The Means To The Ends

Thermoplastic clamp with overmolded tips delivers better safety

Download PDF

Anywhere there are utility line workers repairing high voltage power lines, you’re likely to see insulated safety blankets. And anywhere you see insulated safety blankets, you’ll see plastic clamps—or “diaper pins” in the informal industry vernacular— holding them in place.

Despite the silly nickname, there’s nothing silly about the functionality of these relatively simple and ubiquitous parts. The blankets that they are meant to tightly secure are often the only thing separating a lineworker from thousands of volts of potentially deadly electricity.

But Jim Rauckman, an industry veteran, saw a serious issue in the product’s status quo. The hard plastic clamps called for little rubber “booties” to be slipped on at the ends where they gripped the blanket. However, these booties were notorious for falling off or splitting due to UV exposure, potentially reducing the effectiveness of the clamp. Rauckman Utility Products, Inc. had already developed dozens of innovative products for the utility industry. He was confident that his team could provide a better alternative.

According to Rauckman, every one of the injection molded thermoplastic products in
the company’s large and growing product line uses an RTP Company material. So he knew exactly who to call for help in getting his concept into development.

“What do we like about RTP Company? It’s simple—we explain the product idea and the
characteristics we’re looking for and they take it and run with it, and come back with the custom compounded samples that deliver just what we’re looking for,” he said. “They’re great partners.”

In fact, he notes, over the years RTP Company has helped actualize some of Rauckman’s most innovative products. For example, one of the company’s signature wildlife protection products, the ZAPshield®, picks up an electrical charge from the pole and gives squirrels and other small animals a tiny shock to train them to stay away from the dangerous power lines. It’s so innovative that it’s patented, including the product’s ability to pick up and apply the electrical charge. The charge is delivered thanks to the RTP Company custom compounded conductive thermoplastic material specified in the design.

“I find that there’s no shortage of suppliers who claim that they can make you whatever you want, but then when you see their quote it becomes clear that they don’t really want to do it, and they’ll just try to steer you back to something they have on the shelf,” noted Rauckman. “Not RTP Company—they are true custom compounders.”

In his vision for the new clamp, Rauckman sought a number of high performance properties. He wanted to ensure that the rubbery portion of the clamp would provide superior grip and could never fall off like the current booties did. In addition, he wanted the rubbery ends to match the durometer of the blankets used in the industry so they would not cause indentation and wear, delivering even greater value to lineworkers. And, for the hard plastic portion, he wanted to provide longer-lasting performance than incumbent clamps, which were subject to degradation and failure due to cold weather.

True to form, RTP Company took all of these criteria and compounded a long fiber Nylon and a soft Thermoplastic Elastomer optimized for an overmolding process that would help create a complete one-piece blanket clamp that is revolutionary in the industry.

Overmolding combines disparate materials right in the molding process, forming a strong chemical bond and eliminating the need for adhesives or fasteners in all types of components. Also key was the specifying of long fiber, which can provide greater durability than chopped fiber Nylon.

“In addition to optimizing the material, RTP Company also worked with our molder to get the flow patterns just right,” explained Rauckman. “With this type of value-added help and high quality products, it’s no wonder that RTP Company has been our go-to thermoplastics supplier for more than 15 years.”