EXTRUSION TECHNOLOGY

Key word: technology

We are proud of being the owner of 100% of our technology.

This is possible by the fact that all the fundamental parts are produced internally, with high-level production and quality processes.

Evidence of this is the production of the screw construction elements in their entirety, the barrel sectors and, above all, the production of our own gearboxes.

Particular attention is paid to the search for new construction materials to be used to improve the performances of our extruders.

The result is extruders whose strength is their versatility, allowing their use in a wide range of production lay-outs typical of the most varied production types linked to compounding.

Production flexibility is our strength to provide our customers with tailor-made solutions.

DIE

Our die is defined as quick-change, as disassembly takes place by loosening, but not removing, the fixing screws.
In this way, there will be no hot parts to handle and it will be possible to change the final part by lifting it from the special knobs and replacing it according to the cleaning needs or the necessity to change the number or size of strands to be obtained.
In case of extraction of the extruder screws, there is a hinged system that can be opened which allows, only by extracting some of them, to be able to access the tips quickly. Therefore, only four screws will need to be handled, there are neither hot parts nor a certain weight to support.
Another significant aspect is the side heating of the die. In many cases, and especially on the new high-productivity machines, the supply chain is very wide and involves the possibility of different temperatures being encountered between the various areas, which in turn generate irregular flows with consequent strands of different diameters. There are also heating elements positioned laterally that allow to vary the heating and compensate for this phenomenon.

BARRELS AND SCREWS

The barrel, which constitutes the process area, is configured through the use of different modules
having different functionalities.
From the construction point of view, they are available in two geometric shapes: round or square.
The different shapes also distinguish the use of different types of electrical heating elements. In the case of the round shape, ceramic or cast (aluminium, steel or bronze) heating elements can be used, while candle or cast (aluminium, steel or bronze) heating elements can be used for the square cylinder.
Regarding the construction materials - depending on the applications – there are more options: from the nitrided barrel to barrels with removable inserts in special anti-wear, anti-corrosion steels or the combination of the two properties. These steels range from fully hardened materials to HIP and bimetallic materials: we are always at the forefront in the search for new materials to improve the performance of our extruders.
The screws are positioned inside the barrels, consisting of two shafts and modular screw elements. These elements are made with the same steels used for the barrels and can have multiple geometries and functions: transport, kneading and special elements.
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GEARBOX

Our gearboxes are built and designed in-house.
Co-rotating twin screw extruders require special gearboxes able to transmit the high torque density required by this type of machines.
The gearbox is designed using drawing and calculation programs that allow to obtain the expected results and withstand the stresses to which it will be subjected. The design is carried out by calculating the parts in real dimensions and on three-dimensional models.
These are special gearboxes where the motion is divided between various power branches and re-joined to be able to transmit the power to the two screw shafts. This generates a very complex gearbox with special devices and adjustments to ensure that each screw shaft receives exactly half the power.
The high torque density requires the use of advanced materials and treatments that must be controlled. By manufacturing the parts entirely, manufacturing and machining them in-house, we can evaluate all aspects of the manufacturing process.
In the same way, all the gearboxes are dimensionally checked by our internal testing.
The lubrication system is placed outside the reducer and will carry the oil to the individual parts. The lubrication system has sensors to prevent any malfunctions from damaging the gearbox.

MAIN MOTOR

Our company always takes extreme care in choosing the motor to install on its machines.
The motor can be supplied in various types, such as:
- Servo ventilated A.C. motor
- Water cooled A.C. motor
- special executions of motors and extruders according to ATEX regulations
The motor is equipped with temperature sensors, encoders for more accurate speed control and, in the case of water-cooled motors, a system that checks temperature and flow. In addition, the system is equipped with a solenoid valve and a filter to prevent the entering of foreign parts into the engine.
A torque limiter is inserted between the motor and the gearbox to eliminate overloads, which can be generated by possible locking of the screws, preserving the gearbox. These devices, purchased externally, are however analysed together with the supplier and customized according to the use. The release of the limiter, which completely zeroes the torque, is indicated by a microswitch that stops the motor to prevent the latter, generated by the motor due to inertia, from discharging on the reducer.

SIDE DEGASSING

The side degassing system is a device used to optimize atmospheric degassing / venting in the extrusion process. Some processed materials, in fact, due to their specific rheological characteristics, can cause clogging of the standard degassing chimney, thus preventing the correct devolatilization of the gases. In these cases, it is necessary to use the side degassing system, where the degassing chimney is mounted on a double screw device, which guarantees high volumes of devolatilization and, at the same time, no clogging, no stagnation of material, no pollution due to the degraded polymer.
The side degassing device is therefore composed of a housing and a pair of co-rotating transport screws very similar to the side feeding machines, but the standard hopper has been replaced by a chimney. The hermetic seal guarantees a correct seal during operation with vacuum levels commonly used in compounding processes.

SIDE FEEDER

The twin-screw side feeder is a device that allows the feeding of materials along the extrusion process. The materials introduced can be additives, polymers, resins or fillers, either in form of powders, granules or fibers.
Its use, based on the formulations, is indicated when it is necessary to increase the percentage of a filler, increase production capacity and in some cases increase the quality of the compound produced. The number of side feeders used varies according to the formulation and the process, from one for standard compounds up to three for highly filled compounds (eg polyolefins with 86% CaCO3).

DEAERATION SYSTEM

for side feeder

The deaeration system is an equipment patented by us that allows to improve the introduction capacity of some types of powders inside the extrusion process.
The goal is to increase the bulk density of the material by removing the air contained in the powders (fillers).
The operation of this equipment takes place through the application of vacuum on a porous filtering surface that allows the removal of the air contained in the fillers to be fed into the extruder.
The use of this technology, compared to a standard side feeder, can therefore increase the filling of the screw and consequently the production capacity, the reduction of specific energy - therefore energy consumption - and more generally, obtain a reduction of production costs.