Results 1 to 12 of 12

Thread: Plastic Comparisons of Delrin, Acrylic, and Lexan

  1. #1

    Plastic Comparisons of Delrin, Acrylic, and Lexan

    Delrin/Acetal (Polyoxymethylene) vs Acrylic/Lucite/PlexiGlass (polymethyl methacrylate) vs Lexan (Polycarbonate)

    I work with Delrin, Acrylic, and Lexan alot and been trying to find strengths and weakness of the three types of plastics. Since plastics are all slightly different depending on it's use and make, I was wondering if the below is a good general assumption of the three:

    Hardness
    Acrylic > Delrin > Polycarbonate

    Density
    Delrin > Acrylic > Polycarbonate

    Transmittance (Clearity)
    Acrylic > Polycarbonate > Delrin

    Refraction (Reflection)
    Polycarbonate > Acrylic > Delrin

    Yellowing (Yellowing Due to UV)
    Polycarbonate > Acrylic > Delrin

    Chemical Resistance
    Delrin > Acrylic > Polycarbonate

    Thermal Expansion (Retains Shape as Heated)
    Delrin > Polycarbonate > Acrylic

    Tensile Strength (Pull until break)
    Polycarbonate > Delrin ~ Acrylic

    Flex Strength (Bend until break)
    Acrylic > Delrin > Polycarbonate

    Compression Strength (Crush until break)
    Delrin > Polycarbonate > Acrylic

    Shear Strength (Tear until break)
    Delrin > Polycarbonate > Acrylic

    Modulus of Elasticity (Rigidity)
    Delrin > Acrylic > Polycarbonate

    Coefficient of Friction
    Acrylic > Polycarbonate > Delrin

    Corrections and additional plastics or comparisons are appreciated.

  2. #2
    Join Date
    Mar 2005
    Location
    Anaheim, California
    Posts
    6,903
    The comparison factors that are most of interest on this forum are:

    1. Laser "friendliness" (toxicity/corrosiveness when heated)
    2. Laserability (vector cutting)
    3. Laserability (rastering)

    The other factors you list may be of interest to the end-user, but any decisions involving them are usually made before they get to us.
    Yoga class makes me feel like a total stud, mostly because I'm about as flexible as a 2x4.
    "Design"? Possibly. "Intelligent"? Sure doesn't look like it from this angle.
    We used to be hunter gatherers. Now we're shopper borrowers.
    The three most important words in the English language: "Front Towards Enemy".
    The world makes a lot more sense when you remember that Butthead was the smart one.
    You can never be too rich, too thin, or have too much ammo.

  3. #3
    Join Date
    Nov 2007
    Location
    Glenelg, MD
    Posts
    12,256
    Blog Entries
    1
    Liana,

    This type of comparison is probably more suited to forums that specialize in plastics molding, manufacture, etc. Lee hit the main points of interest to most here... unless I'm the designer (and that does sometimes happen as a laserer), those material specs are irrelevant. The person coming to you may ask if you suggest one plastic over another for a particular application, but if I'm the one they go to for help with choosing an appropriate coefficient of friction or tensile strength, they need to hire a designer first, not me.
    Hi-Tec Designs, LLC -- Owner (and self-proclaimed LED guru )

    Trotec 80W Speedy 300 laser w/everything
    CAMaster Stinger CNC (25" x 36" x 5")
    USCutter 24" LaserPoint Vinyl Cutter
    Jet JWBS-18QT-3 18", 3HP bandsaw
    Robust Beauty 25"x52" wood lathe w/everything
    Jet BD-920W 9"x20" metal lathe
    Delta 18-900L 18" drill press

    Flame Polisher (ooooh, FIRE!)
    Freeware: InkScape, Paint.NET, DoubleCAD XT
    Paidware: Wacom Intuos4 (Large), CorelDRAW X5

  4. #4
    Join Date
    Oct 2004
    Location
    Cape Town, South Africa
    Posts
    3,922
    Well , you can really only compare lexan and acrylic , deldrin is hardly used in the areas where these 2 are.
    In essence lexan or polycarbonate is ONLY used where high impact resistance is required and is not really processable with our lasers so in reality one would almost exclusively use perspex or acrylic.
    Apart from laserablity and properties , one has to bear in mind the stock thicknesses , sheet size and cost of the various plastics when considering which one to use.
    Rodney Gold, Toker Bros trophies, Cape Town , South Africa :
    Roland 2300 rotary . 3 x ISEL's ..1m x 500mm CnC .
    Tekcel 1200x2400 router , 900 x 600 60w Shenui laser , 1200 x 800 80w Reci tube Shenhui Laser
    6 x longtai lasers 400x600 60w , 1 x longtai 20w fiber
    2x Gravo manual engravers , Roland 540 large format printer/cutter. CLTT setup
    1600mm hot and cold laminator , 3x Dopag resin dispensers , sandblasting setup, acid etcher

  5. #5
    I wasn't offering this information, I was asking if this information was correct. I was just trying to summarize everything I picked up from the boards and other sources.

