POLYPROPYLENE PREFORM FOR THE PRODUCTION OF BOTTLES OR SIMILAR BY MEANS OF BLOW MOULDING OR STRETCH BLOW MOULDING, AND METHOD OF BLOW MOULDING OR STRETCH BLOW MOULDING SAID PREFORM

摘要

The invention relates to the production of containers (2) comprising a narrow opening and a long body, such as bottles or similar, from polypropylene by means of blow moulding or stretch blow moulding. According to the invention, during the blow moulding or stretch blow moulding step, the polypropylene preform (1) undergoes longitudinal stretching at a ratio (L/l) of between approximately 2 and 3.5 and radial stretching (D/d) at a ratio of between approximately 2 and 3.