Nicholas Yeager, Artifex Equipment, Inc., (707) 664-1672
info@artifexequipment.com
Update on Dri-Gel Sheet Desiccant
August 17, 2005 - Artifex Equipment, Inc., is moving towards production of its breakthrough desiccant product, called Dri-Gel, interest in its application as a disaster recovery option has continued to grow in the preservation and disaster recovery fields.
The problem of drying wet books in a safe, cost-effective and expedient fashion has plagued libraries for as long as books have been collected. Although the field of book conservation has begun to embrace new technologies, innovations have been slow to materialize. Vacuum freeze-drying constitutes the most effective development to date. This process requires that books be transported off site and takes up to six months to complete.
In the Spring of 2003, Nicholas Yeager, CEO of Artifex Equipment, Inc. investigated using a starch-based super absorbent polymer to dry water damaged (damp and wet) library materials. This polymer had been invented by the USDA's Agricultural Research Service in the 1970s and has been used in agricultural as well as industrial applications. Yeager and Kathleen Hayes, an information specialist at USDA's National Agricultural Library, secured a Material Transfer Agreement Cooperative Research and Development Agreement (MTACRADA) to develop an interleaving product to dry books using the polymer's capacity to soak up many times its weight in water. The resulting product invented by Yeager and Hayes has been named "Dri-Gel" and has patent-pending protection.
The new hydrogel desiccant makes use of the chemical polyacrylate's ability to:
- absorb fifty times its weight in water
- release water through evaporation, and
- take on water and retain it under pressure - a key element to water removal in books
In addition to drying wet materials, Dri-Gel will have other conservation uses. It can be used as a poultice or humidity blanket for relaxing brittle items because it has the ability to take on clean water that evaporates slowly and evenly.
Dri-Gel was developed with the aid of the SBIR grant. The objectives for this grant proposal required that the desiccant remain safely within its enclosure, and that the product has good wet strength and does not alter the book in any way.
Some surprising things were discovered while working out the method of carrying the material safely into a book to dry it:
- Desiccant capacity is directly affected by proximity. The closer the desiccant is in contact to wet material, the quicker moisture is absorbed. The chart below describes this corollary:
| Interleaving Dri-Gel per number of leaves |
Time required for drying |
|---|---|
| 15 leaves (30 pages) | 12 hours/ six changes |
| 10 leaves (20 pages) | 5 hours/ four changes |
| 5 leaves (10 pages) | 1.5 hours/three changes |
| Every page | 10 minutes with 1.5 hours labor inserting Dri-Gel sheets between leaves of the book with no change of Dri-Gel |
- Passive moisture absorption occurs in freezers where Dri-Gel is present. Wet books awaiting treatment are placed in a container and frozen to avoid mold growth. Placing Dri-Gel in the container (often a zip-lock bag) removes 50% of the water while the item is stored for two weeks. This lowers labor cost and drying time when the book is finally processed
- Early tests show that Dri-Gel can be used on other porous materials that require drying such as loose paper items and works of art on paper.
Artifex is currently fine tuning the manufacturing process of Dri-Gel for optimal use of the desiccant and cost-effective production methods. Dri-Gel uses environmentally friendly materials, and is 70% biodegradable. Yeager hopes to offer the product for sale by the end of the year.