Understanding the Basics of Moisture Protection: True or False Tests Your Desiccant Knowledge

July 1, 2000

4 Min Read
Understanding the Basics of Moisture Protection: <I>True or False</I> Tests Your Desiccant Knowledge


Understanding the Basics of Moisture Protection: True or False Tests Your Desiccant Knowledge
by Robert Crossno

Moisture presents a serious threat to product integrity in a variety of industries, including the nutraceuticals industry. Sensitive products can begin to deteriorate at a mere 30-percent relative humidity (RH). Many products require a constant RH of 10 percent to 15 percent or less for stability and an extended shelf life.

Desiccants eliminate moisture contamination, but the many choices available may cause confusion. Take a moment to answer this true or false quiz. It may help you minimize product degradation and maximize your profits.

1. Moisture damage can always be visually detected in products.

FALSE. While moisture damage can sometimes be detected visually in the form of rust on metal parts, mildew on cardboard or paper, or mold on food or fabric, there are many products that do not show the effects of moisture damage until they are in the customer's hands. Medical diagnostic kits tainted by moisture look fine, but can give inaccurate results. Many products will show no signs of moisture damage--they simply will not work.

2. Desiccants protect products by absorbing moisture.

FALSE. Desiccants do not"ab"sorb moisture, they "ad"sorb. Absorption occurs when one substance is chemically integrated into another. Adsorption means that moisture is held inside a desiccant by physical bonds; no chemical change actually occurs. Besides protecting products from external elements, a certain amount of moisture inherent in all hygroscopic (moisture absorbing) items can also be trapped within sealed packaging. Desiccants adsorb this moisture quickly andthoroughly, preventing condensation during transport and storage.

3. All desiccants are synthetic.

FALSE. Montmorillonite clay, silica gel, and molecular sieve are the three most commonly used desiccants, but montmorillonite clay stands out as a naturally occurring substance. The least expensive of the desiccant materials, this activated clay's layered structure attracts and adsorbs moisture onto its surface and between its layers. Silica gel is a form of silica manufactured from sodium silicate and sulfuric acid, and is processed into either granular or beaded form. Its active interconnected pores form a vast surface area that attracts and holds water through adsorption and capillary condensation.

Molecular sieve is derived from sodium potassium, or calcium alumina silicate, and contains a uniform network of crystalline pores and empty adsorption cavities. As a synthetic desiccant, the pore size on the molecular sieve particles can be controlled in the manufacturing process, allowing for a large range of adsorptive capabilities.

4. Choosing a desiccant involves consideration of the package's ambient environment.

TRUE. In weighing the various choices of desiccants, it is important to consider the ambient environment within the package in relation to the desiccant's individual capabilities. Key parameters are initial humidity, amount of moisture in the packaged product, volume of both product and container, Moisture Vapor Transmission Rate(MVTR), length of storage time, activity curve of the desiccant, and the maximum level of relative humidity permitted within the enclosed package. Humiditylevels and temperature can fluctuate drastically during shipping and, of course, different materials' responses to these variables will varygreatly. Consequently, packagers should consider all variables when formulating comprehensive moisture protection programs.

5. The type of product you are protecting does not affect yourchoice of desiccant.

FALSE. The type of product is a very important factor when choosing the most effective desiccant. Many products simply require consistent, long-term protection against humidity. Activated clay or silica gel provide sufficient protection in these cases. Sensitive chemicals or diagnostic kits with an extremely low tolerance to moisture are often protected with molecular sieve, which is capable of rapidly reducing ambient humidity to zero percent.

6. Desiccants can be used with any type of packaging.

FALSE. Desiccants do have finite adsorption capacities, and therefore must be used inside sealed, airtight packaging. Common packaging materials that provide this necessary moisture barrier are foil, film, plastic and metal containers.

7. Desiccants can be incorporated directly into certain containers.

TRUE. Moisture protection can be incorporated directly into plastic containers through injection molding. The desiccant is injected into a polymer "shell," providing moisture protection without interfering with package aesthetics or shape.

8. Special protective packaging is available for effervescent tablets.

TRUE. Effervescent tablets have long been a mainstay in Europe and they are increasing in popularity in the United States. They have traditionally been packaged in expensive heat-sealed foil pouches, however, inventive new packaging that incorporates desiccants into customized tubes is now available. This new packaging combines a durable, rigid tube-shaped container with desiccants built into the cap. No loose desiccant tablets need to be inserted, streamlining packaging workflow and eliminating customer confusion and accidental ingestion. The cap also has a soft spring that protects delicate tablets from breakage during shipping and handling. Tubes can be customized with full-color printing to enhance brand identity and strengthen point-of-purchase appeal.

9. Desiccants will affect more than the bottom line.

TRUE. Using desiccants will reduce the number of product returns and increase shelf life, but the intangible benefits of using desiccants are even more important. Desiccant protection allows companies to consistently deliver products of uncompromising quality and integrity. With the tremendous costs associated with research and development, manufacturing, packaging and distribution, it makes sense for companies to protect these investments by using a quality desiccant appropriately. The returns--increased product quality and customer satisfaction--will make it well worth the time and effort.

Robert Crossno is the Regional Sales Manager with Sud-Chemie Performance Packaging; (800) 989-3374; FAX (505) 864-9296,www.s-cpp.com.

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