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Dear Business Partner
It is our top priority to serve you in the best possible way, despite the current turbulences with the Corona virus. I therefore want to give you an update on the status of the Sefar Group, which also includes Monosuisse.
• The Sefar Group complies to all the local regulations with respect to the containment of the Corona virus.
• We have taken additional internal precautions to assure the continuation of our production and the deliveries to you.
• All of our spinning and weaving plants worldwide are currently operating without limitations.
• There is a possibility of national restrictions in countries, where we operate our decentralized fabrication units. This may cause delays in fabricated items. For details, please contact your local Sefar subsidiary.
• Global limitations on freight capacity, in particular for air shipments, may also affect the delivery time.
Being a fully integrated supplier, Sefar controls and ensures the entire supply chain of our technical fabrics, from the yarn production at Monosuisse to the shipping of the fabrics or the finished articles. You are in good hands at Sefar.
Should your operation face any supply challenges where we might be able to help, please let us know. Your contact person is reachable at any time.
We will keep you updated on any changes affecting our delivery performance.
I wish you good health!
Making a step exposure
A step exposure is best made with a test positive containing at least 5 identical images featuring positive and negative fine lines and half-tones.
Masking film (miscellaneous)
The mask must block UV-A light (100 % opaque). Ascertain the number of steps for determining
the correct exposure time!
: The exposure time is assumed to be around 80 units. So: 20 units per step, such that step four lies approximate to the correct exposure time.
: Under- and over-exposed areas should become visible within the five steps afforded
by the exposure test film.
During development, it becomes apparent that stepped exposure times produce different degrees of coloring on the stencil.
The difference between steps is especially visible if the first three steps are underexposed.
There is no color difference between the remaining steps. We can therefore assume that step four is the minimum exposure time. At step four, the stencil should no longer be smudged on the squeegee side. This indicates a correct exposure.
On the other hand, when there is no color difference between the first and second steps (already hardened through), make another step exposure based on a shorter exposure time.
With diazo coatings, the color difference between individual steps is easily recognisable. The effect is more subtle with pure photopolymer coatings, although it is possible to judge exposure based on the presence of smudging: no smudging = hardened through.