Source: Link Testing Instruments Co.,Ltd.
I. Scope of Application of the Standard
GB/T 10003-2008, "Double Oriented Polypropylene (BOPP) Film for General Purposes," specifies the test method for the heat shrinkage of BOPP film. This standard applies to both standard and heat-sealable BOPP films made from double oriented polypropylene resin. Specifically, these films include the following types:
General packaging films: films for daily necessities, textiles, and electronic products;
Heat-sealable films: composite packaging materials with a heat-seal layer, used for applications requiring heat sealing, such as food and pharmaceuticals;
General industrial films: basic film materials suitable for conventional processing techniques such as printing and bag making.
This standard does not apply to special-purpose BOPP products such as matte films, capacitor films, and cigarette packaging films.
II. Definition of Heat Shrinkage
Heat shrinkage refers to the proportional change in a film's dimensions after heating under specific temperature conditions. The calculation formula is: T = L − L1/L × 100%
T: Heat shrinkage (%)
L: Length before heating (mm)
L1: Length after heating (mm)
III. Test Conditions and Requirements
Specimen Size: 100mm x 100mm (5 specimens each longitudinally and transversely).
Heating Temperature: 120±3°C (Constant Airflow Oven).
Heating Time: 120 seconds (different from the 5 minutes specified in GB/T 12026-2000).
Conditioning: Specimens must be conditioned in an environment of 23±2°C and 50±10% humidity for ≥ 4 hours (according to GB/T 2918).
Performance Requirements:
Class A Standard: ≤ 4.5% longitudinally, ≤ 3.0% transversely.
Class B Heat Seal: ≤ 5.0% longitudinally, ≤ 4.0% transversely.
IV. Test Instrument
Recommended Equipment: Link Testing LTRSY-03 Thermal Shrinkage Tester
Technical Features:
Digital P.I.D. temperature control, temperature control accuracy of ±0.3°C (better than the standard requirement of ±3°C).
Constant airflow heating, high temperature uniformity.
Automatic timing function (accurate to the second).
Supports specimen sizes ≤ 140mm × 140mm.
V. Test Procedure
Remove the outer three layers from the film roll and cut five 100mm × 100mm specimens along the width.
Mark the measurement points 10mm from the longitudinal and transverse edges of the specimens (a scriber or ink marker can be used).
Condition the specimens in an environment of 23±2°C and 50±10% humidity for ≥4 hours.
Place the specimens in the heating chamber of the LTRSY-03 Thermal Shrinkage Tester, set the temperature to 120±0.3°C, and heat for 120 seconds.
After heating, remove the specimens and cool to room temperature (23°C).
Use a steel ruler with a 0.5mm accuracy to measure the lengths (L and L1) of the longitudinal and transverse marked points before and after heating.
Calculate the heat shrinkage of five specimens and take the arithmetic mean as the final result.
If a specimen breaks at the heat seal or if the measurement error is large, retest and recalculate.
VI. Precautions
Temperature Control: Strictly adhere to the 120±3°C requirement to avoid temperature fluctuations that could cause test deviations.
Specimen Marking: Ensure that the vertical and horizontal measurement points are clearly marked to prevent displacement during heating.
Repeatability Testing: Test five specimens and take the average value to ensure data reliability.
Instrument Calibration: Regularly calibrate the heat shrink tester's temperature control system and measuring tools to ensure test accuracy.
Summary:
By adhering to the GB/T 10003-2008 standard and utilizing specialized testing equipment, companies can more accurately evaluate the heat shrinkage properties of BOPP film. The LTRSY-03 Thermal Shrinkage Tester (Link Testing) has become a common device for testing the heat shrinkage properties of BOPP films due to its precise testing capabilities, convenient operation, and stable performance, helping companies improve product quality and testing efficiency.
For more details please visit www.linktesting.org
