The value of primary plastics machinery (injection moulding and extrusion) shipments in North America decreased marginally in the third quarter according to the Plastics Industry Association (PLASTICS). Shipments were valued at $293.7 million for the quarter, with single- and twin-screw extruder shipments up by 5.3 and 13.9 per cent respectively, but injection moulding down 1.9…