INTRODUCTION Bearer Bars are essential to ensure an even thickness during moulding and to ensure consistent thickness is achieved on every occasion. As rubber is generally moulded from a mould board that has itself been moulded and as the thickness of mould board is substantially greater than the thickness required for rubber we recommend that two sets of bearers be used. SET 1 - For moulding matrix board. 1. Accurately measure the thickness of the matrix board. 2. Accurately measure the thickness of the non image area of your pattern plate (the floor thickness). 3. Accurately measure the thickness of the release materials used (cloth, foil or papers). 4. Add the measurements together to calculate the total stack height. 5. Deduct 0.5mm (0.020") for compression to determine the correct bearer thickness. Set 2 - For moulding rubber. 6. Accurately measure the thickness of the mould board in the non image area. 7. Accurately measure the thickness of the release materials. 8. Add the measurements together to determine the stack height. 9. Add the desired rubber floor thickness (usually between 1 and 1.5mm or 0.040" and 0.060") to determine the correct bearer thickness. Suggestion: Permanently mark the bearers with their actual thickness or with the words "RUBBER" and "MATRIX" so that they can be quickly and accurately identified. |