such a way as to reciprocate rectilinearly. The preform supporting rod 320 includes a preform supporting part 321 on which the bottom of the preform P is seated and supported, and a threaded fastening part 322 which extends from the bottom of the preform supporting part 321 and engages with the nut 310. The spring 330 is installed in the second insert hole 100b of the base block 100 and elastically biases the nut 310 and the preform supporting rod 320 fastened to the nut 310 in an upward direction. In this case, as shown in FIGS. 1 to 3, the base block 100 must have a first insert hole 100a and a second insert hole 100b. The first insert hole 100a receives the threaded fastening part 322 of the preform supporting rod 320, and the second insert hole 100b receives the nut 310 and the spring 330. In this case, reference numeral 340 denotes a stopper which is fitted into the second insert hole 100b of the base block 100 so as to prevent the removal of the nut 310. Reference numeral "350" denotes a bushing which surrounds the nut 310 and is installed in the second insert hole 100b of the base block 100 so as to prevent the base block 100 and the nut 310 from coming into direct contact with each other.

[6] The power transmission part 110 of the base block 100 is coupled to the additional transfer means via a power transmission means, such as a belt (not shown) or a sprocket. The lower opening 201 of the holder 200 is fastened to the holder coupling part 120 of the base block 100 via a fastening member 11, such as a screw or a bolt. In this case, reference numeral "200a" denotes a hole for exposing the preform P inserted into the holder 200 to the outside and naturally cooling the preform P, and reference numeral "200b" denotes a fastening hole into which the fastening member 11 for fastening the holder is inserted.

[7] The operation of the supporting device will be described below.

[8] When the preform P is inserted into the holder 200 through the upper opening 202 of the holder 200, the bottom of the preform P is seated in a preform seat 321a of the preform supporting part 321, so that the preform P is supported on the preform supporting part 321. At this time, the base ring Pa of the preform P maintains a predetermined interval from the upper opening 202 of the holder 200.

[9] In such a state, the base block 100 is rotated and moved in a processing direction by the additional transfer means, so that the preform P inserted into the holder 200 is rotated along with the supporting unit and is moved in the processing direction. While the preform P is transferred as such, the neck portion of the preform P, exposed to the upper portion of the upper opening 202 of the holder 200, is heat-treated at a high temperature.

[10] According to the prior art, the preform P is elastically supported by the elastic preform supporting unit 300, so that the base ring Pa of the preform P is spaced apart from the upper opening 202 of the holder 200 by a predetermined interval. Thus, the heat treatment of the preform P is satisfactorily conducted at a temperature. When the neck portion of the preform P is heated via the heater (not shown), the upper opening 202 of the holder 200 and the neck portion of the preform P are heated together by the heater. However, portions of the holder 200 other than the upper opening 202 of the holder 200, which is exposed to and heated by the heater, are not exposed to the heater but are exposed to the atmosphere to be rapidly cooled. Thus, the holder 200 is not heated to a temperature exceeding a predetermined level {because the heat treatment and crystallization of portions other than the neck portion of the preform P results in a defective product in a subsequent blowing process, the holder 200 is usually made of a metal material having high heat conductivity}. Thus, when the neck portion of the preform P is heat-treated, portions other than the neck portion of the preform P are naturally cooled through the hole 200a of the holder 200 which maintains a low temperature. Thereby, the holder is not heated to a temperature exceeding a predetermined level.

[11] Further, the nut 310 and the preform supporting rod 320 are elastically supported by the spring 330. Hence, even if the preform P is inserted into the holder 200 or the core chuck (not shown) for cooling the heated neck portion of the preform P while the preform P being fitted into the holder 200 is press-fitted into the neck portion of the preform P, the spring 330 prevents the base ring Pa of the preform P from colliding with the upper opening 202 of the holder 200, thus preventing the base ring Pa from b eing damaged.

[12] Further, since the nut 310 engages with the threaded fastening part 322 of the preform supporting rod 320 in such a way as to adjust a height, it is possible to support preforms having various sizes.

[13] However, the conventional supporting device for the preform of the polyethylene terephthalate bottle is problematic in that the preform P is elastically supported via the elastic preform supporting unit 300, so that the construction is very complicated, and thereby the cost of a product is increased, and maintenance and repair are difficult.

[14] Further, in order to prevent the nut 310 from rotating in the second insert hole 100b of the base block 100, a fastening hole 100c is formed in the holder coupling part 120 of the base block 100, and a rotation preventing notch 310a is formed on the nut 310. Thereafter, the nut 310 must be fastened to the base block 100 via the fastening member 12, such as a screw or a bolt. Further, in order to prevent the height of the preform supporting rod 320 from being changed by the rotation of the preform supporting rod 320, a rotation preventing hole 321b is formed in the preform supporting part 321, and the preform supporting rod 320 must be fastened to the holder 200 via a fastening member 13, such as a screw or a bolt, thus a manufacturing process is complicated.

