JP4962724B2 - Synthetic resin cup-like container and thermal crystallization treatment method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cup-shaped container having excellent heat resistance by solving a technical problem of attaining heating of a limited part which is the vicinity of a flange part regarding the cup-shaped container made of synthetic resin and its thermal crystallization treatment method for giving thermal crystallization treatment to the vicinity of the flange part. <P>SOLUTION: The thermal crystallization treatment method comprises fitting a fitting cylinder part disposed at the upper end of a support tool, to the outer periphery of the cup-shaped container or its preform with a projecting rib arranged around the periphery of a lower part of a flange, from below so that the upper end abuts against the lower end of the projecting rib, and heating the vicinity of the flange part from the outer peripheral surface side of the flange by an infrared heater. The cup-shaped container is circumferentially provided with the projecting rib with a width in a range of 0.5-1.5 mm in a predetermined height position of the upper end of a body part, and an upper part including the flange is thermally crystallized from the upper end base part of the projecting rib. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

The present invention relates to a synthetic resin cup-shaped container having a flange around its upper end, and particularly relates to a synthetic resin cup-shaped container in which the vicinity of the flange portion is subjected to thermal crystallization treatment, and a thermal crystallization treatment method thereof.

  Containers such as so-called PET bottles obtained by biaxial stretch blow molding of a polyethylene terephthalate (hereinafter referred to as PET) resin have mechanical strength, heat resistance, transparency, barrier properties, hygiene, etc. It is excellent and widely used in food containers such as beverages.

  In addition to PET bottles, taking advantage of the above-described superior properties, coffee, milk beverages, etc. are used for high temperature filling for sterilization at about 80 to 90 ° C. or for applications requiring aseptic filling. Wide-mouth cup-shaped containers made of stretch blow molded PET resin or polypropylene resin are in widespread use. The cup-shaped container is used by sealing the container by adhering a lid material such as aluminum foil or resin synthetic paper using the upper surface of a flange provided around the top of the outer casing.

  For example, Patent Document 1 discloses a biaxial stretch blow molding method for a wide-mouth cup-shaped container made of PET resin (see FIG. 7). This biaxial stretch blow molding is shown in the schematic explanatory diagram of FIG. The flange 114 portion of the small cup-shaped preform 111 having the flange 114 provided around the upper end is fixed, and biaxial stretch blow molding is performed to form the cup-shaped container 101.

  Here, in the biaxially stretched blow-molded product, the biaxially stretched portion has improved heat resistance due to orientation crystallization by stretching, but the mouth tube portion of the PET bottle or the cup-shaped container described above Although the flange 114 in the preform 111 is in an unstretched state and has a heat resistance of about 70 ° C., it is thermally deformed by a filling process at a high temperature as described above or a hot air sterilization process of hydrogen peroxide.

  In order to improve the heat resistance of such non-stretched parts such as the mouth tube part and the flange, only these parts are heated in a preform state or in a container state to perform thermal crystallization treatment (so-called whitening treatment). ). For example, in the case of a PET bottle, a method of irradiating the mouth tube portion with an infrared heater is often employed in a preform state. At this time, a test tubular preform is fixed to a jig, and is made uniform over the entire circumference of the mouth tube portion while rotating around the central axis.

Further, as a thermal crystallization treatment method for a flange of a cup-shaped container or a flange and a neck, Patent Document 2 describes a method of partially thermal crystallization by bringing a hot plate into contact with the flange or the like.
JP 2004-268570 A JP 2004-58602 A

  Here, whereas the mouth tube portion of the PET bottle is a thick cylindrical shape, the flange or neck of the cup-shaped container is relatively thin, and there is a slight difference in the strength of the thermal crystallization treatment (spots). Due to this, it is greatly deformed.

  On the other hand, regarding the thermal crystallization treatment process, for example, when only the flange is thermally crystallized, it is necessary to heat a very limited portion called the flange, but this is a conventional method using an infrared heater. The partial heating of is difficult.

