Injection mould for flexible tube

摘要

An injection molding device for injection molding a flexible sleeve body for a squeezable tube, comprises a male mold part and a female mold part, which in combination with the male mold part forms a sleeve body cavity for forming the flexible sleeve body between them. The sleeve body cavity extends from a top end to an opposite bottom end in a longitudinal direction. The molding device further comprises a runner end part, which in combination with the female mold part and the male mold part forms a runner cavity at the top end of the sleeve body cavity. The runner cavity comprises a passage constituted by one or more openings connecting the annular shaped distribution channel with the sleeve body cavity for guiding the molten plastics material from a runner distribution channel into the sleeve body cavity. The one or more openings is/are evenly distributed along the perimeter of the sleeve body cavity and is/are narrow compared to the distribution channel upstream of the passage, such that the passage initially prevents the flow of molten plastics material from entering the sleeve body cavity, which results in a pressure build up in the runner cavity which eventually results in a pressure high enough to force the flow of molten plastics material through the passage into the sleeve body cavity.

主权项

1. Injection moulding device (1) for two stage injection moulding a flexible sleeve body and a shoulder body for a squeezable tube by injection moulding a runner body and the flexible sleeve body in a first stage, and injection moulding the shoulder body adjacent the runner body and the flexible sleeve body in a second stage, such that the shoulder body is injection moulded integral with the runner body and the flexible sleeve body, the injection moulding device comprising:
a male mould part (6); a female mould part (7) which in combination with the male mould part (6) forms a sleeve body cavity (8) for forming the flexible sleeve body (4) between them, which sleeve body cavity (8) extends from a top end (9) to an opposite bottom end (10) in a longitudinal direction, a runner end part (11), which in combination with the female mould part (7) and the male mould part (6) forms a runner cavity (12) at the top end (9) of the sleeve body cavity (8), which runner cavity comprises:
an injection opening (13) for injecting a flow of molten plastics material into the runner cavity (12);an annular shaped distribution channel (14) located along the top end perimeter of the sleeve body cavity (8);one or more runner channels (15) which extend between the injection opening (13) and the annular shaped distribution channel (14);a passage (30) constituted by one or more openings connecting the annular shaped distribution channel (14) with the sleeve body cavity (8) for guiding the molten plastics material from the distribution channel into the sleeve body cavity, which one or more openings is/are evenly distributed along the perimeter of the sleeve body cavity (8) and is/are narrow compared to the distribution channel (14) upstream of the passage such that the passage initially prevents the flow of molten plastics material from entering the sleeve body cavity, which results in a pressure build up in the runner cavity (12) which eventually results in a pressure high enough to force the flow of molten plastics material through the passage into the sleeve body cavity (8); a shoulder end part (17), which in combination with the female mould part (7) and the male mould part (6) forms the shoulder body cavity (18) for forming the shoulder body (5), which shoulder end part (17) comprises an injection opening for injecting a flow of molten plastics material into the shoulder body cavity (18), for injection moulding the shoulder body in the shoulder body cavity adjacent the runner body and the flexible sleeve body, such that the shoulder body is injection moulded integral with the runner body and the flexible sleeve body.