Avoid these three misconceptions and easily achieve precise selection of thin film tensile testing machines

Faced with a wide variety of testing machine models in the market, how to avoid "high configuration waste" or "low configuration shortage"? In this article, the editor of Fule Instrument will provide a detailed procurement and configuration guide from four dimensions: force range, fixture selection, deformation measurement, and compliance with standards.

1. Clearly define testing requirements and execution standards

Before selecting, it is necessary to first define the testing object and purpose:

Material type: Is it ordinary PE cling film, BOPP packaging film, or high-strength aluminum-plastic composite film, biodegradable biofilm

Test items: mainly focus on tensile strength, elongation at break, peel strength, and heat sealing strength

Adhere to standards: Confirm the standard system that needs to be met. For example, pharmaceutical packaging often follows YBB standards, while general plastic testing follows GB/T 1040 or ASTM D882.

2. Key core parameter configuration

Range and accuracy:

Ultra thin films (such as graphene films,<0.02mm optical films): It is recommended to choose a micro force testing machine with a range of 10N-50N and a sensor resolution of up to 0.001N or even 0.0001N to ensure linearity under small force values.

Composite membrane/geomembrane: The range is usually between 500N-2kN, and selecting equipment with a precision of 0.5 level (indication error ± 0.5%) can meet the majority of industrial quality inspection requirements.

Fixture selection is the soul:

Pneumatic flat pushing fixture: For plastic films with smooth or slippery surfaces, it is strongly recommended to use pneumatic fixtures. Its clamping force is constant and adjustable, which can effectively prevent the sample from breaking at the jaws (invalid data), while manual fixtures have low efficiency and poor repeatability.

Anti slip treatment: The contact surface of the fixture should have a rubber or corrugated surface, which increases friction without damaging the specimen.

Deformation measurement (elongation):

Displacement method: applicable to straight bar specimens. However, it should be noted that the gap between the equipment crossbeam itself and the deformation of the rack can introduce errors.

Non contact/large deformation extensometer: For dumbbell shaped specimens specified in GB/T 1040 or elastic films with elongation exceeding 100%, a large deformation extensometer (usually with a gauge length of 25mm and a range of 800mm or more) or a video extensometer must be equipped to truly track the deformation within the gauge length and avoid false data caused by beam displacement.

3. Intelligence and Compliance

For the pharmaceutical and electronics industries, software for equipment is crucial. It is necessary to ensure that the testing machine has multi-level user permission management, audit tracking, and data encryption functions to comply with GMP (Good Manufacturing Practice) regulatory requirements.