What differentiates UNIBLEND from other machines is its screw, which is recessed at 90 or 120° interval all along the periphery, and performs an axial stroking movement simultaneous with the rotation, completing one stroke with every revolution. Correspondingly, the barrel is fitted with four or three rows of kneading pins, which are also spaced at 90 or 120° inside the barrel, The excellent dispersion of unmeltable compounds into the molten polymer matrix is achieved due to shear generated between the flanks of the screw flights and the stationery kneading pins. The synchronous back and forth movement of the screw also provides a high degree of product exchange in the axial direction. thus producing an outstandingly ‘Uniform Blending’ over a remarkably short process length.
A significant advantage of this kneading system over twin screw is that no pressure peak or high radial pressure is generated during the kneading process. The matrix is sheared, dispersed and simply reoriented or refolded several times. This makes the UNIBLEND Kneader especially suitable for compounding of heat and pressure sensitive polymers as well as formulations containing high filler proportions or reinforcing materials like glass fibre.
SPECIAL FEATURES OF UNIBLEND KNEADER
AXIALLY SPLIT BARREL
The barrel of UNIBLEND is designed to split open longitudinally up to an angle of 120°. The bolts securing the two halves of the barrel can be opened quickly with an electrical tool provided with the machine, and the barrel can be opened at the desired angle with a soft start power system. The heating on barrel as well as screw can be maintained even in open condition of the barrel, enabling the quickest and the easiest cleaning of screw and barrel compared to any other system.
SEGMENTAL SCREW AND SLEEVED BARREL
The screw of UNIBLEND is of segmental construction. Each screw element is machined from a special alloy steel and coated with a highly wear and corrosion resistant coating. The barrel also comes fitted with wear resistant sleeves. This system enables replacement of the specific elements where intensive wear has occurred without having to change the entire screw/barrel, and that too in minutes.
INDEPENDENT DISCHARGE SYSTEM
The two process steps viz: Compounding and Discharge have been completely isolated in UNIBLEND. Whereas, compounding remains a virtually pressure less process, the necessary pressure for extrusion through a strand die is generated by a small separate extruder connected at right angle to the kneader barrel
ELABORATE DEGASSING FACILITY
The UNIBLEND machine has four degassing ports in the longer version and three in the medium length model. Vacuum is generally applied to the last DG port in the kneading section. However, the backward degassing ports provided before the side feeder inlets offer a distinct advantage, as the air and humidity which have an adverse influence on the process are removed before the beginning of the dispersion process.
PRECISE TEMPERATURE CONTROL
The barrel of UNIBLEND is fitted with metal cast heaters. Also, the screw shaft comes with a cartridge heater fitted in select zones, enabling very fast and efficient heating of the stock. The temperature is sensed in each thermal zone by RTDs inserted directly into the kneading pins and is accurately controlled by auto tuned PID controllers.
GENTLE PRODUCT HANDLING
Since the shear gradient in UNIBLEND is much lower (as low a 1/3rd that of twin screw), the adiabatic heat generation is correspondingly low. Also due to short barrel length the dwell time of the stock within the barrel is short. Thus, kneading although intense and vigorous, still remains a low temperature, low pressure process.
LOW ENERGY CONSUMPTION
Because of the fundamental difference in the operating principle, UNIBLEND consumes much lower electrical power per kg of compound produced compared to other compounding systems.
LOW SPACE REQUIREMENT
UNIBLEND is an exceptionally compact machine and acquires far less floor space than any other twin or single screw machine of comparable through put capacities. Also, the outflow direction of strands, which is at right angle to the axis of the machine, results in optimal utilization of the floor space.
THE ECONOMY FACTOR
UNIBLEND Kneader implies fullest appreciation of money. While it stands out as a truly outstanding machine with trend setting features, its cost, both initial and operational, is substantially lower than that of other similar machine.
APPLICATION AREAS OF UNIBLEND KNEADER
Due to its unique operating principle as well as flexibility of design UNIBLEND stands out as the most versatile machine which can be tailor- made to handle with ease and efficiency a wide range of applications such as
✦ Filled and Reinforced Thermoplastics
✦ Polymer Blends and Alloys.
✦ Automotive Compounds.
✦ Thermoplastic Elastomers.
✦ Sioplas Flame Retardant Compounds.
✦ Telecomunication Cables, Fiber Optics.
✦ Rigid PVC Pipes, Fittings, Window Frames,
✦ Flexible PVC hoses, Shoe Soles, Seals,
✦ HouseHold Appliances.
✦ Black, White and Colour.
✦ Phenolics, Ureas.
✦ Epoxy Moulding Compounds,
✦ Unsaturated Polymers
✦ Epoxy, Acrylic, Urethane and Polyester Resins.
✦ Toners for copiers and laser Printers