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| Plastic Cassettes |
All types of RADAC Single-Envelope Plastic Cassettes are of the same basic design. They consist of a single envelope, open at one end, through which film and screens are loaded and unloaded.
The open ends of the envelopes fold over, producing an effective light seal. They are then held closed by means of 'VELCRO' nylon fastener.
There is an extra finger-tab at the bottom to assist in holding the cassette to the bench for easier and quicker unloading.
Closure is normally made on the shorter side of a rectangular cassette, but special ones, with the opening on the long side, can be made to special order.
One-Seam Reinforced Single-Envelope Cassettes
These represent the first major advance in cassette design since the introduction of 'VELCRO' fastening. Constructed in rugged nylon-reinforced PVC, they are made to outlast any other type of flexible cassette.
They are constructed without side-seams - there is just one joint on the back of the cassette. This design overcomes the weakness of other single envelopes that are welded along the sides: there is no tendency to split.
The cassettes are made from specially- formulated, heavy-duty, nylon-reinforced PVC. They are coloured black on the inside for light-tightness and yellow on the outside for easy recognition.
Standard Single-Envelope Cassettes
These are made from 400 micron black PVC and have become, over the years, the standard cassette for industry.
In cold weather PVC hardens and at very low temperatures can become quite brittle and liable to crack.
We do not recommend the use of standard single envelope cassettes in very cold weather and advise great care in loading and unloading them in sub-zero temperatures.
Reinforced Single-Envelope Cassettes
Are made from thin, yet strong PVC/ nylon/PVC laminated material, The nylon reinforcement is in the form of a mesh and reduces the tendency of the PVC to split at the seams, even after much use.
The PVC laminate retains its flexibility in cold climates. Reinforced cassettes are therefore more suitable for use at low temperatures than the standard type.
Heavy-Duty Single-Envelope Cassettes
Are made from double-thickness material consisting of one layer of standard PVC and one layer of the nylon-reinforced material.
This combination produces a cassette capable of withstanding very rough treatment at normal temperatures.
Double-Envelope Cassettes
RADAC Double-Envelope Cassettes consist of two plain, black envelopes without any means of closure.
Film and screens are loaded into the inner envelope, the smaller of the two. This is then inserted, open end first, into the larger, outer envelope. Light tightness is assured because the open end of the inner envelope is up against the closed end of the outer.
They are made from the standard 400 micron material and are clearly marked 'RADAC BACK' on both the inner and the outer envelope for easy identification in the darkroom and on site.
The main advantage of double envelope cassettes is that they lie perfectly flat, having neither fold-over ends nor 'VELCRO' fastening,
Special Cassettes
RADAC can also make special cassettes to
the customer's own requirements in any
of the available materials. For example:
