Machining Acrylic and Residual Stresses
Machining Acrylic and Residual Stresses
(OP)
I am machining a tube of acrylic. I am noticing that afterwords when putting the acrylic into contact with solvents(Alcohol in particular), is cracking at a very rapid rate. However when I place the stock material in contact with this same solvent it does not crack. What can I vary within the machining process to lessen the residual stress that is causing it to crack much more rapidly when exposed to alcohol.
Just use a sharper tool? I know I can switch to cast, but since this is a production issue that will be very expensive. Also a material change isn't an option for an unrelated reason. The
Just use a sharper tool? I know I can switch to cast, but since this is a production issue that will be very expensive. Also a material change isn't an option for an unrelated reason. The





RE: Machining Acrylic and Residual Stresses
They should draw blood when you touch the edges.
Use kerosene for coolant, or at least use a different coolant than what you're using now.
Mike Halloran
Pembroke Pines, FL, USA
RE: Machining Acrylic and Residual Stresses
RE: Machining Acrylic and Residual Stresses
surely there is some thermal treatment for stress relieving even if done with a heat gun.
I also agree with having razer sharp tools.
I believe there should be no coolant, You may want to do a test with no coolant. I use too get involved with screw machining plastic, if I remember right no coolant was used. look below for the recommended cutting fluids.
the machining data handbook list the following feeds & speeds
acrylic cast,or extruded. single point & box tools
depth of cut speed(FPM) feed carbide tool
.040 600 .005 c-2
.150 550 .010 c-2
.300 500 .012 c-2
recommended cutting fluids
0~dry
4~Emulsifiable oils
6~chemicals & synthetics
Mfgenggear
RE: Machining Acrylic and Residual Stresses
If you are running alcohol through the acrylic as part of your process then one thing I've found that helps is taking smaller bites out of the material. For example, if you are drilling a 1" hole through a thick acrylic plate make it in multiple steps rather than just hogging it out with a 1" drill bit. Those finish cuts makes a big difference.
Dan
www.eltronresearch.com
Dan's Blog
RE: Machining Acrylic and Residual Stresses
Thomas J. Walz
Carbide Processors, Inc.
www.carbideprocessors.com
Good engineering starts with a Grainger Catalog.
RE: Machining Acrylic and Residual Stresses
A.R. "Andy" Nelson
Engineering Consultant
anelson@arnengineering.com
RE: Machining Acrylic and Residual Stresses