By Sarah Hammond, marketing manager, MoistTech

The moisture content in a product can have serious effects on its final quality, including in the production of labels and release liners, which are critical components in packaging, converting and product identification. In these applications, improper moisture levels can lead to label curling, adhesive failure or liner delamination, causing significant quality and efficiency problems.

Controlling and adjusting the moisture content throughout the process can eliminate many common manufacturing issues. While laboratory and other manual methods have been utilized for years, new automated moisture measurement and control systems can play an important role in improving product-quality monitoring and increasing plant efficiency.

There are several available methods for moisture measurement in industrial manufacturing settings, including visual inspection, manual testing, oven weight loss and moisture sensors. Manufacturers that rely on simple “guesstimates” based on sight or feel, determined in a visual inspection, cannot provide the necessary consistency or quality. Conducting manual testing by taking samples and bringing them to a laboratory for analysis adds considerable time to the entire process chain.

A more robust technology is the use of moisture sensors. One example is MoistTech’s moisture sensor technology, a non-destructive method of measuring and controlling moisture content. Based on near-infrared (NIR) technology that enables moisture measurement without coming into contact with the product, the moisture-sensing technology avoids wasted product; provides instant, accurate and repeatable results; and employs a simple light source for measurement, allowing for longer use of equipment.

Under the hood of near-infrared (NIR) technology

Insensitive to material variations such as particle size, material height and color, NIR technology provides continuous, reliable readings with zero maintenance. There is a one-time calibration with a non-drift optical design, allowing operational personnel to make immediate process adjustments confidently based on real-time measurements.

Online sensors are mounted in different locations, depending upon the application, and installed about 4 to 16 in. from the product using a bracket on the back or top of the sensor. Sensor units are standalone and require no software or external output device. Display options are available but are not required for operation.

In addition to moisture, the sensors can measure coating weight, sheet and film thickness, oil, protein, temperature and other elements that absorb NIR. Accuracy and repeatability are in the +/- 0.01% to 0.1% range, depending on the application.

Labeling and release liners: Critical considerations for moisture control

In the converting and packaging industries, moisture control not only is crucial for the primary product but also plays a significant role in the performance of labeling materials and release liners. Labels are essential for product identification, branding and regulatory compliance, while release liners serve as the carrier for pressure-sensitive adhesives utilized in labels, tapes and other products.

Release liners typically are constructed from paper or film substrates coated with a non-stick material, such as silicone, that allows labels or adhesives to be removed easily during application. Excess moisture in either the label stock or the release liner can lead to a range of quality issues, including curling, loss of adhesive performance and even liner delamination. Maintaining optimal moisture levels ensures that labels remain flat, adhesives retain their tack and liners cleanly separate during high-speed automated labeling processes.

Moisture measurement and control solutions, such as those provided by the author’s company, increasingly are being integrated into label and release liner production lines (see Figure 1). By monitoring moisture content in real time, manufacturers can prevent defects, reduce waste and achieve consistent product performance. This especially is important for industries such as food, pharmaceuticals and consumer goods, where label integrity and readability are critical.

In addition, the trend toward sustainability in packaging has led to the development of thinner, lightweight liners and recyclable materials, which can be more sensitive to fluctuations in moisture. Advanced moisture sensors help producers adapt to these new materials without compromising on quality or efficiency.

Benefits of sensors for moisture control

The benefits of moisture sensor use for moisture control in labeling and release liner manufacturing include the following:

• Improved label performance:Real-time moisture control ensures that labels maintain dimensional stability, preventing wrinkling or curling that can interfere with automated application.
• Enhanced Release Liner Functionality:Properly balanced moisture levels help maintain the integrity of silicone coatings, ensuring consistent release force and clean separation of labels or tapes during dispensing.
• Reduced Downtime:By minimizing moisture-related defects, manufacturers reduce the frequency of line stoppages for adjustments or cleaning – especially important in high-speed labeling operations.
• Sustainability: Moisture control supports the use of recycled and lighter-weight liner materials, which are more sensitive to environmental changes, enabling greener packaging solutions without sacrificing quality.

Moisture control is a foundational element not only for core manufacturing processes but also for the production of high-quality labels and release liners. By leveraging advanced moisture-measurement technologies, manufacturers can optimize performance, reduce waste and support the evolving demands of modern packaging and labeling markets. 

Sarah Hammond is a recognized expert in moisture measurement, serving as the marketing manager at MoistTech Corp. in Sarasota, FL. Hammond is skilled at understanding the critical role moisture control plays in manufacturing processes, ensuring product consistency and quality while helping clients optimize efficiency and reduce waste. She can be reached at www.moisttech.com.