PSTC 16
Loop Tack Testing of Pressure Sensitive Tapes and Films

The PSTC 16 standard plays a vital role in quality control for adhesive products such as pressure-sensitive tapes, films, medical dressings, and industrial labels. Among the many parameters assessed in adhesive performance, loop tack—or the initial “stick” upon contact—is one of the most critical. This property determines how well a material bonds on first touch, impacting everything from user experience to functional reliability.

In this article, we will explore the fundamentals of PSTC 16, how the pressure sensitive tape loop tack test works, and how Cell Instruments’ Loop Tack Tester provides accurate, efficient, and compliant solutions for industry professionals.

Understanding Loop Tack and Its Role in Adhesive Performance

Loop tack is the peak force required to separate a pressure-sensitive adhesive (PSA) from a test surface after brief contact under minimal pressure. Unlike peel adhesion, which measures sustained force over distance, loop tack quantifies instant adhesion. This makes it especially important for:

• Labels and stickers applied in automated or high-speed environments

• Medical adhesives like wound dressings and electrode patches, where reliable contact is vital

• Protective and masking tapes that must adhere quickly to various surfaces

• Packaging materials that require firm initial bonding under minimal application pressure

By assessing loop tack using PSTC 16, manufacturers gain clear, quantitative insights into adhesive responsiveness—crucial for optimizing formulations and process settings.

Loop Tack, Pressure Sensitive Tape Loop Tack Test, and PSTC 16

The pressure sensitive tape loop tack test defined in PSTC 16 provides a repeatable, controlled procedure to evaluate tackiness. The process includes:

1. Sample Preparation: A strip of adhesive tape (typically 25 mm × 175 mm or 125 mm) is formed into a loop with the adhesive facing outward.

2. Contact Phase: The loop is gently lowered onto a standardized test plate (usually polished float glass) using gravity alone.

3. Separation Phase: The plate or loop is moved vertically at a controlled speed (e.g., 300 mm/min).

4. Measurement: The tester records the maximum force (peak load) needed to initiate separation. This is the loop tack value, typically reported in Newtons (N).

This method simulates real-world application conditions, ensuring that adhesives meet customer and regulatory expectations.

Standards Compliance: PSTC 16, ASTM D6195, and FINAT FTM 9

While PSTC 16 is widely used in North America, international testing may reference related standards such as:

• ASTM D6195 – Test Method C closely mirrors PSTC 16 procedures

• FINAT FTM 9 – A European counterpart for tack evaluation

Regardless of the standard, the core principle remains consistent: quantify the instantaneous bond strength of pressure-sensitive adhesives under defined conditions. For manufacturers, testing in accordance with these methods ensures compatibility with global clients and regulatory bodies.

Cell Instruments’ Loop Tack Tester: Precision Meets Simplicity

The Loop Tack Tester from Cell Instruments delivers accurate and repeatable testing in full compliance with PSTC 16 and related methods. Key features include:

• Industrial-grade PLC control with 7-inch touchscreen for intuitive operation

• Customizable speed, dwell time, and stroke length for full procedural flexibility

• High-resolution load sensors capable of detecting slight variations in loop tack force

• Standardized float glass test plate for repeatable contact conditions

• Microprinter and RS232 data port for instant test reports and data export

• Multi-unit force display (N, gf, kgf, lbf) to meet regional requirements

Whether testing PSA tapes, medical adhesives, or labeling materials, Cell Instruments’ system supports R&D, QC, and production-level evaluations with ease.

Conclusion

Testing to PSTC 16 standards is essential for validating the loop tack of pressure-sensitive adhesives used in tapes, labels, medical dressings, and industrial laminates. The pressure sensitive tape loop tack test delivers critical data on initial bond strength, supporting both performance optimization and regulatory compliance.

For laboratories and production environments seeking accuracy, efficiency, and repeatability, Cell Instruments’ Loop Tack Tester offers an advanced solution tailored to real-world needs.

Understanding and applying ASTM D3420 ensures that your packaging and film materials meet performance expectations under dynamic stress. By using a film pendulum impact tester—especially one like the Cell Instruments PIT-01—you can standardize quality control, reduce product failure rates, and comply with international specifications. Whether you’re developing new films or conducting batch testing, ASTM D3420 remains an essential tool in your testing arsenal.

FAQs

1. What is PSTC 16?
PSTC 16 is a standard method used to measure the initial tack or bonding strength of pressure-sensitive adhesives using a loop tack test.

2. Why is loop tack important?
Loop tack reflects the adhesive’s ability to bond instantly upon contact, which is crucial for performance in fast-paced applications like labeling and medical taping.

3. What materials can be tested with a loop tack tester?
Pressure-sensitive tapes, labels, films, medical adhesives, protective laminates, and more.

4. How does the Cell Instruments Loop Tack Tester ensure compliance?
It uses standardized surfaces, adjustable parameters, and accurate sensors, all aligned with PSTC 16, ASTM, and FINAT standards.

5. Can this tester be used in both R&D and QC environments?
Yes. It is designed for versatile applications, from formulation development to production quality checks.