Corn Fiber: Properties, Manufacturing, Benefits and Uses

What is corn fiber?

Corn fiber is a comparatively new innovation in the textile industry.Vietnam is deloping in many natural and innovative development and procesing them in garment and fahsion industry; in among of them is corn fibre. Corn Fibre is also called Ingeo fibre . Corn is an agricultural product with large quantities of starch which manufacturers extract from the plant fibers and break down into sugars that are then fermented and separated into polymers. At this point, the corn fibers are paste-like substances which are extruded into delicate strands that are cut, carded, combeded and spunned into yarn. Besides the chemical processes, the rest of the process is similar to what is done with wool procedures.

Corn is only for eating but also wearing

Corn fiber is a manmade fiber derived entirely from annually renewable resources. These fibers have the performance advantages often associated with synthetic materials, and complementing properties of natural products such as cotton and wool. Corn fibre is composed of lactic acid, which is produced by converting corn starch into sugar & then fermenting it to get lactic acid. Lactic acid can be considered a commodity chemical sleeping giant, with advantages including:

1. It can be made from biomass.
2. It has both an hydroxyl group and a carboxylic acid group.
3. It is optically active.

The fabric made from corn fibre is easy to care for, cheap and very comfortable to wear. Moreover, it is stain-resistant and UV resistant. This fabric can be used for several applications such as ready-made apparel, diapers, bedding, carpets and upholstery. Moreover, the production of this fabric requires the use of less fuel, and is hence environment-friendly as well.

The process for manufacturing the polymer is used to make corn fibers on an industrial scale centers on the fermentation, distillation and polymerization of a simple plant sugar, maize dextrose.

The production and use of corn fiber means less greenhouse gases are added to the atmosphere. Greenhouse gases are the chief contributor to global climate change. Compostability and chemical recyclability mean that under the right conditions and with the right handling, the complete life cycle of production, consumption, disposal and re-use is neatly closed.

The important attribute of corn fibre

The fiber comes entirely from corn which is fully eco-compatible and has exceptionally qualitative features. The properties associated with the corn fiber are:

1. Corn fiber is available in both spun and filament forms in a wide variety of counts from micro denier for the finest lightest fabrics to high counts for more robust applications.
2. It is derived from naturally occurring plant sugars. When products come to the end of their useful life, they can be returned to the earth, unlike petroleum based products that can only be disposed of through thermal recycling, physical recycling or landfill.
3. Corn fiber balances strength and resilience with comfort, softness and drape in textiles. Corn also uses no chemical additives or surface treatments and amazingly, is naturally flame retardant.
4. It is reported to have outstanding moisture management properties and low odor retention, giving the wearer optimum comfort and confidence.
5. Corn fiber filament is said to have a subtle luster and fluid drape with a natural hand offering a new material to stimulate creativity.
6. Corn fiberfill allows outerwear garment makers to offer a complete story and a more environmentally friendly alternative to polyester and nylon combinations in padded garments.
7. It reportedly outperforms other synthetics in resistance to UV light, retaining strength color and properties overtime.
8. Easy care, independent wash and dry-cleaning tests have shown that the Corn fiber garment tested can be laundered using standard washing and drying machines.
9. Independent testing has confirmed Corn fibers have superior or equal performance to polyester in key active wear applications.

The advantages of corn fibre

1. High melting point.
2. High crystallization degree and good clarity.
3. The fiber also has the high strength which is same as normal poly fiber, so its use is very abroad.
4. The Corn fiber has the characteristics of lustrous silk, has excellent hand touch and brightness and so on. Garments in corn fiber reportedly demonstrated good soil release, quick drying and show excellent after-wash appearance.

The advantages of corn fibre

1. The Corn fiber textile is too rigid and frail.

Manufacturing process of corn fibre 

First step is the process of separating starch from the bio-mass basically wet milling is the process adopted. The starch is processed into dextrose that is then converted to lactic acid using a fermentation process using bacteria e.g. Homolactic Lactobacteriaceae family. Monomer lactide collected through condensation and then purified through vacuum distillation. Using a solvent free process like Ultrafiltration, Nanofiltration and Ion-exchange process we obtain PLA resin from the lactide.

