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HP-RTM Solutions for the Market Leaders
The manufacture of Carbon Composite parts for Automotive applications relies more and more on Cannon wet and dry equipment, for both Epoxy- and Polyurethane-based formulations.
HIGH PRESSURE RESIN TRANSFER MOULDING( HP-RTM) IS THE MASS PRODUCTION VERSION OF THE CONVENTIONAL RTM( RESIN TRANSFER MOULDING) PROCESS AND MAKES USE OF FAST CURING CHEMICALS. T H E P R O C E S S C O N S I S T S I N T H E IMPREGNATION OF A PREFORM WITH A MATRIX THAT IS MIXED THROUGH A MIXING HEAD CONNECTED TO THE MOULD.
The impregnation and moulding stage is the heart of HP-RTM technology. A Carbon fibre preform is loaded into the moulding press and a high pressure injection of liquid matrix takes place. In order to exploit the fast reactivity of the new generation chemicals, the components of the formulation are kept separated and are mixed on demand, when the part needs to be injected. Being the reaction time very short, the viscosity of the chemical grows significantly within the injection window. This results in a very severe pressure rise into the mould( this phenomenon gives the name to the process). Typical values in the industry go from 50 to 120 bar. The mixing and subsequent injection of the matrix is performed through a dedicated dosing and injection unit. The unit is designed to bring the chemicals at the required temperature while guaranteeing a proper degassing and to dose at the correct flow and mixing ratio of the components. The machine is equipped with jacketed tanks, diathermic oil thermoregulator and heat exchangers that can bring the components up to 100 ° C. The tanks are equipped with dedicated vacuum degassing systems to degas the chemicals to avoid the formation of holes and voids in the final cured part. The heart of the technology is the mixing head. Inside the mixing head the pressure energy that has been generated with the metering pumps is converted into kinetic energy through dedicated injectors. The injectors ' nozzles are placed into a mixing chamber where two or more streams of chemicals are collided one against the other. The collision generates a very severe turbulence that guarantees a proper mixing.
A Cannon E-System in Germany A major German car manufacturer has equipped their development laboratory with a new Cannon E-System 5 Enhanced, the latest Cannon dosing unit specifically designed for HP-RTM technology. The threecomponent machine will be used to develop their next generation of Epoxy-based Composite parts. Their work on Composites generated a number of technological developments that have greatly influenced the design and the efficiency of modern passenger vehicles. In 2015 a project for a new dosing unit for laboratory use was started, specifying a number of innovative technical features. A bid was launched among the most qualified competitors, Cannon Afros quoted accordingly and, thanks to a proposal that was both technically compliant and valuable, won the contract. The machine supplied is an E-System 5 Enhanced with 70-litre stainless steel tanks and circuits for resin and hardener. The unit can meter from 15 to 140 g / s of a three-component formulation at typical process mixing ratios. The whole metering section for the resin is enclosed in a heated and thermally insulated box, allowing to work with a constant
The E-System highpressure dosing unit is available in different configurations.
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