AU2005203451B2 - Container with handle, preform with handle, and method and device for molding container with handle - Google Patents

Abstract

CONTAINER WITH HANDLE, PREFORM WITH HANDLE, AND METHOD AND DEVICE FOR MOLDING CONTAINER WITH HANDLE A preform (28) with a handle (80) includes an open neck portion (110), a cylindrical bottomed body portion (108), and a handle portion (80) formed to protrude from the neck portion (110). The handle portion (80) has a thin portion (81) which is formed by compressing and stretching a part of the handle portion by pressing and has a 10 higher density than a remaining area of the handle portion. - -0o----; A,-,-.T 717 80a 80b 80b 78a r7 73c- ., 78b 73b - -74c 108 0 -75 73 74b 73a 74a 80 74 73c 0 7 74c 108 78a 73b -78b 28 73a 1 1 0 -7 74a 80 74

Description

S&F Ref: 730788 AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name and Address Nissei ASB Machine Co., Ltd., of 4586-3, Koo, Komoro of Applicant: shi, Nagano, 384-8585, Japan Actual Inventor(s): Kiyonori Shimada Address for Service: Spruson & Ferguson St Martins Tower Level 35 31 Market Street Sydney NSW 2000 (CCN 3710000177) Invention Title: Container with handle, preform with handle, and method and device for molding container with handle The following statement is a full description of this invention, including the best method of performing it known to me/us:- CONTAINER WITH HANDLE, PREFORM WITH HANDLE, AND METHOD AND DEVICE FOR MOLDING CONTAINER WITH HANDLE BACKGROUND OF THE INVENTION 5 The present invention relates to a container with a handle, a preform with a handle, and a method and a device for molding a container with a handle. A container made of a synthetic resin, such as a container made of polyethylene terephthalate (PET bottle), has been widely used particularly as a container for beverages. Accompanying an increase in the capacity of PET bottles, an improvement 10 of handling properties of PET bottles has been demanded. To deal with this demand, a synthetic resin container with a carrying handle has been proposed. A molding method has been proposed in which, when injection molding a preform for forming a synthetic resin container, a handle portion is molded at the same time as the preform (JP-A-10-113978). 15 In such a handle portion, a thin portion (hinge) is formed in the vicinity of the opening in the container. It is known that a thin hinge of an injection molded product made of polypropylene or the like has flexibility due to molecular orientation during injection molding. However, flexibility comparable to that of polypropylene has not been obtained for PET bottles or the like. 20 SUMMARY A first aspect of the invention relates to a preform with a handle and made of a synthetic resin, the preform comprising: an open neck portion; a cylindrical bottomed body portion; and a handle portion 25 formed to protrude from the neck portion, wherein the handle portion has a thin portion which is formed by compressing and stretching a part of the handle portion by pressing and has a higher density than a 2 remaining area of the handle portion. A second aspect of the invention relates to a container with a handle and made of a synthetic resin, the container comprising: an open neck portion; a body portion; a bottom portion; and a handle portion 5 formed to protrude from the neck portion, wherein the handle portion has a thin portion which is formed by compressing and stretching a part of the handle portion by pressing and has a higher density than a remaining area of the handle portion. A third aspect of the invention relates to a container with a handle, obtained by io blow molding the above preform. A fourth aspect of the invention relates to a method for molding a container with a handle, the method comprising: an injection molding step of injection molding a preform including an open neck portion, a cylindrical bottomed body portion, and a handle portion formed to protrude 15 from the neck portion: a pressing step of pressing a part of the handle portion to form a thin portion; and a blow molding step of stretch blow molding the preform to form the container which has a higher density than a remaining area of the handle portion. 20 A fifth aspect of the invention relates to a method for molding a container with a handle, the method comprising: an injection molding step of injection molding a preform including an open neck portion, a cylindrical bottomed body portion, and a handle portion formed to protrude from the neck portion; 25 a blow molding step of stretch blow molding the preform to form the container; and a pressing step of pressing a part of the handle portion to form a thin portion which has a higher density than a remaining area of the handle portion. A sixth aspect of the invention relates to a device for molding a container with a 30 handle, the device comprising: a pressing section which presses a part of a handle portion made of a synthetic resin; a pressure receiving section provided opposite to the handle portion with the part of the handle portion interposed between the pressing section and the pressure receiving 3s section; and AH21(5971963):MIw r 3 a moving mechanism which moves the pressing section toward