The Guide: CompoBast Fibres

FIBERS

Fibers are hair-like materials that tend to stick to each other. They can be twisted together to form filaments or teased into mats. Filaments can be twisted into yarn, thread, or rope. These can be woven to create textiles with tensile strength in two directions or knitted to create elastic textiles. Mats are made using randomlyoriented shorter fibers. These can be needle-punched to create felted textiles. Each technique presents different structural possibilities for designing with fiber. When combined with polymers to form a composite, the orientation and structure of the fibers is to be chosen in order to counter the structural stresses inherent in the object designed.

Currently, man-made fibers such as glass fiber and carbon fiber dominate as composite reinforcements, but natural fibers can be used in addition or in substitution for these man-made fibers. Potential natural fibers include bast fibers, seed fibers (for example, cotton), bamboo fibers, and leaf fibers (such as sisal). The most commonly harvested bast fibers for use in manmade composites are flax (linen), hemp, ramie (nettle), kenaf, and jute. This study will explore structural, ethical, and creative possibilities and limitations for using natural and bast fibers in the design of composite household products and fashion.

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This study will explore structural, ethical, and creative possibilities and limitations for using natural and bast fibers in the design of composite household products and fashion.

bast fibers close-up of outher side cross-section of hemp plant Some bast plants can be grown on land that is unusable for farming.

AV E R AG E F I B E R P RO D U C T I O N AV E R AG E F I B E R P RO D U C T I O N ( K G ) P E R H E C TA R E ( K G ) P E R H E C TA R E F L

ADVANTAGES OF BAST FIBERS IN COMPOSITES

DISADVANTAGES OF BAST FIBERS IN COMPOSITES

Might biodegrade prematurely, weakening composite

Look of natural fiber composite is not aesthetically pleasing to some people.

Skin might be necessary to conceal natural fibers.

Less tested methods for using in composities.

Overall resources consumed may be less over the entire life cycle in some synthetics(when compared through MIPS calculations -note: they do not take into account toxicity or type of land use).

Longevity in composites not yet comprehensively tested.

Renewable resource Look of natural fiber composite is not aesthetically pleasing to some people.

Tensile strength is comparable to synthetics Less tested methods for using in composities.

Some bast plants can be grown on land that is unusable for farming.

Longevity in composites not yet comprehensively tested.

Bast fiber plants, the same as a tree, contain cellulose fibers that are oriented to hold the stem upright. The inner bark (just underneath the skin) is the location of food-conducting tissues in the plant, or phloem, and contains the fibers known as bast fibers. Like wood, they are both strong and flexible, and also useful for man-made composites. In nature, the fibers are held upright using lignin and pectin. To make use of the fibers, they must first be separated from the xylem (a brittle, woody inner core) by softening the natural polymers in the plant (in bast plants these are lignin and pectin). This process is called retting. Water is the traditional method of softening the core, but chemicals or enzymes can also be used.

The bast fibers are separated from the woody core using rollers (breakers). The clumps are then cleaned and broken up then combed in a process called carding. Fibers are then processed in one of several ways. They can be twisted together and spun (to make thread for weaving or knitting), matted (for non-woven mats or needle-punched uses), or pulped (for paper making). Production: Flax Plant -Linum usitatissimum, grows annually up to 120 cm, flowering in the color blue. Its fruit is a round, dry capsule 5-9 mm diameter, containing several small brown seeds, 4-7 mm long. Flax belongs to the group of Bast-fibres, which means their fibres are "collected from the inner bark, or bast, of the stem. " [3] Flax grows in 12 stages, and its life cycle consists of a 45 to 60 days vegetative period, 15 to 25 days flowering period, and a maturation period of 30 to 40 days. Best climate to grow flax is in the northern latitudes, where it is cool and wet. The soil should be moist and ploughed. World wide two types of flax are used for industrial production: Fibre Flax and (Lin)Seed Flax.

"Flax grown for seed is allowed to mature until the seed capsules are yellow and just starting to split; it is then harvested and dried to extract the seed. " [4] "Fibre Flax uses different harvesting methods mechanical but also includes manual work for high quality and long fibres, which increases the price enormous. " To get the best and longest fibres, the flax needs to be pulled out and not cut. After harvesting it will be left on the fields to dry and then remove the seeds. "Then flax is exposed to moisture to break down the pectin that binds the fibres together. "[5] Next step is the retting, which has the highest environmental impact throughout the production process. "The preferred method is to spread out in the fields and exposed to rain, dew and sunshine for several weeks. After that the fibres are separated from the straw (shives), and then graded into the short fibres (tow) which is used for coarser yarns, or the longer fibres (line) which will be used to create the finest linen yarn. " [6] The Flax fibres' length can be up to 90 cm, and average 12 to 16 microns in diameter. The fibres are already much longer than for example cotton (about 3.5 cm) but shorter than Hemp which measures from 90 cm to 460 cm.

FLAX/ /

Common Use & Feeling

Linen is a fabric made from flax fibres, most commonly used in high-quality products because through the process of production it becomes an expensive fibre/material. It is very well known for its cool-and lightness feeling for summer clothes.

The shorter flax fibers may also be used in high-quality sheets and kitchen wear. It is also a valued material for premium quality artist canvas. "Linen is preferred to cotton for its strength, durability and archival integrity. For industry, it serves as a pigment binder for oil paint and a drying agent for paints, lacquers and inks. It is sometimes used as a wood finish, in varnishes, printing inks, and soaps, and can be combined with cork to make linoleum. "[7] Flax is also considered an environmentally orientated alternative to synthetics fibres in fibre-reinforced bio-composites. [

Benoit Millot

Disadvantages

Commonly grown, the farming uses agricultural chemicals, fertilizers, and pesticides which keep weeds under control. It can grow also without the use of fertilizers as long as there is enough water available. For growing high quality fibres there is a need for moist, but mild climate. Flax also has a relatively low yield per acre, which increases its price. There is also the issue of field rotations about every three years. The tensile strength of the oil-seed flax is way lower, if compared to other bast plants, such as hemp.

Main problem concerning the environmental impact is the retting, which implies the process when the fibres get separated from the stalk. Commonly used methods work with open retting ponds, retting on the field or earlier; running-water from a river. Small bundles of stalks are let to rot, to then easily separate the fibres from the woody parts. This process causes a huge amount of waste water, which needs to be dealt with.

Advantages

Water usage for growing flax is not very high, which prohibits high environmental impact on water consumption. As positive aspects, it should be mentioned that linen (also bast fibres as hemp, jute and kenaf) can be grown on fields unsuitable for food production, regarding to e.g. contamination with heavy metals, because the fibre-plants tend to clean the soil.

Linseed flax would be a very efficient plant, because nearly all the parts are valuable for further production. The main product are the seeds, which will be further processed. They can be used for cooking, cracked or whole, or ground into flour. Another major use is the production of oil, which is supposed to be very healthy because it contains high amount of "essential omega-3 fatty acids; the oil is believed to provide benefits to arthritis and lupus patients by reducing inflammation. " [9] After pressing the oil, the seeds make a good feed for e.g. chickens and other livestock. They serve them with a lot of protein and dietary fibre. The flax straw in this case, is a by product, which makes it a very cheap material. At the current stage, most commonly the straw is removed from the field and handled as waste, burnt on the fields. Either way, a waste of resources and increase of landfill waste or CO2-rise. PRODUCTION Hemp can be cultivated in most climate zones, except the Sub Arctic and Tropical Wet-Dry. Hemp is a fast growing crop and the land requirements are low. More so, it also absorbs heavy-metal contamination from the air and the soil, improving water quality in the area where it is grown. It is therefore used as a rotation crop because of its "soil healing" properties, in contrast to cotton for example, which degrades the soil properties. Hemp produces more fiber than cotton and flax when grown on the same land.

PESTICIDE FREE

In general, hemp is resistant to pests. Even though there are pests that can attack hemp, this can be avoided without use of chemicals.