[15] Moreover, the preform P inserted into the upper opening 202 of the holder 200 and seated on the preform supporting part 321 of the elastic preform supporting unit 300 is not supported in all directions, so that the preform P may incline and come into contact with the upper opening 202 of the holder 200. Thus, heat loss occurs through a contact part between the preform P and the holder 200. As such, when the preform P heat- treated under high temperature contacts the holder 200 maintaining a low temperature, the preform P is not sufficiently heat-treated due to the heat loss of the contact part, thus causing a defective product.

[16] In order to solve the problem, the inventor proposes a supporting device for a preform of a polyethylene terephthalate bottle, which is disclosed in Korean Patent Appln. No. 2004-101849.

[17] The supporting device is constructed so that a rounded contact part is directly or indirectly formed on an upper opening of a holder, and a base ring of a preform is directly seated on the contact part of the holder.

[18] Thus, the supporting device does not need the conventional elastic preform supporting unit 300, so that the construction of the supporting device is considerably simple, the cost of the supporting device is considerably reduced, and maintenance and repair thereof are easy.

[19] The part of the supporting device on which the base ring of the preform is seated and supported is rounded, so that the contact area between the holder and the preform is minimized, and thereby the non-crystallized part of the base ring of the preform is minimized. However, the contact area between the holder and the preform is inevitably increased compared to the supporting device having the elastic preform supporting unit 300 of FIGS. 1 to 4, so that it is rather difficult to crystallize the neck portion of the preform {the neck portion of the preform P must be heated for a longer period of time under the same temperature conditions, or the temperature to which the neck portion of the preform P is heated must be increased, given a constant heating period, in consideration of the loss of heat}. Disclosure of Invention Technical Problem

[20] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a supporting device for a preform of a polyethylene terephthalate bottle, which has a simple construction, and allows a neck portion of the preform to be satisfactorily crystallized. Technical Solution [21] In order to accomplish the object, the present invention provides a supporting device for a preform of a polyethylene terephthalate bottle, having a base block, which includes a power transmission part and a holder coupling part, and a holder, which has a shape of a circular pipe and is constructed so that a lower opening is secured to the holder coupling part of the base block, the supporting device including a holder sleeve mounted to an upper opening of the holder, the holder sleeve supporting a base ring of the preform, and being made of an insulating material for preventing heat transfer between the holder and the preform.

Advantageous Effects

[22] As described above, according to the present invention, a holder sleeve, which supports a base ring Pa of a preform P and is made of a heat insulating material for preventing heat transfer between a holder 200 and the preform P, is mounted to an upper opening 202 of the holder 200, so that heat transfer between the preform P and the holder 200 is prevented by the holder sleeve 400 made of the heat insulating material, thus rapidly and uniformly heating a neck portion of the preform P to a proper temperature without heat loss and thereby satisfactorily crystallizing the neck portion of the preform P. Further, the base ring Pa of the preform P is directly seated on and supported by the holder sleeve 400, thus dramatically simplifying the construction of a supporting device. Brief Description of the Drawings

[23] FIG. 1 is an exploded perspective view showing important parts of a conventional supporting device;

[24] FIG. 2 is a sectional view showing the conventional supporting device;

[25] FIG. 3 is an enlarged view showing portion A of FIG. 2;

[26] FIG. 4 is an enlarged view showing portion B of FIG. 2;

[27] FIG. 5 is a sectional view which corresponds to FIG. 2, but shows a supporting device according to an embodiment of the present invention;

[28] FIG. 6 is an enlarged view showing portion C of FIG. 5;

[29] FIG. 7 is a sectional view which shows a supporting device according to another embodiment of the present invention, and corresponds to FIG. 1 showing the conve ntional supporting device;

[30] FIG. 8 is a sectional view showing the supporting device of FIG. 7, and corresponding to FIG. 5; and [31] FIG. 9 is an enlarged view showing portion D of FIG. 8.

[32]

[33] -Description of reference characters of important parts-

[34] 11, 12, 13, 14; fastening member 100; base block

[35] 100a; first insert hole 100b; second insert hole

[36] 100c; fastening hole 110; power transmission part

[37] 120; holder coupling part 200; holder

[38] 200a; hole 200b, 200c; fastening hole

[39] 201; lower opening 202; upper opening

[40] 300; elastic preform supporting unit 310; nut

[41] 310a; rotation preventing notch

[42] 320; preform supporting rod

[43] 321; preform supporting part 321a; preform seat

[44] 321b; rotation preventing hole

[45] 322; threaded fastening part

[46] 330; spring 340; stopper

[47] 350; bushing 400; holder sleeve

[48] 410; insert part 420; locking step

[49] 420a; reinforcing-member insert hole 421 ; protruding step

[50] 500; reinforcing member 510; first insert part

[51] 520; second insert part P; preform

[52] Pa; base ring

Mode for the Invention

[53] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

[54] FIGS. 5 and 6 are views showing the present invention. The same reference numerals are used for components which are equal to those of FIGS. 1 to 4, and a detailed description of the components shown in FIGS. 1 to 4 will be omitted.

