Direct compounding/sheet extrusion lines continue to flourishDirect compounding/sheet extrusion lines continue to flourish

Officials at Coperion Werner & Pfleiderer and one of its key competitors, Berstorff, say the market remains eager for compounding lines linked directly to processing machinery such as profile or sheet extrusion lines. During its March technical seminar, Coperion officials noted that direct processing of nondried post-consumer recyclate PET (PCR-PET, typically bottles or films) appears to be on the rise as processors take advantage of a more steady supply of PCR-PET. Coperion says the decrease in intrinsic viscosity of the PET during extrusion in its MEGA compounder ZSK units is held to less than .04 dl/g.

Berstorff (machine pictured below), headquartered in Hannover, Germany, late last summer supplied a coextrusion line to RPC Cobelplast (Montanante, Italy), part of the RPC Group, for processing of three-layer thermoformable PET sheet. The new line, which will process a mixture of production scrap and virgin material, nearly doubles the processor's current 13,000 tonnes/yr throughput achieved on three lines fed from single-screw extruders. Attila Menghini, managing director at Cobelplast, estimates European PET sheet demand is about 300,000 tonnes per annum with a 10%/yr growth rate.

Berstorff is now able to supply complete lines such as this one, which included a ZE 90A x 34 D UT twin-screw extruder, horizontal three-roll smoothing stack, and laminating unit, following its acquisition last year of Seide Engineering (Buchholz, Germany), a noted smoothing stack and laminating unit manufacturer. Indeed, at the time of the acquisition, Berstorff officials reckoned it would help them better penetrate the market for thermoformable sheet. The line for Cobelplast is designed to process sheet in thicknesses ranging from 100 µm up to 1.8 mm. A filter system in the extruder is used to remove any contaminants from the production scrap. Coperion Holding GmbH, Stuttgart, Germany; +49 711 897 2301; www.werner-pfleiderer.de; Berstorff GmbH, Hannover, Germany; +49 172 511 9623; www.berstorff.de