RedRubber/PTFE as a new synthetic rubber quality for septa



For standard analysis’ in GC and HPLC Natural Rubber is often used as a septa material, as it is a cost-effective product suitable for a huge number of non-critical routine applications. It has some disadvantages with regard to analytical purity and is also a relatively hard liner material that is not always easy to penetrate.

Therefore La-Pha-Pack® offers now a PTFE-laminated synthetic Rubber called ”RedRubber/PTFE“, which is much softer than natural rubber and also shows a lower fragmentation. As a synthetic rubber RedRubber, however, has a different molecular structure than natural rubber und thus is not characterized with the outstanding resealability properties that make natural rubber the first choice in cases of multiple injections. On the other hand synthetic rubber is purer than natural rubber, although it does not achieve a comparable analytical purity to that of silicone/PTFE septa. Cost wise both types of rubber are at the same level and thus an economically excellent septa material for routine analyses. Temperature resistance of both materials is also comparable and ranges between -40°C and 110° compare to 120°C for natural rubber. The new septa material can be obtained as 8mm screw seals, 9mm short thread closures, 8mm or 11mm crimp closures or as 11mm snap ring seals. Replacement septa are also offered for some of these closures.

Here again the most important advantages summarized:

  • Standard quality for HPLC and GC
  • Synthetic rubber is much cleaner and softer than natural rubber
  • Low fragmentation
  • Cost-saving septa material