Mixing Systems – TriVolution™ Tri–Kneader
The Tri–Kneader is a new advanced technology centered around the operating principal of the reciprocating kneader. It is intended for operation in technical compounding and reactive extrusion operations.
The Reciprocating Kneader – Operating Principle
The reciprocating kneader, which was invented in 1947 has remained largely unchanged since those early days. Traditionally, three-rows of screw flights were available to interact with three pins located in the barrel wall. The flights of the screw are interrupted and, as the screw rotates, it also oscillates creating a series of shearing, scissoring and folding action that create the mixing effect on the product. Because the folding action is unique to this technology in the realm of continuous compounding extruders, it has been given the “kneader” designation.
The nature of the mixing action is relatively low-shear and thereby more suited toward thermoplastics and thermoset materials which are sensitive to heat and shear stresses.
What Makes a Tri–Kneader Different?
Currently, all models of reciprocating kneaders available on the market have a single oscillation per revolution of the screw shaft. They have three rows of flights and pins. In 2006, new variations of the kneader were introduced to offer four rows of flights and pins. Even that minor change had a major impact upon machine performance.
The Tri–Kneader, has three oscillations per revolution of the screw shaft thereby broadening the degree of variability of the machine. Anywhere between three and twelve rows of flightsand pins are available. This presents a dramatic shift in the operation window of the machine. With the Tri–Kneader, we've been able to shrink the process zone, slow the machine down and get excellent distributive and dispersive mixing in the shortest L/D. This also means greater energy–efficiency.
Not since the invention of the Ko–Kneader in 1947 has there been such a technological advancement in the realm of the reciprocating kneader.
Commercializing a Revolutionary Technology
The first generation of Tri–Kneaders commercially available on the market are branded the TriVolution series. Effectively, the TriVolution is crossing over into the territory previously reserved for twin–screws only while maintaining the ability to perform low–temperature and low–shear–intensity compounding that has traditionally been reserved only for reciprocating kneaders.