Further, the method described in Patent Document 2 for heating partially by bringing a hot plate into contact has the following problems.
(1) Small crater-like irregularities are generated on the flange surface in contact with the hot plate, the appearance is impaired, and the sealing performance by the lid is incomplete. The unevenness is presumed to be generated by trapping the component volatilized by heating between the flange surface and the hot plate.
(2) In order to heat only the flange in contact with only the flange, it is necessary to make the hot plate extremely small, and it is difficult to make the heating uniform over the entire circumference of the flange.
For example, if thermal crystallization proceeds in a part of the body of the preform due to the influence of the hot plate, stretching in the biaxial stretch blow molding becomes non-uniform. Further, the appearance is damaged by whitening of the portion.
(3) Since it is not non-contact like infrared irradiation, the preform or the final molded product cannot be rotated and heated uniformly over the entire circumference.

Therefore, the present invention enables heating of a limited part, such as the vicinity of the flange part including the flange, while taking advantage of the feature of the heating method by the infrared heater that can perform uniform thermal crystallization processing in a short time without contact. It is an object of the present invention to provide a cup-shaped container having excellent heat resistance without deformation.

In order to solve the above technical problem, the basic thermal crystallization treatment method of the present invention is:
It is a thermal crystallization treatment method in the vicinity of the flange portion of a synthetic resin cup-shaped container having a flange in the form of an outer casing at the upper end,
Using a cup-shaped container with ridge ribs arranged continuously or intermittently at a predetermined height position of the neck arranged just below the flange,
In this cup-shaped container, the fitting cylinder part disposed at the upper end part of the support jig is externally fitted from below so that the upper end surface of the fitting cylinder part comes into contact with the lower end face of the protruding rib,
Heating the vicinity of the flange portion from the outer peripheral surface side of the flange with an infrared heater in a state where the fitting tube portion is externally fitted as described above.
It is said.

Another of the basic thermal crystallization treatment methods of the present invention is:
A thermal crystallization treatment method in the vicinity of a flange portion of a preform for forming a synthetic resin cup-shaped container by biaxial stretching blow molding with a flange in the form of an outer casing at the upper end,
Using a preform in which the rib ribs are continuously or intermittently provided at a predetermined height position of the neck disposed immediately below the flange,
To this preform, the fitting cylinder part disposed at the upper end part of the support jig is externally fitted from below so that the upper end surface of the fitting cylinder part comes into contact with the lower end face of the protruding rib,
In the state where the fitting cylinder part is externally fitted, the vicinity of the flange part is heated by the infrared heater from the outer peripheral surface side of the flange.
In this method, the portion near the flange is preliminarily thermally crystallized in the preform state.

  In the present invention, the flange vicinity portion is a portion including a predetermined range of the flange portion or the flange portion and a portion directly below the flange (so-called neck portion), and the range of the thermal crystallization is the shape of the cup-shaped container, It is set according to the required heat resistance.

  The above-described two thermal crystallization treatment methods were devised in consideration of the advantages and problems of heating by the infrared heater described above. According to this thermal crystallization treatment method, a cup-shaped container or preform ( Both may be collectively referred to as a molded product hereinafter.), And the fitting cylinder portion disposed at the upper end portion of the support jig is arranged so that the upper end surface is in contact with the lower end surface of the protruding rib. Also, it is fitted from the bottom so that the upper end is in close contact with the molded product, and the vicinity of the flange is heated by an infrared heater from the outer peripheral surface side of the flange, regardless of the heating method using the infrared heater. It becomes possible to realize the heating of the limited part.

Heating by the infrared heater is due to radiation, and it is difficult to limit the heating part with high accuracy, but the molded product part that externally fits the metal fitting cylinder part is not heated, so the height of the rib ribs is formed. The heated part and the non-heated part can be divided according to the position, that is, the height position of the upper end of the fitting tube part.
Here, there is heat inflow from the lower end of the heated part to the upper end of the non-heated part, but by using a material with good heat conduction such as metal or ceramic for the fitting tube part, Heat can be dissipated from the abutment portion of the rib and the fitting tube portion through the fitting tube portion, and the boundary between the heating portion and the non-heated portion can be made uniform in the circumferential direction. it can.

  And, if the formation position of the ridge rib is just below the flange, only the flange portion can be heated, and if this formation position is lowered a little if necessary, the predetermined height range of the neck as well as the flange is thermocrystallized. Can be processed.

Here, the ribs exhibit the function of determining the contact height position of the fitting cylinder part, and are not only continuously provided in the periphery, but also the heat dissipation efficiency from the contact part is not impaired. It can also be intermittently installed in the range.
In addition, when a cup-shaped container is formed from a preform by biaxial stretch blow molding, the neck portion directly below the flange is a portion having relatively little heat resistance due to stretch deformation and is easily deformed in a high temperature filling process, By forming the ribs on the part, there is an effect of suppressing such deformation.

