Within the current technologies from which the textile world can benefit, we must review nanotechnology, let’s first define this concept in order to understand how we can apply this technology to the textile sector.
Nanotechnology is the study, design, creation, synthesis, manipulation and application of materials, devices and functional systems through the control of matter on a nano scale, and the exploitation of phenomena and properties of matter on a nano scale. A nanometer is one millionth of a millimeter, and with these units of measure it will be the ones that will work on this technology.
When we manipulate matter on such a tiny scale of atoms and molecules, totally new phenomena and properties are achieved. Therefore, scientists use nanotechnology to create new and inexpensive materials, devices and systems with unique properties. The true potential of nanomaterials, or materials on a nanometric scale, lies in the exceptional behavior they manifest as a consequence of their small size.
Properties such as electrical and thermal conductivity, color, chemical reactivity, elasticity and resistance are increased and favored by the smaller size of matter. Nanotechnology is being studied and applied in sciences such as Physics, Chemistry, Molecular Biology, Biochemistry, Electronics and Computer Science.
The types of nanoparticles currently being worked on are divided into four main groups, according to their origin:
- Those derived from silicon: nano-clays, Poss, silica nanospheres.
- Carbon derivatives: where we will find Fullerenes, Carbon nanotubes and Carbon nanofibers.
- Of metallic origin and derivatives: Ag, Au, Cu, Zn, ZnO, CuO, Sb2O5, TiO2, etc …
- And polymeric origin: Dendrimers and nanocapsules.
Due to their tiny size, most nanomaterials can pose a serious health hazard, eg: (if inhaled, spontaneous combustion risks, possibility of catalytic activity, introduction to the organism dermal route, etc …); this usually occurs for example during the period of time between its entire synthesis process and its preparation for the additivation of polymeric matrices; although in other sectors there is also a high risk of exposure to these nanoparticles. Hence, the methodology and legislation for the manipulation and control of nanomaterials are very restrictive.
Nanotechnology applied to the textile sector is divided into different general applications, these are: the development of technical fibers additives with NPs, the creation of nanofibers, nano-finishes and other applications such as nano-velcro and high performance fiber spinning from Carbon nanotubes.
Regarding the development of technical fibers additive with nanoparticles, the process is based on spinning by extrusion, where once the pellet is already made with the nano material or nanomaterials needed for the search of a certain property in the final product, It is placed in the hopper of the spinning machine and after the extrusion process, plus a stretch and a winding, we will achieve the desired filament.
The creation of nanofibers is based on three main systems: These are electro spinning and bicomponent fibers; the third is the so-called “islands in the sea”, in this last system and thanks to the extrusion heads that with certain shapes and diameters are used in its manufacture and to the mixture of two polymers of different nature (the two polymers added in the hopper and subsequently cast, are guided in a liquid state through a complex system of thin metal sheets with numerous holes) a two-component filament is obtained, where there are several inner souls of the desired nanofiber and a “coating” of these nanofibers. Later we can eliminate that part of the filament that covers the nanofibers, due to its soluble characteristic, remaining only with the nanofibers.
The types of technical nano-finishes applicable on fabrics of different nature through nanotechnological techniques are the following:
- Nano-finished anti-stains.
- Nano-finished antimicrobial.
- Photocatalysis Self-cleaning fabrics (selfcleaning effect).
- Nano-finished pollen.
- Flame retardant nano-finishing.
- Nano-finished anti-odor.
- Nano-finished for UV protection.
Currently there are other lines of research in reference to new possibilities within nano-finishes such as adsorption and shielding effects of infrared radiation, color-changing dyes and thermal regulators. There is already a commercial brand on the market that also offers a nanotechnological alternative to the use of fluorocarbons.
The application of nano finishes by Sol-Gel technology, allows the application of nano particles of a synthetic polymer with a certain load, which turns the article into a reagent, the reaction between the nano-finishing and the fibers gives it a permanent character. Advantage that gives the final product a very large added value. Obtaining high performance fibers from CNTs is another innovation with a future that nanotechnology offers, to obtain these types of fibers, spinning and twisting and even braiding processes of carbon nanotubes are being investigated and developed. These processes are technically “similar” in conception to those used in micrometric scale for more conventional fibers.
We will now explain in a general way the processes of nanoparticles additivation to thermoplastic polymers. What is needed is to achieve the additivation of the nanomaterials precisely to be able to have a very good dispersion within the polymer matrix and we will achieve it with the help of gravimetric feeders and a polymer extrusion system, finally after touring the fields available to the extruder, the pellet with the homogeneously mixed nanomaterials becomes a molten “asparagus”, which is cooled and cut into a pelletizer to convert it into pellet again. As we have said before, a series of security measures are required in their processing
The examples of nanotechnology applications in the textile sector can be seen in industrial textiles, functional textiles, High-tech textiles (astronautics, smart textiles, etc.), high performance textiles, engineering textiles; in textiles that provide exchange functions such as filtration, insulation, conductivity, drainage, permeability, impermeability and absorption; functions of biocompatibility and biodegradability, anti mites and bacteria and finally also protection against mechanical, chemical, radiological, fire, etc.
NANOTECHNOLOGY APPLIED TO BOBBIN LACE
With the fibers described above, nanotechnology applied to bobbin lace, achieving a better ductivility in our work, our technique is not limited to natural fibers, but that, nanotechnology opens up a range of possibilities and discoveries for new fields of exploration.