1. Feeder Excessive oil on the shears   1. Feeder Check oil in shear spray   2. Machine Setup and Operation Excessive swabbing or oil spray Blank and/or blow mold dirty Excessive sulphur Dirty delivery equipment Insufficient cooling wind Dirty scale on the delivery equipment 2. Machine Setup and Operation Reduce frequency of swabbing - use correct type and shape of swab Change blank and/or mold User less sulphur Keep all delivery equipment clean Adjust mold cooling wind Clean or change the delivery equipment   3. Mold Equipment Poor quality mold castings 3. Mold Equipment Check quality of mold castings - change as required