Film and Fiber Dynamic Mechanical Analyzer

What is the Film and Fiber Dynamic Mechanical Analyzer?

A film and fiber dynamic mechanical analyzer applies very small forces in tension with high displacement resolution, measuring thin films, filaments, fibres, tapes and coatings. It resolves the mechanical behaviour of specimens only micrometres thick.

Overview

Tensile clamps with fine adjustment, low-mass grips and force resolution of about 1 millinewton allow films from 10 micrometres thick and fibres from 20 micrometres diameter to be measured without damage. Specimen alignment is critical: any off-axis mounting introduces bending and lowers the measured modulus, so fixtures often include a positioning template and a pre-tension adjustment. Free length is kept between 5 and 20 millimetres to obtain measurable strain at low force. Temperature range typically covers minus 150 to 300 degrees Celsius, and humidity or immersion accessories allow conditioning of hygroscopic films. The technique is used for packaging films, separator membranes, optical films, textile fibres, single filaments and coatings, where the specimen may be only a few milligrams. Modulus and tan delta repeatability depend strongly on specimen preparation, so cutting and mounting procedures should be standardized.

How does it work?

The instrument clamps the specimen in a chosen geometry and applies a sinusoidal stress or strain while measuring the response. Because a viscoelastic material does not respond instantaneously, the strain lags the stress by a phase angle, and the ratio of amplitudes together with that phase angle yields the complex modulus. Its real part is the storage modulus, describing elastic energy stored per cycle; the imaginary part is the loss modulus, describing energy dissipated as heat; and their ratio is the damping factor, tan delta, whose peak defines the glass transition temperature. Measurements are made in single or dual cantilever, three-point bending, tension, compression or shear mode, with the geometry chosen to suit the sample stiffness. Temperature ramps of 0.5 to 5 degrees Celsius per minute, frequency sweeps from 0.01 to 100 hertz, and single or multi-frequency operation allow activation energies, cure profiles and master curves to be derived.

What are the key features?

• Force resolution of about 1 mN for delicate films and fibres
• Tensile clamps with positioning template for specimen alignment
• Free length adjustable from 5 to 20 mm
• Temperature range from −150 to 300 °C with humidity option
• Pre-tension adjustment to keep specimens taut without damage
• Specimen preparation kit for consistent film strips and filaments

What are the technical specifications?

A typical film and fiber dynamic mechanical analyzer configuration offers force range of 0.001–10 N, force resolution of 0.001 N, displacement resolution of 1 nm, temperature range of −150–300 °C, frequency range of 0.01–100 Hz and specimen thickness of 10 µm–1 mm. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Film and Fiber Dynamic Mechanical Analyzer is used in packaging and barrier film characterisation, battery separator membranes, textile fibre and filament testing, optical film dimensional stability and coating and paint free film analysis. Across the wider DMA class, laboratories also deploy it for composite and laminate viscoelastic characterisation, elastomer and rubber compound testing and thermoset cure monitoring.

Which standards and certifications apply?

Relevant standards and methods include ASTM D4065, ASTM D5023, ASTM D5024, ASTM D5026, ASTM E1640 and ISO 6721-1. Certification candidates for this model are CE, IEC 61010-1 safety and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Specimen geometry must be measured accurately, because modulus depends on the cube of thickness in bending and on cross-sectional area in tension, so a dimensional error is amplified. Clamp the specimen without pre-stress or slippage, verify that the measured stiffness lies in the instrument's reliable range, and check linearity by repeating at a second amplitude. Calibrate the instrument with certified stiffness standards or reference materials and record the geometry, amplitude, frequency and atmosphere for each run. Beware of thermal lag at higher heating rates, which shifts transition temperatures upward, and of clamp expansion that can add apparent strain. For thermosets, run the cure in a multi-frequency mode so gelation and vitrification can be separated. Purge gas is required for measurements above room temperature to avoid oxidation, particularly in elastomers.

How do I select the right Film and Fiber Dynamic Mechanical Analyzer?

Choose the film and fibre configuration when specimens are too thin or too compliant for bending and compression clamps. For bulk plastics and composites, a benchtop or high-force instrument is more appropriate. In an RFQ, state specimen dimensions, force resolution, temperature range and whether humidity or immersion is required.

How does it compare with other DMA variants?

Choose the clamping geometry before anything else, because it determines the specimen dimensions and the usable stiffness range: three-point bending suits stiff bars, single and dual cantilever suit medium-modulus plastics and composites, tension suits films and fibres, and compression or shear suit soft gels and foams. Then match the force range to the material: stiffer samples and composites need higher force and a rigid frame, while thin films and gels need very low force with high displacement resolution. Check the temperature range and the cooling system, since liquid nitrogen is needed for sub-ambient glass transitions. Frequency range, multi-frequency capability and the software for master curve generation matter for research, while a simple temperature sweep with specification limits is enough for quality control. For hydrogels, biological samples or humid environments, ensure the instrument can accept a submersion or humidity accessory.