  In order to make the heating by the infrared heater uniform in the circumferential direction, one or more infrared heaters are arranged at predetermined positions along the outside of the outer peripheral surface of the flange, and a molded product using a support jig. It is preferable to heat while rotating around the central axis.

Other methods of the present invention, in addition to the basic method described above,
The width of the ridge rib is in the range of 0.5 to 1.5 mm.

According to the above method, by setting the width of the ridge rib in the range of 0.5 to 1.5 mm, the heat radiation action by the fitting tube portion that contacts the lower end surface of the ridge rib is effective in this thickness range. The boundary between the thermally crystallized region and the non-crystallized region by the infrared heater can be made substantially the height position of the upper end base portion of the protruding rib.
That is, the thermal crystallization region can be set to a desired height position including the flange by the circumferential height position of the protruding rib having the width in this range.
It should be noted that the extent of the width of the ribs in the range of 0.5 to 1.5 mm is appropriately determined in consideration of the radiation dose by the infrared heater, the heat radiation action by the fitting tube portion, and the like. be able to.

  According to still another method of the present invention, after heating with an infrared heater, the softened flange is cooled in a pressed state with a cooling jig.

By cooling the flange in a pressed state with a cooling jig, it is possible to effectively suppress warpage deformation and wave deformation at the flange due to thermal crystallization and thermal contraction.
In this way, the flange surface is flattened by suppressing warping deformation and wave deformation on the flange surface, so that the cup-shaped container can be used to cover the cover material such as aluminum foil or resin synthetic paper using the upper surface of the flange. It can be easily bonded and the container can be reliably sealed.

In order to solve the above technical problem, means relating to the synthetic resin cup-shaped container of the present invention,
In a synthetic resin cup-shaped container with a flange in the form of an outer casing at the upper end of the cylindrical body, continuously or intermittently at a predetermined height position of the neck disposed immediately below the flange A projecting rib having a width in the range of 0.5 to 1.5 mm is provided around the upper end of the projecting rib, and the upper part including the flange is subjected to thermal crystallization treatment. There is.

  The synthetic resin cup-shaped container having the above-described configuration can make the thermal crystallization region up to a desired height position including the flange depending on the circumferential height position of the ribs, so that the shape of the container and particularly the high temperature In consideration of the use environment, a desired limited region is a thermal crystallization region using an infrared heater or the like, and a cup-shaped container having heat resistance according to the purpose of use can be provided.

  Another configuration relating to the synthetic resin cup-shaped container is to make the cup-shaped container made of a PET-based resin.

  The PET resin can provide a cup-shaped container having excellent transparency and high rigidity by injection molding, biaxial stretch blow molding of a preform, and heating a sheet molded product into a biaxial stretch shape. By molding, a cup-shaped container having more excellent heat resistance, rigidity, strength, and gas barrier properties can be provided.

  As the PET-based resin, a PET (polyethylene terephthalate) resin is mainly used. However, as long as the essence of the PET resin is not impaired, a copolymer polyester mainly containing ethylene terephthalate units and containing other polyester units can also be used. In addition, for example, in order to improve gas barrier properties and heat resistance, resins such as nylon resins and polyethylene naphthalate resins can be blended and used. Examples of the component for forming the copolyester include dicarboxylic acid components such as isophthalic acid, naphthalene 2,6 dicarboxylic acid, and adipic acid, propylene glycol, 1,4 butanediol, tetramethylene glycol, neopentyl glycol, cyclohexanedimethanol, Mention may be made of glycol components such as diethylene glycol.

Furthermore, as a PET-type resin cup-shaped container or preform, as long as the essence of the PET resin is not impaired, for example, to improve heat resistance and gas barrier properties, PET resin / polyethylene naphthalate resin, or It may be laminated with other resins such as PET resin / nylon resin / PET resin.

The crystallization treatment method of the present invention is a method having the above-described configuration, and has the following effects.
In the basic method of the present invention, the molded product portion that is externally fitted with the metal fitting tube portion is not heated, so the height position of the rib ribs, that is, the contact height of the fitting tube portion Depending on the position, combined with the heat dissipation effect from this fitting cylinder part, the heated part and the non-heated part can be clearly separated, and heating of a limited part such as the flange vicinity regardless of the heating method by the infrared heater Can be realized.

