Direct recycling of thermosets? Perception is reality

In his presentation at an SPE Retec earlier this year, Randy Lewis of P.R. Lewis Consulting (Bayamón, PR) quoted a line from George Orwell?s novel 1984. He used the quote ?perception is reality? to describe the reason why a guy he knew was trying to get thermoset resins out of his plant. Lewis said this fellow told him, ?ISO 14000 says your company is following rules, and our ISO 14000 rules only call for us using materials that can be recycled.?

As previously reported, Lewis? impassioned Retec address dealt with how the commonly held perception that thermoset resins cannot be recycled is based more on fiction than on fact (see ?Thermosets 2000,? June 2000 IMM, pp. 124-127). During his talk, Lewis hinted at a recyclable epoxy materials development program under way at Cuyahoga Plastics (Cleveland, OH) that could forever change the prevailing perception.

Cuyahoga Plastics has developed a new epoxy combining the shelf life, easy moldability, and recyclability of even commodity thermoplastics with the performance properties of a thermoset composite.

It is available in granular form, BMC, or single-part liquid. And it can be modified with a wide range of fillers to fit almost any application. Current versions range from one with a Tg of 204C and conductive grades, to a glass-filled version with a 10-ft-lb notched Izod impact. One grade passed a test where a part was alternately dipped in liquid solder and then in liquid nitrogen for five 15-second intervals without cracking.

Molding machine manufacturer and cellular automation specialist C.A. Lawton Co. (Green Bay, WI) has already begun to develop an injection unit for its latest series of vertical molding machines. It is being designed to exploit the processing ease of Cuyahoga?s epoxy (see September 2000 IMM NPE Showcase, p. 30 for details on Lawton?s newest press).

In With the New

For a number of years, old-type epoxies have been the material of choice for many high-performance products in a wide variety of industries, including E/E, integrated circuit, coil and sensor encapsulation, military applications, composites, and aerospace components. Epoxies were chosen because of their ability to seal around inserts, their dimensional stability, and their high continuous-use temperatures.

Excellent chemical resistance and superior bondability to fillers and inserts are other reasons why epoxies make the grade. But these high-tech composites require special shipping and storage because of their short shelf lives. They also can be difficult to mold, and are not easily recycled.

Containing as much as 33 percent regrind, Cuyahoga?s new epoxy has been successfully molded into an under-the-hood sensor. Butch Cormier, a senior manufacturing engineer for a major automotive supplier, tells us the material delivered identical performance properties to the old-fashioned epoxy.

But Cormier appreciates the fact that the newer material?s long shelf life allows it to be shipped without using dry ice and stored without having to use a freezer. ?Recycling is the icing on the cake and makes it a clear choice for this application,? Cormier concludes.?Carl Kirkland

Cuyahoga Plastics
Cleveland, OH
Phone: (800) 805-9549
Fax: (216) 261-3537
www.cuyahogaplastics.com
[email protected]