When selecting a reinforcement fabric, knowing the characteristics of the possible weaves offers an understanding of the available possible options that are best suited for each specific application. The available options may determine the various design elements, and the suitability of any weave of fabric for each specific layer that will make up the final product. As a result, the correct fabric choices determine the level of the technical and economic optimization of any final product.
Thus, it’s essential to understand the unique characteristics of each type of weave. Below are the key features of the available weaving styles, which will guide in selecting the most suitable choice for your specific application and performance requirements.
PLAIN
Plain weave is the simplest weave, made by interlacing yarns in an alternating over and under pattern. The pattern gives uniform strength in two directions with more crimp. For this reason it exhibits more stability, frays less (when cut in small pieces for example for repairs,) and is more forgiving in layup misplacement. Plain weave drawback is that it does not drape (or follow curves) so well. For this reason it is mostly used for flat or slight contour surfaces such as wing skins.
Fibermax symbolizes plain weave with the letter "P" on the code number of the plain fabrics.
TWILL 2X2
In Twill 2X2 weave each yarn passes alternately over two warp yarns and then under the next two, thus having less crimp than plain weave, and consequently being a little smoother and more drapable. Twill 2X2 weave is the more popular, as it exhibits the most average properties of all weaves. Also, it is usually used on the visible external surface, as it gives an illusion of a 3D visual diagonal pattern that seems appealing to many people. It is softer, less stable and frays more than plain weave, so it must be handled with more care.
Fibermax symbolizes Twill 2X2 weave with the alphanumeric "T2" symbol on the code number of the Twill 2X2 fabrics.
SATIN
In satin weaving style, each yarn is carried over several yarns before going under a single yarn, this way forming long ridges. Satin weaves are fundamentally twill weaves modified to produce fewer and shorter intersections of warp and weft. As a result, we get a fabric that is soft, shiny, more elastic and thus can comply to complex contours and spherical shapes. Also, we have less load concentration points and an infinitesimal better final part stiffness. Relatively to its great drape, we have good fraying chararacteristics. Due to the shininess we get very low print-through. Typically available in four and five harness (S4 and S5) but also up to eight harness (S8), the larger the harness number, the greater the enhancement of its unique properties.
Fibermax symbolizes satin weave with the letter "S" on the code of the satin fabrics, followed by the number of its harness.
TWILL 4X4
In Twill 4X4 weave each warp and weft yarn passes alternately over four yarns then under the next four, thus having less crimp than 2X2 and consequently being considerably shinier, smoother and very soft. As a result, it is more likely to be used in external surfaces as it gives very low print through, and the visual illusion of a very large 3D diagonal pattern that seems very appealing to some people. Much like satin, Twill 4X4 fabric is more drapable and can comply to complex contours and spherical shapes, so it is ideal for laying complex contoured surfaces. It is fraying more than other weaves, so it is not suitable to be cut in small pieces, and is less stable, so it is the least forgiving to mishandling.
Fibermax symbolizes Twill 4X4 weave with the alphanumeric "T4" symbol on the code number of the Twill 4X4 fabrics.
UNIDIRECTIONAL, WOVEN
This weave has most yarns running in the warp direction, giving almost all the strength towards the length of the fabric. It is woven in plain weave, with a very thin yarn as weft, just enough to keep the warps together. It is somewhat drapable. It is not considered stable, and can be curved better along the length (warp) axis.
Fibermax symbolizes unidirectional weave with the letter "U" on the code number of the unidirectional fabrics.
UNIDIRECTIONAL, GLUED
This weave also has most or all yarns running in the warp direction, giving almost all the strength towards the length of the fabric, but here the warp yarns are forced to stay together with some kind of a glue. The glue could be chemically of thermally activated. The resulting UD glued fabric, when compared to its woven counterpart, is much more stable, and drapable only in one direction, its draping characteristics reminding of a sheet of paper. If thermally stabilized, its stabilization could be loosened by heat, increasing its draping and forming characteristics.
Fibermax symbolizes unidirectional weave with the letter "U" on the code number of the unidirectional fabrics.
JACQUARD
Jacquard weaves, when carefully analyzed, may be seen to contain any combinations of plain, twill, satin and other weaves, even in the same crosswise yarn. The yarns are woven into unlimited decorative designs, with often intricate effects, that may offer something "different" and appealing to some people.
Fibermax symbolizes jacquard weave with the letter "J" on the code number of the jacquard fabrics.
MULTIAXIAL, STITCHED
This “weave” can consist of either 1 (Unidirectional), 2 (bidirectional or biaxial), 3 (Triaxial) or 4 (quadraxial) layers (plies) of unidirectional fabrics that are sewn altogether. This adjustable orientation arrangement gives the fabric the corresponding proportional strength in each respective layer direction. The placement and the number of unidirectional plies, their angles and their direction (degrees) can be changed according to customer needs. This way multiaxial stitched fabrics are great in providing anisotropic properties to the laminate. They exhibit less crimp and a bit higher final part stiffness than others. Depending on the type of stitch they can be very stable, but at the same time are soft and have good drape. Also, they have a great cost advantage as they can utilize thicker (heavier) yarns that are usually cheaper and have higher mechanical qualities than the thinner ones. Their drawbacks, all coming from the stitch, are high print through (higher than other weaves), and possible concentration of loads on the stitch.
Fibermax symbolizes multiaxial fabrics with the following letters on their code number: "X" for Biaxial +45/-45o, "H" for Biaxial 0/90o,"XE" for Triaxial +45/-45/0o, "XI" for Triaxial +45/-45/90o, "XH" for Quadriaxial +45/-45/0/90o.
Biaxial "X" +45/-45o Biaxial "H" 0/90o Triaxial "XE" +45/-45/0o Triaxial "XI" +45/-45/90o Quadriaxial "XH" +45/-45/0/90o
Overall, weaving styles are not only changes on the appearance of fabrics. More or less, they affect handling, processing and laminate characteristics. For our customer weave selection convenience, we offer the following table that outlines and compares the general properties of most weaving styles offered by FIBERMAX.
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Weaving styles comparison table (with somewhat equivalent or corresponding fibers and yarns)
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Plain
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Twill 2X2
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Fish
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Twill 4X4
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Satin
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Unidirectional, woven
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Unidirectional, stabilized
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Multiaxial, stitched
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Fray
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**
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***
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***
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*****
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****
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*****
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*
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*
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|
Drape
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**
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****
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*****
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*****
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*****
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**
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*
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***
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Stability
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****
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***
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**
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**
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**
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**
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*****
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*****
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|
Pinholes/Porosity
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****
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**
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**
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**
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*
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***
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***
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**
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Thickness
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****
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***
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**
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**
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**
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*
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*
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*
|
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Ease of impregnation
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***
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****
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****
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****
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*****
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****
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***
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***
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Imprint/Print-through
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****
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**
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*
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*
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*
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****
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***
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****
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***** ⇒ Very low
***** ⇒ Low
***** ⇒ Moderate
***** ⇒ High
***** ⇒ Very high