An important part of the textile industry that is developing is medicine, health protection and hygiene sectors. There has always been a need for complex technical textiles with high standards in medical processes. The size of the development has grown in parallel with the progress and developments in textile technology and medical textile processes. These products start from the smallest finger bandages, surgical threads, complex composite structures used in bone transplantation, vascular prostheses and heart valves (valves) and urology. AIDS or hepatitis virus. Surgical gowns and sterile fabrics that provide protection against the smallest amount of body fluids that can carry body fluids are increasingly in demand. Diseased vessels are finely knitted or woven with tubular products; Ligaments damaged in the heart and knee during the By-Pass can also be replaced with strong textile, woven or knitted fabrics. It is an inevitable fact that the increasing world population has also grown this market.
An example of vascular tissue used for medical purposes (vascular occlusion, etc.) woven from bovine collagen and crimped polyester produced under the name Hemashield Gold-4 is shown below.
TECHNICAL YARNS AND THEIR CLASSIFICATION
Among the forms in which technical textile products are found, the building block of all except non-woven surfaces is yarn. Threads used in the production of technical textiles are called technical threads.Technical yarns are classified according to their raw material, form and structure.
Technical yarns according to their raw materials
Technical yarns are divided into two main groups as natural and synthetic according to the fibers used. It is possible to examine the yarns produced from natural and synthetic fibers in subgroups as low, high and very high strength yarns.
According to their structure and form technical threads
Technical yarns are divided into 6 groups according to their structure and form: filament, staple, plied, cable, braided and core yarns.
1-Filament threads
filament yarns; It is examined in four groups as monofilament, multifilament, center and strip yarns.
a-Monofilament yarns
Monofilament yarn is a yarn consisting of a single filament with a diameter of 100-2000 µm (0,1-2,0 mm).The cross-section of the filament can be round, profiled or hollow, depending on the end use. The cross-section of the fiber affects the properties of the yarn. For example, fibers with non-round cross-section increase the surface area and increase absorbency.
Monofilament yarns are yarns with high bending stiffness and abrasion resistance, and the diameter of the yarn varies according to the place of use.
b- Multifilament threads
Multifilament yarn is a yarn consisting of thin monofilaments in bundles of infinite length in a twist determined by the manufacturer. The cross-section shape of the filaments determines how close the fibers can get to each other in the yarn. ; Yarns consisting of filaments with non-round cross-section become more voluminous because the filaments in their structure prevent them from coming together. Multifilament yarns have a more flexible structure than monofilament yarns with the same properties.
c-Center or fused threads (Intermingled/commingled)
Centered or fused yarns are filament yarns in which the centering process is applied instead of twisting to prevent the fibers from separating from each other.'
Threads in which the same type of filaments are formed by centeringintermingled” can also refer to yarns in which two or more different types of filaments are formed by stabbing “commingled” yarns (such as carbon and polyester stabbing).'
The basis of the centering process, which is preferred in cases where low twist is desired; It is based on the fact that the air sent rapidly through the jet allows the filaments to pass into each other.The threads appear compressed, as regularly distributed punctuation points hold the filaments together.
d-Strip threads
Ribbon yarn;They are thin, narrow and ribbon-like film yarns produced from synthetic polymers such as polyamide, polyester and polyethylene.Ribbon yarn production; It is performed by cutting a flat polymeric plate or film 20-40mm wide and 60-100µm thick for technical applications. In addition, multifilament yarn-like strip yarns produced by fibrillating the strips separately and mechanically are also available.
2-Cut yarns
Staple or spun yarns are linear groups of short and staple fibers.The fibers are held together by twisting and twist is the most important parameter for these yarns. Synthetic or natural fibers (cotton, wool, jute, etc.) are used as raw materials.When synthetic fibers are used, they are cut into short lengths so that their physical dimensions resemble natural fibers; thus, they can be processed both in machines designed for natural fibers and as blends. Staple yarns have a yarn surface where a large number of fiber ends protrude and the fibers show a helical array.
