| Abstrakt: |
This article reviews the previous history of difficulties with the original mould con struction based on epoxy fiber glass construc tion with a filled lossy layer. It will then trace the investigation work for a material with a suitable permittivity and loss angle, preferably obtainable in composite form, it should be economical, simple to form and manipulate and should permit to a large de gree transparency to micro-wave energy. This resulted in a mould material, known as a felt, manufactured from phenolic resin and asbestos, which is manufactured in pre-im pregnated sheets. The techniques of manu facture of moulds will be discussed, together with the necessary safeguards in obtaining a mould with long life which is reasonably in expensive. [ABSTRACT FROM PUBLISHER] |
