Standard Elements
EXEMPLIFYING ENGINEERING EXCELLENCE
STEER is a global EPZ specialist and commands over 22% of the global market share. Our expertise and understanding of the Extruder Processing Zone and our mastery of the ‘element and barrel’ configuration has made us the preferred choice of over 5500 extruder lines around the world.
STEER’s EPZ replacement elements and parts are the preferred choice for multiple extruder lines including companies like COPERION, TOSHIBA, LEISTRITZ, JSW, BERSTORFF, MARIS, ENTEK and several others.
THE RIGHT TECHNOLOGY FOR THE RIGHT OUTCOMES
Several actions are carried out within the EPZ as the material works its way through the extruder and exits from the die. Depending on the nature of work being carried out, the EPZ is divided in to zones — Intake, Melting, Venting, Mixing, Vacuum venting, and Metering. STEER replacement elements are purpose-built for performance and deliver outstanding process efficiency.
INTAKE ZONE
FREE VOLUME, HIGH CONVEYING EFFICIENCY AND ABILITY TO BREAK UP AND COMPACT
The modular design of the extruder screw assembly provides options for a wide selection of screw elements, for configuring in the ‘intake Zone’. The popular elements are Single Flight Elements (SFE), Normal Right-hand Screw Elements (RSE), Schubkanten Elements (SKE) and Single Flight SK Elements (SSKE). STEER’s Shovel elements are specially designed for starve-fed and feed limited applications. Their supreme conveying efficiency makes them a preferred choice, Besides, they have the ability to handle materials that tend to get fluidised during flow.
MIXING ZONE
INCREASING THE UNIFORMITY OF COMPOSITION
Efficiency Mixing helps the ingredients experience the forces of shear, elongation or compression, bending, erosion and impact.Achieving a chemical union (wetting) of two or more components is an important objective of the compounding process. Mixing elements help with higher wetting besides establishing a uniform effect of shear on the processing material.
MELTING ZONE
UNIFORM AND INTENSE SHEAR
The melting process in a co-rotating extruder is different and the thermoplastic is subjected to intense shearing. This work is done by Kneading Blocks. Multiple lobe geometry is essential in getting the shear uniformity without sacrificing the shear intensification. With this the probability of material degradation is reduced. Kneading Elements with multiple-lobe geometry enhance the melting efficiency in metallurgy.
VACUUM ZONE
EFFECTIVE REMOVAL OF GASES
Degassing in an extruder helps to conserve the quality of the melt that is affected by the presence of monomers, solvents, moisture and other volatiles. These generally separate from the melt only at low to high vacuum conditions. Vacuum elements expose the material by continuously thinning the melt for effective degassing. This task of smearing the melt on the barrel surface by thinning for degassing is efficiently exhibited by long forwarding screw elements or SK type elements.
VENTING ZONE
ENHANCED MOISTURE AND AIR REMOVAL
Removal of moisture to prevent hydrolysis of condensation polymers such as Nylon and PET is one of the most important requirements. Additionally, down-stream to the venting Zone, entrapped air may be pumped into the extruder from a side-feeder that needs to be removed in order to increase the capacity of the extruder. The most important controlling factor affecting the functioning of this Zone is the ‘degree of fill’ (Dof). Dof is the ratio of actual space (volume) occupied by the material to the actual free space in that particular section of the extruder. The Dof in an extruder is controlled by factors such as extruder speed, feed rate, element design and element configuration. Venting elements ensure enhanced moisture and air removal.
METERING ZONE
THE RIGHT AMOUNT OF PRESSURE FOR CONTINUOUS STREAMLINED OUTPUT
The compounded polymer melt is transported towards the die by drag flow caused by the rotating screws. Screws with higher degrees of fill with shorter leads are optimum for this Zone to create the pumping effect, thus building up the required pressure. Metering forms the final processing Zone in an extruder. The function of the elemtents in this Zone are to build the required pressure for a continuous streamlined output.