The lactic acid exists in two optical isomers L-isomer & D-L isomer. The polymer produced from D-L isomer by using direct condensation requires solvent under high pressure & high vacuum. Hence L isomer is used. Lactic acid firstly condensed to transform it into short chain PLA. It is then converted into lactic acid by using vacuum distillation. No solvent is required during distillation. The final stage is ring-opening polymerization.

Flow of Manufacturing:

Corn fiber production sequence is:

Seeds, Soil, Water, Carbon dioxide, Sunlight

↓Grow-months↓

Biomass, ideally corn

↓Harvest/Wet Mill↓

Starch

↓Acid/Enzyme Hydrolysis↓

Dextrose

↓Fermentation↓

Lactic Acid

↓Polymerise↓

Crude Polylactic Acid Pre-polymer

↓Depolymerise↓

Crude Lactide monomer

↓Fractional Distillation↓

Pure lactide monomers

↓Blend/Polymerise↓

Polylactic Acids

↓Modification for end-use↓

Granules for extrusion etc.

↓Melt Spinning↓

“Crop-Based” Fibres

Producing the lactide with the right purity and stereochemistry to make decent fibres is not trivial. In a recent Cargill patent, the refining process, intended to be able to cope with crude lactic acid feedstock, was illustrated as follows:

Feed Crude Lactic Acid to Evaporator continuously
↓
Remove water or solvent → discard or recycle water, solvent or by-products
↓
Feed concentrated lactic acid to a pre-polymer reactor
↓
Polymerize to form pre-polymer by removing water → discard or recycle water, solvent or by-products contaminated with lactic acid
↓
Feed in catalyst→ Feed pre-polymer to lactide reactor→Remove high-boiling unreacted polymer
↓
Remove crude lactide as vapour
↓
Partially condense crude lactide →Remove lactide impurity as a vapour
↓
Purify crude lactide in a distillation column →Remove lactide impurities
↓
Remove purified lactide as high-boiling bottoms from the column
↓
Polymerisation

Yarns, fabrics and garments made from corn fibres can be processed on conventional machinery through all of the manufacturing stages; there is no need for any capital investment in plant. In many of the downstream sectors fibre spinning, yarn spinning, fabric production and dyeing and finishing- corn fibre is comparable with polyester. Both are available in filament and staple form; they are melt spun; weaving and knitting set up conditions are similar; fabrics can be heat treated to give dimensional stability and they are both dyed with disperse dyes.

Yarn of processing of pure corn fibre and its plends

 

Corn fibre is processed into pure Corn yarn and also blended with natural fibre like cotton, wool, silk and synthetic fibres that include polyester, viscose etc. by ring spinning method which include:

Cotton Spinning System

Spinning through cotton spinning system involves following stages:

 A. Opening, cleaning and blending:
Staple fibres in form of large bales arrive at the yarn processing plant. It is very important to separate or open the fibre mass to single fibre state or as close as possible. the opening and blending machine separate and blend the fibres from different bales.

 B. Carding:
The carding is one of the most important processes of short staple spinning. Carding is a process where the tufts of fibres are converted into individual fibre forms. Carding is often called the heart of the spinning because of its main cotton opening mechanism. It is very important to individualize fibres in the card to make them able to convert in yarn in the later processes.

C. Combing:
This is an optional step for high quality of superior evenness, smoothness, fineness and strength, fibres are combed. Card sliver are fed to the machine where several card slivers are combined. This smoothness out the card sliver pulls out the fibres into layer and reforms a new sliver called as a comb sliver.

D.  Drawing:
In the Drawing section is doubled, blended and drafted to parallel all fibres and to control and even sliver for production of high-quality yarn.

