Understanding the Unique Challenges of High Precision Converting
September 19, 2024
Die cutting soft, flexible cellular materials can present distinct challenges when it comes to holding tight dimensional tolerances. Often, design engineers are accustomed to working with metal or rigid plastics, and as a result, they may specify tight tolerances that cellular foams and silicones cannot routinely hold, such as +/-.005”.
When a blade, even a sharp one, presses down on soft material, it will compress the material, effectively making it thinner. As the material compresses, it will initially resist the blade, then restructure itself to move material away from the cutting blade, a principle known as deflection. Compression and deflection are what make it difficult to predict how the material will conform to precise dimensions once it returns to a normal state after being cut.
The Rubber Manufacturers Association publishes tolerance tables based on material type, thickness, width, length, and other variables. Even so, these tables cannot account for the constantly-evolving compositions of today’s elastomeric foams. Nor can they account for variables such as environment, cutting blades and beds, laminations and a number of other features that can affect tolerance.
Insul-Fab has over 50 years of experience in cutting and dimensionally inspecting elastomeric foams made from neoprene, vinyl nitriles, EVAs, urethanes, silicones, and a wide range of cellular materials. Our engineers have compiled data which reveals the true dimensional tolerances of the most common elastomerics in use today. What’s more, we have invested in high-precision cutting technologies apart from standard steel rule die cutting, such as rotary cutting, CNC water jet cutting, laser cutting, oscillating knife and several other methods. Even though there are ways to enhace the precision of a cut, each of these methods comes with its own advantages and disadvantages, and each method must be assessed based upon the part being made.
InsulFab’s twenty-year affiliation with the Gasket Fabricators Association (GFA), a trade organization dedicated to the precision fabricating and die-cutting industry, has also helped it to stay on top of the most recent innovations in high precision die cutting.