The Effect of Developer Agitation on Density Uniformity and Rate of Development

Non-uniformity of development is aggravated by short developing times and particularly at gammas far below gamma infinity. This non-uniformity can be partially overcome by agitation of the developer and a number of essentially different methods of developer agitation of interest, in motion picture work have been studied experimentally. The case of continuous agitation was studied by flowing the developer through a conduit in which the film was located. It was found that good uniformity is attainable not merely when turbulent flow is established but only when the intensity of turbulence is sufficiently great to reduce and make uniform the thickness of the quiescent liquid layer at the film surface. — When agitation is of the intermittent type such as supplied by some of the present-day submerged jet systems or the cascade method, increased agitation is attainable usually by increased frequency of jet application rather than by greater liquid flow. Little improvement can be obtained by moderate increases in the film running speed or the rate of general circulation of developer in most of the present-day machine tanks. The agitation intensity could be increased much beyond the levels of present-day practice but, except for a slight reduction in fog in certain cases, the effect of increased agitation on quality would not be significant. — Methods of agitation are discussed in relation to the problems of application to machine design.

Print ISSN

0097-5834

Published

1943-02

Content type

Original Research

DOI

10.5594/J14279