WM Thermoforming Machines has announced the availability of a new line of extruders for use with its inline systems that are said to deliver higher productivity and energy savings.
The line of extruders, known as ‘N.EXT’, includes screw diameters of 45-75-90 mm, L/D (length/diameter) ratio of 36 and output capacity range from 450 to 900 Kg/h for polypropylene.
All the extruders are single screw operated by water-cooled AC motors for high-energy efficiency and low noise emissions.
All cylinders and screws are made of nitride steel, but special versions made of bimetal and stellite (tipped hard metal) are available upon request, for the processing of filled materials.
Particular care has been dedicated to the design of the screw profile in order to obtain a better and optimal homogenisation and plasticisation values of the material, says WM Thermoforming.
The temperature control settings are made through the industrial PC B&R operated by touch-screen.
Special stainless steel covers protect the heating zones and can be easily removed for maintenance. All extruders are supplied with continuous hydraulic screen changers in order to avoid material flow interruption. A separate hydraulic power unit for the filter exchange can also be supplied to be used with other co-extruders.
A gear pump system is supplied as standard on all the main extruders to eliminate the possible pulsations during the melting process, guaranteeing constant and uniform feeding of the extrusion flat die head.
In case of additional extruders, a co-extrusion feed block is installed before the flat die head, in order to distribute the material flow in different layers in function of the sheet characteristics required for the final product.
The extrusion flat die head is provided of a flexible lip adjustable through nuts that works by pulling and pushing to control the sheet thickness, while the deckling bars adjust the sheet width manually.
The vertical calenders are available in different versions, according to the extruder and the required output capacity.