The Chemistry of Knitting

Introduction

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  • Knitting is a craft that has existed for hundreds of years.  The oldest knitted artifact dates back to 11 CE in Egypt!  Knitting requires yarn, and two knitting needles.  It has been used commercially to produce goods such as stockings, and has turned into a craft more than a trade good this century.

  • I chose to study knitting’s chemistry because I love to knit!  Knitting provides a therapeutic method to reduce stress.  It is no longer an old woman’s hobby as many men and women learn the craft to express themselves through their craft.  Yarnbombing is form of graffiti where knitted goods cover a building, statue, or other public display.  Many designers use knitted wear to express their personality and technique in the trade.  

  • Knitting affects my life as my mom taught me how to when I was in elementary school and I have made hats, socks, sweaters, and everything in between.  She is a knitting designer and has even written her own book.  I can make my own products however I’d like.  I can change things and add my own spin to my creations.


Composition of ...

Wool- a common fiber used in yarn.

  • Keratin 33%, (proteins)

    • Formula for all but one protein:  +NH3-CHR-CO2

    • Carbon 50%

    • Hydrogen 12%

    • Oxygen 10%

    • Nitrogen 25%

    • Sulpher 3%.  

  • Grease 28%

  • Suint 12%

  • Different Impurities 26%

  • Mineral Water, 1%

Needles

  • Bamboo

    • 5.2% Water (H2O)

    • 2.35% Ash

    • Holocellulose 70.28%

    • Klason Lignin 25.52%

    • Pentosan 17.58% (C2H6Na2O10S2)

    • Cellulose 52.70% (C6H10O5)

  • Aluminum

  • Steel

    • 2.1% Iron

    • 97.9% Carbon

  • Wood

    • 50% Carbon

    • 42% Oxygen

    • 6% Hydrogen

    • 1% Nitrogen

    • 1% Other Elements

Main Chemicals, Compounds, Components

Yarn is commonly made up of wool, even though it can be made up of many substances such as cotton, silk, and acrylic.  Wool is made up of many different components.  Keratin and suint is one of them.  Keratin is a protein similar to our hair and nails. +NH3-CHR-CO2 is the base formula for all but one protein.  Keratin is made up of 50% Carbon, 12% Hydrogen, 10% Oxygen, 25% Nitrogen, and 3% Sulfur.  Wool comes off the sheep and then processed, or woolscoured, to clean the wool. It removes suint, dirt, and woolgrease.  Purified woolgrease is lanolin which is used in medicinal preparations and toiletries.  Detergents clean this wool.  The wool is then dried and spun into yarn.  This yarn is then sent to textile or carpet mills to be woven into fabric, made into carpets, or further dyed and spun into yarn.  

But in order to knit, you would need knitting needles.  Needles have been made out of wood for ages.  Wood is naturally produced by trees or other woody plants. The first woody plant was discovered in New Brunswick approximately 395 to 400 million years ago. Wood has been used for millennia as fuel or as a construction material.


Chemistry's Role

Wool is naturally produced by sheep, or the hair other animals such as alpaca or llama.  Wool is first shorn off the sheep, then it is sent to be woolscoured, or cleaned.  Detergents clean the suint, dirt, and woolgrease out of the wool.  Once the wool is cleaned and dried, it is spun to form yarn.  Wool’s keratin plays a large role in its structure. There are three protein shapes.  Intermediate filament (IF) protein are “Fibrillar” as they consist of rod-like structures of α-helices, and have globular or random-coil configurations.  Intermediate-filament associated proteins (IFAPs) are known as “Matrix” proteins as they form less-organized non-directional matrix where rods are embedded.  They contain very high levels of sulfur (up to 25% of amino-acid residues may be half-cystine), and they are the most common.  Matrix proteins are responsible for disulphide bond crosslinking, gives fiber mechanical and chemical integrity.  The last protein is High tyrosine-glycine (HGT) protein.  They are rich in tyrosine and glycine. Their occurrence is limited to certain parts of the fiber.

