Screen Printing – Measurements (mesh, Emulsion, Stencil Thickness)

The PosiTector 6000 FS precisely and non-destructively measures mesh, emulsion and stencil thickness, as well as substrate and dry ink deposit thickness. The PosiTector 6000 FS makes use of the magnetic induction principle to rapidly measure the thickness of nonmagnetic materials.

Silk Screen Printing Origins

The modern silk display printing process was patented in 1907. It involved silk stretched on frames to assist hand painted stencils. In 1914 the method was expanded for multicolor printing with a screen course of. Presently silk screening popularity increased and an industrial printing course of for flags, banners and promoting signs in shops began. While high quality enhancements have been made within the gear and supplies used for silk display printing, little has changed in the precise process. Today, display screen printing is used all over the place. Applications embrace store displays, posters, advertising boards, electronic equipment marking, textiles, clothes and bumper stickers.

Screen Printing Process

The process begins with a tremendous nylon mesh stretched over a wood or aluminum body. The mesh is coated with a light-sensitive emulsion or movie that, when dry, blocks the holes in the mesh. The image to be printed is output onto a movie transparency. The optimistic film transparency and coated mesh are placed together after which exposed to ultra-violet gentle. A jet of water is used to scrub from the display any of the emulsion that has not been hardened by the ultra-violet mild, making a stencil corresponding to the picture on the movie. The display screen is match to a press. A substrate to be printed is placed under the display screen. Ink is placed on the top facet of the screen and a rubber squeegee blade is pulled throughout the top of the screen, pushing the ink by way of the stencil onto the substrate. When printing multiple objects the squeegee floods the screen once more with a return stroke. Each item is then heat cured to permanently set the ink. The method is repeated as typically as required for multi-coloured objects.

Mesh Thickness Measurement

The PosiTector 6000 FS (Screen Printing) gage was particularly designed for thickness measurements on fabric and stencils. The huge surface of the probe bridges the mesh openings enabling the probe to consistently measure from knuckle to knuckle of the mesh and stencil. Since during the tensioning process, the thickness of the mesh changes as in comparison with the thickness identified by the manufacturer, it is important to determine the mesh thickness on a stretched display at printing tension. After zeroing the PosiTector 6000 FS probe on the included ferrous base plate, the gage is prepared to offer an correct thickness measurement of any substrate or display mesh positioned flat in opposition to the bottom plate.

Accurate mesh thickness measurements are important as they’re a essential factor in formulation used to foretell a mesh’s wet ink deposit. Resulting from variations in display screen mesh thickness, repeatability might be improved using the statistics mode out there in selected fashions. With statistics enabled, the gage robotically calculates a running average of the readings taken. The measurement vary of the FS is as much as 60 mils (1.5 mm). The PosiTector FS has a variable accuracy of 1%. Should you liked this post and you would want to be given details regarding coustic mesh for sale i implore you to pay a visit to our own web-site. As much as a 0.05 mil (1 micron) resolution.05 mil (1 micron) decision.

Stencil Build-Up Thickness Measurement

The ability to measure the thickness of the mesh and stencil enables the person to foretell and control critical parts of the display screen printing course of. For course of control it is critical to manage mesh. Emulsion thickness throughout the floor of the stencil. Stencil thickness ought to even be periodically inspected with a PosiTector 6000 FS gage, particularly for outlets that manually coat their screens.

For basic printing of non-ultraviolet ink purposes and jobs that don’t require extreme element, an emulsion construct up of roughly 20 p.c of the mesh thickness usually provides wonderful print decision and edge definition. A measurement of 20 percent EMR (emulsion over mesh ratio) gives enough emulsion build-up on the print side to effectively lift the threads off the floor of the substrate at the shoulder of the print decreasing any loss of printed image by allowing the ink to fill your complete image area.

Applications involving positive detail, multi-colour or ultraviolet printing require thinner total stencil thickness. 10 percent EMR is extra widespread as it provides the stencil just sufficient relief from the mesh on the substrate side, however nonetheless reduces total screen thickness (mesh plus emulsion) in order that very high-quality detail can release from it without bleeding.

The thicker the mesh, the thicker the emulsion coating required to encapsulate the mesh and type a stencil with a clean stencil surface (Rz-value). Thinner mesh is normally simpler to coat, and gives a smoother stencil at a given thickness.

Stencil Thickness

To find out the thickness of build-up on the stencil, it’s first essential to zero the FS probe on the stretched mesh. By inserting the included metallic base plate underneath the mesh and attaining a mean zero value (to account for variations within the mesh), the mesh turns into the zero value. Now when measurements are taken on the coated display the gage will display the EOM (emulsion over mesh) build-up on the display screen. As with all tough substrates or coatings, better repeatability could be obtained by calculating the typical of a number of measurements.

Measuring Emulsion Thickness

If the emulsion coating is just too skinny, it is not going to provide a correct gasket seal. The ink will bleed underneath the stencil. This will cause the print to have rough looking edges (saw-toothing). Other symptoms of inadequate emulsion thickness include smeared pictures, dot loss in the highlights and dot acquire in the shadows. If emulsion construct-up is just too high, the print shoulder will have too high of a vertical wall or column, and the ink could or might not completely fill into this space. If the ink doesn’t fill the area, the resulting print will show voids. If the ink does truly fill the column it could not release correctly throughout printing. Even when the ink does launch, coustic mesh for sale a lot ink may deposit into the image.

Dry Ink Deposit Thickness Measurement

Using a similar course of to Emulsion measurement, the Dry Ink Deposit Thickness might be attained. Place the bare substrate over the steel base plate and zero the FS probe. After attaining a median zero value (to account for variations in the substrate), the substrate thickness turns into the zero value. Now when measurements are taken on the printed substrate the gage will display only the thickness of the dry ink deposit.

The measurement of dry ink deposits on substrates clearly demonstrates the advantage of electronic gages over most mechanical thickness measurement units (calipers and screen printing mesh micrometers). Along with its accuracy and simplicity, an digital gage can easily measure any area of a print without the necessity to cut the substrate to achieve entry for the measurement gadget.