First Phenolic powder has to be produced. All manufacturers use powders with different specific gravities to achieve their desired weights for the various models. The powder manufacturer has to design the powders to suit the moulder’s requirements of flow characteristics, colour, surface finish, etc.
After the ingredients are blended, the initial process to produce the powder can commence which involves both heat and pressure. The chemical bonding process begins at this point, and the resulting “cake” is ground to the powder size specified by the moulders. Checking that the specific gravity is correct is a regular feature throughout the production and can be altered to ensure conformity to the requirements of the customer.
Next is the moulding of the blank. It is believed that the moulding “blank” for a bowl is the largest solid mass of Phenol compound moulded successfully. Before the powder is placed into the mould it is passed through a radio frequency preheater which ensures that the moisture is removed and that the “cake” is heated right through. This also restarts the chemical bonding process and thus helps reduce the time required in the mould. After the pre heating is completed the “cake” is put into a computer-controlled 160 tonne compression moulding press, the platens of which, are heated to 200°C. The “cake”, which is then pressed into the final shape, remains in the press for 5.5 minutes and then merges as a blank which we can use in our computer-controlled lathes.
The blanks are then left to cool under controlled conditions so that the full cure can be successfully completed. Then they are sonic-checked for voids before being ready for use.