2 IntroductionRayon is technically neither an artificial fibre or a natural fibre. It is derived from cellulose which is a natural product but it requires a lot of processing to become Rayon.
3 Viscose ProcessThe vast majority of rayon is fabricated using the viscose process. This process started in the early 1900’s.
4 Step 1: Cellulose; The purified cellulose that is used in the fabrication of rayon comes from processed wood pulp that is of a higher grade that that used for paper. Also known as “dissolving cellulose” or “dissolving pulp”. It is composed of long chain molecules.Step 2: Steeping; The sheets of cellulose are saturated in sodium hydroxide and left to set so that the sodium hydroxide can penetrate the sheets and transform it into “soda cellulose”.Step 3: Pressing; The soda cellulose is wrung out to remove the excess sodium hydroxide.Step 4: Shredding; The sheets of cellulose are shredded so they can be processed easier. Shredded cellulose is commonly referred to as “white crumb”.Step 5: Aging; Because white crumb has such a high alkalinity, so it is oxidized to lower molecular weights.Step 6: Xanthation; the cellulose crumbs are allowed to react with carbon disulphide to form cellulose xanthate.Step 7: Dissolving; The yellow crumb is disolved in an aqueous solution.
5 Step 8: Ripening; The viscose is allowed to stand for a period of time. Step 9: Flitering; It’s filtered to remove any undesolved materials that could cause defects.Step 10: Degassing; Bubbles of air that could also cause defects are removed.Step 11: Spinning; the material is moved into a bath containing; sodium sulphate, sulphuric acid and zinc sulphate. This causes the rayon filaments to bond together tightly.Step 12: Drawing; the newly bonded rayon filaments are stretched.Step 13: Washing; the rayon gets washed to remove any impurities that may remain.Step 14: Cutting; to be made usable the rayon is passed through a rotary cutter to create a fibre that can be processed the same as any other.
6 PropertiesHigh lustre, easily made to look like several types of fabric. (cheaper version of those fabrics)Highly absorbent.Does not insulate body heat.Not very durable.The original type of rayon was dry-clean only.It has a low elastic recovery (does not reclaim its original shape easily)
7 Pros Cheap Easily dyed Versatile Can be woven or knit Biodegradable BreathableEasily dyedBiodegradableSoft
8 ConsThe production method releases harmful chemicals into the environment.The fabric yellows with age.There are cheaper fabrics (i.e. nylon)Some people are allergic.
9 Bibliography"Making Rayon Fiber." Mindfully.org | Mindfully Green. Web. 9 June <http://www.mindfully.org/Plastic/Cellulose/Rayon-Fiber.htm>."Rayon Fiber - Rayon Staple Fiber, Rayon Textile Filament Fiber, Rayon Industrial Filament Fiber." FiberSource: The Manufactured Fiber Industry. Web. 10 June <http://www.fibersource.com/f-tutor/rayon.htm>."What Is Rayon?" WiseGEEK: Clear Answers for Common Questions. Web. 10 June <http://www.wisegeek.com/what-is-rayon.htm>.