Design of Conex^® Extruders

BASIC CONSTRUCTION OF CONEX^®

¨ The screw, called rotor, is deep conical in a given angle

¨ Both sides of the rotor surfaces are utilized for screw geometries

¨ The rotor is surrounded by two stationary barrels called stators

¨ A multi-channel configuration is applied for geometrical and process reasons. A channel geometry is also added to the stator faces

¨ All conventional mixing configurations are adaptable to the Conex rotor and stator faces - and even more : the unique SuperMixer and UniCone configurations

¨ The rotor is fixed to and turned by a specially constructed gear

¨ Granules or powder are fed through the front stator and feeding is controlled by separate feeding screws. The machine is thus feed controlled

¨ Material feeding to outer and inner sides of the rotor is separated to create two layers, of different or same materials, as required

¨ The die and tools are integrated into the extruder and no melt distributors are required. This eliminates the need for high die pressures

¨ Every rotor and stator has its own stand placed on steel rails creating a telescopic frame for quick, easy and safe opening and handling of the extruder without lifting

¨ Process control with data sourcing and maintenance with fully computerized soft– and hardware

MATERIAL FEEDING & MELTING

¨ The materials, i.e. polymer resins / additives / and possible reinforcing fibres and fillers, are fed to the rotor(s) by separate feeding units integrated in the Conex extruder

¨ The polymer materials and additives become molten on the rotor/stator multi-channel geometries by shear friction under strictly controlled circumstances

¨ The melt is thoroughly mixed and homogenized without inducing additional shear heat at the latter rotor/stator section containing an unique mixing geometry

FIBRE ORIENTATION

The helical material flow causes inorganic fibres like glass in polymers to orient themselves in the direction of the flow pattern. When two rotors are set rotating in opposite directions, the two emerging middle layers create a cross-directional fibre matrix on top of each other.

¨ This is beneficiated in fibre reinforced products in their mechanical and dimensional stability properties

HIGH EFFICIENT MIXING

The self-cleaning SuperMixer mixing & compounding rotor/stator configuration generates an extremely well dispersed and homogenous melt without material degradation.

¨ For on-line mixing & compounding in direct extrusion

¨ See VTT report Pro C-0201 & C-0202: On-line mixing of carbon black

EACH ROTOR WITH OPTIONS

Each rotor and material is controlled individually to suit best processing conditions required optimally for each material layer.

MULTI-LAYER PRODUCTS

Multi-layer profiled products of 2 layers are made with 2-rotor extruder and 3 layer products with 3-rotor Conex^® extruder. For sheets and boards the number of layers is multiplied by x2 as multilayer tubular melt becomes flattened.

TYPES AND SIZES

Conex^® extruders are manufactured in the following standard types and sizes :

¨ 1-, 2-, and 3-rotor extruders in 150/300/380 and 500 mm sizes (diameter of the rotor at back) for products of 1 to 6 layers giving an output range from 0,25 kg/h to 750 kg/h depending on extruder type, size and materials

¨ The design is extremely compact; e.g. 380 mm Conex-extruder requires only apprx. 1,5 x 1,5 m footprint