E. Roving
Roving is an intermediate process during the conversion of fibres into yarn. The purpose of roving is to prepare a better input package for the ring frame. The roving is produced on compact small packages called bobbins, which are more convenient to transport and have less chances of damage as compared to sliver cans. That is why roving is still an important process in ring spun yarn.

F. Spinning
The final process in this system is the spinning operation. During spinning, the roving is attenuated to the desired diameter called the final draft and the desired amount of twist is inserted.

G.Weaving
Weaving is the process of interlacing warp and weft yarns for constructing fabric.

H. Warping
Tensions should be kept low. In general, 0.3 to 0.35 g/Denier has been adequate for warping without compromising the fiber’s stretch characteristics nor the warping efficiency. Where Friction Textured yarn is to be used in the warp then this should be clearly specified to the yarn supplier to ensure sufficient lubrication (0.75% oil content if the yarn is to be sized), and a high degree of interlacing (normally 110 tacks/meter level). When warping spun Corn fiber yarns and a break occurs, care should be taken that the ends are tied two inches above the break point of each end. Due to the high fiber resiliency the yarn tends to un-twist near the break point and create weak spot.

F. Sizing
Friction Textured Filament Corn fiber yarns have been warped and woven successfully without sizing. These yarns were specifically prepared with 1.75% oil content minimum, and a compaction level of 110 tacks/meter (NSY, no size yarn). However, the success of being able to use the Corn fiber Friction Textured Filament yarns depends on many variables. These include yarn Denier and filament count, fabric construction such as density and weave design, loom type and operating conditions. Size selection, as outlined before is dictated by the conditions necessary for its removal during wet processing. Both PVA and Polyester (WD size from Eastern Chemicals) are suitable for sizing the Corn fiber yarns. Both can be applied in relatively mild conditions, size solution and drying temperatures). Also, both can be washed off at mild alkaline conditions (below a pH of 7.5), and relatively low temperatures (normally not exceeding 80ºC). Further yarn lubrication can be achieved by a kiss roll application of an over-oil after the yarn has been sized and dried, before the Slasher Reed.

The amount of size required on the yarn is dictated by the amount necessary to have a good encapsulation of all the yarn fibers. Typically, for a Filament Corn fiber yarn 4 to 5% size pick-up, and for staple yarn 8 to 10% size pick-up have produced good results.

Typical sizing conditions for filament Corn fiber yarn are listed below:

• Type of size; PVA mixed at 10% solids solution.
• Size box Temperature 35 to 40º C
• Drying temperature of 75 to 85º C
• Neutral to slightly overfeed (6%) warp sheet tension.

G. Weaving
No special points beyond those normally used for the fabric construction/yarn counts/loom types have been noted in weaving trials to date when correct warp yarns and preparation have been followed. Key points to keep under consideration are as follows:

• Greige fabric construction should be planned so as it takes into consideration a 15 to 20% greige to finished fabric shrinkage.
• Warp tension should be kept at a minimum. Usually slightly higher than the tension required to form a good shed opening. However shed height also needs to be considered and kept at a minimum in order to minimize the cyclic yarn tensioning during weaving.
• A reed with the maximum Air space is also highly recommended as it reduces the yarn to yarn friction and the possible Velcro effect.
• Weft yarn tension should be carefully controlled. In the case of the spun yarns in the weft, care should be given that the accumulator brushes are not stiff and abrasive.
• Loom speed is also a variable that needs to be considered and adjusted to keep loom stoppages to a minimum.