the pressure receiving section, wherein the moving mechanism compresses the part of the handle portion by moving the pressing section toward the part of the handle portion which is in contact with s the pressure receiving section to reduce a thickness of the part of the handle portion to form a thin portion which has a higher density than a remaining area of the handle portion. Brief Description of the Several Views of the Drawing 10 FIG. I is a side view of a preform according to one embodiment of the invention. FIG. 2 is a plan view of a preform according to one embodiment of the invention, FIG. 3 is a side view of a container according to one embodiment of the invention. is FIG. 4 is a plan view showing a stretch blow molding device according to one embodiment of the invention, FIG. 5 is a plan view showing a press forming section according to one embodiment of the invention. FIG. 6 is a side view showing a press forming section according to one 20 embodiment of the invention, FIG. 7 is a side view (partial enlarged view) showing a press forming section AH21(594716l);MLW according to one embodiment of the invention. FIG. 8 is a front view showing a press forming section according to one embodiment of the invention. 5 DETAILED DESCRIPTION OF THE EMBODIMENT The invention may provide a container with a handle and a preform with a handle having a handle portion with improved mechanical strength. The invention may also provide a method and a device for molding a container with a handle having a handle portion with improved mechanical strength. 10 One embodiment of the invention provides a preform with a handle and made of a synthetic resin, the preform including: an open neck portion; a cylindrical bottomed body portion; and a handle portion formed to protrude from the neck portion, wherein the handle portion has a thin portion which is formed by compressing 15 and stretching a part of the handle portion by pressing and has a higher density than a remaining area of the handle portion. One embodiment of the invention provides a container with a handle and made of a synthetic resin, the container including: an open neck portion; a body portion; a bottom portion; and a handle portion 20 formed to protrude from the neck portion, wherein the handle portion has a thin portion which is formed by compressing and stretching a part of the handle portion by pressing and has a higher density than a remaining area of the handle portion. According to this embodiment, since the thin portion of the handle portion 25 formed by pressing is compression-formed and stretch-oriented by pressing, the thin portion has a higher density than the remaining area of the handle portion to exhibit high mechanical strength. Moreover, since the thin portion of the handle portion is 4 formed by pressing, the injection mold is not required to have a narrow section, whereby the resin injected into the mold easily flows. Moreover, whitening due to generation of heat by shear does not occur. The handle portion may include a plate-shaped connection portion connected 5 with the neck portion, and a holding portion formed at a free end of the handle portion, and the thin portion may be formed in the connection portion and formed closed to the neck portion. According to this configuration, since the connection portion is in the shape of a 10 plate, the thin portion can be easily formed by pressing. Moreover, since the thin portion is close to the neck portion, the connection portion is reliably bent at the thin portion when holding the container, whereby the amount of flexural stress applied to the remaining area of the connection portion is small. A container with a handle according to one embodiment of the invention is 15 obtained by blow molding the above preform. According to this configuration, since the handle portion having the thin portion is formed in the preform in advance, a container with a handle can be obtained by merely blow molding the preform. A method for molding a container with a handle according to one embodiment 20 of the invention includes: an injection molding step of injection molding a preform including an open neck portion, a cylindrical bottomed body portion, and a handle portion formed to protrude from the neck portion; a pressing step of pressing a part of the handle portion to form a thin portion; 25 and a blow molding step of stretch blow molding the preform to form the container. According to this embodiment, since the injection molded handle portion can be 5 press formed before the blow molding step, a sufficient space for disposing the mechanism for press molding can be secured around the handle portion. In the case of press forming the thin portion immediately after injection molding, since the handle portion is provided with heat during injection molding, it is advantageous for press 5 forming. Since the thin portion of the handle portion is compression-formed and stretch-oriented by pressing, the thin portion has a higher density than the remaining area of the handle portion to exhibit high mechanical strength. A method for molding a container with a handle according to one embodiment of the invention includes: 10 an injection molding step of