Technical fibers, such as Basalt, Carbon, Glass, etc, can be carded and then formed into a sliver.
A Sliver is a long bundle of fibers that is generally used to spin yarn. A sliver is created by carding or combing the fiber, which is then drawn into long strips where the fiber is parallel. When a sliver is drawn further and given a slight twist, it becomes roving. This roving then can be used for weaving, knitting or other textile processes. Depending on the fibers use, intermediate processes such as slashing may apply.
The advantage of carding and forming slivers is to combine various fibers and utilize their individual properties to precisely engineer desired properties for the final application.
Factors which may influence the choice and % of fibers formed into a sliver can be: Thermal or electrical insulation, strength, weight, cost, productivity, etc.
While Roving or texturized yarns typically do not need any special additional treatment of seizing, the finer yarns typically do.
Slashing is a process in which the strand will be applied an additional seizing, aiding the weaving process. Without this additional seizing, the yarn in the warp will be starting to create “fuzz” from broken filaments. This is due to the reed rupturing the warp strands. The fuzz in return will influence the shedding behavior of the neighboring fibers. This may cause those fibers not to clearly separate from each other, when the shedding takes place. This will result in either a simple miss pick or in a complete yarn breakage in the warp.
The slashing typically handles two production steps in one;
a) application of the required additional seizing
b) warping the strands to a loom beam. (Note:Slashing can also be offered on a “bobbin-to-bobbin”-process, as well.)
In case of slashed bobbins, a second process may have to take place, which is called warping.
Warping is the process in which single strands of fibers (yarns) will be wound to a beam which is called a loombeam. This loombeam can then be either attached or connected to the weaving loom or put on a separate A-Phrame construction.
Depending on the desired weave construction, at times, two loombeams can be implemented. In that case, a top beam stand is mounted to the machine, holding the second beam.
There are three basic Warping Techniques:
a) Sample Warping
Sample Warping is typically for around 30 yards or under 100 yards, as needed, just for weaving samples. Other lengths apply, but in essence it is meant for short runs.
b) Sectional Warping
A Sectional Warper draws e.g. 200 single ends at a time and winds it to a loombeam. This is then called a section. After the desired quantity has been wound, e.g. 5,000 yards, the second section will be applied with the same yard count. In order to do so, the warper will be moved a small distance on a rail system, to be centered again in front of the next section. This process will be repeated, until the desired total end count has been reached.
C) Direct Warping
A Direct Warper draws all the required strands at one time and applies the desired quantity of yards in this one process. Therefore, while Sectional Warping and Direct Warping both result in the same end count with the desired max quantity per strand, the sectional warping process calls for multiple production steps, while the Direct Warper produces it in one production step.
The choice of the correct warping system depends on the mill’s setup.
Caution with warping, as glass fiber has a very low elongation coefficient, precise machine adjustments and tension systems are required.
Typically, for weaving glass fibers, the fibers are chemically treating in a slashing process. This treatment reduces the friction during the weaving process.
In weaving cloth, the warp is the set of lengthwise yarns that are held in tension on a weaving machine. The yarn that is inserted over-and-under the warp threads is called the weft or filler. Each individual warp thread in a fabric is called a warp end.
Because the warp is held under high tension during the entire process of weaving, the warp yarn must be strong. Therefore, warp ends are usually spun or plied (twisted). Technical fibers (man made fibers), such as Basalt, Carbon, Glass, Kevlar, etc can be woven.
In Technical Fiber weaving, the most common weave patterns are
Twill & Broken Twill Weave
In Basket weave or Panama weave, groups of warp and weft threads are interlaced so that they form a simple criss-cross pattern. Each group of weft threads crosses an equal number of warp threads by going over one group, then under the next, and so on. The next group of weft threads goes under the warp threads that its neighbor went over, and vice versa.
Basketweave can be identified by its checkerboard-like appearance made of two or more threads in each group.
