Industry News

To specify a replacement single screw, send four groups of information: machine and interface details, a controlled dimensional record, the processed material and operating duty, and clear acceptance requirements. A worn sample helps, but it is evidence of both the original design and subsequent damage. The factory must distinguish between the two before approving a drawing.

The screw and barrel manufacturing process usually includes application review, material and surface-system selection, blank preparation, rough and finish machining, heat treatment or hardfacing, precision finishing, dimensional inspection and protected packing. The order is not universal. It must be planned around the geometry, treatment and final dimensions of the specific part.

A parallel twin screw extruder has two constant-diameter intermeshing screws built from modular elements. Most are co-rotating, running at high speed for intensive mixing — which makes them the standard machine for compounding, masterbatch, WPC and pelletizing. Unlike a conical machine, the screw profile can be rebuilt for each new formulation.

A single screw barrel is one screw rotating inside a heated cylindrical barrel, conveying, melting and pumping plastic through a die. Performance is set mainly by three things: L/D ratio, compression ratio and screw type (standard, barrier or mixing). It is the most economical choice for high-output extrusion of uniform material — film blowing, pipe from pellets, sheet and granulation.

A twin screw extruder uses two intermeshing screws inside a twin-bore barrel to feed, melt, mix and pump plastic through a die. The two main families are conical (tapered screws, best for direct PVC pipe, profile and board extrusion) and parallel (constant-diameter, segmented screws, best for compounding, granulation and high-filler mixing).

A parallel twin screw barrel has two intermeshing screws of constant diameter running side by side in a matching twin-bore barrel. Unlike a conical barrel, the screws stay the same size end to end, and the barrel is usually built from segments. Co-rotating parallel screws suit compounding, granulation and masterbatch; counter-rotating parallel screws suit PVC and high-filler work.