That may sound OK to Earthy-crunchy do-gooders, but not me, thanks to the unusual education, or trauma, of my childhood.

Back to the caps in a bit, but long before recycling became a household chore, my father was in the plastics business. A necessary skill was being able to identify different types of plastics. Polyethylene is incompatible with polypropylene and with polystyrene. If you try to mold an object out of more than one polymer, it’ll fall apart.

Atlee Washington’s technique was to smell the plastic’s distinctive odor when ignited, which became something of a hobby. “Polypropylene!” he’d say gleefully after setting fire to one of my toy soldiers. It looked like it stepped out of a Dali painting.

Later in life, he concentrated on decontaminating plastic molding pellets accidentally mixed together at factories. The science was specific gravity: Put two different types of plastic into a vat of water and add salt; one plastic will sink, the other will float. But he never perfected an efficient way of drying the separated plastics before he passed away.

My brother, Glen, is a chemical engineer and he gave the company a go. I helped by suggesting we try a clothes dryer.

“That might work,” he said — though like the Manhattan Project physicists who weren’t entirely certain a sustained nuclear reaction wouldn’t ignite the atmosphere, we couldn’t guarantee it wouldn’t blow up.

I volunteered to test it. Living in a large Chicago apartment complex, I poured about 20 pounds of wet plastic pellets into a pillowcase and threw it in a laundry room dryer in the middle of the night. I returned an hour later. A nice lady smiled at me. Since she was alive, that meant it hadn’t exploded. I opened the dryer and found the plastic had dried perfectly.

That convinced Glen, and he set about buying all the used dryers in town. We bought a rail carload of highly expensive Delrin plastic contaminated with polyethylene and separated it for a very good profit. But we soon found industrial contamination on that scale was a fluke and, being the mid-1980s, household recycling hadn’t yet taken hold. Glen went on to pharmaceutical validation and I stayed with journalism.

So why are recyclers asking you to throw away the more valuable material and reclaiming the cheap stuff?

Several reasons, says Duluth’s Greg Hartel. “It becomes difficult to bale a plastic bottle when the top is on,” he said, relating horror stories of caps turning into projectiles when the bottles are crushed.

In that case, duck. The real issue, though, is economics.

“It’s not necessarily that something can’t be processed, but whether a particular process makes it economically feasible to do it,” Hartel said, adding the no-cap policy of his family’s business may change with an impending expansion. “I don’t think we’ve made up our minds which direction we want to go in regards to caps.”

At two bucks a pound, I’ll help — except I might have competition. Mike Lunow from Waste Management in the Twin Cities said the company’s Duluth operation does accept caps.

“The mills we deal with aren’t fond of them,” he said, though they’ve solved the problem.

“What they’ll do is water float them.”

Hey! That was our idea.

Hmm … think I can interest them in used clothes dryers?