PETpla.net Insider 04 / 2010

Vol.6 PET planet print PREFORM PRODUCTION 16 PET planet insider Vol. 11 No. 04/10 www.petpla.net The Rapid Guide to Perfect Preforms by Rick Unterlander and Ottmar Brandau Symptom: A thin layer of plastic protrudes out of the preform at one of the parting lines. Cause: Plastic material that has seeped through intersecting mould components either from too low a melt viscosity or insufficient clamping tonnage. Solutions: 1. Check injection time isn’t too low (injection rate too fast) and adjust if necessary. Injection rate should be about 10 – 12g/sec/cavity. 2. Check to ensure injection pressure isn’t too high, especially when peaking at the transition point. 3. Check to ensure hold (packing) pressure isn’t too high, especially near the beginning of hold time. Troubleshooting guides have suffered in the past from being locked away in offices and not being available to the people that actu- ally need them. Considering the high cost of machine and tools high scrap rates can be a costly proposition eating away at already tight margins. PETplanet’s “Rapid Guide to Perfect Pre- forms” takes a different approach. Bound in laminated paper that is easy to clean off, the small format of the book of 108 mm by 151 mm (4.25” by 6”) allows easy storage in back pockets or tool boxes. It has been written for the people on the floor of injection mould- ing companies to support their daily work in making the best preforms possible. The product of two industry experts, Rick Unterlander and Ottmar Brandau, it gives concrete advice on 35 of the most common problems in preform manufacture, most illustrated by pictures. From high AA levels to wavy bodies processors can find help when they need it. PET planet print vol.6 The Rapid Guide to Perfect Preforms machine no./name 10. Flash