General Information About Ion Exchange Resins and Shelf Life

Many conditions can affect the efficacy of ion exchange resins. This page reviews basic characteristics of resin and presents tips for maintaining resin quality during transportation and storage. Basic preconditioning and sterilization recommendations are also noted.

General Information About Resins

• All ion exchange resins should undergo pretreatment prior to service – particularly resins used in food processing and potable water treatment.
• Ion exchange resins are supplied in specific ionic forms, and can be converted to a different ionic form through regeneration or in-service duty.
• Depending on the conversion, resins can swell, remain unchanged, or shrink in volume. Some resins, such as acrylic strong base resins, also undergo irreversible swelling in the first few operating cycles. Sevice units must be designed to accommodate any changes that may occur.
• Although most resins are supplied as fully swollen moist beads, some special resins are supplied in a dry or semi-dry condition and may expand considerably when rehydrated. To accomodate the increase in volume during rehydration, adequate space should be allowed in the vessel.
• Regardless of form, Purolite ion exchange resins can be stored succesfully for extended periods of time without significant deterioration as long as resin-specific transportation and storage guidelines are followed.

Shelf Life

Many factors affect the shelf life of ion exchange resins, including storage conditions, preconditioning, and intended application. To maximize shelf life, it is essential to protect the resin from extreme temperatures and direct sunlight. Covered vehicles and containers should be used for transport, and the resin should be stored in a temperature controlled, indoor warehouse. Table 1 provides a guide to the expected shelf life for Purolite resin families, in months for common ion exchange resins and applications.

The guidelines presented in Table 1 assume that products are transported, stored and introduced in the prescribed manner. Purolite products may be successfully introduced into service in many applications even after extended periods of storage. However, if users are unsure about the exact transport and or storage conditions or when over 50% of the expected shelf life has been reached, extra precautions should be taken when first using the resin – particularly for critical or regulated applications. In these instances, we recommend additional pre-treatment before placing the resin in service.