  In the case where the width of the rib is in the range of 0.5 to 1.5 mm, the boundary between the thermal crystallization region and the non-crystallized region by the infrared heater is approximately the height of the upper end base of the rib. The thermal crystallization region can be set to a desired height position including the flange by the circumferential height position of the rib rib.

  After heating with an infrared heater, if the flange is cooled with the softened flange held in a pressed shape with a cooling jig, warpage deformation or wave deformation of the flange due to crystallization or thermal contraction will occur. It can be effectively suppressed.

Moreover, the synthetic resin cup-shaped container of the present invention has the above-described configuration, and a rib rib having a width in a range of 0.5 to 1.5 mm at a predetermined height position of a neck portion disposed immediately below the flange . And the upper part including the flange from the upper end base of the rib rib is subjected to a thermal crystallization treatment, so that the thermal crystallization region can be changed depending on the circumferential height position of the rib rib. Can be provided up to a desired height position including the flange, and a cup-shaped container having heat resistance according to the purpose of use can be provided.

In the case where the cup-shaped container is made of a PET-based resin, the PET-based resin can provide a cup-shaped container having excellent transparency and high rigidity by injection molding. A cup-shaped container having more excellent heat resistance, rigidity, strength, and gas barrier properties can be provided by stretch blow molding or thermoforming a sheet molded product into a biaxially stretched shape.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described along examples with reference to the drawings.
1 to 3 show an embodiment of a thermal crystallization treatment method of the present invention, which is an example of a thermal crystallization treatment method for a flange of a preform, and FIG. 1 shows a half longitudinal section of a preform 11 to be used. FIG. 2 is a schematic explanatory diagram of the heating process using the infrared heater IR, and FIG. 3 is a schematic explanatory diagram of the cooling process using the cooling jig 31.

The preform 11 shown in FIG. 1 is made of PET resin, and is formed into a deep-drawn shape by the biaxial stretch blow molding shown in the schematic explanatory view of FIG. 7, and the synthetic resin cup-like container of the present invention shown in FIG. 1 is formed.
This preform 11 is a small cup-shaped injection-molded product, is colorless and transparent, is entirely in an amorphous state, has a bottom portion 13, and has a short portion at the upper end of a cylindrical body portion 12 that expands upward. A flange 14 is provided around the outer periphery of the flange 14 via a cylindrical neck portion 15. The flange 14 has a width of 4 mm, an average thickness of 2 mm, and an outer diameter of 80 mm.

  Further, a rib rib 16 having a width of 1 mm is formed in a circumferential shape at a position directly below the lower end surface of the flange 14 of the neck portion 15. The upper end base portion 16 b of the protruding rib 16 is formed so as to be connected to the lower end surface of the flange 14.

FIG. 2 is a schematic explanatory diagram of the heating process by the infrared heater IR.
In a state where the preform 11 of FIG. 1 is fitted and assembled to a metal support jig 21 having a bottomed cylindrical shape, the preform 11 is disposed in the immediate vicinity of the outer peripheral surface of the flange 14 while being rotated around the shaft body 21c. The flange 14 portion is heated from the outer peripheral surface side by a pair of left and right infrared heaters IR. The upper end portion of the support jig 21 is a cylindrical fitting tube portion 21 a formed along the peripheral wall of the neck portion 15, and the upper end surface of the fitting tube portion 21 a has a protrusion on the upper end surface. It fits around the peripheral wall of the neck portion 15 so as to contact the lower end surface of the rib 16. (Refer to the enlarged view near the flange 14 in FIG. 2)
In the present embodiment, the entire support jig 21 is made of metal. However, if at least the fitting tube portion 21a is made of metal, other parts than the metal material can be used as long as the heat dissipation function described later is not impaired. These materials can also be used.

When the flange 14 is heated from the outer peripheral surface side of the flange 14 by the infrared heater IR while the preform 11 is rotated around the shaft body 21c in the external fitting state by the fitting cylinder portion 21a as described above, the flange 14 The 14 portions can be thermally crystallized in a limited manner (see the crystallization site C cross-hatched in the partially enlarged view in FIG. 2).
A gap of 1 mm corresponding to the width W of the protruding rib 6 is formed between the lower end surface of the flange 14 and the upper end of the fitting cylinder portion 21a, and the radiant heat of the infrared heater reaches this gap portion. However, thermal crystallization of the gap portion did not proceed due to the heat dissipation effect of the metal fitting tube portion 21a, and whitening accompanying crystallization was not observed.