injection molding a preform including an open neck portion, a cylindrical bottomed body portion, and a handle portion formed to protrude from the neck portion; a blow molding step of stretch blow molding the preform to form the container; and 15 a pressing step of pressing a part of the handle portion to form a thin portion. According to this embodiment, since the pressing step of the handle portion is performed after the blow molding, the pressing step of the handle portion is rarely affected by the limitation due to the molding cycle and the degrees of freedom of the molding step are.increased. Moreover, since the thin portion of the handle portion is 20 compression-formed and stretch-oriented by pressing, the thin portion has a higher density than the remaining area of the handle portion to exhibit high mechanical strength. With any of these methods for molding a container with a handle, the pressing step may include pressing the part of the handle portion by using a pressing section 25 which has been heated to a temperature equal to or higher than a glass transition temperature of the synthetic resin. According to this configuration, stress whitening due to pressing can be 6 prevented, and the pressed part of the handle portion can be stretch-oriented. A device for molding a container with a handle according to one embodiment of the invention includes: a pressing section which presses a part of a handle portion made of a synthetic 5 resin; a pressure receiving section provided opposite to the handle portion with the part of the handle portion interposed between the pressing section and the pressure receiving section; and a moving mechanism which moves the pressing section toward the pressure 10 receiving section, wherein the moving mechanism compresses the part of the handle portion by moving the pressing section toward the part of the handle portion which is in contact with the pressure receiving section to reduce a thickness of the part of the handle portion to form a thin portion. 15 According to this embodiment, the thin portion can be formed in the handle portion by compressing the part of the handle portion using the pressing section and the pressure receiving section so as to sandwich the part of the handle portion. Since the thin portion of the handle portion formed by such a device is compression-formed and stretch-oriented by pressing, the thin portion has a higher density than the remaining 20 area of the handle portion to exhibit high mechanical strength. With this device for molding a container with a handle, the moving mechanism may be disposed between an injection molding section which injection molds a preform and a blow molding section which blow molds the preform, and 25 the pressing section may be moved toward the part of the handle portion formed in the preform by the moving mechanism. According to this configuration, since the injection molded handle portion can 7 be press formed before blow molding, a sufficient space for disposing the mechanism for press molding can be secured around the handle portion. In the case of press forming the thin portion immediately after injection molding, the handle portion is provided with heat of injection molding. Therefore, it is advantageous for press 5 forming. With this device for molding a container with a handle, the moving mechanism may move the pressing section toward the part of the handle portion formed in the blow molded container. According to this configuration, the handle portion of the blow molded container 10 can be reliably press formed. A problem during clamping of the blow mold does not occur by press forming the thin portion after molding the container, even if a molding failure such as deformation of the handle portion due to press formingoccurs. With this device for molding a container with a handle, the pressing section and the pressure receiving sections may be moved toward the part of the handle portion by 15 the moving mechanism to compress the part of the handle portion from two opposite sides to reduce the thickness of the part of the handle portion. According to this configuration, since the part of the handle portion can be compressed from both sides, the thin portion can be stretch-oriented on both sides due to pressing, whereby the handle portion having higher mechanical strength can be 20 obtained. With this device for molding a container with a handle, the pressing section may be heated to a temperature equal to or higher than a glass transition temperature of the synthetic resin. According to this configuration, since the handle portion can be deformed while 25 being stretch-oriented during pressing by using the pressing section, a thin portion having high mechanical strength can be obtained. An embodiment of the invention is described below in detail with reference to 8 the drawings. FIGS. I and 2 are diagrams showing a preform according to one embodiment of the invention. FIG. 3 is a diagram showing a container according to one embodiment of the invention. FIGS. 4 to 8 are diagrams showing a stretch blow molding device 5 according to one embodiment of the invention. FIG. 1 is a side view of a preform 28, and FIG. 2 is a plan view of the preform 28. The preform 28 is made of a synthetic resin such as polyethylene terephthalate, and includes an open neck portion 110, a cylindrical bottomed body portion 108, and a 10 handle portion 80 formed to protrude from the neck portion 110. The handle portion 80 includes a thin portion 81 which is compressed and stretched by pressing a part of the handle portion 80 and has a higher density than the remaining area of the handle portion. The handle portion 80 is integrally injection molded when injection molding the preform 28. 