The proper storage of thermoset materials is key to maintaining optimum processability. Thermoset materials have a theoretical shelf life as determined by standardized laboratory measurements. Shelf life is affected by ambient temperature and is also dependent on the parameters and latitude of the molding process, along with tool and part design. As a result, actual shelf life may vary, perhaps significantly, from the theoretical shelf life for the material. Change in flow characteristics during the storage of material does not occur suddenly, but gradually over a period of time.

Plenco thermoset materials should always be stored in a clean, dry environment to minimize an increased or decreased moisture content. Store in the unopened original containers until ready for use. Opened containers should be re-sealed to prevent the gain or loss of moisture or other volatiles, which will adversely affect processing. Opened paper bags should be placed inside a re-sealable plastic liner.

When Plenco thermoset material is stored below 18° C (65° F), it should be allowed to warm to 18° C (65° F) to avoid molding or preforming problems. Cold material might take several days for the entire package to reach 18° C (65° F). Preforms of Plenco material should be stored in a sealed container with a re-sealable plastic liner, to prevent the preforms from gaining or losing moisture.

The theoretical shelf life of Plenco stored in a relatively dry area has been determined to be:

Material Shelf Life Storage Temperature
Single Stage Phenolic
6 months*
Less than 30° C (86° F)
Two Stage Phenolic
2 years or more
Less than 30° C (86° F)
9 months*
Less than 30° C (86° F)
Granular Polyester
2 years
Less than 30° C (86° F)
Black BMC
1 month
Less than 21° C (70° F)
Colored BMC
2 months
Less than 21° C (70° F)

* The theoretical shelf life of Single Stage Phenolic and Melamine-Phenolic molding materials may be increased by storing at less than 18° C (65° F). This information is suggested as a guide to those interested in processing Plenco Thermoset molding materials. The information presented is for your evaluation and may or may not be compatible for all mold designs, press configurations, and material rheology. Please feel free to call Plenco with any questions about Plenco molding materials or processing and a Technical Service Representative will assist you.


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