Knowledge Hub
02/04/2018
Can Plastic Really Replace Metal?
As a plastic prototype manufacturer RP Technologies have seen an increase in requests for metal replacement plastics in the last 12 months. RP turn to their trusted partner EMS Grivory for their extensive knowledge to ensure they match customers’ specifications.
EMS Grivory products are targeting metal replacement from the concept idea to the sustainable transformation into injection moulding. In the Automotive Industry the drivers behind metal replacement are the reduction of component cost & component weight, which can be achieved by intelligent integration of functions and also as a result of no post treatment processing.
But the question we often hear around metal replacement in the modern day vehicle is; can plastic really replace metal? And is it possible to prove this before committing to production tooling?
It is clear that metals have strong solid properties; however with impressive design techniques, high performance polymers are now challenging metals. Using sophisticated FEA and MF software component predictability is improving. There is a strong trend towards virtual component development and testing, which makes it possible to greatly shorten development times while achieving better component quality. However consideration has to be given at the start of a project for the prototype phase of introducing polyamides for metal replacement.
Grivory HT Polyphthalamides (PPA) need to be processed correctly to ensure all the characteristics of the material are optimised. Incorporating this at prototyping phase by utilising aluminium tooling involves less risk as it’s a cheaper and faster process to produce prototype components for testing.
One of RP Technologies’ specialities is processing high temperature metal replacement materials such as Polyphthalamides (PPA) whilst using aluminium prototype tooling. Their extensive experience in this field gives customers high quality, reliable prototype components.
When processing PPAs there are many different factors that have to be taken in to consideration from a tooling point of view. The grade of aluminium used, how the temperature is controlled and the type of lubricant used on the tool to overcome the extremes of temperature (140°C – 180°C) have to be given serious consideration to ensure components are produced within the correct process conditions of the Polyphthalamides.
If all of these conditions are correct, then a robustly designed part will have the structural integrity of the material which gives the moulded component its optimum condition. This results in prototype parts of production quality that can not only withstand full testing and development but also meet critical tight tolerances.
Grivory PPAs are characterised by their high-performance properties. Technical injection moulded parts made from Grivory HT retain their shape even at high operating temperatures. Characteristics such as stiffness and strength, among the most important in metal replacement are achieved due to little change in property values after absorption of water. In addition low warpage, good dimensional stability, chemical resistance & surface quality are possible.
A great example of Grivory polyamides being utilised is for a new generation of adaptive front lights, the AFL (Adaptive Forward Lighting) system.
AFL uses moveable lenses to enable the light to be dynamically adjusted to suit the road. The required manoeuvrability in the headlight unit, which weighs about 0.4 kg, is provided by a swivelling module made of Grivory HT1. This component is exposed to temperatures of up to 150°C for long periods. To guarantee precise angling of the light cone, the swivelling module must not become deformed, nor must any vibrations impair the functioning of the lighting system. Grivory HT1, with its extremely high rigidity, durability and heat resistance, offers the required level of performance for this demanding application where tolerances must be kept to a minimum.
If you have a project that could benefit from using Grivory Polyamides please visit www.emsgrivory.com for more details, or contact RP Technologies to discuss how their capabilities will fit in with your project.