3- Storey threads
Ply yarns are formed by twisting two or more single yarns together.Twisting is usually given in the opposite direction of the twist of the single ply yarn at the time of folding. In this way, a balanced structure in terms of twisting is ensured. Plied yarns according to the number of folded yarns;They are called 2-ply, 3-ply or multi-ply. Ply yarns are smoother, more stable, durable and have lower hairiness than single-ply yarns with the same properties.
4- Cable threads (I enduredbusiness bükülü threads)
Cable yarns are formed by combining several ply yarns and twisting them in opposite directions. Cable yarns can be SSZ or SZS or ZSZ or ZZS twist combination in single ply, ply and cable stages. These yarns are smoother and stronger.
5- Hair örgü thread
Knitting yarns are produced in tube form or as a single piece. Generally, 8-36 threads intertwine to form a braided structure at a certain angle. The way the threads are interlaced is in plain or twill pattern. The final yarn is twist stable and does not tend to untwist when stretched.They are quite flexible and their elongation rates are lower than twisted yarns with the same properties.
In the production of braided yarn, the braid is formed by wrapping and rotating the bobbins, which are arranged in pairs on a flat table, around each other. As seen below, there is a gear for each knitting yarn and an orbital channel in which this gear moves. There are two, three or multi-wheel machines according to the number of yarns available in the hair weave.
PROTECTIVE CLOTHING
Protective clothing is the clothing worn to prevent the risk of exposure to harmful substances and bad environmental conditions, to protect them from this risk and/or to reduce this risk.
- Firefighters working in various risk environments,
- Security personal,
- auto racers
- medical personnel
- heavy industry workers etc.
Clothing produced for the purpose of protecting people from external factors is called protective clothing.
The features of these garments vary according to the needs and expectations of the industry in which they are used.
This type of clothing;
They are produced with high-performance fibers that can withstand high temperatures and have high strength, or with minor changes in yarn structures and various finishes. The most important issue in protective clothing is the protection of human life. The garment itself provides protection rather than a separate textile material. In this area, fabric is the critical element in all protective clothing and other protective textiles. It is the properties of the fabric that will determine the degree of injury suffered by the victim of an accident, as the safety barrier between the wearer and the potential source of injury.
The types of protective equipment specifically mentioned in the literature are as follows;
- tents
- Helmets (helmets),
- Gloves (for hand and arm protection)
- sleeping bags
- Survival bags and suits
- Fire-protective clothing
- heat resistant clothing
- double sided jackets
- ballistic resistant vests
- Biological and chemical protective clothing
- explosion proof vests
- Flame retardant caps and gloves
- Molten metal protective clothing
- buoyancy vests
- Military protective clothing, including anti-freeze and ducted warm weather clothing
- Submarine protective suits
- Diving suits and diving skins
- life rafts
- Special towels and cloths
- Radiation protective overalls
- survival clothes
- Ropes and seat belts
The types of work and activity specifically mentioned in the literature, for which protective clothing and materials are produced, are:
Police and security guards
Mountaineering
caving climbing
Kayak
Aircraft personnel (military and civilian)
soldiers
sailors
submariners
Foundry and glass workers
firefighters
Water sports
Winter sports
Commercial fishing and mountaineering
Seabed oil and gas equipment workers
health care
racing drivers
astronauts
Coal mining and health warehouse workers
Technical textiles offer important properties for military forces that need to move, live, survive and fight, especially in hostile environments. Military forces must carry or wear all the essentials for their comfort and survival and therefore they need the lightest, unbreakable, robust and high performance special uniforms and equipment.
The vital requirements to protect individuals from the environment and the dangers of war have led the world's leading nations to spend significant resources developing and providing the most advanced technical textiles for military use.
