Twaron

Key takeaways

Twaron belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Twaron to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Twaron from memory before moving on to harder problems.

Reference excerpt

Twaron (a brand name of Teijin Aramid) is a para-aramid, high-performance yarn. It is a heat-resistant fibre, helps in ballistic protection and cut protection. Twaron was developed in the early 1970s by the Dutch company Akzo Nobel's division Enka BV, later Akzo Industrial Fibers. The research name of the para-aramid fibre was originally Fiber X, but it was soon called Arenka. Although the Dutch para-aramid fiber was developed only a short time after DuPont's Kevlar, the introduction of Twaron as a commercial product came much later than Kevlar due to financial problems at the Akzo company in the 1970s. As of 2000, Twaron had become a global material and had been integrated into the global markets. Twaron has been around for over 30 years.

History

This is a chronology of the development of Twaron:

In 1960s a research program starts for "Fiber X." In 1972 the ENKA Research laboratory develops a para-aramid called Arenka. In 1973 Akzo decides to use sulfuric acid (H2SO4) as a solvent for spinning. In 1974 New process route was found at Akzo Research laboratory, using N-methylpyrrolidone (NMP) with a co-solvent (auxiliary solvent) with an ionic component (Calcium Chloride (CaCl2) to occupy the hydrogen bonds of the amide groups in order to dissolve the aromatic polymer. In 1976 a pilot plant is built. In 1977 first production starts. In 1984 the product is renamed Twaron. In 1986 commercial production is started at five locations and nine plants. In 1987 Twaron is introduced as a commercial product. In 1989 the aramid business of Akzo becomes an independent Business Unit called Twaron BV. Since 2000 Twaron BV has been owned by the Teijin Group, now called Teijin Twaron BV and based in Arnhem, Netherlands. The main production facilities for Twaron are in Emmen and Delfzijl. In 2007 Teijin Twaron expands for the fourth time in six years and also changes its name into Teijin Aramid.

Production

Polymer preparation Twaron is a p-phenylene terephthalamide (PpPTA), the simplest form of the AABB para polyaramide. PpPTA is a product of p-phenylene diamine (PPD) and terephthaloyl dichloride (TDC). To dissolve the aromatic polymer Twaron used a co-solvent of N-methyl pyrrolidone (NMP) and an ionic component (calcium chloride CaCl2) to occupy the hydrogen bonds of the amide groups. The invention of this specific process was done in 1974 at AKZO Research Laboratory in Arnhem by a team consisting of Leo Vollbracht, Teun Veerman (assistant of Leo Vollbracht) and Wim Engelhard (trainee, who actually discovered NMP as the appropriate solvent to keep the growing polymer as long as possible in solution; he also discovered that high speed mixing of PPD and TDC was necessary to obtain a sufficiently long polymer chains). The patent of the newly discovered process route led to a patent war between AKZO (Fibre X) and DuPont (Fibre B) as Dupont initially used the carcinogenic HMPT (hexamethylphosphoramide). Despite heavy research DuPont now also applies the AKZO patent for their Kevlar process and use the less hazardous NMP.

Spinning

After the production of the Twaron polymer in Delfzijl, the polymer is brought to Emmen, where fibres are produced by spinning the dissolved polymer into a solid fibre from a liquid chemical blend. Polymer solvent for spinning PPTA is generally 100% anhydrous (water free) sulfuric acid (H2SO4). The polymer is dissolved by mixing frozen sulfuric acid in powder form with the polymer in powder form and gently heating the mixture. This process, which differs from the more difficult DuPont process, was invented by Henri Lammers and patented by AKZO.

Use

Twaron is a para-aramid and has automotive, construction, sports, aerospace, and military applications, e.g., in modern body armor, fabric, and as an asbestos substitute.

Protective gear (heat resistant / ballistics) flame-resistant clothing, protective clothing and helmets, cut-fast or heat-hardy gloves, sporting goods, textiles, ballistic vests Composites composite materials, technical paper, asbestos replacement, hot air filtration, sailcloth, speaker woofers, boat hull material, fiber reinforced concrete, drumheads Automotive brake pads, turbo hoses, V-belts and Timing belts, tires that incorporate Sulfron (sulfur modified Twaron), mechanical rubber goods reinforcement Linear tension optical fiber cables (OFC), ropes, wire ropes, electrical cables, umbilical cables, electrical mechanical cable (EMC), reinforced thermoplastic pipes Yacht construction on monohulls and catamarans (such as the Catana 581), the glass fibre hull may have an inner skin of Twaron aramid fabric laminated over the core to increase stiffness and impact resistance.

See also Fibers Kégresse track Nylon Technora Vectran

References

JWS Hearle (2004). High-performance fibres. Woodhead Publishing Ltd., Abington, UK - The Textile Institute. ISBN 978-1-85573-539-2. Doetze J. Sikkema (2002). "Manmade fibers one hundred years: Polymers and polymer design". J Appl Polym Sci. 83 (3): 484–488. Bibcode:2002JAPS...83..484S. doi:10.1002/app.2254. L. Vollbracht and T.J. Veerman, US Patent 4308374 (1976)

External links Official Twaron website General Aramid information

Worked examples

Example 1 — a first encounter with Twaron

Start with the simplest possible case. Write down what Twaron claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Twaron before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Twaron ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Twaron

In research: Twaron appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Twaron in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Twaron is common in secondary-school and first-year university syllabi. It links to neighbouring topics Brand name materials, Bulletproofing, Cables, so understanding it makes those chapters shorter.
In everyday life: Look for Twaron outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Twaron in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Twaron means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Twaron out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Twaron in simple terms?

Twaron (a brand name of Teijin Aramid) is a para-aramid, high-performance yarn. It is a heat-resistant fibre, helps in ballistic protection and cut protection.

Why does Twaron matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Twaron?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Twaron.