A resin part, wherein the resin part has an asymmetrical shape in a thickness direction, so that a portion in which an increase in internal temperature by heating is relatively quick is positioned closer to one end of the resin part in the thickness direction while a portion in which an increase in internal temperature by heating is relatively slow is positioned closer to the other end of the resin part in the thickness direction, wherein the resin part has an asymmetrical shape in a width direction, so that the portion in which the increase in internal temperature by heating is relatively quick is positioned closer to one end of the resin part in the width direction while a portion in which an increase in internal temperature by heating is relatively slow is positioned closer to the other end of the resin part in the width direction.

The invention provides a heat-shrinkable polyester-based film roll obtained by winding a heat-shrinkable polyester-based film with a shrinkage ratio of 30% or more in a film main shrinkage direction in hot water at 90° C. for 10 seconds. The film roll has a winding length of 2000-25000 m and a width of 400-2500 mm. The film has a thickness of 5-40 μm. In thickness unevenness in a width direction of the film on a surface layer of the film roll, there are positions having concave thickness patterns, and in a concave portion that has a maximum thickness difference (maximum concave portion), thickness unevenness in the maximum concave portion, which is obtained from the maximum thickness difference in the maximum concave portion and an average thickness of the film is 10% or less. The winding hardness of the surface layer of the film roll is 400-800.

The invention provides a heat-shrinkable polyester-based film roll obtained by winding a heat-shrinkable polyester-based film with a shrinkage ratio of 30% or more in a film main shrinkage direction in hot water at 90° C. for 10 seconds. The film roll has a winding length of 2000-25000 m and a width of 400-2500 mm. The film has a thickness of 5-40 μm. In thickness unevenness in a width direction of the film on a surface layer of the film roll, there are positions having concave thickness patterns, and in a concave portion that has a maximum thickness difference (maximum concave portion), thickness unevenness in the maximum concave portion, which is obtained from the maximum thickness difference in the maximum concave portion and an average thickness of the film is 10% or less. The winding hardness of the surface layer of the film roll is 400-800.

The embodiments relate to a polyester film, which comprises a copolymerized polyester resin comprising a diol component and a dicarboxylic acid component and has a heat shrinkage rate of 30% or more in the main shrinkage direction upon thermal treatment at a temperature of 80° C. for 10 seconds and a melting point of 170° C. or higher as measured by differential scanning calorimetry, which not only solve the environmental problems by improving the recyclability of the polyester container, but also are capable of enhancing the yield and productivity, and a process for regenerating a polyester container using the same.

The embodiments relate to a polyester film, which comprises a copolymerized polyester resin comprising a diol component and a dicarboxylic acid component and has a heat shrinkage rate of 30% or more in the main shrinkage direction upon thermal treatment at a temperature of 80° C. for 10 seconds and a melting point of 170° C. or higher as measured by differential scanning calorimetry, which not only solve the environmental problems by improving the recyclability of the polyester container, but also are capable of enhancing the yield and productivity, and a process for regenerating a polyester container using the same.

A method for forming an uncured rubber component, the method includes conveying an uncured extruded rubber strip extruded continuously from an extruder using a conveyor, the conveyor including a first conveyor and a second conveyor located at a downstream side of the first conveyor in a convey direction, the step of conveying including shrinking the uncured extruded rubber strip, wherein the step of shrinking is such that the uncured extruded rubber strip, in a relaxed state of a U-shaped manner, passes through fluid held in a tank between the first conveyor and the second conveyor without being restrained so that the uncured extruded rubber strip shrinks freely while receiving buoyancy from the fluid, and cutting the uncured extruded rubber strip in a predetermined length to form an uncured rubber component, after the step of shrinking.

A method for forming an uncured rubber component, the method includes conveying an uncured extruded rubber strip extruded continuously from an extruder using a conveyor, the conveyor including a first conveyor and a second conveyor located at a downstream side of the first conveyor in a convey direction, the step of conveying including shrinking the uncured extruded rubber strip, wherein the step of shrinking is such that the uncured extruded rubber strip, in a relaxed state of a U-shaped manner, passes through fluid held in a tank between the first conveyor and the second conveyor without being restrained so that the uncured extruded rubber strip shrinks freely while receiving buoyancy from the fluid, and cutting the uncured extruded rubber strip in a predetermined length to form an uncured rubber component, after the step of shrinking.

The invention provides a heat-shrinkable polyester film roll containing a paper tube and a heat-shrinkable polyester film wound around the paper tube to form the heat-shrinkable polyester film roll, wherein (1) the film winding length is 2000-20000 m, (2) the film width is 400-2500 mm, (3) the film thickness is 5-30 μm, (4) unevenness in thickness in the film widthwise direction in a film roll surface layer part is 12% or less, (5) the paper tube has an inner diameter of 3 inches, a difference in clearance of the paper tube in a widthwise direction after removal of the film from the film roll is 0.5 mm or less, and a flat compressive strength of the paper tube after removal of the film is 1700 N/100 mm or more, and (6) the average value of winding hardness in the widthwise direction in the film roll surface layer part is 500-850.

The resin composition includes a block copolymer including a vinyl aromatic hydrocarbon-derived structural unit and a conjugated diene-derived structural unit, the resin composition satisfying the following (1) to (3): (1) an area ratio of components having a molecular weight in terms of polystyrene of equal to or more than 400,000 with respect to all components is equal to or more than 8% and equal to or less than 50%; (2) at least one main peak of a loss tangent value (tan δ) measured under a condition of a frequency of 1 Hz at a temperature rising rate of 4° C./min in accordance with ISO 6721-1 is present in a range of equal to or more than 70° C. and equal to or less than 100° C.; and (3) a strain hardening degree (λ max) of a compression-molded specimen prepared in accordance with ISO 293 is equal to or more than 2.0.

The resin composition includes a block copolymer including a vinyl aromatic hydrocarbon-derived structural unit and a conjugated diene-derived structural unit, the resin composition satisfying the following (1) to (3): (1) an area ratio of components having a molecular weight in terms of polystyrene of equal to or more than 400,000 with respect to all components is equal to or more than 8% and equal to or less than 50%; (2) at least one main peak of a loss tangent value (tan δ) measured under a condition of a frequency of 1 Hz at a temperature rising rate of 4° C./min in accordance with ISO 6721-1 is present in a range of equal to or more than 70° C. and equal to or less than 100° C.; and (3) a strain hardening degree (λ max) of a compression-molded specimen prepared in accordance with ISO 293 is equal to or more than 2.0.