Would someone please explain to me the difference between lexan and plexiglas? I seem to remember one of the two can be worked (bent to shape or molded) with heat, but I can't remember which is which. Any pointers on using the workable stuff would be helpful as well. I'm thinking about a project for my Formula involving this material...
Thanks

A guy here at work uses lexan for his homemade fishing lures because it won't become brittle when the lure is in cold water. It can also be heated to round off sharp edges without the effect of a brittle end from the heat.

Based on that, it appears that lexan is the stuff that can be worked more easily.

Dave

Both acrylic (Plexiglass) and polycarbonate (Lexan) can be heat formed, but acrylic has been used a lot longer (so the processes are well understood) and is somewhat easier to work with.

Beyond the difference in working with them, the two materials have very different properties at room temperature. Acrylic is rather brittle and will shatter upon moderate impact, but it has a relatively hard surface and doesn't scratch very easily. Polycarbonate is flexible and quite impact resistant, but it is soft and scratches all too easily.

Despite the better strength and impact resistance of polycarbonate, most light aircraft windshields and canopies continue to be made of clear acrylic primarily due to its better scratch resistance.

[This message has been edited by Marvin McInnis (edited 10-27-2005).]

lexan is a brand of polycarbonate - thought it is a very soft formula - there are much stonger/stiffer formulas that are not as common and not as redily available

along those lines the lexan (polycarbonate) is much stronger and les brittle than acrylic - but otherwise has very similar properties

lexan:
does not need to be heated to be bent, it actually resists heat
does not like to be cut - it fights you
darker edges than acrylic - usually
more impact resistant
easily scratchable

acryllic:
scratch resistant
i think its more cost effective
crystal clearity
endures weather well
it comes both casted and extruded -
casted is more expensive and the better of the two,
extruded is more suseptible to stress and fractures extruded also has small waves in thickness
over long stretches

- all info was presented in a plastics college course

If I remember right Lexan discolors (yellows) in direct sunlight over a period of time. Double check that though. I did research a while back, but I don't exactly remember which one it was. Could be the Acrylic. Something to think about if considering use for windows.

Polycarbonate makes great bullet resistant windows. I saw a display at TAP plastics once. They had something like a 2" thick sheet of Acrylic (plexiglas) that they shot with all sorts of small calibers - 9mm, .45, .44 mag, .22 mag. It was seriously cracked up where the rounds hid and It put cracks all the way through but it just barely managed to stop things like the .44.

Then next to it was a sheet of Polycarbonate - similar types of rounds, but the sheet was only half an inch thick. It didn't have a single crack in it - just smooth deformations where the bullets hit. Very impressive.

I also made the mistake one day, when CD-R's were expensive and unreliable, of trying to shoot one with a pellet gun in frustration. I took it outside and shot it - only to recieve a riccochet to the eye - ow. It never broke the CD, they're made of Polycarbonate. Thankfully my eye is fine. I also noticed that my polycarbonate sunglasses are very scratch resistant, making me hesitant to believe that acrylic really is better at scratch resistance, but it's possible that it's also coated in some manner. Long story short, if you want to make bulletproof Fiero windows... go with Polycarbonate. Otherwise I guess Acrylic is easier to work.

poly is much easier to work IMO, and I do it every day. You can actually take a sharp knife and peel a sliver off the edge of it. Try that with acrylic and the knife will just skip along the brittle edge. It can be drilled and threaded better too. Lexan bends easier, and holds it's bend better. It's more expensive usually. It will yellow, but you can order it with UV resistant properties if it's going to be in sunlight.

https://www.fiero.nl/forum/Forum2/HTML/066948.html

[This message has been edited by maryjane (edited 10-26-2005).]