Stretching Screen Mesh
The most important part of the screen printing process involves how your mesh is tensioned. The common school of thought is tighter is better. Quite often a ‘ballpark’ figure is used, ‘I stretch all my screens to 30 newtons.’ Lets look at this to determine if it is a ‘best practice.’ Best practices for one shop could spell disaster for another, it all depends on a shop‘s presses, personnel, and other factors as we will see. Let’s start at a mesh guide.
Here is the link: http://www.murakamiscreen.com/documents/MeshGuidefromCatalogweb.pdf
Not all mesh should be stretched to a blanket statement like the one above. A mesh guide points this out. Look at the recommended tensions below for a 110T and 110S mesh. Mesh tension capacity is a factor of the thread size used, the number of threads per inch and finishing techniques. Thinner threads require less tension than thicker threads, otherwise any rough handling of the screen will cause mesh to pop. Lower tensions applied to thinner thread doesn’t affect registration when using Smartmesh like other import mesh. Smartmesh has mesh memory. The term in the past was low elongation which refers to how well the thread resisted stretching when under tension. Smartmesh’s mesh memory takes this a step further to also resist the forces of the squeegee during printing even when lower tensions are used. So tension is one part of great prints, but the meshes’ ability to return to the same location during printing results in non-stop printing with excellent registration for the entire run at a workable tension. That is key to long term screens. Selecting a ‘workable tension’ that produces great prints and a screen that won’t explode under normal handling.
What is a Workable Tension for my Shop?
Ask yourself these questions first. These conditions are common to most shops, modifying them will help you improve screen life, or allow for more critical types of printing like simulated process where dot on dot register is required using finer meshes and if you want today’s soft hand plastisol feel, finer threads. 1. How much off contact is normal for your press? 2. How do your employees handles screens? 3. How do your employees set up screens on press? 4. During breakdown are squeegees, flood bars, and clips dropped onto the screen? 5. What is the condition of your stretcher? Click here to continue reading the article: Stretching Smartmesh on Common Stretching Devices