Pressure Sensitive Coating & Moisture

Implementing Proper Measurement

Pressure sensitive adhesives exhibit a distinctive characteristic of being permanently tacky at room temperature. They bond to surfaces under pressure through polar attractive forces instead of creating chemical bonds. The two primary categories are rubber and acrylic based adhesives. While rubber-based adhesives are more cost-effective, they do not offer the same level of physical and chemical stability as acrylic-based adhesives.

There are three unique methods for applying PSAs:

  • Solvent-based – where the adhesive components are polymerized in solvent and then applied onto the web.
  • Hot melt – where hot melt adhesive is applied onto the web and then cooled before or during winding.
  • Emulsion-based – where the adhesive components are polymerized in water, applied onto the web, and then dried.

PSAs can be single-coated, double-coated, pattern-coated, and self-wound.

Control Moisture Levels Now!

Single coatings are adhered to a single surface known as the face stock, which can be film, PE foam, paper, tissue, or non-woven material. A release liner, which is silicone coated and made of PET, PE, or poly coated Kraft, is then applied to protect the adhesive layer. Double coatings are utilized to bond two substrates together, with different PSAs applied on each side of a carrier such as plastic film, tissue, or non-woven material to enhance the adhesive configuration. Transfer tape is an unsupported adhesive film that is coated onto a release liner and is commonly used in medical packaging with pattern coating. Self-wound systems consist of face stock coated with PSA on one side and silicone release on the other, examples include diaper tapes and short roll lengths of tape. PSAs play a crucial role in the production of specialty tapes, medical packaging, surgical drapes, and laminated film.

There are two primary reasons why measuring coat weight is crucial. Firstly, for adhesive coating to effectively adhere to the desired area, it must be uniformly applied. This ensures a strong coefficient of adhesion between the two substrates. Secondly, in order to reduce the consumption of expensive acrylic, it is essential to apply the minimum amount of coat weight necessary to achieve adhesion.


Our equipment never comes into contact with the product, allowing for less waste

zero drift

Our sensors are guaranteed not to drift over time – which saves time and money

closed loop

Create a closed-loop process by tying a moisture sensor into your PLC. Full control over the line!

no recalibrations

We’ve mastered the art of moisture sensors – your unit will never need to be recalibrated for the same product twice!

Saving Time, Energy & Money

The application method for adhesives depends on the specific product being manufactured. Generally, solvent-based and aqueous-based adhesives are applied using either an excess application system, such as a Mayer rod coater, or a metered system, such as a transfer coater or gravure roller. The available options for application vary depending on the manufacturing process. When applying a PSA in an aqueous solution, the most accurate measurement is taken at the wet end, where the water content is measured and the dry coat weight is inferred from the solid’s ratio percentage. On the other hand, measurements at the dry end are taken for PSAs and solvent-based systems to avoid the need for a NEMA 4 sensor housing for the latter. While it is possible to use a solvent at the wet end, especially for low coat weights, it is crucial to maintain solvent ratios and carefully control sampling errors to ensure accuracy.

Our pressure sensitive hot melt thickness transmitter has un-matched precision and accuracy. Making thousands of measurements per second, the IR-3000 takes instant non-contact measurements in percentage wet and dry allowing you to quickly adjust your product either manually or automatically. In addition, it tests chemical composition, water-based coating, and temperature accurately. Built to withstand the harshest manufacturing conditions, our pressure sensitive hot melt thickness sensor will increase the quality of your product.


Locate the point in the production process in which measuring moisture will be the most crucial and beneficial. Identify how you will use the moisture measurement data for improvements and if it will tie into your PLC.

Remember this could involve more than one installation point!


We offer service and support throughout the world for our moisture measurement sensors and would be happy to connect you with a rep in your area. Contact us today for more information!

Understand the Process

Moisture control in any manufacturing environment is important in multiple ways: quality, efficiency, plant operations, machine life and more. Learn more about MoistTech’s NIR moisture control systems: