Materials that adhere living tissues together are being used more frequently in surgical procedures as adjuncts to sutures or as replacements. ASTM F2458 – 05 is a standard test method for determining the comparative wound closure strength of tissue adhesives. With the appropriate substrate, F2458 can also be used in quality control testing of tissue adhesives. This test method can be used to compare adhesives for chance of fatigue, type of failure, and environmental changes.
A testing machine capable of a constant rate of crosshead movement is required .
The tensile grips used for holding the test specimen can be either fixed or self-aligning.
Gripping pressure should be ajustable to prevent damage to the substrate.
To help prevent specimen slippage in the grips, sandpaper or plastic scrubbing pads should be placed between the substrate and the grip faces.
For comparative testing fresh or frozen porcine skin graft may be used.
For application specific testing the tensile grips must prevent substrate slippage or being crushed by the grips. See Sections 6-8 and Appendix X1 for more information of substrate materials; their storage and preparation prior to test.
Two substrate samples are required for each test specimen. An adhesive butt joint is formed by applying the adhesive to a small region across the seam between the two substrates. Figure 1 is a depiction of the test sample geometry.
Figure 1 – Depiction of test specimen.
Condition the test specimens as specified in Section 9.1. After conditioning, the temperature of the samples should be stabilized for at least 15 minutes. Phosphate buffered saline (PBS) must be used to keep the samples moist throught sample preparation and testing.
Place the specimen in the grips so that the distance from the adhesive butt seam to each grip face is 5 cm. Load the specimen to failure at a constant crosshead speed.
Record the adhesive cure time, maximum force and type of failure.
Each system is offered with manual or pneumatic vise grips.
Use MTESTQuattro, ADMET’s PC Based materials testing system to ensure error free repeatable testing. You will be able to quickly setup and store F2458 test procedures, run tests and generate reports.
This test may require an environmental chamber with heating and cooling or a bath depending on the type of substrate tested. ADMET offers many different grips, fixtures, accessories, heating and cooling units, and baths to choose from.