Nanolayers Come to Tubing
Nanolayer technology, an active area of development in films, is also making its way to tubing extrusion. Guill Tool & Engineering, W. Warwick, R.I., recently introduced the patented NanoFlow die, which can create more than 1000 layers from a single extruder in thicknesses in the micron (1 millionth of a meter) to nanometer (1 billionth of a meter) range. The tool allows processors to save money by making more judicious use of expensive resins. Nanolayers are also said to produce tubing with increased impact and fracture toughness and/or tear strength. Brittle materials prone to cracking can be combined with soft ductile layers to limit crack propagation. What’s more, barrier properties can reportedly be better engineered by designing them as the thinnest possible layers, which will force materials to crystallize and thereby enhance their performance.
A poorly designed profile die—one that does not permit the part to be extruded with the same dimensions from run to run—coupled with a lack of understanding of the extrusion process, is a recipe for scrap generation.
A lot of things must be in place to achieve what I like to call efficient extrusion.
A troubleshooting timeline is essential to help you quickly identify problems and their causes. Here we'll describe such a timeline and how to use it to solve one common problem—melt fracture in tube and profile extrusion.