Fiberglass warp - weft question

0/90 biaxials wave a "warp" direction, and a "weft" direction

the strands that run the length of the roll are they "warp"
or are they "weft"

 

warp runs lengthwise

 

Weft which is the width can be remembered by weft or left to right or weft to right.

 

thanks

 

Other acceptable terminologies used.

By the way, bi-ax or bi axial always refer to cloth oriented at a bias, say 45 degree. BD or bi directional refers to 0/90 type of weave. Beats me, it means the same to me but when the weavers introduced the +-45 degree, they called it bi axial or bi ax (axial for off axis) and the name stuck.

 

when first introduced the +45 -45 fabric was refered to as Double Bias.

 

Quite correct. It was the fiberglass weavers that caused the confusion.

Notice how the early weavers (1990 data) differs in how they describe the weave.

Knytex calls the 0/90 weave as biax and the (+-45) double bias.

Advance textiles just call the 0/90 weave and the +-45 as "knit" but differentiating between the two as "knit" and "double bias".

Before that, we were just ordering the 0/90 fabric from Hexcel as bi directional (BD).

 

RX, any idea who was the first to introduce the knit fabrics? I started using them about the early to mid 1980s as I remember and knytex was the first i was aware of and i still like their product, ATI stuff was also nice and i used a lot of their Triax back in the 90s. A lot of the other weavers did not do a good job of doing nice tight weaves which for us building quality snowboards back then was unacceptable as when pressing under high pressure and temperature the loose weave would show through the topsheet cosmetically.

Steve.

 

You started earlier than me. We started commercially at 1989 to 1990 and the fiberglass cloth is now called "fabric" as opposed to earlier types of bulky and coarse "boat cloth" of about 800-1000 grams/meter2. That was the time also that several types of knits was introduced and with more balanced warp/weft weights.

Knytex was one of the early weavers and Owens/Corning was/is a raw material supplier/weaver. By 1990, the industry standard is the 7781 0/90 by Hexcel, a flattened tight weave of about 300 gr/m2 and 0.23 mm thick. I get very clean layup with 7781.