Dyeing and finishing of corn fibers
Corn fiber dyed at 110-115 deg c as compared to PET fiber which is dyed at 130-135 deg c. the individual dye shades are hypsochromic and brighter than on polyester fibre, show a greater variation in exhaustion levels. During last two years, major dye companies like dystar and Claraint have identified a range of Selected disperse dyes, showing good exhaustation and leveling /migration properties on corn fibres (like Disperse yellow 54, Disperse red 60, Dosperse blue 56 etc). Dystar has recently published an corn fibre coloration pack which gives comprehensive details about selected dyes and the processing parameters for corn fibre and blends. Corn fibre is generally sufficiently clean to only require a mild scour; still then to ensure the complete removal of spinning oils, fabric processing lubricants, etc. if a bleach treatment is to be used for dyeing bright pale shades, then a mild process as below is adequate Soda ash -3 gpl hydrogen peroxide (35%) -3ml/lit. stabilizer -.05 gpl run at 95 deg c for 30 mins hot wash –cold wash –neutralize. If a fabric is bleached then add optical whitener at 110 deg c. Like Disperse only selected optical whitener are used. the normal dyeing temperature is 119 deg c for 30 mins, but in dark shades the temperature is raised to 115 deg c to increase the colour depth and better exhaustion. But care should be taken not to give more hold time at high temperature which may lead to loss of fibre strength. Levelness of shade is not a problem in corn fibre dyeing. For light and medium shade slight soaping is required after dyeing process but in case of dark and heavy dark shades reduction cleaning is required. it may be follows; a. Alkali reduction clearing. b. Acid reduction clearing. Both the above processes have to be followed in such a way to avoid hydrolysis degradation. The process for alkali reduction clearing is: soda ash -2 gpl sodium hydrosulphite (hydros) -2 gpl run at 60 deg c for 15 minutes This leads to no significant change in shade and better wash fastness. But in acidic reduction clearing use cyloconon (ECO (BASF) -1-2 gpl at Ph 4-5) will give less fibre hydrolysis and is considered more environmentally positive. Wash and light fastness results tend to be slightly lower, compaired to the same shade on standard polyester.

Blending with corn fibers
The most common blend is with cotton like cotton/corn 70/30. Besides corn fibre is also blended with wool and silk in various proportions. There is real potential of wool /corn fabric blends because not only of the positive environmental benefits, but also due to their compatible physical stretch and recovery properties .As fabrics in 100% Corn fibre and Corn fibre blends continue to be developed by the mills ,then similarly the amount of technical knowledge on spinning, dyeing and finishing is being expanded. Dyeing with Corn /cotton blends care should be taken of the potential cumulative hydrolysis effect due to high temperature alkaline conditions while bleaching and dyeing of cotton portion .so in such cases the cotton portions is bleached using TAED (tetra acetyl ethylene diamine) at a neutral or slightly acidic pH which leads to minimum hydrolysis degradation of the Corn fibre. Normally bifunctional and Vinly Sulphone reactive dyes are recommended for dyeing of cotton portion. An alternative process for dyeing cotton portion is to use after treated direct dyes. Such an application is done as a single stage all in dyeing. Direct dyes have the following advantage in dyeing Corn/Cotton blends a. they are not applied in dyeing an alkaline medium and therefore do not cause degradation. b. A shorter and straighter forward dye cycle. C. Good all round colour fastness including dark shades, using a cationic after treatment such as Sirius B (Dystar).

Properties of corn fibers

• Corn fibre combines the quality of natural and synthetic fibres in a new way.
• Strength and resilience are balanced with comfort, softness and drape in textiles.
• Corn fibre is naturally flame retardant and good moisture management characteristics.
• It has good stain resistance properties.
• Corn fibre also use no chemical additives or surface treatments, and is naturally flame retardant.
• Corn fibre stain resistance properties make it an ideal carpet fibre for the home, the transportation.
• The melting point is 170 deg c.
• The heatsetting is done at 125-130 deg c for 30 second.
• Hydrolysis degradation of the polymer will occur, particularly under combined aqueous high-temperature and alkaline conditions.

PLA has excellent physical and mechanical properties, forced it to become a good challenger candidate for substitution for petrochemical thermoplastics. The high price for PLA was hurdle which made its use to medical and specialty applications only, but recent breakthroughs in lactic acid fermentation technology have opened up possibilities for the production of PLA in bulk volumes also.

