Storage & Shelf Life of Rubber Elastomers

27 Apr 2020 | Posted by Andrew Onions

Recommended Storage Conditions

Like all things Rubber Elastomers are vulnerable to deterioration over time, and the rate of deterioration can be significantly affected by the storage conditions. Storing material in inappropriate conditions will accelerate the degradation of the polymer and consequently its performance in any application will be less than adequate.

There are several factors which can affect the rate of deterioration, and below we define the ideal conditions. Divergence from some of these will have a more significant effect on deterioration than others and some are more difficult to maintain depending on where you are attempting to store your materials. For example, the optimum temperature will be difficult to maintain in a typical warehouse with no environmental controls – however most elastomers cope well with wider extremes if packaged properly.

• Temperature              store between 15-25°C (59-77°F) and away from direct heat sources

• Light                               avoid exposure to direct sunlight, artificial light or UV

• Humidity                      below <65% recommended

• Ozone                            avoid placing near electric motors or high voltage electrical equipment

• Chemical media        avoid exposure to any liquids or vapours

• Deformation               tension, bending and twisting should be avoided.

Shelf Life of Rubber Elastomers

The Shelf Life of Elastomers is specified in various international standards, below we summarize the table from ISO  2230:2002. This defines an initial storage period and an extended storage period.

The initial storage period assumes materials have been stored in ideal, or as close too, storage conditions. At this point materials or parts need to be visually inspected for evidence of deterioration, typical issues being hardening, softening, cracked surface, or distortion. If any of these issues are identified the material should be discarded as it will not perform as required in any application.

If the material is deemed visually satisfactory then further tests of mechanical characteristics should be undertaken to ensure these remain unchanged. Acceptance at this stage means that the material can continue to be stored for the extended storage period after which the material can be re-inspected in the same way prior to use in any application.

In order to facilitate accurate tracking of material shelf life all material should be supplied with a cure date. MacLellan’s provide this information on the product label, along with batch number and life group as well as on the delivery paperwork, and certificate of conformity.