Triaxial Weaving
Introduction
Triaxial weaving produces material which is structurally superior to many
sorts of rectangular weaving. Since the structural elements run in three
directions, the resulting fabric is much more resistant to shearing forces
and doesn't crimp.
Here are some of the most common types of triaxial weaving:
Dense triaxial weave
This fabric has three layers of material at any point - and
is thus stronger than a rectangular woven fabric made using
the same elements.
Unfortunately, this fabric is relatively difficult to
manufacture.
Sparse triaxial weave
This fabric is sparse. It typically has about a third of the
structural elements of the first fabric.
One of the feature of this fabric that it has holes in it. While this makes it
unsuitable for some applications, it does help with
applications which require ventilation - such as ladies stockings, linen
baskets or underwear.
Alternatively, it is appropriate where a light material is required -
that is still very strong.
This sort of weave is one of the lightest simple weaves known.
First herringbone triaxial weave
This sort of triaxial weaving is not isotropic - but it is fairly common -
perhaps as a result of being relatively simple to manufacture.
Second herringbone triaxial weave
This pattern is similar to the first pattern - however, each diagonal strand
goes under and over two other diagonal strands at a time.
The first pattern is based on an ordinary biaxial weave, and the second is
based on a twill pattern.
More diagrams
These diagrams show what sparse triaxial weaving looks like on a larger
scale:
Statistics
Some calculations relating to triaxial weaving:
| \ |
Density |
| Rectangular |
2.00 |
| Triaxial (sparse) |
1.00 |
| Triaxial (dense) |
3.00 |
| Diamond |
2.00 |
Ribbon-based model
| \ |
Density |
Sphere seive: cost |
Disc seive: cost |
| Rectangular |
2.00 |
2.00 |
2.82 |
| Triaxial (sparse) |
1.73 |
3.00 |
3.46 |
| Triaxial (dense) |
5.19 |
3.00 |
3.46 |
| Diamond |
2.31 |
2.00 |
4.00 |
| Hexagonal |
1.15 |
1.00 |
1.15 |
Wire-based model
The figures are derived from models based on "ribbon" or "wire".
The "ribbon" is considered to be a material which is very wide in one
dimension, while very narrow in another. The "wire" is considered to be a very
thin, but highly inflexible material. In practice, most real materials will
fall somewhere between these extremes.
Sparse triaxial weaving using ribbons typically uses 50% of the quantity of
material to cover the same area as rectangular rectangular weaving - while
dense triaxial weaving uses 150% of material to cover the same area.
If the material is ribbon-like the difference between rectangular weaving and
triaxial weaving is dramatic. However - if the material is wire-like, there's
not very much in it.
The "seive" costs were intended to determine whether it makes financial sense
to build seives out of triaxial woven fabrics. Two sorts of seive were
considered - based on whether the objects being seived were spheres or discs.
The figure represents the material cost (per unit area) to prevent the passage
of objects with diameter 1 unit.
The "Hexagonal" entry is not really a weave - it is a configuration
similar to a wire-net. It is impossible to construct it using continuous
strands. The figures are given to allow comparisons with the ideal
arrangement.
Even if you ignore the problems caused by the variable-size pores; triaxial
weaving probably makes little sense in the context of constructing seives.
Applications
What applications are suitable for using triaxial techniques?
The main selling points of triaxial weaving are:
- Light weight;
- Low material cost;
- Isotropy;
- Shear-resistance.
These are desirable traits for many applications.
In particular, light shades, basketware,rIntroduction hats and high-performance applications
demanding isotropic strain resistance seem particularly attractive
applications for this sort of weaving.
Construction
Sparse triaxial weaving uses three sets of parallel fibres, known as the
warp, the whug and the weft.
The whug is not present in conventional rectangular weaving. During
construction it acts very much like a second warp.
The warp can be laid down in simple parallel lines. The whug is then
laid down on top of it - again in simple parallel lines.
Finally the weft is woven in and out of both layers - to create the final
fabric.
Patent
Triaxial fabrics have been the subject of many patents. We maintain a list
of some of them here.
References
Tim Tyler |
Contact |
http://hexdome.com/
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