  Next, FIG. 3 is a schematic explanatory diagram of a cooling process using the cooling jig 31. After the heating step described above, within the time in which the PET resin is still in the softened state, the upper end surface, the lower end surface, and the outer peripheral surface of the flange 14 are thus divided into upper and lower portions and the cooling pipes 31a are respectively provided. By cooling by sandwiching the cooling jig 31 in a pressed state, it is possible to prevent deformation due to crystallization and thermal contraction such as warpage deformation and wave deformation of the flange 14 surface.

FIG. 4 shows an embodiment of the synthetic resin cup-shaped container of the present invention obtained by biaxial stretch blow molding of the preform 11 of FIG. 1 as described above.
This cup-shaped container 1 has a body portion 2 and a bottom portion 3, and a neck portion 5 formed as a part of the body portion 2 at the upper end of a cylindrical body portion 2 that gradually increases in diameter upward. A flange 4 is provided around the outer casing. Further, a rib rib 6 is provided around the flange 4 of the neck portion 5 in the same manner as the preform 11 described above, and only the portion above the upper end base portion 6a of the rib rib 6, that is, the flange 4 portion. Is limited to thermal crystallization (see the crystallization site C cross-hatched in the partially enlarged view in FIG. 4).

  Since the preform 11 in FIG. 1 is smaller and thicker than the cup-shaped container 1 in FIG. 4, the thermal crystallization process of the present invention is performed at the stage of the preform 11. Although it is relatively easy, the cup-shaped container 1 can of course be implemented in the same process as the preform 11 in consideration of the entire manufacturing process and the like.

Moreover, although the example which thermally crystallizes only the flange 14 was described in the said Example, according to the intended purpose, thermal crystallization process including the predetermined height range of the neck 15 just under the flange 14 may also be implemented. it can.
For example, in the example of the biaxial stretch blow molding shown in FIG. 7, the neck portion 115 of the preform 111 is slightly stretched in the longitudinal direction but hardly stretched in the lateral direction. The heat resistance of 105 may be insufficient, and in such a case, thermal crystallization processing is required for the neck portion 115 as well as the flange 114 of the preform 111.

FIG. 5 is a longitudinal sectional view of the vicinity of the flange 14 in the example of the preform 11 of FIG. 1 in which the circumferential height position of the protrusion rib 16 is lowered downward. The width W of the ridge rib 16 is 1 mm, and the distance between the upper end base portion 16b and the lower end surface of the flange 14 is 3 mm.
When the infrared heater IR is heated as shown in FIG. 2 with the upper end of the fitting tube portion 21a in contact with the lower end surface of the rib rib 16, the flange radiates by the heat radiation action of the fitting tube portion 21a. 14, thermal crystallization of the neck portion 15 proceeds in the height range up to the upper end base portion 16 b. (See the cross-hatched crystallization site C in FIG. 5.)

  As described above, in the thermal crystallization treatment method of the present invention, the thermal crystallization is performed in consideration of the required heat resistance depending on the shape and usage of the cup-shaped container depending on the circumferential height position of the protruding ribs 16. The height range to be processed can be easily controlled.

FIG. 6 is a longitudinal sectional view in the vicinity of the flange 4 showing another embodiment of the synthetic resin cup-shaped container of the present invention obtained by biaxial stretch blow molding of the preform 11 of FIG.
The overall shape of the cup-shaped container of the present embodiment is the same as that of the cup-shaped container 1 of FIG. 4, and the circumferential height position of the rib rib 6 and the range of the thermal crystallization site C are different. 5 is the same as the preform 11 of FIG. 5, the width W of the rib rib 6 is 1 mm, and the distance between the upper end base portion 6 b and the lower end surface of the flange 4 is 3 mm. And the neck 5 which is a part of the trunk | drum 2 in the height range to the upper end base 6b with the flange 4 is thermally crystallized. (See the cross-hatched crystallization site C in FIG. 6.)

As mentioned above, although embodiment of this invention was described along the Example, this invention is not limited to an above-described Example.
For example, the preform and cup-shaped container used are not limited to those made of PET resin, and those made of polypropylene resin can also be used.