- Heat
- Alev
- Molten metal splashes
- Extreme cold and freezing
- Protection from radiation sources and the like
It is the main demand for both civil and military protection applications. Conditions affecting demand;
- Special environmental hazards
- Degree of protection
- comfort level
- Durability of clothing
- Aesthetics and laws
The consumer's awareness of possible dangers and similar sociological factors. One of the ways to protect yourself from the sun's harmful UV rays is clothing that protects from the sun. Although many fabrics block the sun's UV rays, not all fabrics can be included in the class of sun-protective clothing. Clothes that protect from the sun are separated from the classic summer fabrics. Wearing clothing that protects against UV rays is the healthiest and most common method known to reduce the risk of developing skin cancer. Determining the properties of protective clothing according to the color of the skin and the reflection rates of the environment will lead people to use protective clothing more consciously.
In general, protective clothing can be classified into 8 main categories;
1-Thermal Protective Clothing:
These are clothing that protect against heat, flame, splashes of molten metals, radiation and extreme cold. Thermal protective clothing covers a wide range of materials that resist exposure to flame and heat or insulate against heat transfer in extreme environmental conditions. This type of clothing ranges from uniforms worn by petrochemical and electrical workers to clothing worn in foundries and other high-temperature facilities. Garments can be single or multi-layered.
2-Nuclear, Biological and Chemical (NBC) Protection Clothing:
These are mostly for military use. They are multi-layered structures, often woven from synthetic or natural fibers, as well as carbon fibers and foam.
3- Protective Clothing Against Chemicals:
It is clothing that provides protection against chemical substances that harm people. More than 100 thousand chemicals with very different toxic properties are used in the world. As the risks arising from toxic chemicals have emerged, the use of clothing and equipment acting as protective against chemicals has increased. This is partly due to regulations and standards that prescribe the use of chemical protective clothing and equipment.
4- Protective Clothing Against Mechanical Factors:
This type of clothing is worn to protect against damage such as cuts, tears, abrasions and metal splashes. In order to provide protection against all these factors, the clothes must be produced from high-strength textile fibers.
5- Electrical Protective Clothing:
This type of clothing is worn to protect against electrical damages, which are examined in two separate groups as electromagnetic and electrostatic. Persons working with high voltage should definitely prefer non-flammable, durable and comfortable conductive protective clothing. For this, clothes made of natural, synthetic and metal threads are preferred.
6- Cleanroom Clothes:
The clothes called with this name are the clothes that protect the environment from pollution caused by humans. Considering that the human body sheds 1 billion skin cells every day and the human body and clothing contain some dust, hair, ions, cosmetics, perfume, tobacco, how much does this type of clothing prevent pollution in the optics, space vehicles, food and pharmaceutical industry and automotive industry? It cannot be denied that it has an important place.
7-Protective Clothing Against Radiation:
This type of clothing is necessary for workers working in X-ray environments, working in cancer treatment centers and other environments exposed to ionizing radiation.
8-High Visibility Clothing:
These garments are also considered as protective clothing. Basically, it is necessary to examine it as three different types.
- Reflective (reflective) materials: They glow when under the influence of light.
- Photoluminescent materials: They absorb and store daylight or artificial light and turn green-yellow in the dark.
- Fluorescent materials: It appears as a red orange color throughout the day.
The comfort of the clothing is also important for the protective clothing to fulfill the function of protecting human health and safety. A garment that does not provide adequate comfort reduces efficiency in performing the task undertaken. Steel vests, which used to be made of heavier materials, are now made of lighter and more durable textile materials. (in aramidsn) is produced. Because the health and safety of employees in many workplaces around the world are in danger, international and local legal regulations that require the use of protective clothing have been tightened. In sectors that require the use of protective clothing, awareness of wearing protective clothing is increasing. In addition to the factors mentioned above, the current wars in the world and the existence of the constant threat of war, developments in the sector and business lines that require the use of protective clothing, and severe climatic conditions are the most important factors determining the demand for the sector.
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