Converting process – Paul Wu's Blog

Hydraulic Pressure Gauges

There are two types of pressure gauges for hydraulic applications:

Liquid Surface Tension Measurement by Pendant Drop Method

In the coating applications, liquid surface tension measurement is critical, which include liquid-air interfacial tension and liquid-substrate (solid) interfacial tension. Contact angle measurement is a common method for the surface tension measurement; however liquid surface tension might not be available for the measurement. Pendant drop method is a good for this purpose.

Notes about servo and stepper motors

The following notes are from the choice between servo motors and stepper motors.

Taper Tension Control in Winding

Winding converts flat web into roll form and typically there are 3 types of winding as the following:

Metals for Coating Equipment

Different metal materials are used in coating industry. The following is a comparison among them

Web-tension isolation by pull rolls

Proper web handling is to provide good web-tension isolation between the unwind, process and the winding tension. Pull rolls are critical components in web handling system

Tension control

For professional coater, the tension is isolated into 3 zones: unwinding zone, internal zone, rewinding zone. Tension=torque/roll radius. During coating, the diameters of unwinder and rewinder are constantly change; therefore, to keep tension constant, torque should change according to roll diameter change.

Web spreading

Web spreading is a critical technology to remove wrinkles in web handling. There are three techniques to achieve the purpose:

Plasma Basics

What is plasma?

An ionized gas consisting of ions (mainly positive ions) and free electrons in proportions
Electrons are moving much faster than ions, due to mass difference
Quasi-zero overall electric charges
The 4^th state of matter
Important parameters about plasma: plasma density, plasma potential, ion energy

Category: Converting process