Barrier Feedscrews Solids are blocked from passing into the melt channel The pellets are compacted against the inner barrel surface by the rising solids channel Frictional heat energy is generated

Barrier Feedscrews The melt polymer passes over the barrier flight The polymer then collects in the deepening melt channel Removal of the melted plastic from the solids channel allows for the continuous renewal of solids to the barrel surface This results in more efficient heat generation and transfer

Barrier Feedscrews In the barrier section the solids bed is maintained and compacted longer Melting is most efficient when this occurs When solids break up, for example on a general purpose screw, and become surrounded by melt polymer, melting is hindered by the insulating effect

Barrier Feedscrews At the end of the barrier section, the solids channel becomes fairly shallow. A dam is typical at this location The dam ensures all material passing into the melt channel has passed over the barrier flight. At this point the two channels merge together to form the metering section

–Feedscrew technology implemented to solve specific processing issues. –Technology that maximizes conductive melting as the primary melting mechanism –Technology that improves melt quality at higher rates –Technology that provides a more uniform temperature distribution as compared to the typical barrier screw Plastec Now Offers Barr Inc. Feedscrew Technology

Increased Temperature Uniformity High Specific Rate (Lb/hr/rpm) Low Shear Melting Increased Machine Efficiency US Patent #4,405,239 Energy Transfer BARR-E.T.® Screw

Feed Transition E.T. Section Partition flight clearance (2.5 to 4.0 mm) typical B ChannelA Channel Solid/Melt Mixing in E.T. Screw

UndercutMain Flight Flow Peaks Flow Path in E.T. & V.B.E.T Solid / Melt Design

V.B.E.T. Section Standard E.T. Section 30 to 50% Longer Mixing/Melting Section Compared to Our Standard E.T. Section Variable Barrier Energy Transfer V.B.E.T.® Screw

–Processing HDPE - 5 gal pails on a reciprocating unit lower melt temperatures excellent recovery rates reduced over all cycle time by 1.5 seconds –Processing Valox contributed in resolving a screw motor torque limited issue –Processing Delrin eliminated heat over-ride issues –Processing flame retardant PS (Television Cabinets) eliminates splay Successes With the ET (Energy Transfer Screws)