Processing of Technora fibre in textile industries

Excerpt: TECHNORA is an aramid that is useful for a variety of applications that require high strength or chemical resistance. Technora is a para-aramid fiber made from co-polymers.

Dr. N.N. Mahapatra

Vice-President, Business Development, Colorant Ltd. 3225, Phase IV, G.I.D.C. Vatva, Ahmedabad-382445, Gujarat, India

TECHNORA is an aramid that is useful for a variety of applications that require high strength or chemical resistance. It is a brand name of the company Teijin. In other words, Technora is a para-aramid fiber made from co-polymers. It was independently developed by Teijin and has been commercially available since 1987. Technora, is a close relative of Kevlar and Twaron. It is a black-coloured fibre originally developed to replace steel belting in tyres. It is a very durable fibre and is resistant to breakdown from either flex or UV. Technora has low stretch characteristics but does not out perform carbon or Kevlar. It is particularly suitable for combining with carbon or Twaron in a sail to increase durability and it is also used to reinforce those areas which experience a lower initial load, but are required to maintain strength for longer.

Production of technora fibre

Technora is produced by condensation polymerization of terephthaloyl chloride (TCl) with a mixture of p- phenylenediamine (PPD) and 3,4'-diaminodiphenylether (3,4'-ODA).The polymer is closely related to Teijin's Twaron or DuPont's Kevlar. Technora is derived from two different diamines, 3,4'-ODA and PPD, whereas Twaron is derived from PPD alone. This relatively simple process uses only one amide solvent, and therefore spinning can be done directly after the polymer production. During development, the advantage of these superior properties make to meet the specific requirements of a great many applications.

Technora is made from copolymers and is produced in the different process from PPTA(poly-paraphenylene terephthalamide Besides meta-aramids like Nomex, other variations belong to the aramid fiber range. These are mainly of the copolyamide type, best known under the brand name Technora, as developed by Teijin and introduced in 1976. The manufacturing process of Technora reacts PPD and 3,4'- diaminodiphenylether (3,4'-ODA) with terephthaloyl chloride (TCl).This relatively simple process uses only one amide solvent, and therefore spinning can be done directly after the polymer production.

Properties of technora fibre 

Technora fiber is a very strong para-aramid fiber ideal for dynamic performance applications involving significant motion. It is strong and light weight. Technora is 8 times stronger than steel and 3 times stronger than fiberglass, polyester or nylon yarns. It shows little loss of strength even during repeated abrasion, flexing and stretching. Its molecular structure leads to a high modulus of elasticity, low creep and low stress relaxation, low thermal shrinkage and excellent dimensional stability. Technora is highly resistant to acids, alkalis and organic solvents, and is not vulnerable to damage caused by steam or sea water. The properties can be summarized as below; 

1. High tensile strength – weight for weight, Technora is eight times stronger than steel 

2. Abrasion resistant 

3. Low creep 

4. Low thermal shrinkage 

5. Long-term Dimensional stability 

6. Resistant to acids, alkalis and organic solvents 

7. Does not degrade in sea water or steam 

8. Thermal decomposition threshold of 932°F.

9. Good fatigue resistance 

10. Excellent resistance to corrosion, heat, chemicals and saltwater These characteristics are the result of a 100% paracrystalline structure with molecular chains preferentially oriented along the fiber axis.

 

  1. The above properties can be explained as below;

(1) High tensile strength** The tensile strength of Technora is 28g/de(24.7cn/dtex,350kg/mm2), which is 8 times as strong as steel and 3 times as strong as fiberglass, polyester and nylon of the same weight. This property will serve significantly to reduce weight.

(2) Fatigue resistance

High tenacity fibers generally show a loss of strength against repeated abrasion, flexure and stretch, it has excellent fatigue resistance, as compared to the other high tenacity fibers.

(3) Dimensional stability

It has a stiff and highly oriented molecular structure which leads to a high modulus, low creep and low stress relaxation. Due to its low thermal shrinkage, it has good dimensional stability.

(4) Heat resistance

It has a decomposition temperature of 500 C. It can be used at 200 C for long periods of time and, even at 250 C, it maintains more than half of its tensile strength that was measured at room temperature.

(5) Chemical resistance

It exhibits high resistance to both acids, alkalis and organic solvents. It is also resistant to sea water and steam. Technora offers a balance of advantages between meta-aramids (i.e. Conex and Aramet) and para-aramids (i.e Paramyd) by exhibiting a molecular structure which has both para and meta linkages. For safety/protective applications, Technora has been widely utilized as to be blended with Carbex to achieve superior FR properties versus other commercially available products. These blended products have been made available in knitted and woven forms. Compared to meta-Aramids (i..e. Aramet, Conex and Nomex) Technora's major advantages include (1) greater tensile strength and abrasion resistance (2) lower shrinkage at high temps (3) lower moisture regain. Compared to para-Aramids (e.g. Paramyd, Twaron, Kevlar) Technora's major advantages include (1) greater chemical, elongation and abrasion properties (2) lower moisture regain.

Uses of technora fibre;

a. It was also used to suspend the NASA Mars rover Opportunity from its parachute during descent. b. Automotive and other industries: c. Turbo hoses d. high pressure hoses e. Timing and V-belts f. Mechanical rubber goods reinforcement g. Linear tension h. Optical fiber cables (OFC) i. Ram air parachute suspension lines j. Ropes, wire ropes and cables k. Umbilical cables l. Electrical mechanical cable (EMC) m. Windsurfing sails n. Hangglider sails o. Drumheads p. Industrial Rope and Cord q. Parachute Cord r. Aerospace Applications s. Sports and Extreme Sports Rope and Cord t. Safety Rope u. Rescue Rope

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