France, England, Germany and the Netherlands have all commercially cultivated hemp without the use of pesticides. Eastern European and Chinese hemp fabrics have been shown to be free of harmful substances, in accordance with standards established by the Natural Textile Association (Arbeitskreis Naturtextilien) -http:// www.green.net.au/gf/hemp_cultivation.htm.

Hemp fibers are famous because of their ultimate strength. They are widely used by US Army for producing ropes and parachutes. Interestingly enough, the US Army preferrs imported fibers that are water retted to ground retted domestic ones. An added value of hemp is its oilseed, used in the food industry.

PRODUCTION PROCESS

Hemp fiber is usually ready to harvest in 70-90 days after planting. A special machine with rows of independent teeth and a chopper is used for harvesting hemp for textile use.

Once the crop is cut, the stalks are allowed to rett (removal of the pectin [binder] by natural exposure to the environment) in the field for four to six weeks -depending on the weather -to loosen the fibers. While the stalks lay in the field, most of the nutrients extracted by the plant are returned to the soil as the leaves decompose. The stalks are turned several times using a special machine for even retting and then baled with existing hay harvesting equipment. Bales are stored in dry places, including sheds, barns, or other covered storage. The moisture content of hemp stalks should not exceed 15%. When planted for fiber, yields range from 2-6 short tons (1.8-5.4t) of dry stalks per acre, or from 3-5 short tons (2.7-4.5 t) of baled hemp stalks per acre in Canada.

[13] 30 31 Wikimedia Anja-Lisa

GRAIN PROCESSING

Hemp seeds must be properly cleaned and dried before storing. Extraction of oil usually takes place using a mechanical expeller press under nitrogen atmosphere, otherwise known as mechanical cold pressing. Protection from oxygen, light, and heat is critical for producing tasty oil with an acceptable shelf life. Solvent extraction methods are also emerging for removing oil since they achieve higher yields. Such methods use hexane, liquid carbon dioxide, or ethanol as the solvent.

Refining and deodorizing steps may be required for cosmetics manufacturers. A dehulling step, which removes the crunchy skin from the seed using a crushing machine, may be required. Modifications to existing equipment may be required to adequately clean the seeds of hull residues.

FIBER PROCESSING

To separate the woody core from the bast fiber, a sequence of rollers (breakers) or a hammer mill are used. The bast fiber is then cleaned and carded to the desired core content and finesse, sometimes followed by cutting to size and baling. After cleaning and carding, secondary steps are often required. These include matting for the production of non-woven mats and fleeces, pulping (the breakdown of fiber bundles by chemical and physical methods to produce fibers for paper making), and steam explosion, a chemical removal of the natural binders to produce a weavable fiber.

STANDARDS

In many countries, the cultivation of hemp is forbidden by legislation, this is because of THC -delta-9 tetrahydrocannabinol that is commonly used as a drug. This prohibition was established at the beginning of the 20th century. Today, in Europe and Canada, cultivation of hemp is allowed for research and commercial purposes if its THC level does not exceed 0,3%.

In the United States, some states (e.g. Hawaii, Kentucky or Montana), approved a law to allow for the cultivation of hemp, "HOUSE BILL 1250 -Industrial Hemp -Pilot Program. " The regulation uses the same 0,3% THC level to define industrial (legal) hemp. Farmers require a license for cultivation, according to guidelines of the bill. There are ongoing works on hemp cultivation legislation (regarding its legalization) in other States as well.

Industrial hemp, however, is characterized by having low levels of THC (delta-9 tetrahydrocannabinol) and high in CBD (cannabidiol), approximately 1%. 32 33 fibers APPLICATIONS Carbon fiber is broadly used in composites since it is very light, extremely strong and durable. Because of its high cost and low availability, carbon fiber is mainly used in specialized technology including aerospace and nuclear engineering, transportation, and sports equipment manufacturing. It has chemical resistivity and non-corrosive properties. Carbon fiber is thermal conductive and is unusually flame retardant. Electric conductivity properties of carbon provide new uses in electronics technology.

