SML Extrusion Technology, Ft. Gibson, Okla., describes its developmental HO-LT line of single-screw extruders as a “dream come true” for processors because of a combination of benefits. The extruders reportedly provide high output at low melt temperature, consume less energy, facilitate material changes, and are flexible enough to process multiple materials well.
SML attributes all this to a new screw and barrel feed section that provide a controlled pressure profile and outstanding process stability. Compared with conventional smooth-bore designs, output is said to be especially linear, resulting in extremely low, stable melt temperature at high outputs. The new screw is said to handle high and low die pressures with little effect on output or melt temperature.
SML has subjected the first such extruder, sized at 35 mm, to intensive testing with a wide range of materials. One screw geometry “perfectly” processed 95% of all materials tested. The machine reportedly outperformed extruders more than one size larger. SML is now testing larger models.
Editor PickSizing the Barrier Gap
Here’s a less complex way to properly size the barrier gap for barrier screws.