Getting threaded inserts into a plastic part, or any other material, is a challenge — whether they are molded in or mechanically inserted. It's no wonder the automotive industry, among others, is increasing the use of adhesives instead of hard fasteners.
Even so, there are plenty of plastics parts that require threaded fasteners. And credit a molder with coming up with a better way, at a low cost, to check for missing and improperly installed threaded inserts.
This month, Best Practices takes you to Machesney Park, Ill., near Rockford, the home of Littlestar Plastics Inc. and its invention, IndiCert. The company does fabrication and machining, and injection molds plastics on eight injection presses with clamping forces ranging from 40 to 200 tons.
The company supplies some demanding industries such as automotive, medical, food service and fuel cells. But its major business comes in the precision aerospace field. Initially the company developed IndiCert for its aerospace customers. But now Littlestar Plastics is selling the product on the open market, through a newly created website, www.indicert.com.
IndiCert is a simple plastic device you twist by hand into the threaded insert opening. No tools are required. Littlestar offers 25 sizes to fit any threaded inserts.
IndiCert will not seat, so it falls out if an insert is not present. For helical inserts, known by the trade name Heli-Coil, the IndiCert cannot be installed if the driving tang is still present. (The tang is used during installation of helical inserts, and is supposed to be discarded after installation.)
It's a simple, affordable solution. Littlestar President Phil Preston said there has not been a way to quickly identify whether all the threaded inserts have been installed, and installed correctly. Even a single missing insert can cause big problems during assembly and disrupt the supply chain.
“A lot of the companies we work with are on very tight schedules and if they miss testing dates it can cost them millions,” Preston said.
The brightly colored testing product makes it easy to see problems at a glance.
“You know you have an issue if you have a hole where an IndiCert should be,” Preston said.
Preston said Littlestar Plastics developed the IndiCert to help improve its own production. He founded the company in 1991, and today the company has about 50 employees.
“We're really a solutions company,” he said. “Companies come to us because our engineers know how the manufacturing process works. We can get into a design, break down the process, and find a way to make it better.”
Now IndiCert can help any company using threaded inserts make it better as well.