High Temperature Thermoplastics can help with metal to plastic conversion projects when you know how to manage them.
Many markets including automotive and avionics are looking for help to solve design issues and looking toward metal to plastics conversion. The new high temperature thermoplastics offer a number of advantages but come with some processing baggage. Knowing how to handle their issues go a long way to getting your project up and on line within project timelines. Preparation for going forward usually focus on managing the heat issues, both press and mold related, as you use these thermoplastics.
You need to select the proper sized press whether working in prototype tooling or full production is critical to achieve controllable processing. The temperatures these resins process at are very high. Managing melt temperature and time at temperature are critical. Long soak or static movement time can lead to material degradation. Product testing may see a failure and it could be incorrectly assessed as design related when the degraded material was at fault. Even worse is passing development testing and having degraded material effect real world performance with your customer.
In order to process consistently, all material must be in the same relative state at time of melt. Many if not most of the high temperature thermoplastics are hygroscopic. They absorb and retain moisture and as such need to be dried consistently right up to the time of melt to assure consistency.
Design the mold and its features with high temperature resins in mind. You need to account for the heats that we have discussed, when steel is selected. Correct steel is also a factor as many of these resins are used with fiberglass or other fillers for strength. As such, wear becomes a critical issue. The mold also needs to be adequately planned for heat. You need to accommodate getting the mold up to heat for initial processing, and then extracting very high heat during production. Alternative cooling systems to standard water, like circulating hot oil are necessary to manage these high temperatures. Lastly, design the mold cavity and runner features with high temperature resin is also critical. Hot tip considerations, gating and runners all have to be accommodating of these higher temperatures.
These new high temperature resigns are helping designers solve many problems like weight, corrosion resistance and even cost. As with many opportunities, prior planning prevents poor performance.
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