Friday, November 2, 2012
First Try w/ Rubber Stamps
Today I did some experiments with a new material called neoprene, which I used to make a rubber stamp. It was a challenging material to work with, but as you can see in the pictures, it was worth the extra effort.
Neoprene is a medium density synthetic compound which has most of the properties of natural rubber. It's flexible, available in many differing levels of softness, and is generally non-marking. I chose to make a stamp out of neoprene instead of natural rubber because it was what I had easily available to me.
Neoprene is challenging to work with in the laser cutter for a few reasons. First, it is messy and produces a lot of very stinky fumes. Before engraving, the neoprene has a very strong smell like new shoes or fresh tires. During and after engraving it takes on the acrid odor of burning rubber, a smell so oppressive I had to leave the room while the laser was engraving it.
The neoprene engraves very well, holding small details. It won't hold onto details in the 1000 DPI range, but so far I haven't found a material that can consistently do that anyway. However, the engraving doesn't cleanly vaporise the neoprene, but instead it burns with a bright and dirty flame during the engraving process, covering the piece with a heavy layer of soot. This needed to be cleaned off with copious amounts of soap and water afterwards.
Despite being easy to engrave, the neoprene was surprisingly difficult to cut with the laser. I tried many different power settings, but no matter what I tried it wouldn't turn out. If I moved the beam slowly it would simply melt the neoprene into a gooey mess, but if I moved the beam quickly and with multiple passes the neoprene would begin to warm up and would form back together in between passes, like a cheese on a hot pizza. Making enough passes to actually cut through would take a very long time, so my solution was to simply engrave a "ditch" around the design and cut it out with a sharp pair of scissors. This worked out much better.