As a group, natural adhesives represent the oldest adhesives known to man. Throughout history, natural sources have dominated the adhesive formulators' stockpile of raw materials. In fact, it has only been since just before World War II that synthetic adhesives have found widespread use. Today, the consumption of naturally occuring adhesive raw materials has decreased to about 30 percent of total non-volatile adhesive consumption; however, real volume has actually been increasing in recent years.
The major reasons for the relative decline in the use of natural adhesives have been the greater use of synthetic adhesives in structural as well as non-structural applications and the greater uniformity and control that can be exerted over the synthetic products. However, adhesives based on natural products are generally:
* lower in cost than their synthetic counterparts,
* viewed as environmentally friendly since many are based on renewable products, and
* finding renewed interest and research funding for development in applications such as medical adhesives and in formulations with synthetic products.