Injection mould for flexible tube

Injection moulding device (101) for two stage injection moulding a flexible sleeve body and a shoulder body for a squeezable tube by injection moulding the shoulder body in a first stage, and injection moulding a runner body and a flexible sleeve body in a second stage such that the runner body and the flexible sleeve body are injection moulded integral with the shoulder body, the injection moulding device (101) comprising:

• a shoulder base part (111);
• a shoulder end part (117) which in combination with the shoulder base part (111) forms a shoulder body cavity (118) for forming the shoulder body between them, which shoulder end part (111) comprises an injection opening (113) for injecting a flow of molten plastics material into the shoulder body cavity (118), and wherein the injection mould comprises a pin (131) to provide the shoulder body with an opening adjacent a second injection opening (132) in the shoulder end part;
• a male mould part (106);
• a female mould part (107) which in combination with the male mould part (106) forms a sleeve body cavity (108) for forming the flexible sleeve body between them, which sleeve body cavity (108) extends from a top end (109) to an opposite bottom end (110) in a longitudinal direction, and
• wherein the shoulder end part (117) including an injection moulded shoulder body, in combination with the female mould part (107) and the male mould part (106) forms a runner cavity (112) at the top end (109) of the sleeve body cavity (108), which runner cavity comprises:
• the opening of the shoulder body for injecting a flow of molten plastics material from the second injection opening (132) in the shoulder end part (117) via said opening into the runner cavity (112) for injection moulding the runner body and the flexible sleeve body integral with the shoulder body;
• an annular shaped distribution channel (114) located along the top end perimeter of the sleeve body cavity (108);
• one or more runner channels (115) which extend between the opening in the shoulder body and the annular shaped distribution channel (114);
• a passage (130) constituted by one or more openings connecting the annular shaped distribution channel (114) with the sleeve body cavity (108) for guiding the molten plastics material from the annular shaped distribution channel into the sleeve body cavity, which one or more openings is/are evenly distributed along the perimeter of the sleeve body cavity (108) and is/are narrow compared to the annular shaped distribution channel (114) upstream of the passage (130) such that the passage initially prevents the flow of molten plastics material from entering the sleeve body cavity (108), which results in a pressure build up in the runner cavity (108) which eventually results in a pressure high enough to force the flow of molten plastics material through the passage (130) into the sleeve body cavity (108).