HOT & HEAVY.

* Plastics have succeeded for decades by doing things metals can't match. Now they are doing what metals can do but plastics aren't supposed to. Senior Editor Lilli Sherman explores on p. 52 the new realm of plastic compounds that conduct heat almost as well as metals. They come in handy to draw heat away from sensitive components of laptops and lighting fixtures.

Did you hear about the U.S. Army's new plastic bullets? Executive Editor Bob Leaversuch explains on p. 58 why normally lightweight plastics are now prized for being as heavy as lead.

Next month, we'll look at yet another area where plastics behave like metals--molded magnets. And in the near future, we will report on plastics that conduct electricity and dissipate static charges.

All of these cases show how plastics are extending their domain without the benefit of new polymer chemistry. Rather, these advances come from exploiting new additive and compounding technologies. Another example, which we'll explore next month, involves using a pinch of one polymer to modify another.

In all, you might say we are enjoying a golden age of compounding. New entrepreneurs in specialty compounds are opening up shop on every street corner. Overseas compounders are launching new branches on U.S. soil. And when resin companies come out with a new polymer, they enlist independent compounders to find out what those new materials can do when paired with fillers and other additives.

Now even molders and extruders want to get into the act. Some of the more adventurous ones have gotten the urge to compound in line with production of a finished part.