EXTRUSION: Tool’s ‘Layer Overlapping’ Feature Improves Tube Quality

Also said to be less complex more cost effective than alternative technology.

The 800 Series Hybrid from Guill Tool & Engineering Co., Inc.., W. Warwick, R.I. incorporates the benefits of layer overlapping typical of crosshead and inline tools while reducing unnecessary complexity. A design in which layers are overlapped in each semi-deflector, using a single cone, reportedly has made the technology more cost-affordable for processors.  

The overlapping technology is also said to reduce weld lines to generate a more consistent finished product. The new tool is also reportedly less sensitive to changes in viscosity and line speed. It can be used in processing a wide range of materials and multi-layer configurations, is compact in design, and offers low residence times and a low tolerance stack-up error factor, all reportedly resulting in improved concentricity.  

Stagnation points are reduced because overlapping layers are more inherently balanced than single layers, and also because each semi-deflector is “tuned to flush,” Guill says. Conventional deflectors must simultaneously achieve a balance between flushing, balancing and eliminating the weld line. There is less difference between the slowest moving material and the fastest moving material in the deflector channels, thus making the viscosity more consistent in the deflector.