Double Bias?

Discussion in 'Fiberglass and Composite Boat Building' started by idkfa, Apr 30, 2009.

  1. idkfa
    Joined: Sep 2005
    Posts: 329
    Likes: 6, Points: 18, Legacy Rep: 79
    Location: Windward islands, Caribbean

    idkfa Senior Member

    Double Bias Carbon
    45W27-6k +45/-45 15 osy, 12K 90 12 osy, 27 osy

    This seems a lot more than double bias, can anyone decipher, thks.
  2. Craig_Hastie
    Joined: Jun 2004
    Posts: 11
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Airlie Beach, Australia

    Craig_Hastie Junior Member

    Perhaps you should ask these people, as they appear to have it as a carbon product.

  3. marshmat
    Joined: Apr 2005
    Posts: 4,127
    Likes: 149, Points: 63, Legacy Rep: 2043
    Location: Ontario

    marshmat Senior Member

    I hate it when manufacturers do this.... drove me nuts back when I was working with the stuff, trying to translate from one supplier's notation to another's, or to an actual description of the material.

    I'll try to interpret, but don't take this as for sure, because some manufacturers mix things up in weird ways:
    45W27 - this is probably the product number, ie. the number you use to order it.
    6k +45/-45 15 osy - this describes a 15 ounce per square yard biaxial, fibres running at +45/-45 degrees to the warp axis, made with roughly 6000 filaments per tow.
    12k 90 12 osy, 27 osy - this appears to describe a layer of 12 and/or 27 ounce, 12k tow count fibre running perpendicular to the warp axis.

    But, as I said, don't quote me on that. Check with the actual supplier.

  4. Eric Sponberg
    Joined: Dec 2001
    Posts: 2,018
    Likes: 231, Points: 73, Legacy Rep: 2917
    Location: On board Corroboree

    Eric Sponberg Senior Member

    Marshmat is pretty much correct in his interpretation of the specifications. The construction is a weft Triaxial of 27 ounces per square yard, not a double bias fabric. The +/-45, 6K fibers are the biaxial part at 15 ounces per square yard, and the 90-deg, 12K fibers are weft part at 12 ounces per square yard. The total weight of the fabric is 15 + 12 = 27 ounces per square yard.

    The 45W27, therefore, refers to the fact that it is a "+/-45 weft triaxial fabric at 27 ounces per square yard." I don't know who makes this fabric, but as Marshmat says, get back to your supplier for confirmation. If you are looking for a double biax fabric, you'll need a different one than this.

    I hope that helps.

Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.