The case of the troublesome tops
I had just gotten to the office and was about to get into my first cup of coffee when Sam got my ear with the phone.
“KC, I can’t get consistent torque on my caps. I need help now!” she told me.
The marvels of modern movement soon had me in her plant in front of her chuck capper.
“So what seems to be the problem, Sam?” I inquired.
“We have a setup fixture that lets us set the release torque with a gauge,” she replied. “In the past this has worked pretty well. Lately we seem to be getting a lot of variation in the cap removal torque. “We have checked everything and it is fine. Nothing is loose or out of adjustement that we can see. When we check a chuck release setting with the gauge, we find it spot on. What’s up with this, KC?”
“Let’s pull out a chuck and have a look inside,” I suggested. Once we got it apart I saw the problem.
“Fiddlesticks on wandering clutches”, I expostulated. “Feel this chuck.”
As she ran her finger over the contact surface of the chuck I saw the penny drop.
“Its slippery,” she said.
“Right. You have silicone buildup,” I pointed out.
“But how?” she wondered.
“Some molders use a silicone release to assist the molding process,” I replied. “You probably will never see it in the cap. Over time it will build up the chucks allowing slippage. Clean the chucks and your problems will disappear. At least this one will.”