Problems & Solutions
On this page you can find some issues that you may encounter, possible causes and solutions.
Blowholes at parting lines
cause: Vent too small or blocked.
cause: Uneven cooling (only cooling from outside the part).
solution: Pressurising and internal air cooling using Technovent; or internal water cooling using Supacool.
cause: Uneven or early release of the part from the mould due to uneven or excessive use of external (conventional) mould release.
solution: SORIN RM12 internal mould release allows controlled release of the part from the mould.
Permanent decoration for polyolefins
cause: Chemical nature of polyolefins.
solution: Duragraf permanent decal.
cause: Air trapped at the surface of the part (surface porosity) can be influenced by the type of material being used, too short a moulding cycle and poor or excessive use of mould release.
Insufficient powder build-up in an area of the mould
cause: Insufficient heat reaching area while material is laying up.
solution: Heat pipes transport energy very effectively to heat critical areas of the mould and so improve wall formation.
Poor dimensional consistency from part to part
cause: Venting is different from one cycle to the next.
solution: Supavent, Smartvent, Tuvent and Intellivent, vent in a reliable repeatable fashion. The QC department will love them.
Gas bills are too high
solution: Reduce energy use by using Supavent, Smartvent, Tuvent or Intellivent. Generally we have found that, when switching to these venting systems from standard open vents, reducing oven temperatures by 20°C (and therefore gas usage) produces parts with similar levels of cure.
Parts moulded from polypropylene are failing
cause: Material is suffering from excess thermal degradation.
solution: Reduce the oven cycle, so exposure to hot oxygen, by using Supavent, Smartvent, Tuvent and Intellivent.
Cycle time uneven, too long in cooler
cause: Thick parts can be cured relatively quickly but if cooled only from the outside must be cooled very slowly to avoid warpage.
solution: Use Supacool to cool rapidly from the inside too and get your cooling cycle back in line with heating.
Cycle time too long
Operator injury while trimming parts
cause: Using exposed blade.
solution: Use Thrift Products Flash trimmer.
Powder leaks out of the mould through the flanges
solution: To prevent this happening, use Sorex DF15 mould release designed specifically for flanges.
Parts scrapped because vent packing material has stuck inside
solution: Use Supavent, Smartvent, Tuvent or Intellivent.
Need a weld as strong as the virgin material
solution: Use the Drader Injectiweld.
Need to customise a part?
solution: Use the Drader Injectiweld to fit lifting hooks, inlets, outlets, and anything else you require.
Parts moulded from recycled material are failing
cause: Material is suffering from thermal degradation.
solution: Reduce the oven cycle, so exposure to hot oxygen, by using Supavent, Smartvent, Tuvent or Intellivent.
Want to mould polypropylene on the same arm as polyethylene but polypropylene needs more heat than polyethylene
solution: Use a Supavent, Smartvent or Intellivent in the PP mould and reduce its heat requirement to balance with the PE cure.
Shipping large parts full of air around the world
solution: Design parts to nest for transit and then weld on site using Powercore.
Messy parting line
cause: Wrong flash trimming tool.
solution: Use thrift products Flash trimmer.
Part too big to ship
solution: Mould component parts and then assemble and weld on site using Powercore.