Contact angle measurement technology principle and its application field
What is contact angle?
Contact angle , θ , is a quantitative measure of the wetting of a solid by a liquid. It is defined geometrically as the angle formed by a liquid at the three phase boundary where a liquid, gas and solid intersect as shown below:
It can be seen from this figure that a low values ​​of contact angle (θ) indicates that the liquid spreads, or wets well, while a high contact angle indicates poor wetting. If the angle θ is less than 90 degrees the liquid is said to Wet the solid. If it is greater than 90 degrees it is said to be non-wetting. A zero contact angle represents complete wetting.
The measurement of a single static contact angle to characterize the interaction is no longer thought to be adequate. For any given solid/ liquid interaction there exists a range of contact angles which may be found. The value of static contact angles are found to depend on The recent history of the interaction. When the drop has recently expanded the angle is said to represent the 'advanced' contact angle. When the drop has recently contracted the angle is said to represent the 'receded' contact angle. Range with advanced angles approaching a maximum value and receded angles approaching a minimum value.
If the three phase (liquid/solid/vapor) boundary is in actual motion the angles produced are called Dynamic Contact Angles and are referred to as 'advancing' and 'receding' angles. The difference between 'advanced' and 'advancing', ' Dynamic contact angles may be measured at various rates of speed. Dynamic contact angles measured at low velocities should be equal to properly measured static angles .
Applications
RFID Plastic Cards, Custom printed, plain or with scratch-off or magnetic stripe, may be used as swipe cards, ID cards, loyalty or membership cards.
Plastic Cards
Custom Plastic Cards,Printing Plastic Card,Plastic Business Cards,Plastic Membership Cards
Guangdong Xinye RFID Label Application Co., Ltd , https://www.xinyerfid.com