Articles

Kolsite Battenfeld Twin Screw PVC Pelletizing Lines

PVC compounding is a process of mixing homogenously the different ingredients of compound formulation, to achieve various properties as required by the end application. The basic ingredient, Polyvinyl Chloride is compounded with a number of additives such as stabilizers, lubricants, property modifiers, pigments, plasticizers, filers etc. These elements of compound, in definite proportions, are mechanically mixed in a high speed mixer. The output is normally called “Premix” or Dry blend “which is in the form of free flowing powder. In certain applications the dry blend can be used directly in the processing equipment. In many other applications the dry blend is necessarily melt compounded and pelletized. PVC compounded pellets are widely used to various applications like shoes, cable insulation and sheathing, fittings, bottles, medical bags and tubing etc.

For producing compounded PVC pellets, many different types of process equipment are available. Kabra Extrusiontechnik offers the ideal range of counter rotating twin screw extruders which have many advantages stated below.

• Higher Operational reliability


• Dust free operation


• Easy handling


• Friction independent, gentle feed behavior


• Higher pressure built up with smaller temperature increase


• Larger degree of freedom in formulation

The essential units in the line are: Extruder, DFC system, Pneumatic conveying system and Pellet coolers.

Twin Screw Extruders : Kolsite - Battenfeld extruders, manufactured in the state of the art modern KET factory with technical know how from Battenfeld Cincinnati are equipped with a number of features to ensure good quality processing like:

• Low shear heat generation


• Uniform and superior dispersion of fillers and additives


• Effective venting – free from pores pellets


• Low maintenance with minimum machine downtime


• Positive feeding of dry blends and manipulating pressure output


• Vertical crammer feeder facilitates positive and continuous feed of poor flowing dry blends

Die Face Cutter : The compounded hot melt is required to be cut at faster speed in form of circular, even shaped granules. Die face cutter having variable speed motor with VF drive perform dry cutting action. The main advantages are:

• Short contact period prevents heating up of blades


• Clean incision with uniform shape and size of pellets


• No contamination due to SS construction

Pneumatic Conveying System and Pellet Cooler : The pellets cut by the DFC drop down to be transported through a tunnel having air flow through blowers and suction. Diverter valves are provided. At the end of conveying system the pellets are semi cooled and for further lowering of heat to the ambient temperatures they are cooled in Pellet Cooler. In order to prevent sticking, deformation and possible thermal degradation, it is important to extract heat from the pellets rapidly.It consists of a main silo in which the pellets are unloaded, a small silo through which the pellets are passed on to the cooling screen having perforations and vibrator. Cooling of pellets by the medium of air offers many advantages:

• No contamination


• Pellets not allowed sintering together


• Moisture fee pellets

Kabra has installed more than 1600 of such PVC palletizing plants successfully. Besides India many compounders in Saudi Arabia, South Africa, Ethiopia, U.A.E, Bangladesh, and Kuwait have greatly benefited from KET’s Twin Screw PVC Pelletizing Lines