These proteins relate to the yarn’s structure.  Cross-linking between filaments and the matrix proteins are responsible for observed mechanical properties of the fiber.  Stretching causes α-helices to extend into β-pleated sheets.  Recovery is assisted by retractive force of strained disulphide bond network, similar to rubber.  These structures are similar to polysulphide rubbers.  There is a protective layer of scales that surround the cortical cells.  It is similar to high class climbing ropes, where coiled bundles are coiled, and then surrounded by a protective sheath.

Knitting needles are made of wood, bamboo, and metal needles are all naturally occurring substances.  Needles, simply put, are pointed sticks.  Plastic is synthetic yet made out of petrochemicals from oil.  Needle material type affects how the yarn interacts with the needles.  Metals can be slippery and sharp, plastic tends to be grippy, bamboo is smooth and light, wood is similar to bamboo, but not as light or nice.  Plastic are lower quality needles, even though cheap needles can be made out of each substance.


Background Research

Nålebinding (translates to “needle-binding” in Dutch) is older than knitting and crocheting.  It is the first method related to knitting and crochet.  The oldest knitted artifact is a pair of Egyptian socks dated to 11th Century CE.  However it is suggested that knitting is older due to advanced stitching techniques.

The earliest known knit items in Europe were made by Muslim knitters hired by Spanish Christian royal families.  Several European paintings depict the Virgin Mary knitting.   The earliest known knitting pattern published in 1524.   Queen Elizabeth I preferred silk stockings over wool stocking as they were softer, finer, more decorative, and much more expensive.  Some of these stockings still exist to this day.  Knitting schools were established to help the poor learn how to knit and how to manufacture it.  

In Scotland, families were dedicated to creating sweaters, socks, etc.  Fair Isle, a technique of stranded colorwork, developed there. Wool sweaters were necessary to keep sailors warm as the natural oils, lanolin, suint, and woolgrease, in wool provided element of protection against the rain and weather.  Cables knits developed in the early 20th century creating Aran sweaters.  Cables provided warmth as the cable created pockets of air to warm the sailors.

However, the knitting machine called the stocking frame, was invented in 1589.  This caused knitting to shift from handmade to machine-made goods during the Industrial Revolution.  Families would own one of these machines, employing the entire family.  In the mid-nineteenth century, knitting transitioned to work in steam-powered factories.  Hand-knitting transitioned a hobby during this time.  Knitting resurged during the twenty-first century, employing a new type of media called yarn-bombing, a form of graffiti where knitwear is used to cover statues, benches, trees, etc.   

Yarn starts out on the sheep, where the sheep is shorn.  The wool may be cleaned at this time, or the wool will be cleaned after being sent in bales to the factory.  A picker then combs through the wool to pick out lumps.  The wool is then carded through a carding machine.  A carding machine has hundreds of wires meant to separate and pull the fibers into a parallel form.  After the wool is carded, it is pulled through a funnel-shaped device to produce a thicker, rope-like string of fiber.  The wool is combed if the yarn needs to smooth and fine.  The wool is referred to as a sliver at this point of the process. These slivers combine, and move along rollers to elongate and twist the sliver into a longer strand.  These drawn-out strands may be drawn-out again if needed.  The sliver is then fed through a roving machine, elongating and twisting the sliver more.  The sliver is now called roving.  Spinning is the last step for the roving.  People have spun recreationally using spinning wheels.  Commercially, roving is spun with ring spinning, and open-end spinning.  Open-end spinning eliminates the roving step.  Yarn may be dyed before or after it is spun.


Resources

About the Author
Paul Haesemeyer is a senior at Billings Senior High School.  He has painted a mural for Billings Senior High’s 75th anniversary.  Paul is Student Body President and looks forward to studying out-of-state next fall.  Paul has lettered in Orchestra, and is a member of National Honor Society.







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