Dupont bm processing manual

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DuPont Engineering Polymers

Blow Moulding Processing Manual

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Blow moulding processing manual
Table of contents
1 DuPont resins for blow moulding ........................... 1.1 Why blow mould engineering resins.............. 1.2 ZYTEL® nylon resins for blow moulding......... 1.3 HYTREL® and CRASTIN® polyesterresins for blow moulding .......................................... 2 Description of blow moulding processes............... 2.1 General............................................................ 2.2 Continuous extrusion machines...................... 2.3 Accumulator head machines .......................... 2.4 Co-extrusion and sequential 3-D blowmoulding................................................ 2.5 Injection blow moulding ................................ 3 3 3 4 7 7 7 7 7 9 5 Handling of blow moulding resins ......................... 21 5.1 Effects of moisture ......................................... 21 5.2 Drying............................................................. 22 5.3 Regrind ........................................................... 22 5.4 Bulkstorage.................................................... 23 6 Mould design guidance .......................................... 25 6.1 General............................................................ 25 6.2 Materials of construction................................ 25 6.3 Blow-up (draw) ratio ...................................... 25 6.4 Mould shrinkage allowances and partdimensions........................................ 25 6.5 Pinch-off designs ............................................ 25 6.6 Other mould considerations............................ 26 7 Troubleshooting guide ............................................ 27

3 The blow moulding machine – Important considerations ........................................ 11 3.1 Screw and barrel design.................................. 11 3.2Manifold/adapter design................................. 11 3.3 Accumulator and continuous extrusion head design ..................................................... 12 3.4 Die/head tooling design ................................. 12 3.5 Parison cutters ................................................ 13 3.6 Mould clamping force .................................... 13 3.7 Temperaturecontrol........................................ 13 3.8 Auxiliary equipment ....................................... 13 4 Machine operating conditions ............................... 15 4.1 Quick reference – Processing conditions ....... 15 4.2 Barrel temperatures ........................................ 15 4.3 Adapter, head and die temperature................. 16 4.4 Accumulator push-out pressures andspeeds....................................................... 16 4.5 Parison programming ..................................... 16 4.6 Mould temperature ......................................... 17 4.7 Start-up procedures......................................... 17 4.8 Purging and shutdown .................................... 17 4.9 Secondary operations: trimming, welding ..... 18 4.10 Special conditions forinjection blow moulding and “Pressblower” operation ......... 19

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DuPont resins for blow moulding
Why blow mould engineering resins?
ZYTEL® blow moulding resins ZYTEL® BM7300THS Unreinforced PA6 ZYTEL® BM73G25THS 25 % glass reinforced PA6 ZYTEL® BM73G15THS 15 % glass reinforced PA6 ZYTEL® BM7300FN ZYTEL® CFE8005HS ZYTEL EFE7340
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There are many reasons why engineering resins havebecome established in blow moulding applications, for example: • Cost and weight reduction • Recyclability ( replaces rubber for example) • Innovation: – Multifunctional parts – Reduce number of parts in the engine compartment • Higher temperature requirements • Easier assembly and disassembly • Reduce number of materials • Improve performance • Reduce noise • Availability of special resin grades...