PETpla.net Insider 04 / 2011

PREFORM PRODUCTION 15 PET planet insider Vol. 12 No. 04/11 Table of Contents i..............About the Authors ii...................... Introduction chapter 1................... AA Level High 2..............Accordion Preform 3............ Air hooks / Streaks 4.....................Black Specks 5............................Bubbles 6....................... Burn Marks 7.. Colour Streaking / Peeling 8....................... Crystallinity 9......................Drool Marks 10............................... Flash 11...............Gate Depressions 12.....................Gate Peeling 13....... Gate Voids / Pin Holes 14.............. Internal Gate Sink 15..................... Internal Sinks 16............................. IV Loss 17................. Long Gate Nub 18.................... Milky Preform 19..................Moisture Marks 20..... Neck Finish out of Round 21............ Parting Line Crease 22...... Parting Line Deformation 23...............Preform Yellowing 24....................... Short Shots 25............................... Sinks 26...............................Splay 27.................Stretched Necks 28.......................... Stringing 29.............. Surface Blemishes 30...............Thread Flow Lines 31.... TSS (Top Sealing Surface) ...............................Sink 32............................ Unmelts 33......Wall Thickness Variation 34...................... Wavy Body 35....................... Weld Lines Symptom: Grooves formed around the circumference of the preform. Cause: The melt front has made contact with moisture on the moulding surfaces. The moisture is pushed along the length of the preform until enough water has built up to interfere with the melt flow, causing the melt front to buckle and form improperly. Y O U R PA R T N E R F O R B L O W M O U L D S . Sidel • SIG • Krones • SIPA • MAG • ADS • Kosme • Nissei a. o. Röders GmbH / Scheibenstr. 6 / 29614 Soltau / Germany / www.roeders.de Telephone +49 5191-603-53 / Fax +49 5191-603-36 / E-Mail mold@roeders.de For our subsidiaries in China, USA and Latin America please check our website. PET STRETCH BLOW MOULDS Benef i t of 30 Years of Exper ience in Blow Mould Manufactur ing! Solutions: 1. Check to ensure that no moisture exists on the moulding surfaces, either from water leaks or condensation. This may obstruct normal melt flow and cause filling problems. The environmental dewpoint should be below the chilled water temperature to eliminate the risk of condensation. 2. Check hardware for worn, damaged or failed components, specifically the cavity / gate insert o-rings, mould neck insert o-rings, core o-rings, and stripper plate hoses.