Tensile Tests
Film Burst Tests
Burst & Relaxation
Film Friction
Film Burst & Relaxtion
Film Conductivity
Film-Film Adhesion
Mutiple Film Burst Rig
It's hard to believe in today's day & age that film testing has changed so little while the functional expectations that films are expected to perform have changed so dramatically. ASTM Method D882 remains the most common method of testing the tensile properties of films according to published papers in major journals and annual meetings.
The TA.XTPlus can be used to conduct standard ASTM D882 testing, and the analysis of the generated plots can be automated to report exactly the attributes called out by the standard. While the D882 standard calls for seperating at a fixed rate of speed the TA.XTPlus is capable of performing constant strain rate tensile (or compression) tests. Constant strain rate tests highlight other elastic properties of films.
Of perhaps greater importance are all of the other tests we can conduct on films.
Many films are used under a constant stress, load or pressure. While films are traditionally measured for their firmness and possibly their stiffness (modulus) any lab just using ASTM D882 would have no idea of how their films retain energy and otherwise behave under stress. Relaxation and creep tests are very useful to understand the nature and durability of the crosslinking as films are produced.
Films are notoriously difficult to manufacture consistently on either a lab bench or in production environment. If just a single aspect of the manufacturing process is different the distribution of solids or the cure patterns can be different - and the results are all over the place. ASTM D882 tests generate extremely variable results - almost as much due to operator mounting and sample presentation differences than furmulation differences. With the TA.XTPlus film testing techniques do not have the same variability - and thus those brittle behaviors are more easily discerned and attributed to formulations rahter than operators. The TA.XTPlus captures data very quickly and plots it at up to 500 points per second - as a result those brittle behaviors are capable of being fully captured and analysed.
TTC's TA-108s Film Rig is used to measure film's behavior before and after being stretched beyond its point of plastic deformation or burst point. The same rig allows you to quantify the returned energy and the film's complete recovery behavior. The rig is available in for mounting single samples, 5 samples or 60 samples.
Adhesion and tack characteristics are critical for most film applications. These parameters are measured using a half dozen metrics which differentiate even the most subtle film formulations. The results lead to a film adhesion vs film cohesion analysis, a critical element for proper film formulation.
Films can be mounted very creatively in both compression and tension to then be repeatedly stressed to measure their fatigue characteristics.
Some of the most interesting insights our clients gain about thier films are about how the films swell and disintegrate over time while being exposed to or submerged in moisture. The TA.XTPlus can very precisely measure how films and film coated materials swell - withstand swelling - disintegrate - or withstand disintegrating.
By using the Resistance Conversion Unit in conjunction with the TA.XTPlus Texture Analyser's multi-channel data acquisition capability enables the characterisation of electro-mechanical products by measuring and analysing the force-distance and resistance-distance characteristics simultaneously.
Film to film adhesion can be measured using a block method, even if the films have very little residual tack. The method tacks advantage of the TA.XTPlus' 1 micron distance resolution and is precise PID controls to maintain a controlled bonding profile before debonding and measuring the tack between two films.
It is possible to debond film coatings from pharmaceutical tablets by using either SMS' Tablet Adhesion Rig or the Fassihi Method .
