Rotational molding consultant Paul Nugent called rotomolding the quintessential low-cost process, but he thinks that's both good and bad.
We lose the perception of quality, as an industry, Nugent said in an April 13 keynote speech during a rotomolding conference held by the Society of Plastics Engineers' Rotational Molding Division in Cleveland.
Nugent said low cost always will be the strongest attraction of rotomolding, as molds and machinery are all relatively inexpensive. But the industry pays for that with slower cycle times, he said.
I don't say there's anything wrong with focusing on low cost. All I say to you is, be careful about focusing on low cost to the exclusion of all else, he said.
Nugent, a consultant in Reading, Pa., spelled out what he called the good, the bad and the ugly of rotomolding.
The good: design freedom, flexible manufacturing, the ability to run multiple molds of different sizes on one arm, low-volume runs and no part size limits.
The bad: slow cycle times, a reliance on one main material polyethylene and a dependence on ambient air and changes in temperature and humidity.
And the ugly: rotomolders say they want new technology, but often they are unwilling to pay for it.
Molders also should improve employee involvement by offering training and improved working conditions, he said.
Nugent called improving controls an absolute necessity for the industry, pointing out that injection and blow molders already control their processes closely.
He said the most effective technology is IRT, or Infrared Thermometry Technology, which measures the temperature of the mold and sends that data back to the machine controller.
And technically, the industry is moving up. Part consolidation and making complex parts is really the next level of attraction for rotational molding. That's what's really bringing in a lot of high-end molders, Nugent said.
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