GB931385A - Film developing envelope - Google Patents

Abstract

931,385. Developing films. D. TELSON. Feb. 13, 1962, No. 5537/62. Class 98 (1). A package comprises a radiation-sensitive film (e.g. X-ray film) completely enclosed in a container which is opaque to light but waterpermeable, between the film and the container is a barrier comprising a plurality of spaced elements so as to permit the passage of liquid therethrough, the material of both barrier and container being transparent to the said radiation. Fig. 1 shows the separate components of one form of the invention. The film sheet 16 is placed inside a folded barrier sheet 12 of vinyl coated fibre-glass, and this assembly then inserted into an outer container envelope having a flap 11, so that the entire interior of the container is light-tight. A preferred material for the container is black filter paper. The film sheet may be exposed to X-rays in situ within the container, which is then immersed in a bath of developing liquid. This penetrates through the permeable envelope 10 and circulates freely round the film, which is kept by the barrier sheet from coming into contact with the envelope wall. Washing and fixing may be carried out in a similar manner. An additional barrier of limp water-pervious material such as cheesecloth may be interposed between the fibre-glass barrier and the envelope. In a modification (Fig. 6, not shown), the barrier is formed by coating the inner surface of the envelope with separated particles of a suitable plastic.