[55] Referring to FIGS. 5 and 6, a supporting device for a preform of a polyethylene terephthalate bottle, according to the present invention, includes a base block 100, a holder 200 having the shape of a circular pipe, and a holder sleeve 400. The base block 100 is provided with a power transmission part 110 and a holder coupling part 120. The holder 200 is constructed such that a lower opening 201 thereof is coupled to the holder coupling part 120 of the base block 100. The holder sleeve 400 is mounted to an upper opening 202 of the holder 200, supports a base ring Pa of the preform P, and is made of an insulating material to prevent heat transfer between the holder 200 and the preform P. [56] The holder sleeve 400 must have heat resistance superior to that of the preform P of the polyethylene terephthalate bottle. As long as it prevents heat transfer between the holder 200 and the preform P, any material may be used for the holder sleeve 400. According to this embodiment, the holder sleeve 400 is made of fluoric resin, that is, Poly Tetra Fluoro Ethylene (PTFE), the brand name of which is Teflon. The PTFE has perfect chemical inertness, heat resistance, and superior insulating properties. Further, the PTFE has non- adhesiveness and a low coefficient of friction. Thus, when the holder sleeve 400 is made of PTFE, the preform P is smoothly inserted into or removed from the holder sleeve 400 without friction, thus preventing the preform P from interfering with the holder sleeve 400, and preventing the preform P from being scratched or damaged. In this regard, it is preferable that the holder sleeve 400 be made of the PTFE.

[57] Further, according to this embodiment, the holder sleeve 400 includes an insert part

410 and a locking step 420. The insert part 410 is inserted into the upper opening 202 of the holder 200. The base ring Pa of the preform P is seated on the locking step 420 to be supported thereon. Of course, the shape and construction of the holder sleeve 400 may be variously changed as necessary. For example, the holder sleeve 400 may have the shape of a simple pipe without the locking step 420. In this case, the holder sleeve 400 must protrude upwards from the upper opening 202 of the holder 200 so that the base ring Pa of the preform P fitted into the holder sleeve 400 does not interfere with the upper opening 202 of the holder 200.

[58] The operation of crystallizing the neck portion of the preform using the supporting device according to the present invention will be described below.

[59] First, the insert part 420 of the holder sleeve 400 is inserted into the upper opening

202 of the preform 200. In such a state, the preform P is inserted into the holder 200 via the holder sleeve 400, so that the base ring Pa of the preform P is seated on the locking step 410 of the holder sleeve 400.

[60] Next, the base block 100 is moved in a processing direction by an additional transfer means, so that the preform P inserted into the holder 200 moves in the processing direction along with the supporting device. Thus, when the preform P is transferred, the neck portion of the preform P exposed to the upper portion of the upper opening 202 of the holder 200 is heat-treated by an additional heater (not shown).

[61] In this case, even if the neck portion of the preform P is heated by the heater, heat transfer between the preform P and the holder 200 is prevented by the holder sleeve 400 made of the insulating material. Thus, the neck portion of the preform P is rapidly and uniformly heated to a proper temperature without the loss of heat, so that the neck portion is satisfactorily crystallized. Actually, the supporting device disclosed in Korean Patent Appln. No. 2004-101849 has a larger heat loss than the supporting device shown in FIGS. 1 to 4, so that the heating temperature or a heating period must be increased to satisfactorily crystallize the neck portion of the preform P. However, in the case of the supporting device according to this invention, heat transfer between the preform P and the holder 200 is completely prevented by the holder sleeve 400. Thus, even if the heating temperature or the heating period is reduced compared to the supporting device of FIGS. 1 to 4, the neck portion of the preform P is satisfactorily crystallized.

[62] Meanwhile, FIGS. 7 to 9 show a supporting device, according to another embodiment of the present invention, which will be described below.

[63] Referring to FIGS. 7 to 9, a reinforcing-member insert hole 420a having an enlarged inner diameter is formed in a holder sleeve 400, and a protruding step 421 is provided on the upper end of the holder sleeve 400 on which the base ring Pa of the preform P is seated, in such a way as to protrude toward the center of the holder sleeve 400. The supporting device includes a reinforcing member 500 which has a first insert part 510 and a second insert part 520, and has the shape of a pipe. The first insert part 510 is inserted into the upper opening 202 of the holder 200. The second insert part 520 is inserted into the reinforcing-member insert hole 420a of the holder sleeve 400. The holder sleeve 400 is inserted into a gap defined between the upper opening 202 of the holder 200 and the second insert part 520 of the reinforcing member 500. Preferably, the reinforcing member 500 is made of a metal material having high heat conductivity, like the holder 200. The reinforcing member 500 is inserted into the upper opening 202 of the holder 200, which maintains a low temperature, so that it maintains a low temperature, like the holder 200.