Larry C. Wadsworth created following list regarding application of carbon divided by the major properties: HISTORY "The existence of carbon fiber came into being in 1879 when Thomas Edison recorded the use of carbon fiber as a filament element in an electric lamp.

In the 1960s, it was realized that carbon fiber is very useful as reinforcement material in many applications. Since then, researchers in the USA, the UK and Japan have greatly improved the process. In the 1960s, high-strength PAN-based carbon fiber was first produced in Japan and the UK, and pitch-based carbon fiber was first produced in Japan and the USA. "[15]

PRODUCTION Carbon fibers are manufactured by controlled pyrolysis, a process of organic precursors in fibrous form. Basically the process of making carbon fibers consists of many stages of heating at different temperatures and atmospheres, depending on the step during the process and the type of the material a precursor is used. It consists of a heat treatment that removes the oxygen, nitrogen, and hydrogen from the precursor and changes into almost pure carbon. Two most commonly used precursors for production of Carbon Fibers are PAN and Pitch.

PAN -Polyacrylonitrile-based carbon fiber is more expensive to produce but offers higher tensile strenght. Polyacrylonitrile is a vinyl polymer.

Pitch-based carbon fibers are produced from coal tar and petroleum products.

Other procursors used in production of carbon fibers are: Cellulosic fibers (viscose rayon, cotton), Mesophase pitch-based carbon fibers, Isotropic pitch-based carbon fibers and Gas-phase-grown carbon fibers and certain phenolic fibers.

"Mesophase pitch fibers, offer designers a different profile. They are easily customized to meet specific applications. They often have a higher modulus, or stiffness, than conventional PAN fibers, are intrinsically more pure electrochemically, and have higher ionic intercalation. Mesophase Pitch fibers also possess higher thermal and electrical conductivity, and different friction properties. " [16] There are many methods for producing carbon fibers, but all of them uses huge amount of energy. Heating temperature during production process of carbon fibers Graphitization: depending on the type of fiber required, the fibers are treated at temperatures between 1500-3000°C, which improves the ordering, and orientation of the crystallites in the direction of the fiber axis.

Graphitization: depending on the type of fiber required, the fibers are treated at temperatures between 1500-3000°C, which improves the ordering, and orientation of the crystallites in the direction of the fiber axis.

PITCH PROCESS:

Pitch preparation: it is an adjustment in the molecular weight, viscosity, and crystal orientation for spinning and further heating.

Spinning and drawing: in this stage, pitch is converted into filaments, with some alignment in the crystallites to achieve the directional characteristics.

Stabilization: in this step, some kind of thermosetting is done to maintain the filament shape during pyrolysis. The stabilization temperature is between 250 and 400 °C.

Carbonization: the carbonization temperature is between 1000-1500°C.

RAYON PROCESS:

Stabilization: stabilization is an oxidative process that occurs through steps. In the first step, between 25-150°C, there is physical desorption of water. The next step is a dehydration of the cellulosic unit between 150-240°C. Finally, thermal cleavage of the cyclosidic linkage and scission of ether bonds and some C-C bonds via free radical reaction (240-400° C) and, thereafter, aromatization takes place.

Carbonization: between 400 and 700°C, the carbonaceous residue is converted into a graphite-like layer.

Graphitization: graphitization is carried out under strain at 700-2700°C to obtain high modulus fiber through longitudinal orientation of the planes.

HIGH QUALITY CARBON FIBER PRODUCTION:

"It is well established in carbon fiber literature that the mechanical properties of the carbon fibers are improved by increasing the crystallization and orientation, and by reducing defects in the fiber. The best way to achieve this is to start with a highly oriented precursor and then maintain the initial high orientation during the process of stabilization and carbonization through tension. Us Army was also experimenting with other use of glassfibers. Few experimental planes were build from fiberglass composite during II World War.

