Yoshino Kogyosho Co., Ltd.

Yasuhiro Ishizawa

Hiroshi Hosokoshiyama

Tamotsu Toyoda

Mamoru Sato

Hideaki Soyama

An injection molding device including a middle flow channel which forms an intermediate layer of a preform which is subject to biaxial stretch blow molding. The middle flow channel s segmented into a predetermined number of flow sub-channels by vertical blocking rib piece(s). Side wall's upstream portions of the vertical blocking rib piece are formed as angled surfaces whose distance from each other decreases from the downstream side to the upstream side, and/or, an end portion of the vertical blocking rib piece that is located on the downstream side is tucked in at least one of the inner flow channel and the outer flow channel.

Preform injection molding device

A preform-molding device has a nozzle section including three cylindrical layer-forming flow channels, which include an inner flow channel and an outer flow channel for forming the substrate layers of the main resin, and a middle flow channel for forming the intermediate layer, and also includes a predetermined number of vertical blocking rib pieces disposed at a downstream end of the middle flow channel, in parallel in the circumferential direction, so that the intermediate layer would be segmented in the circumferential direction into a predetermined number of vertically running streams, wherein flow behavior of the intermediate-layer resin flowing through the middle flow channel is adjusted by positioning the vertical blocking rib pieces in the circumferential direction so as to minimize a difference in height between a maximum height point and a minimum height point that appear in a leading edge of the intermediate layer of the preform.

Device for injection molding a preform

A problem to be solved by this invention is to control the above-described problem of delamination in the laminated and biaxially drawn, blow molded bottle. A major means of this invention to solve this problem is a biaxially drawn, blow molded bottle characterized in that vertical connecting zones having no intermediate layer and having substrate layers welded directly with each other are formed in parallel in a circumferential direction and in a plural number along an axial direction of the bottle and are disposed on both right and left sides of each intermediate layer segment to be formed in this height range, and that horizontal connecting zones having no intermediate layer and having substrate layers welded directly with each other are also formed in parallel in an axial direction and in a plural number along a circumferential direction of the bottle and are disposed on both upper and lower sides of each intermediate layer segment to be formed, thus allowing the intermediate layer to be segmentalized in the circumferential and axial directions by both the vertical and horizontal connecting zones.

Laminated synthetic resin bottle, injection molding device, and process for molding a laminated preform

A biaxially drawn, blow molded bottle characterized in that vertical connecting zones having no intermediate layer and having substrate layers welded directly with each other are formed in parallel in a circumferential direction and in a plural number along an axial direction of the bottle and are disposed on both right and left sides of each intermediate layer segment to be formed in this height range, and that horizontal connecting zones having no intermediate layer and having substrate layers welded directly with each other are also formed in parallel in an axial direction and in a plural number along a circumferential direction of the bottle and are disposed on both upper and lower sides of each intermediate layer segment to be formed, thus allowing the intermediate layer to be segmentalized in the circumferential and axial directions by both the vertical and horizontal connecting zones.

Growing community of inventors

Tochigi, Japan

Yasuhiro Ishizawa