Yarn made from corn
Yarns made from corn, such as Kollage yarn’s Corntastic or Bernat’s Cot’n Corn (a blend of corn and cotton fibers). To turn corn into yarn, manufacturers extract a plant sugar called dextrose from the plant fibers. Next, they ferment the corn sugar and distil it, using the same process used to make beer, and then extract the lactic acid that is produced. The lactic acid forms a long chain, or polymer, called Polylactic Acid (PLA) .Once it is spun into yarn, PLA has a texture similar to cotton or even silk, depending on how it is spun, and it is less dense than cotton or wool, so it can be used for lighter weight garments.

Quality of corn fibers

Breathable yarn from corn fiber is similar to cotton in its appearance. More resilient than cotton, the knitted fabric is springier, resulting in a fluid drape. The corn fiber yarn may also be easier on the hands when knitting. Other properties include low odor retention, quick drying, and stains that do not set as easily as with cotton.

Corn yarns are perfect for lightweight, summer projects since their texture is similar to cotton while being less dense than cotton. knitted fabric had a “plump, elastic feel” despite the fiber not being stretchy. swatches softened with wear and that they pilled slowly.

Fabrics are made from corn fibers

Iscra is a durable, high-performance fabric that is made entirely from corn, a 100 percent renewable source. It’s attention-getting, especially for customers who are committed to environmental responsibility. Kira can be composted, and it contains no petroleum products. A fabric Kira is available in six colors and can be used on systems panels and Ethospace tiles, as well as flipper doors, tack boards, and screens. it can be turned into compost that can help grow crops, Kira fabric has a “closed loop” life cycle, as depicted in this graphic. To make compost, Kira is mixed with sawdust and organic material and then heated to 140 degrees. The process takes just three day.

Charactors of corn fibers

Corn fiber is a kind of yogurt polymer. It is tested that Corn knitted fabric will not stimulate skin, and it is beneficial and comfortable to wear. Corn fiber has excellent drape, slippery, moisture regain and air permeability, and it has full luster and elasticity.

• This fiber has living creature and can decline a solution.
• Corn fiber is light and soft to slip to follow.
• The strength is big, absorbing wet well ventilated.
• The product processed have the sheen and comfortable skin touch
• Good heat-proof and anti- ultraviolet ray function.
• Fiber doesn’t use petroleum to equalize work raw material completely.
• The wastes can decline a solution under the aquatic microorganism function of the soil and the sea will not pollute environment.

Benefits of corn fabrics

1. It has good strength and resiliency.
2. It has natural comfort and drape.
3. It is naturally insulating.
4. It has moisture wicking.
5. It is more breathable than polyester.
6. It provides odor control.
7. It is stain resistant and color fast.
8. It has low pilling.
9. It does not shrink dries quickly.
10. It is hypoallergenic.
11. It is natural UV resistance.
12. It is ideal for all climates.
13. It has Low flammability and less smoke generation.
14. It has Low index of refraction, which provides excellent color characteristics, with the shiny luster as silk.

Process of corn fibre biodegradation
Corn fibre heads to de-compose as it is from different origin than the regular plastic. The process of de-compose is very important process because of which Corn out served its usefulness. Corn fibre biodegrades slowly in this way – Initially polymer chain of 100,000 to 300,000 molecular weight, break down into its constituent parts (Carbon dioxide and water) within three months in a “controlled composting environment”. While compounding polymer if heat of 75C applied at steady rate helps the microbes to decompose in controlled environment. But it will take far longer in a compost bin and in a tightly packed landfill where no light and presence of oxygen are rare available to assist in the process. Indeed, analysts estimate that a bottle grade Corn fibre may take approximate time from 100 to 1,000 years to decompose in soil. Conventional PET polymer contains molecular weight of 170,000 to 350,000 hence it is highly tough to decompose.

Where we can find corn fibers fabrics?

IGREEN TEX VIETNAM COMPANY LIMITED

Address: No. 83 , A4 Street, Ward 12, Tan Binh Dist, HCMC

Tax code: 0315844409

Email: info@igreentex.com

WhatsApp/Viber/Zalo: +84938.045.900