In this article, we explain the pros and cons of polyester and nylon mesh for screen printing.
Like every other printing process where several parameters are to be critically controlled, screen printing, though a simpler process, also needs a strict check on various factors to achieve accurate results. This starts right from selecting a right mesh fabric, mesh size, frames, stretch pressure and many such variables depending upon the requirements of applications.
When it comes to screen fabric, there are two kinds available in the industry: nylon and polyester. While polyester is being widely used worldover, nylon is the choice of Indian screen printers for majority of applications.
The polyester mesh has several superior properties such as resistance to solvent, high temperature, water, chemicals etc. Also, when acted upon by severe external pressure, its physical performance is stable and stretchability is low. However, as compared to nylon, polyester has poor wear resistance.
Thanks to its dimensional stability, polyester mesh is suitable for applications, where critical control of registration is required such as printing on printed circuit boards (PCB). The drawback of Nylon mesh is large stretchability and low tension retaining capacity. Therefore, after a period of time, the net stretch will reduce and make the screen plate flabby leading to decline in the level of precision. Therefore, it’s not suitable for printing on PCB.
Screen printing being a wet process, moisture absorption is an important consideration. Nylon, for instance absorbs up to 5% moisture and loses 10-20% of its strength when wet and elongates 26-40% before breaking, while polyester elongates much lesser 19-23%.
Today, high-quality monofilament polyester, the modern mesh fibre is the most suitable mesh fabric. It is round and smooth with superior elongation and strength characteristics. It has no loss of strength when wet and, in fact, absorbs less than 0.8%moisture.
Nylon mesh, therefore, should only be used when printing on irregular surfaces or three-dimensional objects (such as bottles) that might require such properties.