15 The handle portion 80 includes a plate-shaped connection portion 80a connected with a support ring 110 a formed to circularly protrude from the neck portion 110, and a holding portion 80b formed at the free end of the handle portion 80. The free end of the handle portion 80 is formed in the shape of a ring, and the holding portion 80b, which is almost linearly formed at the free end, is formed to have a width which allows 20 the holding portion 80b to be held with several fingers, and preferably four fingers. The thin portion 81 is formed in the connection portion 80a and is formed close to the neck portion 110. The connection portion 80a is injection molded to a thickness of 1.7 mm and a width of 29 mm, for example. The thin portion 81 is formed to a minimum thickness 25 of 0.7 to 1.0 mm, and preferably about 0.75 mm by the subsequent press forming. The thin portion 81 is formed across the width of the connection portion 80a. The thickness of the thin portion 81 is reduced from one side of the connection portion 80a 9 (from the side of the body portion 108 of the preform 28 in this embodiment). As shown in FIG. 3, a container 38 made of a synthetic resin includes the open neck portion 110, a body portion 55 which is reduced in thickness by blow molding, a bottom portion which forms a ground section, and the handle portion 80 formed to 5 protrude from the neck portion 110. Since the container 38 is obtained by blow molding the preform 28 having the handle portion 80, the handle portion 80 is in the same state as in the preform 28, that is, the thin portion 81, which is compressed and stretched by being pressed and has a higher density than the remaining area of the handle portion, is formed in the handle portion 80. 10 The container 38 is formed by an injection molding step of injection molding the preform 28, a pressing step of pressing a part of the handle portion 80 formed in the injection molding step to form the thin portion 81, and a blow molding step of stretch blow molding the preform 28 to form the container 38. The pressing step of pressing a part of the handle portion 80 to form the thin portion 81 may be performed after the 15 blow molding step, that is, after the container 38 has been formed. The pressing step is performed by pressing a part of the handle portion using a pressing section which is heated to a temperature equal to or higher than the glass transition temperature of the synthetic resin used, such as equal to or higher than about 70'C when using a polyethylene terephthalate resin. 20 The step of press forming the handle portion 80 of the injection molded preform 28 is described below in detail together with a description of the device shown in FIGS. 4 to 8. FIG. 4 is a plan view of the stretch blow molding device. The stretch blow molding device includes, on a stage 10, a preform molding 25 station 12, a blow molding station 14, and a transfer section located between the preform molding station 12 and the blow molding station 14. The preform molding station 12 includes a rotary disc 18, which includes 10 injection core molds at two locations positioned at an angle of rotation of 180 degrees and intermittently and rotationally carries the injection core molds along a rotary carrying path. An injection molding section 22 is provided at each stopping position of the injection core mold at a position facing an injection device 20, and a removal 5 section 24 is provided opposite to the injection molding section 22. The injection molding section 22 includes an injection cavity mold 68 which is relatively clamped onto the injection core mold, and simultaneously injection molds three preforms 28, each having the handle portion 80 at the neck portion 110, for example. The removal section 24 can remove the preforms 28 from the injection core 10 mold by relatively releasing the preforms 28 from the injection core mold. In this embodiment, the neck portion of the preform 28 is molded by using a neck cavity mold (not shown). The preform 28 is transferred to the removal section 24 by means of the rotary disc 18 while being held by the neck cavity mold and the injection core mold. In the removal section 24, after partial release of the injection 15 core mold by lowering the neck cavity mold, the preforms 28 are removed by opening the neck cavity mold. The blow molding station 14 includes rotary carrier means 34 which includes four sprockets 30, a carrier chain 32 suspended around the sprockets, and a device (not shown) which drives the sprockets. The device which drives the sprockets is an 20 electric motor which rotates one sprocket, a rack provided to a hydraulic cylinder and a pinion provided to the sprocket, or