A Cultured Discussion on Cast Polymer Issues
Many educational sessions concern the composites industry as a whole, and others focus on serving specific industries. A Wednesday afternoon session called Ask the Cast Polymer and Solid Surface Efforts gathered a panel of experts to address issues related to manufacturing problems and industry trends.
The session began with a spirited discussion of environmental trends. Though the awareness is only now increasing, Ken Lipovsky, cast polymer application specialist for Reichhold, noted the industry has used a similar mindset in past production. “For years, we’ve used recycled cola bottles and x-ray films for our resins, and they’ve been used in a variety of applications,” he said.
The panel discussed the differences in implementing the greener resins into manufacturing. “Larger molecules are used in the green resins, so they’re more resilient,” said Lipovsky. Tom Pelt, director of technical projects for Bradley Corporation, said color concerns must be addressed. “If you’re not careful, exotherming can cause stress cracking, and that can affect the color consistency,” he said.
When asked how the “green” nature of a product is determined, HK Research Corporation’s President Richard Higgins said there must be a component that’s a renewable resource. “Things such as soybean oil and fatty acids would be in there. The key is renewal sources,” he said. Additionally, it was clarified that a green resin isn’t LEED requirement; that’s determined by the end product itself.
More general manufacturing-related issues were also brought up. The panel discussed scrap elimination and why it occurs. Factors included excessive use of outdated or improper resins. “Most resins have a 90-day shelf life, and it’s possible that the drum of resin may have neared that lifespan when you receive it,” said Lipovsky. Pelt added that there may be problems with an equipment operator. “It may be painstaking to document those procedures, but it’s worth it to fix the problem. Plus, it becomes a training tool for new employees,” he said.
Finally, the discussion turned to mold issues related to curing. Jack Simmons, vice president of sales with ACS International, said that improper usage of resin (whether incorporating too much or letting it migrate too long) was a primary cause of curing problems. Higgins added that the combination of heavy gel coats and slow resins (leading to a short period when the gel is stronger than the matrix) was also a factor.
COMPOSITES 2010: Discover the Future of Composites Today. February 9-11. Mandalay Bay, Las Vegas.www.acmashow.org