[64] In this embodiment, when the preform P is fitted into the holder sleeve 400, the inner circumferential surface of the protruding step 421 of the holder sleeve 400 and the inner circumferential surface of the reinforcing member 500 are exposed toward the preform P. Thus, by adjusting the thickness of the protruding step 421 of the holder sleeve, it is possible to more precisely control the heat treatment for the neck portion of the preform P.

[65] The detailed description of the supporting device is as follows.

[66] After the preform P is fitted into the holder sleeve 400, the neck portion of the preform P is heat-treated at a high temperature. At this time, the neck portion of the preform P exposed to the outside is heated directly by a heater to a high temperature. As such, when the neck portion of the preform P exposed to the outside is heated directly by the heater to a high temperature, the portion adjacent to the neck portion of the preform P is also heated to a high temperature through heat conduction, and is crystallized. In this case, unless the reinforcing member 500 is used, it is actually impossible to control which portions are crystallized through high-temperature heat- treatment. However, if portions other than the portion adjacent to the protruding step 421 of the holder sleeve 400 are rapidly cooled using the reinforcing member 500, the crystallization of the preform P through high-temperature heat-treatment is executed only up to the portion adjacent to the protruding step 421 of the holder sleeve 400. Thus, by adjusting the thickness of the protruding step 421 of the holder sleeve, high- temperature heat-treatment of the neck portion of the preform P can be more precisely controlled {as the thickness of the protruding step 421 of the holder sleeve is increased, the portion crystallized in a downward direction from the base ring Pa of the preform P is increased, while as the thickness of the protruding step 421 of the holder sleeve is decreased, the portion crystallized in a downward direction from the base ring Pa of the preform P is reduced}.

[67] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

[68] For example, according to the embodiment of this invention, the insert part 410 of the holder sleeve 400 is fitted into the upper opening 202 of the holder 200, and is firmly fastened to the upper opening 202 via a fastening member 14. As necessary, the insert part 410 of the holder sleeve 400 may be simply forced into the upper opening 202 of the holder 200, or the insert part 410 of the holder sleeve 400 may be fastened to the upper opening 202 of the holder 200 through a screw-type fastening method. Of course, the insert part 410 of the holder sleeve 400 may be fitted over the upper opening 202 of the holder 200.

[69] Further, the holder 200 may be formed to have a diameter which is large enough to accommodate preforms having various sizes. A proper size of holder sleeve 400 may be selected according to the size of an associated preform P, so that the supporting device can accommodate preforms having various sizes merely by replacing the holder sleeve 400 without the replacement of the holder 200.

Claims

[1] A supporting device for a preform of a polyethylene terephthalate bottle, having a base block (100), which includes a power transmission part (110) and a holder coupling part (120), and a holder (200), which has a shape of a circular pipe and is constructed so that a lower opening (201) is secured to the holder coupling part (120) of the base block (100), the supporting device comprising: a holder sleeve (400) mounted to an upper opening (202) of the holder (200), the holder sleeve supporting a base ring (Pa) of the preform (P), and being made of an insulating material for preventing heat transfer between the holder (200) and the preform (P).

[2] The supporting device according to claim 1, wherein the holder sleeve (400) comprises: an insert part inserted into the upper opening (202) of the holder (200); and a locking step (420) on which the base ring (Pa) of the preform (P) is seated and supported.

[3] The supporting device according to claim 1, wherein the holder sleeve (400) is made of Poly Tetra Fluoro Ethylene (PTFE) which is fluoric resin.

[4] The supporting device according to any one of claims 1 to 3, wherein the holder sleeve (400) comprises: a reinforcing-member insert hole (420a) having an enlarged inner diameter and formed in the holder sleeve (400); and a protruding step (421) provided on an upper end of the holder sleeve (400), on which the base ring (Pa) of the preform (P) is seated and supported, in such a way that the protruding step protrudes towards a center of the holder sleeve (400); and the supporting device further comprises: a reinforcing member (500) having a shape of a pipe and comprising: a first insert part (510) inserted into the upper opening (202) of the holder (200); and a second insert part (520) inserted into the reinforcing-member insert hole (420a) of the holder sleeve (400), so that the holder sleeve (400) is inserted into a gap between the upper opening (202) of the holder (200) and the second insert part (520) of the reinforcing member (500).