the like. A plurality (e.g. 12) of carrier members 36 are secured to the carrier chain 32 at predetermined intervals, and the preform 28 or the container 38 is supported by each carrier member 36. In the carrying path of the carrier member 36, a receiving section 25 40 which receives the preform 28 from the transfer section 16, a heating section 42 which heats the preform 28 received by the receiving section 40 to a temperature equal to or higher than the blow molding temperature, a blow molding section 44 which 11 stretch blow molds the preform 28 heated by the heating section 42 to obtain the container 38, and a container removal section 46 which removes the container 38 blow molded by the blow molding section 44 from the device, are provided. As shown in FIG. 4, the carrier means 34 forms an almost quadrilateral carrying 5 path on the plane of the stage 10, and rotationally carries the carrier members 36 along the carrying path. The receiving section 40 is disposed on the first side of the quadrilateral carrying path, the heating section 42 is disposed on the second side, the blow molding section 44 is disposed on the third side, and the container removal section 46 is disposed on the fourth side. 10 . A heating device 43 is disposed in the heating section 42. The heating device 43 includes a plurality of infrared heaters, each extending along the carrying path, disposed side by side in the direction of the height of the preform. When the preform passes through the heating device 43, a rotation sprocket provided to the carrier member 36 engages a rotation chain to uniformly heat the preform in the circumferential 15 direction while rotating the preform. The blow molding section 44 includes a blow cavity mold 48 which is clamped onto the preform 28 by a blow mold clamping mechanism 45, and blow molds one preform 28, for example. In the blow molding section 44, the preform 28 is clamped by the blow cavity mold 48 formed of a split mold. The container 38 formed along the 20 shape of the cavity surface of the blow cavity mold 48 is stretch blow molded by blowing high-pressure air into the preform 28 and extending a stretching rod. A recess (not shown) for receiving the handle portion 80 in the direction (preform transfer direction) which intersects the clamping direction of the blow cavity mold 48 at right angles is formed in the lower surface of the blow cavity mold 48. 25 The container removal section 46 reverses the container 38 using a removal device 47 and removes the container 38 in an upright state. The transfer section 16 transfers the preform 28 removed by the removal section 12 24 of the preform molding station 12 to the receiving section 40 of the blow molding station 14. In the removal section 24 of the preform molding station 12, the preforms 28 in a number corresponding to the number of preforms 28 simultaneously molded in the 5 injection molding section 22 are removed. The transfer section 16 transfers three preforms 28 simultaneously removed by the removal section 24 to the receiving section 40 one by one, for example. In 'the preform molding station 12, the preform 28 is injection molded in an upright state. On the other hand, the transfer section 16 reverses the preform 28 and 10 transfers the preform 28 to the blow molding station 14 in an inverted state. Two intermittent stopping positions of the preform 28 are provided between the receiving section 40 and the heating section 42. A gate cutting section 60 is provided at the first stopping position, and a press forming section 70 is provided at the second stopping position. The press forming section 70 may be disposed at an arbitrary 15 position between the injection molding section 22 which injection molds the preform 28 and the blow molding section 44 which blow molds the preform 28. The gate cutting section 60 includes a gate cutting mechanism (not shown) disposed therein, and cuts a gate formed to protrude from the bottom of the preform 28 transferred to the carrier member 36. 20 The press forming section 70 includes a press forming mechanism 72 shown in FIGS. 5 to 8 disposed on the stage 10, and press forms a part of the handle portion 80 of the preform 28 which is intermittently stopped. The press forming mechanism 72 includes a pressing section 73 which presses a part of the handle portion 80, a pressure receiving section 74 provided opposite to the pressing section 73 with a part of the 25 handle portion 80 interposed therebetween, and a moving mechanism 75 which moves the pressing section 73 and the pressure receiving section 74 toward a part of the handle portion 80. 