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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!
Half-tone printing process line
Percentage coverage is easily measurable using a commercially available reflection densitometer. The instrument only needs calibrating with the null (printing substrate) and full tone references, then it can be switched to measure tonal values.
Should an instrument be incapable of automatic conversion, the formula is:
A process line traces the variance in tone values, plotted as a curve, between those on the film (or output device) and those in the printed image. The screen printing process line allows a repro expert to identify the dot gain (positive or negative), in order to calculate a compensation guideline for the printed image.
The screen printer initially needs no measuring instrument. A half-tone step wedge with at least 10 tone values should be printed alongside the artwork. The repro specialist uses a transmission densitometer to measure the half-tone values on the positive film, and a reflection densitometer on the print. The results are then compared on a chart.
Film tone value
Printed tone value
Every process line must also specify the following operational parameters:
type, threads/cm, tension N/cm
– Type of stencil
emulsion, capillary film, indirect film
– Stencil thickness
specified in μm
– Surface roughness
Rz value in μm
type, manufacturer, composition, viscosity
hardness, thickness, clearance, angle, pressure, speed
– Printing stock
exact description, e.g. type of paper, etc.
The process line can be significantly influenced by a change in any single item in the list above.