Metallersättning inom byggbranschen
In this paper the possibilities to replace metal with plastic in products for the building industry were looked into. The first part was a market examination where several suitable products were found. After evaluation the door latch for in-house doors was selected to be re-designed to better suit the properties of plastic.New types of mechanisms were designed with different functions that use the benefits of plastic materials. Models of these mechanisms were developed to evaluate their function. The components in the different mechanisms were adapted for manufacturing with injection moulding.To confirm that the plastic material could handle the appearing stresses calculations on the most vulnerable parts were carried out. The result of the re-design process was three types of door latches that all fit in the doors standard cut-out. Model Classic is similar to the existing mechanism but the number of components is less than half and assembly and manufacturing is simplified. Model Magneto uses a magnet to move the locking part when the door is closed. Opening and locking is the same as Classic. Model Push/Pull uses a pushing or pulling motion to open the door depending on which side it is operated from.