13 The pressing section 73 and the pressure receiving section 74 basically have the same configuration. As shown in the side view of FIG. 6, the pressing section 73 and the pressure receiving section 74 respectively include arm sections 73b and 74b formed approximately in the shape of the letter "L", a fulcrum 76 rotatably connects the arm 5 sections 73b and 74b, and a pressing section 73a and a pressure receiving section 74a respectively formed to protrude from the end sections of the arm sections 73b and 74b. The arm sections 73b and 74b which are bent approximately in the shape of the letter "L" are rotatably connected by the fulcrum 76 supported on a frame 11 in the vicinity of the bent sections, and cam followers 73c and 74c are respectively provided at the end 10 sections of the arm sections 73b and 74b on the side opposite to the pressing section 73a and the pressure receiving section 74a. The arm sections 73b and 74b extend from the fulcrum 76 toward the pressing section 73a and the pressure receiving section 74a at a distance greater than the handle portion 80, and are disposed opposite to each other while sandwiching the handle 15 portion 80 from each side (upper and lower sides in FIG. 6). The pressing section 73a and the pressure receiving section 74a are respectively formed at the ends of the arm sections 73b and 74b and formed to protrude from the surfaces facing the handle portion 80. The pressing section 73n has an approximately triangular vertical cross section in which a top is chamfered off, and is formed in the 20 widthwise direction of the arm sections 73b and 74b to a length equal to or greater than the width of the connection portion 80a of the handle portion 80. The pressure receiving section 74a has almost the same width as that of the pressing section 73a, and is formed to have a flat surface so as to come in surface contact with the handle portion 80. The pressure receiving section 74a functions as a pressure receiving section which 25 receives pressure applied to the connection portion 80 from the pressing section 73a during press forming. The pressing section 73a and the pressure receiving section 74a are heated by a 14 heating mechanism (not shown) to a temperature equal to or higher than the glass transition temperature of the synthetic resin used for molding but below the temperature below which the synthetic resin is not melted and does not adhere to the pressing section 73a and the pressure receiving section 74a (in the case of polyethylene 5 terephthalate, the temperature is preferably 70 to 150 0 C, and still more preferably 110 to 140'C). It is preferable to provide a coating treatment for improving releasability to the surfaces of the pressing section 73a and the pressure receiving section 74a. The moving mechanism 75 is used to move the pressing section 73 and the pressure receiving section 74 toward the handle portion 80, and includes an air cylinder 10 77 secured to the frame II vertically provided on the stage 10, and a cam member 78 secured to the end of a cylinder rod of the air cylinder 77. The cam member 78 has cam surfaces 78a and 78b formed by two inclined surfaces which gradually spread, and the cam followers 73c and 74c respectively come in rolling contact with the cam surfaces 78a and 78b. 15 A positioning air cylinder 90 for disposing the handle portion 80 at a predetermined position is provided to the frame 11 of the press forming mechanism 72. A positioning member 79 for disposing the handle portion 80 at a predetermined position is provided to a cylinder rod of the positioning air cylinder 90. In the positioning member 79, two inclined inner surfaces 79a and 79b gradually spreading 20 toward the handle portion 80 are formed. When the cylinder rod of the positioning air cylinder 90 advances toward the handle portion 80, the handle portion 80 rotates the preform 28 while coming in contact with one of the inclined inner surfaces 79a and 79b, whereby the handle portion 80 can be disposed at a predetermined position. The pressing step is described below. As shown in FIG. 6, when the preform 25 28 is intermittently stopped in the press forming section 70, the cylinder rod of the air cylinder 77 advances and moves the cam followers 73c and 74c in the direction away from each other by the cam member 78 to move the pressing section 73a and the 15 pressure receiving section 74a toward a part of the handle portion 80 disposed in the press forming position by the positioning member 79, thereby press forming the part of the handle portion 80 as shown in FIG. 7. In press forming, the thickness of a part of the handle portion 80 is reduced by 5 compressing the part of the handle portion 80 from each side using the pressing section 73 and the pressure receiving section 74 to form the thin portion 81. The connection portion 80a of the handle portion 80 is heated and pressed by the contact with the pressing section 73 and the pressure receiving section 74 and is reduced in thickness and stretched by means of compression forming so that the thin portion 81 has a higher 10 density than the remaining area of the handle portion 80. Since molecular orientation due to stretching occurs in the thin portion 81, mechanical strength is improved. Therefore, the handle portion 80 does not break, even if held and bent at the thin portion 81, whereby cracks do not occur. In this embodiment, the thin portion 81 is formed by reducing the thickness of the handle portion 80 from only one side of the handle portion 15 80 using the pressing section 73a of the pressing section 73. The thickness of the thin portion 81 is set to a desired thickness by changing the pressure of compression air supplied to the air cylinder 77. The thickness of the thin portion 81 may be changed by changing the press forming time. In