In plain weave, the warp and weft are aligned so they form a simple criss-cross pattern. Each weft thread crosses the warp threads by going over one, then under the next, and so on. The next weft thread goes under the warp threads that its neighbor went over, and vice versa
The satin weave is characterized by four or more fill or weft yarns floating over a warp yarn or vice versa, four warp yarns floating over a single weft yarn. Floats are missed interfacings, where the warp yarn lies on top of the weft in a warp-faced satin and where the weft yarn lies on top of the warp yarns in weft-faced satins. These floats explain the even sheen, as unlike in other weaves, the light reflecting is not scattered as much by the fibres, which have fewer tucks.
In glass fiber weaving, satin fabrics are popular when high drape ability is required. If the fabric has to be layed around corner or edges.
This Schematic also shows a traditional shuttle loom woven Satin Pattern.
Twill fabrics technically have a front and a back side, unlike plain weave, whose two sides are the same. The front side of the twill is the technical face; the back is called the technical back. The technical face side of a twill weave fabric is the side with the most pronounced wale; it is usually more durable, more attractive, most often used as the fashion side of the fabric, and the side visible during weaving. If there are warp floats on the technical face (i.e., if the warp crosses over two or more wefts), there will be filling floats (the weft will cross over two or more warps) on the technical back. If the twill wale goes up to the right on one side, it will go up to the left on the other side. Twill fabrics have no up and down as they are woven.
The fewer interlacings in twills allow the yarns to move more freely, and thus they are softer, more pliable, and drape better than plain-weave textiles. Twills also recover from wrinkles better than plain-weave fabrics do. When there are fewer interlacings, yarns can be packed closer together to produce high-count fabrics. In twills and higher counts, the fabric is more durable.
Weaving Glass Fibers:
Due to the low elongation coefficient (% of stretch before it breaks) of approx. 2.0 – 3.5 %, weaving Glass Fibers require very precise machine adjustments. It becomes a little simpler when the yarns have been texturized, as the extra bulk in essence increases the elongation coefficient by the grade of texture.
Due to the “brittle” nature of glass fibers, the finer yarns require preparation to withstand the harsh friction caused by the reed. This preparation is called Slashing.
Weaving Carbon Fibers:
When weaving carbon can be difficult, as it is fairly brittle. Also, it creates a lot of static and precautions need to be considered, in order to dissipate the electrostatics. Carbon dust can get into electrical devices and incur electrical shortages.
More dense or heavier yarns, around 270 tex and up, are preferably woven on creels.
Two basic creel designs:
a) Pin Creel
Here, the bobbin is stuck on a pin.
B) Shelf Creel
Here the bobbin stands on a shelf.
While there are many different designs of pin creels or shelf creels, it appears that the shelf creel provides more flexibility, as some glass fiber manufacturers provide rovings for inside and some for outside unwinding. Rovings with inside unwinding cannot be used for pin creels.
Technical fibers, such as Basalt, Glass, Carbon, Kevlar and others can be carded. The carding process allows also for blending materials. You could have a few feeding stations with weighing capabilities defining the required input. Those materials will then be transferred onto a conveyor belt. From there, they will be brought to a hopper which can blend the materials by the means of air. The hopper conducts the blended fibers to another conveyor system. This system can transport it to the next desired textile process. Often the fibers will be formed into slivers which allow for a spinning process afterwards.
Carder: A typical carder has a single large drum (the swift) accompanied by a pair of in-feed rollers (nippers), one or more pairs of worker and stripper rollers, a fancy, and a doffer. In-feed to the carder is usually accomplished by a conveyor belt and often the output of the cottage carder is stored as a batt or further processed into a roving and wound into bumps with an accessory bump winder.
The Process: Raw fiber, placed on the in-feed table or conveyor is moved to the nippers which restrain and meter the fiber onto the swift. As they are transferred to the swift, many of the fibers are straightened and laid into the swift's card cloth. These fibers will be carried past the worker / stripper rollers to the fancy.
As the swift carries the fibers forward, from the nippers, those fibers that are not yet straightened are picked up by a worker and carried over the top to its paired stripper. Relative to the surface speed of the swift, the worker turns quite slowly. This has the effect of reversing the fiber. The stripper, which turns at a higher speed than the worker, pulls fibers from the worker and passes them to the swift. The stripper's relative surface speed is slower than the swift's so the swift pulls the fibres from the stripper for additional straightening.
