Thermal Shrinkage Tester for ASTM D2732 Plastic Film Tests

Thermal shrinkage is a critical parameter for evaluating the performance of plastic films used in packaging, medical, and industrial applications. The thermal shrinkage tester plays a key role in measuring how plastic film dimensions change when exposed to elevated temperatures. In industries where packaging integrity and thermal behavior matter, thermal shrinkage analysis ensures product quality and production consistency.

Cel Instrumenten’ FST-01 Thermal Shrinkage Tester is a high-precision instrument designed to meet modern quality control and R&D demands. It supports standards like ASTM D2732, making it ideal for companies that require reliable and reproducible shrinkage data across materials.

ASTM D2732 Standard for Thermal Shrinkage Testing

ASTM D2732 is the globally recognized standard for measuring unrestrained linear thermal shrinkage in plastic films and sheeting. It applies to materials with a thickness of 0.76 mm (0.030 in.) or less and specifies how to test shrinkage without applying physical restraints during heating.

This method is particularly useful in detecting residual internal stresses formed during the film manufacturing process. These stresses become evident when the film is subjected to elevated temperatures, and they often result in significant dimensional changes. By following ASTM D2732, manufacturers and QC labs can consistently characterize the heat-shrink behavior of their plastic products.

Why Use a Thermal Shrinkage Tester?

A thermal shrinkage tester ensures precision, repeatability, and compliance with industry standards. Manual methods or uncontrolled heating can lead to inaccurate or inconsistent results. Key advantages of using a dedicated thermal shrinkage tester like the FST-01 include:

Accurate temperature control (±0.5°C), critical for replicable results
Uniform heating using a controlled liquid bath
Standardized sample holders to prevent mechanical constraints
Digital measurements and reporting for quality assurance documentation

Key Components of a Thermal Shrinkage Test

To perform an ASTM D2732-compliant test using a thermal shrinkage tester, the following equipment and conditions are essential:

Constant-temperature liquid bath capable of reaching and maintaining test temperatures (commonly between 90°C and 150°C)
Free shrink holder that immerses the sample without restraining it
Precision ruler or digital measuring device for pre- and post-test dimension measurement
ASTM-compliant thermometer for verifying bath temperature (e.g., ASTM S5C-11)
Sample preparation tools like a 100×100 mm die or cutter with machine direction markers

Each test involves placing film samples into the bath for a specified time, typically around 10 seconds, removing them quickly, and measuring the change in length in both the machine and transverse directions.

Step-by-Step Guide to ASTM D2732 Testing with FST-01

Condition the samples per ASTM D618 (standard temperature and humidity)
Prepare film samples using a die or template; dimensions should be 100 mm × 100 mm
Mark film direction with an arrow to differentiate machine and transverse orientation
Set liquid bath temperature using the thermal shrinkage tester’s digital interface
Place sample into holder and immerse it in the liquid bath for the defined time
Remove and cool the sample, then measure the final dimensions
Calculate shrinkage % using the formula: S = (L0 – L) / L0 * 100%

Applications and Benefits in Industrial Settings

Manufacturers in the packaging, food, medical, and electronic sectors routinely rely on thermal shrinkage data to:

Evaluate film stability and thermal performance
Optimize production settings such as orientation and quenching rates
Monitor process drift and ensure quality consistency
Ensure compliance with international standards and customer specifications

By integrating the Cell Instruments FST-01 Thermal Shrinkage Tester into your workflow, you can streamline testing, reduce human error, and enhance traceability.

Why Choose Cell Instruments FST-01?

The FST-01 model from Cel Instrumenten is engineered to support ASTM D2732 testing with unmatched ease and accuracy. Key features include:

Digital PID temperature control and high thermal stability
Corrosion-resistant liquid bath for long-term usage
Versatile sample holders accommodating different film types
Automatic timing and result recording for improved data traceability

As a result, laboratories and quality control teams can confidently rely on the FST-01 to deliver consistent and standards-compliant results, essential for maintaining customer trust and product reliability.

Conclusion

Understanding the thermal shrinkage properties of plastic films is essential for controlling product performance and maintaining compliance with industry regulations. Using a dedicated thermal shrinkage tester—especially when following the ASTM D2732 protocol—ensures accurate, reproducible results that guide production, quality assurance, and R&D decisions.

With the Cell Instruments FST-01, you can perform these tests efficiently while meeting global standards, ultimately enhancing your product’s market competitiveness.