the blow molding station 14, the carrier means 34 intermittently transfers the 20 carrier member 36, and a section between the heating section 42 and the blow molding section 44 is set as a standby section 50 for allowing the heated preform 28 to be intermittently stopped and to temporarily (one molding cycle time) stand by. The standby section 50 includes a positioning mechanism 116 which limits the handle portion 80 of the preform 28 in the direction along the transfer direction. The 25 positioning mechanism 116 can limit the handle portion 80 in the direction along the transfer direction irrespective of the position of the handle portion 80 of the preform 28 transferred from the heating section due to rotation of the preform 28 in the heating 16 section. The details of the positioning mechanism 116 are not illustrated in the drawings. The positioning mechanism 116 includes a sensor for confirming the position of the handle portion 80, an electric motor which rotates the preform 28, and the like, and prevents interference with the blow cavity mold 48 in the blow molding 5 section 44. The invention is not limited to the above-described embodiment, and various modifications and variations may be made without departing from the spirit and the scope of the invention. In the above-described embodiment, the most popular polyethylene terephthalate 10 resin is used. However, another synthetic resin which can form a synthetic resin container may be arbitrarily selected and used. The optimum thickness of the thin portion varies depending on the resin used. In the above-described embodiment, the thickness of the thin portion is reduced from only one side of the connection portion. However, the thickness of the thin 15 portion may be reduced from the upper and lower sides. In this case, the pressure receiving section 74a may be formed to have an approximately triangular vertical cross section in which a top is chamfered off in the same manner as the pressing section 73a. In the above-described embodiment, both the pressing section 73a and the pressure receiving section 74a are moved toward the handle portion 80. However, the 20 moving mechanism 75 may move the pressing section toward a part of the handle portion 80 in contact with the pressure receiving section to reduce the thickness of the part of the handle portion 80 by means of compression to form the thin portion 81. In the above-described embodiment, a part of the handle portion 80 is press formed in the stage of the preform. However, the press forming section 70 may be 25 disposed between the blow molding section 44 and the container removal section 46. Or, the press forming section 70 may be provided in the middle of a conveyer which transfers the container 38 removed by the container removal section 46. In this case, 17 the moving mechanism 75 of the press forming section 70 moves the pressing section toward a part of the handle portion 80 formed in the blow molded container 38. The shape of the handle portion 80 is not limited to the shape described in the embodiment. The handle portion 80 may be in the shape of the letter "T", or 5 approximately in the shape of the letter "U" which allows the handle portion 80 to come in contact with the neck portion 110 at two locations. Since the connection portions 80a are formed at two locations when the handle portion 80 is approximately in the shape of the letter "U", the arm sections 73b and 74b of the press forming mechanism 72 may also be formed approximately in the shape of the letter "U" which sandwiches 10 the neck portion 110. The stretch blow molding device in which the preform molding station and the blow molding station are integrally provided is described above. However, the preform molding station may be configured as a single injection molding device, or the blow molding station may be configured as a single injection molding device. 15 In the above-described embodiment, the preform and the handle portion are integrally molded by injection molding. However, the preform and the handle portion may be molded by compression molding, for example. EXAMPLE 20 As an example, a handle portion having a connection portion with a thickness of 1.7 mm was subjected to press forming using a pressing section. The pressing section was heated to 130'C, and preform samples in which the thickness of a thin portion of the handle portion was 0.75 mm, 0.99 mm, and 1.05 mm were formed while changing the pressure (cylinder pressure setting). 25 The handle portion of the sample of the example was bent at 90 degrees at the thin portion. After allowing the sample to stand for 3.5 days or more in this state, the handle portion was rapidly bent and deformed in the direction the reverse of the 18 direction in which the handle portion was originally bent while securing the preform. As a result, the three types of samples of the example did not break. In particular, in the sample in which the thickness of the thin portion was 0.75 mm, even minute cracks were not observed with the naked eye at the thin portion after bending. 5 Although only some embodiments of the present invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within scope of this invention. 10 19

