Abstract: An injection molded thermoplastic preform for blow moulding to form a container, the preform base of a central part having a first, downwardly and radially inwardly tapering portion therebetween which increases in thickness from a radially outer end of the first tapering portion adjacent to the hollow transition portion to a radially inner end of the first tapering portion adjacent to the gate part and the middle part opposite the gate part can allow the injected resin to be urged back through the gate at the end of the injection moulding cycle at a lower fluid pressure in the vicinity of the gate which is associated with high resin temperatures. The technical effect achieved by the first tapering portion is that crystallinity in the gate area is minimized or eliminated, which avoids or minimizes partial blocking of the gate which would otherwise restrict the injected resin from being urged back through the gate at the end of the injection moulding cycle.

Abstract: A method of forming a container, the method comprising the steps of: providing an injection moulded preform composed of a biaxially-orientable thermoplastic material, the preform being substantially planar and having a peripheral edge and a central portion; clamping at least a portion of the peripheral edge of the preform in a frame; heating the preform; stretch blow moulding the heated preform, clamped with the frame, within a mould cavity defined by a first female mould to form an intermediate article having a bottom wall and an annular sidewall beneath an upper edge clamped within the frame, the stretch blow moulding step using a stretch rod to engage an inner side of at least the central portion of the preform and axially to stretch at least a part of the central portion of the preform prior to blowing a pressurized gas against the inner side which urges the opposite side of the preform radially outwardly against the mould; and shrinking the intermediate article, clamped with the frame, onto a second male

Abstract: A method of injection moulding an article, the method comprising the steps of: (a) providing an injection mould comprising a plurality of mould parts defining a mould cavity of the injection mould, the plurality of mould parts including first and second movable mould parts, the injection mould further comprising an injection inlet for injecting molten thermoplastic resin material into the mould cavity, wherein the injection inlet is located in the vicinity of the first movable mould part and the second movable mould part is remote from the injection inlet; (b) disposing the first and second movable mould parts in a first configuration so as to define a first intermediate moulding cavity, in which first configuration the first movable mould part is in a first rearward position and the second movable mould part is in a first forward position; (c) injecting molten thermoplastic resin material into the first intermediate moulding cavity through the injection inlet to fill the first intermediate moulding cavity wi

Abstract: An injection moulded thermoplastic preform for blow moulding to form a container, the preform comprising a lower closed base portion, a hollow body portion, a hollow transition portion between the lower closed base portion and the hollow body portion, and an upper open end portion adjacent to an upper part of the hollow body portion, wherein the closed base portion comprises a central portion which extends over at least 50% of an internal radius of a lower end of the hollow body portion and is either substantially flat or has a shallow concave or convex internal curvature, and the transition portion comprises an upwardly and radially outwardly tapering portion extending away from the central portion to connect to the hollow body portion, the tapering portion being inclined at an angle of from 1 to 20 degrees to a longitudinal axis of the preform and the tapering portion increasing in thickness from the central portion to the hollow body portion.

Abstract: A container, in the form of a container body or container closure, or a lid, having a frangible weakened portion formed in a layer of polyethylene terephthalate forming a wall of the container, the weakened portion comprising a groove cut into a first surface of the layer, a first portion of the layer surrounding the groove having a crystallinity of from 35 to 45%, and a second portion of the layer, which second portion is adjacent to the first portion on opposite sides of the groove and remote from the groove, the second portion having a crystallinity at least 5% less than the crystallinity in the first portion, wherein the layer has a thickness of from 200 to 700 ?m and the groove has a depth of from 200 to 500 ?m.

Abstract: A method of forming a container, the method comprising the steps of: providing an injection moulded preform composed of a biaxially-orientable thermoplastic material, the preform being substantially planar and having a peripheral edge and a central portion; clamping at least a portion of the peripheral edge of the preform in a frame; heating the preform; stretch blow moulding the heated preform, clamped with the frame, within a mould cavity defined by a first female mould to form an intermediate article having a bottom wall and an annular sidewall beneath an upper edge clamped within the frame, the stretch blow moulding step using a stretch rod to engage an inner side of at least the central portion of the preform and axially to stretch at least a part of the central portion of the preform prior to blowing a pressurized gas against the inner side which urges the opposite side of the preform radially outwardly against the mould; and shrinking the intermediate article, clamped with the frame, onto a second male

Abstract: A method of forming a blow molded container in the form of a tub, the method comprising the steps of: providing an injection molded preform composed of a biaxially-orientable thermoplastic material, the preform being substantially planar; heating the preform; and stretch blow molding the heated preform within a mold cavity to form a tub having a bottom wall and an annular sidewall having an upper edge, the tub comprising biaxially oriented thermoplastic material in the annular sidewall and at least an outer portion of the bottom wall, the stretch blow molding step using at least one stretch rod to engage an inner side of the preform and axially to stretch at least a part of the preform prior to blowing a pressurized gas against the inner side which urges the opposite side of the preform radially outwardly against the mold.

Abstract: An apparatus for reheating and conditioning an elongate preform for forming a blow molded container, said apparatus comprising: a receiver including an elongate annular non-cylindrical inner surface portion, wherein the surface portion defines a cavity and is adapted to engage with an elongate outer surface of an elongate preform to transfer heat thereto by conduction from said surface portion, wherein the surface portion includes a three-dimensional relief to provide substantially non-uniform contact between the receiver and the elongate preform; and means for heating said receiver.

Abstract: A preform for blow moulding to form a container, the preform being formed of a thermoplastic material, the preform comprising a neck finish at an open end of the preform, an elongate body section and a closed end, wherein the body section has elongate, longitudinally extending inner and outer surfaces each centered about a longitudinal axis of the preform, the inner and outer surfaces defining therebetween a wall of the body section, wherein the wall of the body section has at least one locally thickened portion along the body section, the locally thickened portion being thicker than adjacent first and second thinner portions at respective opposite longitudinal ends of the thickened portion, the thickened portion having an inner surface portion which is nearer to the longitudinal axis than respective first and second inner surface portions of the first and second thinner portions.

Abstract: An injection moulded thermoplastic preform for blow moulding to form a container, the preform comprising a lower closed base portion, a hollow body portion, a hollow transition portion between the lower closed base portion and the hollow body portion, and an upper open end portion adjacent to an upper part of the hollow body portion, wherein the closed base portion comprises a central portion which extends over at least 50% of an internal radius of a lower end of the hollow body portion and is either substantially flat or has a shallow concave or convex internal curvature, and the transition portion comprises an upwardly and radially outwardly tapering portion extending away from the central portion to connect to the hollow body portion, the tapering portion being inclined at an angle of from 1 to 20 degrees to a longitudinal axis of the preform and the tapering portion increasing in thickness from the central portion to the hollow body portion.

Abstract: An apparatus for reheating and conditioning an elongate preform for forming a blow moulded container, said apparatus comprising: a receiver including an elongate annular non-cylindrical inner surface portion, wherein the surface portion defines a cavity and is adapted to engage with an elongate outer surface of an elongate preform to transfer heat thereto by conduction from said surface portion, wherein the surface portion includes a three-dimensional relief to provide substantially non-uniform contact between the receiver and the elongate preform; and means for heating said receiver.