Small blow molded thermoplastic container for fluids has specified wall thickness and axial and radial stretch ratios

摘要

The container(11) is produced by blow molding an injection molded preform(7). Wall thickness of the container between the mouth section(57) and container base(59) is 1.5-3.5mm. Maximum sidewall stretch during blowing is 1:7 in the radial direction and 1:1.5 in the axial direction when related to the original preform shape. Maximum radial stretch is 1:3-1:6, preferably 1:5.2. Maximum axial stretch is 1:1-1:1.5, preferably 1:1.2-1:1.3. Maximum stretch in the container base(59) is 1:3-1:6, preferably 1:5.4. Initial preform wall thickness between the mouth section(57) and the preform base(58) is 6-12mm, preferably 6-7.5mm and more preferably 7mm. Container(11) wall thickness is 1.5-2.5mm, preferably 2mm. The inner diameter of the mouth is 10-35mm. Both preform and container manufacture can be achieved in a single stage process. An independent claim is included for a process for blow molding the container in which an injection molded preform(7) with a wall thickness of 6-12mm is internally pressurized and stretched in both radial and axial directions to form a container with a wall 1.5-3.5mm thick, the axial and radial stretch being as claimed.