Claims (16)

1. A preform with a handle and made of a synthetic resin, the preform comprising: 5 an open neck portion; a cylindrical bottomed body portion; and a handle portion formed to protrude from the neck portion, wherein the handle portion has a thin portion which is formed by compressing and stretching a part of the handle portion by pressing and has a higher density than a remaining area of the handle portion. 10

2. The preform as defined in claim 1, wherein the handle portion includes a plate-shaped:connection portion connected with the neck portion, and a holding portion formed at a free end of the handle portion, and is wherein the thin portion is formed in the connection portion and is formed closed to the neck portion.

3. A container with a handle and made of a synthetic resin, the container comprising: 20 an open neck portion; a body portion; a bottom portion; and a handle portion formed to protrude from the neck portion, wherein the handle portion has a thin portion which is formed by compressing and stretching a part of the handle portion by pressing and has a higher density than a remaining area of the handle portion. 25

4. A container with a handle, obtained by blow molding the preform as defined in claim 1 or 2.

5. A method for molding a container with a handle, the method 3o comprising: an injection molding step of injection molding a preform including an open neck portion, a cylindrical bottomed body portion, and a handle portion formed to protrude from the neck portion; a pressing step of pressing a part of the handle portion to form a thin portion 35 which has a higher density than a remaining area of the handle portion; and AH21(59471261)MNa.LW 21 a blow molding step of stretch blow molding the preform to form the container.

6. A method for molding a container with a handle, the method comprising: 5 an injection molding step of injection molding a preform including an open neck portion, a cylindrical bottomed body portion, and a handle portion formed to protrude from the neck portion; a blow molding step of stretch blow molding the preform to form the container; and 10 a pressing step of pressing a part of the handle portion to form a thin portion which has a higher density than a remaining area of the handle portion.

7. The method as defined in claim 5 or 6, wherein the pressing step includes pressing the part of the handle portion by is using a pressing section which has been heated to a temperature equal to or higher than a glass transition temperature of the synthetic resin.

8. A device for molding a container with a handle, the device comprising: a pressing section which presses a part of a handle portion made of a synthetic 20 resin; a pressure receiving section provided opposite to the handle portion with the part of the handle portion interposed between the pressing section and the pressure receiving section; and a moving mechanism which moves the pressing section toward the pressure 25 receiving section, wherein the moving mechanism compresses the part of the handle portion by moving the pressing section toward the part of the handle portion which is in contact with the pressure receiving section to reduce a thickness of the part of the handle portion to form a thin portion which has a higher density than a remaining area of the handle 30 portion.

9. The device as defined in claim 8, wherein the moving mechanism is disposed between an injection molding section which injection molds a preform and a blow molding section which blow molds the preform, 35 and AH2i(1947186_I):MLW 22 wherein the pressing section is moved toward the part of the handle portion formed in the prefonn by the moving mechanism,

10. The device as defined in claim 8, s wherein the moving mechanism moves the pressing section toward the part of the handle portion formed in the blow molded container.

11. The device as defined in claim 9 or 10, wherein the pressing section and the pressure receiving sections are moved 1o toward the part of the handle portion by the moving mechanism to compress the part of the handle portion from two opposite sides to reduce the thickness of the part of the handle portion.

12. The device as defined in any one of claims 8 to 11, 15 wherein the pressing section is heated to a temperature equal to or higher than a glass transition temperature of the synthetic resin.

13, A preform with a handle and made of a synthetic resin, the preform substantially as hereinbefore described with reference to Fig 1 or Fig 2 of the 20 accompanying drawings.

14. A container with a handle and made of a synthetic resin, the container substantially as hereinbefore described with reference to Fig 1, Fig 2 or Fig 3 of the accompanying drawings. 25

15. A method for molding a container with a handle, the method substantially as hereinbefore described with reference to the accompanying drawings,

16. A device for molding a container with a handle, the device substantially 30 as hereinbefore described with reference to Figs 4 to 8 of the accompanying drawings. Dated I February 2012 Nissei ASB Machine Co., Ltd. Patent Attorneys for the ApplicantiNomiiated Person 35 SPRUSON & FERGUSON AH21(59471_S )! W