Machine Metal Machine Plastics. With Datron, you get super CNC flexibility that will revolutionize your business!

Feeds & Speeds: This is where the true benefit of Datron high-speed machining centers comes in. Machining plastics really requires high speed. Slower spindle speeds allow heat to build up and melt the plastic rather than cutting it. Higher spindle speeds throw chips out of the cutting channel and prevent long chips from bird-nesting around the tool and melting to it. High feeds get you from one place to another quickly without leaving the tool in one vicinity for too long heating the material up. But, since small tooling is often required for the small plastic parts, you can’t have high feeds without high spindle speed because it will result in unaccepatable tool breakage. Moral of the story is that if you’re machining plastics, you need a Datron.

While the switch from metal to plastic machining doesn’t require a new equipment purchase, it may require new ways of thinking and working. That’s because plastics machine differently than metal, differently from one plastic to another, differently from lot to lot and from section to section (due to material inconsistency). Temperature and humidity variance often needs to be addressed since plastics often have a high coefficient of thermal expansion and without air conditioning certain plastics will cut differently from season to season.

Machinists who have been around the block a few times can adapt quickly to challenges and this is a necessity because many of these plastic parts are produced in small runs and problems must be worked out quickly. The more you work with machining plastics the faster you get at solving problems and picking up the tricks of the trade. For example, a plastic with a low Durometer reading (an indication of softness) will machine easily perhaps too easily as the material can be squeezed out rather than cut cleanly out of the cutting channel. So “freeze”. No, we don’t mean stop, we mean freeze the plastic prior to machining it.

In general we avoid using coolants when machining plastics because plastics can expand from absorbing moisture and this can make it tough to hold a tight tolerance. If tight tolerance is required, the part could be rough machined, set up to stabilize and then finish machined to the required tolerance.

The general rules of thumb for feeds and speeds detailed to the left are indeed “general” where plastics are concerned. For example, compared to machining steel, when machining plastics, the RPM can be lower and the feed faster. This way the spindle speed isn’t causing too much friction and the high feeds don’t allow the tool to stay in one area long enough for any heat present to melt the plastic. Another consideration is that if the RPM is too high, heated chips of molten plastic can fling out and melt to the surface of a perfectly good part.

With Datron high-speed machining centers, you have the widest range of speeds and feeds to find the sweet spot that works for any given material plastic or metal.