55291 NDT BROCHURE.indd - NDT Equipment
55291 NDT BROCHURE.indd - NDT Equipment
55291 NDT BROCHURE.indd - NDT Equipment
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Plastic Cassettes<br />
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PLASTIC CASSETTE INFORMATION<br />
All types of Single-Envelope Plastic Cassettes are of the same design. They consist of a<br />
single envelope, open at one end, through which film and screens are loaded and unloaded. The<br />
open ends of the envelopes fold over, producing an effective light seal. They are then held closed by<br />
means of VELCRO’ nylon fastener.<br />
There is an extra finger-tab at the bottom to assist in holding the cassette to the bench for<br />
easier and quicker unloading. Closure is normally made on the shorter side of a rectangular cassette,<br />
special versions, with the opening on the long side, can be made to order.<br />
STANDARD SINGLE ENVELOPE CASSETTES These are made from 400 micron black PVC and<br />
have become, over the years, the standard cassette for industry. We do not recommend their use in<br />
very cold weather and advise great care in loading and unloading them in sub-zero temperatures.<br />
REINFORCED SINGLE ENVELOPE CASSETTES These are made from thin, yet strong PVC/Nylon/<br />
PVC laminated material. The nylon reinforcement is in the form of a mesh and reduces the tendency<br />
of the PVC to split at the seams after much use. The PVC laminate retains its flexibility in cold climates.<br />
Reinforced cassettes are therefore more suitable for use at low<br />
temperatures than the Standard type.<br />
ONE SEAM SINGLE ENVELOPE CASSETTES These represent the first major advance in cassette<br />
design since the introduction of ‘VELCRO’ fastening. Constructed in rugged nylon-reinforced PVC,<br />
they are made to outlast any other type of flexible cassette. They are<br />
constructed without side-seams, there is just one joint on the back of the cassette. This design<br />
overcomes the weakness of other single envelopes that are welded along the sides; there is no<br />
tendency to split.<br />
The Cassettes are made from specially - formulated, heavy-duty, nylon-reinforced PVC. They are<br />
black on the inside for light-tightness and yellow on the outside for easy recognition.<br />
HEAVY DUTY SINGLE ENVELOPE CASSETTES These are made from double-thickness material<br />
consisting of one layer of standard PVC and one layer of the nylon-reinforced<br />
material. This combination produces a cassette capable of withstanding very tough treatment at<br />
normal temperatures.<br />
DOUBLE ENVELOPE CASSETTES These consist of two plain black envelopes without any means of<br />
closure. Film and screens are loaded into the inner envelope, the smaller of the two. This is then<br />
inserted, open end first, into the larger outer envelope. Light – tightness is<br />
assured due to the open end of the inner is up against the closed end of the outer. They are made<br />
from the standard 400 micron material and are clearly marked ‘INTEX BACK’ on both the inner and the<br />
outer envelope for easy identification in the darkroom and out on site.<br />
The main advantage of Double-Envelope Cassettes is that they lie perfectly flat, having no<br />
fold-over ends or ‘VELCRO’ fastening.<br />
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