Comai orders ZSK 70 Mc¹⁸ for masterbatch production

Coperion: Worldwide success for new ZSK series

Stuttgart, April 2011. – The masterbatch producer Comai Ltda. is the first company in South America to place an order for the new ZSK Mc¹⁸ twin screw extruder series of Coperion GmbH, Stuttgart/Germany, formerly Werner & Pfleiderer. Based in Cartagena de Indias, Colombia, Comai will now be able to increase its production capacity for carbon black, white and additive masterbatches based on polypropylene, polyethylene and polystyrene by around 10,000 tonnes/year. The entire production line includes – besides the compounding extruder equipped with 70 mm twin screws – a feeding unit, a ZS-B twin screw side-feeder, a SWZ continuous screen pack changer and an UG underwater pelletizer. Further essential features include the quick-release mechanisms on the vacuum dome and on the hoppers of the feed barrel and the side-feeder.

Two reasons influenced the decision to purchase, as Antonio Sedan, managing director of Comai, explains: “In the first place we have been having very positive experiences since 1999 with the ZSK compounding extruders, of which we meanwhile have three in operation. In particular we appreciate their extreme reliability and the high durability of all components that are subject to wear. Secondly, we shall achieve a considerably higher output with the ZSK 70 Mc¹⁸ and also be able to change over from one product to another much faster and with less cleaning time than hitherto. And we shall be able to respond more flexibly and quickly to customer requirements and to temporary demands of the market.”

For Coperion, this booked order testifies to the ability of the new ZSK Mc¹⁸ to meet the present and future requirements of Comai as a masterbatch producer. The decisive factors for the increased output rate and the improved quality of masterbatch are the optimized features of the process section. The shrink-fit barrel liners, the use of cartridge heaters, the optimized cooling system and the improved temperature control together bring about not only a considerable reduction in energy consumption but also an improvement both in the temperature control of the process section and in the entire thermodynamic state of the compounding process.

The new design of the ZSK Mc¹⁸ also makes for a further improvement in accessibility, thus permitting even faster and easier cleaning. The quick-release mechanisms reduce set-up and modification times. This is particularly advantageous in the case of masterbatch production, as frequent changeovers from one colour and/or additive to another – including the basic polymer – are unavoidable. Moreover, any urgent, unplanned masterbatch orders will necessarily cause temporary interruptions in long-term production runs.

The screws of the new ZSK Mc¹⁸ feature the same diameter ratio as those of the ZSK MEGAcompounder PLUS, namely D_o : D_i = 1.55, where 'D_o' is the outer diameter and 'D_i' the inner diameter of the screw. This ratio readily enables scale-up from an existing ZSK MEGAcompounder PLUS to the new ZSK Mc¹⁸ and thus makes for greater flexibility when using various compounding extruders for the same application.

One last point that deserves mention is that Comai will be able to rely on assistance at very short notice when it comes to the fast delivery of replacement parts and the availability of other services that may be required: within Coperion’s international network, Comai will be served by Coperion’s location in neighbouring Brazil.