    I use a laser, and do a lot of engraving and cutting of plastics with it. I'm more of a hobbyist than a professional, and do a lot of projects for others and end up doing a lot of consulting. In my experience I had to find out what plastics does best with what purpose. I just thought other members of this board who worked with these materials a lot could correct me on the list or show some new insights on the usage. No one ever threw a project at you and you had to figure what materials is best suited for it?

    For example, I use delrin for cutting gears and engraving stamps for embossing due to it's stiffness and low friction properties. In creating a display case, I use acrylic for it's clarity and etching properties. I use polycarbonate for building containers or cases that requires durability.

  6. #6
    Liana,
    From my experience the thinner materials 1/16 " and lower
    Flex Strength (Bend until break) will be
    Delrin > Acrylic > Polycarbonate
    real thin delrin does not break unless I bend it back and forth many times.

    Kim

  7. #7
    Here is some information you might find useful:
    http://www.crclarke.co.uk/Support/pdf/thermo.pdf
    I design, engineer and program all sorts of things.

    Oh, and I use Adobe Illustrator with an Epilog Mini.

  8. #8
    Quote Originally Posted by Kim Vellore View Post
    Liana,
    From my experience the thinner materials 1/16 " and lower
    Flex Strength (Bend until break) will be
    Delrin > Acrylic > Polycarbonate
    real thin delrin does not break unless I bend it back and forth many times.

    Kim
    Thanks good to know. Been using mostly 1/8" and above so far.

  9. #9
    Quote Originally Posted by Doug Griffith View Post
    Here is some information you might find useful:
    http://www.crclarke.co.uk/Support/pdf/thermo.pdf
    Thanks so much! That's the kind of information that I was looking for.

    I'm not sure If I read it on this board or not, but I remember someone once posted a general list of colored flames and smoke and smell from the different types of plastics when they were cut or engraved, especially to identify the more hazardous plastics like PVC. Tried a search and came up nothing and was also wondering if anyone remembers this?

  10. #10
    Join Date
    Nov 2007
    Location
    Glenelg, MD
    Posts
    12,256
    Blog Entries
    1
    Google plastic identification and you'll come up with several charts that show you what tests to run, from burning to dropping in water for a float test.
    Hi-Tec Designs, LLC -- Owner (and self-proclaimed LED guru )

    Trotec 80W Speedy 300 laser w/everything
    CAMaster Stinger CNC (25" x 36" x 5")
    USCutter 24" LaserPoint Vinyl Cutter
    Jet JWBS-18QT-3 18", 3HP bandsaw
    Robust Beauty 25"x52" wood lathe w/everything
    Jet BD-920W 9"x20" metal lathe
    Delta 18-900L 18" drill press

    Flame Polisher (ooooh, FIRE!)
    Freeware: InkScape, Paint.NET, DoubleCAD XT
    Paidware: Wacom Intuos4 (Large), CorelDRAW X5

  11. #11
    Liana, that might be the thread you're looking for http://www.sawmillcreek.org/showthread.php?t=114701

    Andrea
    _______________________________
    LaserPro Spirit 40 W
    OKI ES9431

    Who wants to hear the bells must pull the rope
    Wer die Glocken hören will muss am Seil ziehen

  12. #12
    Join Date
    Dec 2006
    Location
    Fremont, CA
    Posts
    123
    Some of the mechanical comments are incorrect. My apologies for not editing them. Here are my observations:

    Acrylic: Hard, strong, very clear, non-yellowing, great edge quality and easy to cut BUT brittle.

    PETG: Strong, clear, not brittle, tricky edges, messy cut, soft surface. Nearly as good a polycarbonate. Takes cold bends.

    Polycarbonate:strong, not brittle, less clear, nasty cut, soft surface.

    Delrin: hard, slippery, strong, not brittle. Good cut but "melty". Almost like a metal, great for mechanical parts.

    Nylon: close to Delrin but a terrible material to cut.
    LaserPro Explorer II 30W

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •