SCP Contact
Siam Casting Powders Ltd.
SIAM CASTING POWDERS LTD.
SIAM CASTING POWDERS
SUPPLIES THE FINEST-QUALITY
INVESTMENT POWDERS AND
MATERIALS FOR THE LOCAL
CASTING INDUSTRIES
SCP - TECHNICAL DATA
Jewellery Trouble Shooting Mould Rubber Problems
Cut mould does not seal Evenly (warping)
Cause : Rubber used in packing has begun to vulcanise.
REMEDY :
Use new rubber.
Cause : Mould under packed.
REMEDY :
Ensure the work time is fully used.
Normally 8 minutes.
Cause : Mould over packed.
REMEDY :
Review mould packing procedure. Lay strips
in same direction.
Voids in mould (air entrapment)
Cause : modle not filled in with rubber.
REMEDY :
Pack rubber pieces into and around modle.
Cause : Platen not at curing temperature.
REMEDY :
Preheat vulcaniser to 155 C.
Cause : Mould not cured for recommended time.
REMEDY :
Tighten vulcaniser ½ turn past first resistance.
Repeat every two minutes until platens are in
contact with frame and handle cannot be
turned without resistance. Allow 15 minutes
at 155 C for every 6 mm. for intricate moulds
allow 20 minutes at 145 C for every 6 mm.
Mould delaminates after curing
Cause : Surface of strips not clean.
REMEDY :
Use new strips. Do not contaminate surfaces with hands and protect from extraneous dirt or dust.
Cause : Rubber is old.
REMEDY :
Use new rubber.
Cause : Mould not cured long enough..
REMEDY :
Use correct times and temperatures.
Mould soft and sticky in centre
Cause : Under heated..
REMEDY :
Check temperature of platens.
Cause : Cure cycle too short.
REMEDY :
Cure for 15 minutes for every 6 mm.
Mould has pebbly surface.Mould is sticky and scorched. Excessive shrinkage. Lack of flexibility.
Cause : Overheated.
REMEDY :
Check calibration of vulcaniser.