SIMPLEX REFINER PLODDER
Also the simplex refiner plodder is used in soap manufacturing to refine the soap: a combination of intimate homogenization and filtering of the soap. Simplex refiner plodder is a soap extruder composed by a screw made in aluminum alloy or in stainless steel, a barrel that is jacketed for cooling by means of a water chiller to avoid a production rate reduction, a hopper to feed the soap coming from the mixer, a strong gearbox and a basement. At the end of a refining plodder a drilled plate with rotary blades is assembled to extrude refined soap noodles.
DUPLEX VACUUM PLODDER
A duplex vacuum plodder is composed by 2 single simplex plodders connected by means of a vacuum chamber. The first plodder is called refining stage thanks to the drilled plate with blade, while the second plodder is called extrusion stage, for the presence of an extrusion cone assembled at the end of the machine. The two stages are connected with a chamber that work under vacuum to remove small bubbles of air that could be find in the extruded soap bar.
In the past the screws speeds was fixed but in the last 20 years, thanks to the frequency inverters, all the screws have an adjustable speed in r.p.m.
The extrusion cone is heated by means of an electrical heater to give a smooth surface to the extruded soap bar.
During the last 15 years, one of the most important Italian soap machines manufacturer developed a special duplex vacuum plodder able to refine and homogenize the soap, without the use of simplex refiner plodder and roll mill. This special soap plodder, called Transavon / Flexi plodder assembles one or two "combo-screws" (simplex or duplex) characterized by two different diameters that optimized the two main functions of a plodder screw:
- The large diameter infeed section assures an optimal soap infeed.
- Small diameter and long compressing section assures maximum homogenization and compression.
The "combo- screw" has a long useful length with many spirals; the useful length of a combo-screw is 8-10 times the screws diameter. The high number of the spirals increases the working pressure of the soap. A Traditional plodder works the soap with a pressure up to 40 bars, while a "combo-screw" plodder is able to work the soap with a maximum pressure up to 100 bars. This high pressure allows the use of two refining screens in the last section of the barrel. A duplex "combo-screw" plodder assemble 2 refining screen on the first stage and 2 refining screen on the extrusion stage, before the extrusion cone.