I am trying to drill small holes in PPS, a high strength plastic. I am using 0.4mm PCB drills. I made an in line holder bolted to a CAT40 tool and use it in a machining center.
The coolant runs through the spindle and then across the drill region. I am pecking the holes at 2 ipm. The first few holes are perfect. The plastic builds up around the top of the drill and then burns the entry region of the hole. I am running the spindle at 20,000 rpm. The peck distance is about 1 diameter. Is there any way to avoid the build up?
Thank you.