Straightened fibers are carried by the swift to the fancy. The fancy's card cloth is designed to engage with the swift's card cloth so that the fibers are lifted to the tips of the swift's card cloth and carried by the swift to the doffer. The fancy and the swift are the only rollers in the carding process that actually touch.
The slowly turning doffer removes the fibers from the swift and carries them to the fly comb where they are stripped from the doffer. A fine web of more or less parallel fiber, a few fibers thick and as wide as the carder's rollers, exits the carder at the fly comb by gravity or other mechanical means for storage or further processing.
Silica fibers made of sodium silicate (water glass) are used in heat protection (including asbestos substitution) and in packings and compensators. They can be made such that they are substantially free from non-alkali metal compounds.
Sodium silicate fibers may be used for subsequent production of silica fibers, which is better than producing the latter from a melt containing SiO2 or by acid-leaching of glass fibers. The silica fibers are useful for producing wet webs, filter linings and reinforcing material.
They can also be used to produce silicic acid fibers by a dry spinning method. These fibers have properties which make them useful in friction-lining materials.
Silica-Based Woven Textile products have been specifically designed for high temperature use.
Silica is available in a variety of product forms: Woven Fabrics, Woven Tapes, Non-woven Blankets, Bulk Fiber, Modules, Braiding Yarns, and other specialty forms such as Sleeving, Rope Gasket, and Cord.
Silica textiles provide excellent thermal and acoustic protection. These high-temperature resistant textiles products insulate and provide continuous protection in environments up to 1800°F (982°C), while maintaining their strength and flexibility.
Some woven Fabric contain a special coating that provides exceptional functioning when higher temperature performance, up to 2300°F (1260°C), is required
Non-woven Felts are available in a specially processed version that provides higher resistance to residual shrinkage (<1%) and degradation in extreme environments.
Siilica products can withstand excursions to 2900°F (1593°C) with minimal embrittlement and shrinkage.
Silica products are available in > 96% silica content. They resist oxidation, most corrosive solutions and chemicals, and they present no known health hazard.
Applications for Silica products range from welding blankets to satellite shrouds, firewalls to aircraft insulation, furnace curtains to thermal couple insulation wrap.
Silica Needlemats are made from special glass fibers with a filament diameter of 6-9 microns. They represent a modern product generation that, in any aspect, meets with all stringent requirements as to temperature consistency and environmental health standards. Silica glass fibers consist of nearly 95% SiO(2). Because of their low thermal conductivity they are the ideal raw material for the production of flexible insulation mats formed mechanically without the use of chemical bonding agents. These mats keep a very high chemical and physical stability up to 1,800 degr. F. (For application temperatures not higher than 1,200 degrees F, we recommend the more cost efficient E-Glass Needlemat).
The easy handling of the mats allow the cutting of the material into any desired shape and form.
Silica fabrics are consisting of special glass fibers with an average filament diameter of approx. 6 micron. They represent a modern product generation that, in any aspect meets with all stringent requirements as to temperature consistency and environmental health standards. Approx. 95% of the Silica glass fibers consist of SiO(2). They are the ideal raw material for the production of fabrics and tapes with very high chemical and physical stability of up to 1,800 degr. F. As per customers specification these Silica fabrics can be finished with various coatings.
Rebar (short for reinforcing bar), also known as reinforcing steel, reinforcement steel, is a steel bar or mesh of steel wires used as a tension device in reinforced concrete and reinforced masonry structures to strengthen and hold the concrete in tension. Rebar's surface is often patterned to form a better bond with the concrete.
The above description from the Wikippedia does not include Basalt, but nowadays, Basalt is available, as well.
Below are a few highlights utilizing Basalt instead of e.g. the commonly used Steel:
Higher specific strength
Approx. 10% of Basalt Rebar needed to achieve the same results as with Steel Rebars
Resistant to corrosion or deterioration caused by natural elements
Alkaline and acide resistant
Same thermal expansion as concrete, reducing the formation of cracks