Edited by Lara Copeland, contributing editor
SIMPLESTAKE, a subsidiary of ToolTex, located in Grove City, Ohio, developed a new technology to solve issues common with staking methods. “Traditional heat staking is a messy business altogether,” Josh Clark, national sales manager, said. SIMPLESTAKE utilizes impulse staking technology to provide a new level of system control and heating on demand.
“Without a certain level of control for the individual stakes, manufacturers are at the mercy of the system as a whole,” Clark continued. “A very laborious and difficult set-up process is required to obtain and then maintain a consistent weld for plastics parts.” SIMPLESTAKE, with its independent control system, allows manufacturers a simple way to dial in a weld and produce a consistent part.
SIMPLESTAKE technology eliminates one of the biggest challenges in plastic staking – the “stringing” effect. “This happens when a consistent temperature on the heating probe cannot be maintained, and the plastic boss is pulled away from the part before it has been properly cooled, resulting in the plastic stringing away from the parts,” Clark said. Stringing makes the part unusable while also creating time-consuming changes to the system that are needed to rectify the issues. SIMPLESTAKE eradicates this exceptionally difficult maintenance process, which could cost a manufacturer significantly due to machine downtime.
SIMPLESTAKE also can weld both painted and metallized parts without elaborate masking needed. “Masking is the process by which certain plastic bosses are covered to ensure that they maintain weldability,” Clark elaborated. “This process is very time consuming and extremely costly.” SIMPLESTAKE, because it utilizes thermal dynamics with precise temperature control, eliminates the need for the masking process altogether on both painted and metallized parts. Another benefit of using SIMPLESTAKE is no requirement for elongated cycle times for clear plastic parts.
Beyond the aforementioned advantages, SIMPLESTAKE, by the nature of its design, can achieve consistent welds in parts with tight spacing. According to Clark, “Production level parts are being manufactured currently with a plastic boss present within 1 mm of a part wall.” This is especially prevalent in medical, lighting and appliance manufacturing applications. SIMPLESTAKE also requires very little down force, typically under 2 kg, because it is a top-down weld. This means the boss itself is seeing most of the output energy and making a very strong mechanical bond once it is fully formed. The cooling system, by design, is forming the boss under pressure, so a manufacturer gets a very tightly formed weld each time. At the final stage of the process, SIMPLESTAKE’s trademarked clean release technology is what provides an aesthetically pleasing formed boss.
“We couldn’t be more pleased with the response we are receiving,” Clark said. “Some of our customers, who are powerhouse players in the world of automotive manufacturing, are telling us that this will be a market disruptor.” He said the company has done well at R&D/technology centers, which are designing plastic bosses specifically around the SIMPLESTAKE product. “At the production level, some of the most time consuming and costly aspects of heat staking have been eliminated. By doing so, the mechanical and process engineers at the plant level have been made very happy.”
SIMPLESTAKE set out eight years ago to design and create an original product to help its manufacturing partners achieve better and more consistent welds on their plastic bosses. Clark emphasized, “Through years of constant improvements, innovations and technological advances, we have made a product we are very proud to manufacture right here in the US.”
The SIMPLESTAKE welding process is a form of highly controlled resistance heating. The tip is specially designed to heat only where it interfaces with the plastic, which allows for low power and heat on demand staking. In a typical cycle, the tip is brought into contact with the boss using a spring-loaded apparatus. This apparatus allows the tip to make low force contact with the part. The tip will go from ambient to around 400˚F in two seconds.