THE CHALLENGE
The challenges Csplast is set can come from any sector, as in this case where we were asked to study the functioning of an aeroplane propeller.
The company operating in the aerodynamic sector which assigned us the task of developing thermoplastic blades for propellers, presented us with a very ambitious project. The goal was to replace the use of heavy and expensive materials such as the wood or metal usually used to make propeller blades, with a cheaper alternative which required less processing to manufacture.
THE SOLUTION
Engineering
The three-blade propeller redesigned by PlastDesignStudio can be used on aeroplanes with an engine power of up to 100 hp. Its function is to accelerate a mass of air in the opposite direction of aeroplane motion so as to achieve thrust to propel the aeroplane.
Our team of engineers developed a solution for replacing the blades, usually made from aluminium alloy, wood or steel, with a cheaper plastic material starting the redesigning process in a virtual environment. The geometries of the pieces were subjected to numerous FEM analyses in order to accurately assess their suitability, simulating any deformations, strain or movements which could occur in the plastic components. It was then decided that the three blades would be mounted on an ergal boss. The original ogival shape of the blades was kept so as to guarantee optimum aerodynamics and it was decided to make them hollow using gas-injection technology to further reduce the weight and increase dynamics during flight.
Injection mould engineering and construction
To build the injection mould we decided to take advantage of the experience and skills of Csplast, making use of gas-injection technology which made it much more simple to hollow out the inside of the blades.
On the other hand the thermostatic material used was produced exclusively for PlastDesignStudio and Csplast. This material is reinforced with aramid and carbon fibres, which gave the plastic lightness, a high tensile modulus and good resistance to impact in the event of heavy rain or hail.
RESULT
The project to convert propellers confirmed the possibilities of making aeroplane propeller blades with a cheaper and yet just as effective and reliable material. Furthermore, the use of technopolymers can improve blade rotation speed thanks to increased lightness and reduced thickness