In addition to the cup-shaped container formed by biaxial stretch blow molding, the effect of the present invention can be sufficiently exerted for a thermo-formed cup-shaped container or an injection-molded cup-shaped container. This is an extremely effective method for promoting crystallization of a limited portion of the neck, increasing rigidity and improving heat resistance.

As described above, the synthetic resin cup-shaped container and the thermal crystallization treatment method of the present invention can perform the thermal crystallization treatment in a short time and uniformly over a limited height range near the flange portion with high accuracy. It is expected to be widely used and developed with heat resistance according to the purpose of use.

It is a half longitudinal cross-sectional view which shows an example of the preform used for the thermal crystallization processing method of this invention. It is a schematic explanatory drawing which shows an example of the heating process by the infrared heater in the thermal crystallization processing method of this invention. It is a schematic explanatory drawing which shows an example of the cooling process in the thermal crystallization processing method of this invention. It is a half vertical front view of one Example of the synthetic resin cup-shaped container of the present invention obtained by biaxial stretch blow molding of the preform of FIG. It is a longitudinal cross-sectional view of the flange vicinity which shows the other example of the preform used for the thermal crystallization processing method of this invention. It is a longitudinal cross-sectional view of the flange vicinity which shows the other Example of the synthetic resin cup-shaped containers of this invention obtained by carrying out biaxial stretch blow molding of the preform of FIG. It is a schematic explanatory drawing of the biaxial stretch blow molding of a cup-shaped container.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Cup-shaped container 2; Body part 3; Bottom part 4; Flange 5; Neck part 6; Projection rib 6b; Upper end base part 11; Preform 12; Rib 16b; upper end base portion 21; support jig 21a; fitting cylinder portion 21c; shaft body 31; cooling jig 31a; cooling pipe 101; cup-shaped container 104; Neck IR; infrared heater W; width C; crystallization site

Claims (6)

A method of thermal crystallization treatment in the vicinity of the flange (4) portion of a synthetic resin cup-shaped container (1) having a flange (4) around its upper end in the shape of an outer casing,
Using a cup-shaped container (1) in which the ribs (6) are continuously or intermittently provided at a predetermined height position of the neck (5) disposed immediately below the flange (4),
In the cup-shaped container (1), the fitting cylinder part (21a) disposed at the upper end part of the support jig (21) is provided, and the upper end surface of the fitting cylinder part (21a) is the protruding rib (6). ) From the lower side so as to contact the lower end surface of the
A thermal crystallization treatment method, wherein the vicinity of the flange (4) is heated from the outer peripheral surface side of the flange (4) by an infrared heater (IR). Thermal crystallization treatment in the vicinity of the flange (14) of the preform (11) for forming a cup-shaped container made of synthetic resin by biaxial stretch blow molding with a flange (14) around the top of the flange (14) A method,
Using a preform (11) in which the ribs (16) are continuously or intermittently provided at a predetermined height position of the neck (15) disposed immediately below the flange (14),
The preform (11) is provided with a fitting tube portion (21a) disposed at the upper end portion of the support jig (21), and the upper end surface of the fitting tube portion (21a) is the protruding rib (16). Fitted from below so as to contact the lower end surface of the
A thermal crystallization process characterized by heating the vicinity of the flange (14) from the outer peripheral surface side of the flange (14) by an infrared heater (IR) in a state of being externally fitted by the fitting tube portion (21a). Method. The thermal crystallization treatment method according to claim 1 or 2, wherein the width (W) of the ribs (6, 16) is in the range of 0.5 to 1.5 mm. 4. The cooling according to claim 1, 2, or 3, wherein after the heating by the infrared heater (IR), the flanges (4, 14) in a softened state are cooled in a state of being pressed by a cooling jig (31). Thermal crystallization treatment method. Place the flange (4) around the top of the cylindrical body (2) in the shape of an outer casing,
A rib with a width (W) in the range of 0.5 to 1.5 mm continuously or intermittently at a predetermined height position of the neck (5) disposed immediately below the flange (4) (6)
A synthetic resin cup-shaped container characterized in that the upper part including the flange (4) is subjected to thermal crystallization treatment from the upper end base (6b) of the rib (6). The synthetic resin cup-shaped container according to claim 5, which is made of polyethylene terephthalate resin.

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