Authorized Channel Partner
The injection molding process has a high number of physical parameters that must be conditioned in order to obtain an excellent price/performance ratio, and can create very complex products with extremely precise details.
Plastic is heated to the melting point and then injected under pressure into a closed mold to fill the entire cavity. The plastic is then cooled so that it solidifies, after which the mold is opened and the product is extracted.
The main physical parameters involved in the injection process are position, pressure, and temperature. The customer has to precisely monitor these parameters in order to ensure a reliable process and, therefore, a high-quality final product.
A linear transducer is used to measure four movements: position of the injection unit and of
the screw, mold opening/closing, and extraction.
The majority of the movements, such as clamping, metering, and injection pressure, are hydraulic.
Therefore, oil pressure has to be controlled to improve machine performance and guarantee precisely
molded products.
The final parameter to be considered is temperature in the barrel, in the nozzle, and in the hot runners. The temperature influences the viscosity of the thermoplastic material and therefore filling of the mold.
The production lines of Plastic Metal demanded elevated dynamics, precision, and rapid work sequences therefore the factory needed a product that offered high-performance control of brushless motors and servo drives and that should be able to handle and coordinate the main mechanical organs (loading, extraction, injection, and molding).
Plastic Metal needed also an automation product with a software full of options so that the design could be configured and adapted to numerous product lines without having to utilize the development software.
For Plastic Metal, We are the perfect partner: a specialist with years of experience in IMM and in the design and manufacture of transducers to measure main physical parameters as position, pressure and temperature.
To ensure precise control of injection screw movements, Plastic Metal chose the PK rodless (cursortype) rectilinear displacement transducer. Its compact, rodless design offers versions with very long strokes.
To control the movement of the injection unit and of mold opening/closing, Plastic Metal installed an LT series displacement transducer, offering proven technology, easy installation, robustness, reliability, and high resolution (0.01 mm even in extreme conditions).
Plastic Metal chose a TPSA extensimetric transducer to control hydraulic pressure.
With guaranteed robustness and high accuracy (±0.1% FS), the TPSA is one of most suitable products for this type of application, which requires measurement in a very harsh environment with dust, strong vibrations and high temperatures.
To map temperatures in key zones, Plastic Metal installs thermocouples, specifically designed for the plastics processing industry.
ADP200 drive is the right solution for servo pump control, providing precise pressure and flow control and avoiding the energy waste typical of traditional hydraulic systems.
Oil flow and pressure can be set exactly as required by the machine, rather than at higher levels, without discharging oil as in conventional hydraulic machines.
The ADP200 high-performance drive is perfectly in line with the innovative “green manufacturing” design of injection molding machines, creating real added value for customers in terms of energy efficiency and higher mold quality.
WEG’s specific PID algorithm manages both single servo pump systems and multi-pump machines and covers a wide range of applications.
