Filters are rated according to the size of particles they can remove. Particles that are bigger than the indicated pore size are removed. Smaller particles pass through the fabric. The size of particles is measured in micro-meters or 'microns', one micron being equal to one-millionth of a meter, the typical size of coal dust or flour. The smallest bacteria are about 0.5 µm.
Raster ruling L/cm or L/pi
The raster ruling is indicated in lines resp. dots per cm or inch. In screen printing, rasters between 5 L/cm till max. 48 L/cm can be printed, depending on the mesh used.
Guideline: the smallest dot must have a minimal diameter of two threads and one mesh opening.
1: Exact congruence between original (e.g. diapositive) and the printed image
2: Multi colour printing: exact congruence between originals of the various colors and their printed images (color register)
3: Exact congruence of images at the beginning and the end of a print run, or between intermediate printings.
The amount of shrinkage remaining in a fabric after it has undergone all fabric weaving, washing and heat setting steps.
Substance retained in the upstream side of a filter.
RF (radio frequency) welding
Utilizes specific bands of radio frequency waves which are directed through specially constructed tooling to form localized melting/joining of certain dielectric thermoplastic materials. Can be used to form hermetic seals. Also known as high frequency or dielectric welding.
For satin/atlas weave, the weft passes under one warp thread and then over the next two or more. The adjacent weft thread follows the same pattern but staggered by at least two warp threads. In this way a fabric is made in which parallel weft threads predominate on the top surface and warp threads are thus mostly exposed on the bottom surface.
This results in a particularly smooth surface.
The edges of printed lines and areas are spiky. Main reason: coating thickness too small, and/or RZ value too high
Screen printing frame
Aluminium and steel are the mostly used materials for screen printing frames. Aluminium frames are less heavy and easier to handle but to give a comparable strength to steel , the cross sectional area must be enlarged. See also 'frame'
Screen printing moiré
Interference between mesh and halftone dia positive
Precision woven screens made from carbonized threads.
Fluorocarbon precision woven screens.
Precision woven fabrics intended for medical applications, fabrication in clean room class 7.
Nylon precision woven screens
Sieving fabrics for milling applications
Dryer belts for the pasta industry
Polyester precision woven screens
Polypropylene precision woven screens