After the war, many industries started to be interested in possible use for fiberglass. One of the first uses of fiberglass as a part of composite, was in boat construction. Boat hulls made traditionally from wood were very vulnerable to warp, leak, shed paint and were attacked by worms, bacteria and fungi. Fiber reinforced polymers eliminated all of these problems. They are still commonly used for boat and yacht production.

PROPERTIES

Fiberglass has very high tensile strength. Its fiber has higher tensile strength than steel wire of the same diameter while fiberglass has lower weight.

ADVANTAGES

Fiberglass cloth is lower in cost than many other fabrics for similar applications (insulation, composite reinforcement).

DISADVANTAGES

Fiber glass is not biodegradable. It is impossible to recycle when it is part of a composite. Glass alone can be melted, but it is not possible to separate it from a polymer in a composite structure.

FIBERGLASS PRODUCTION

Production process of fiberglass has not changed very much from the times of its invention.

Major ingredients of fiberglass are silica sand, limestone, and soda ash. Different varieties can consist of other ingredients e.g.calcined alumina, borax, magnesite etc.

Waste glass is used also as a raw material for producing fiber glass.

"Silica sand is used as the glass former, and soda ash and limestone help primarily to lower the melting temperature. Other ingredients are used to improve certain properties, such as borax for chemical resistance. "[20]

Although fiberglass can be made directly from those ingredients, it is usually made from ready made marbles of raw glass. Using marbles has two purposes: first, they can be added to the melt at a controlled rate, which helps keep the temperature inside the reservoir of melted glass constant; and second, transparent marbles can easily be inspected for impurities.

[21]

The glass is melted in an electric furnace and then forced through a perforated metal plate called a "bushing. " The bushing is made of platinum or another exotic metal, because molten glass is so highly abrasive that most metals would be unable to resist it. The high melting point of Platinum -3,200 degrees Fahrenheit -allows it to be heated to the temperatures needed to let glass, which melts between 1,800 and 3,800 degrees, flow through.

To form continuous filaments, the molten glass, after flowing through the tiny holes in the bushing, is attached to a winder and pulled until it reaches a diameter between 27 and 180 millionths of an inch (the smaller figure is about 1/100 the width of a human hair).

Hundreds of parallel filaments are gathered on a large steel drum, where they are combined into a fine, untwisted strand called a "sliver. " The sliver is fed onto a spool, and from there it can be put through conventional textile processes, such as twisting or plying, and woven into cloth.

The strands can also be fed into another machine to make a heavy yarn or loose rope called a "roving. "

A different process is employed to make short, noncontinuous strands used for non woven fabrics or insulation. "It uses a bushing with wider holes, which the molten glass passes through by gravity.

ADVANTAGES OF BIOPOLYMER IN COMPOSITES

DISADVANTAGES OF BIOPOLYMER IN COMPOSITES

Biodegradable may not be practical or appropriate, depending on the product.

Less tested, new field. Long term durability unknown.

Not manufactured on large scale, which means they cost more.

The melting point of some (as PLA) is so low that products may deform to easily from weather related or body heat.

Some synthetics may still use fewer resources over the life cycle when compared with MIPS calculations (note: they do not include toxicity or weigh advantages of using renewable resources vs. nonrenewables)

Less toxic processing Less tested, new field. Long term durability unknown.

Some (as PLA) are thermoplastic, which means they can be reused in a closed loop cycle.

The melting point of some (as PLA) is so low that products may deform to easily from weather related or body heat.

POLYMERS

Polymers are the glue that hold the fibers together in a certain orientation. Generally, the higher the polymer content, the harder the composite will feel (unless an elastic polymer like rubber is used)and the higher the fiber content, the more flexible the composite. It might even feel soft like a textile.

Plants have natural polymers (cellulose, lignin, pectin) that hold the plant together. Pulping makes it possible to use these in composites, like paper.

Plastic polymers are grouped into thermoplastic or thermosetting types. Thermoplastics can be formed into a shape, then melted and reused in a closed loop system of production. They are commonly used to make reinforced plastics products that are injection or rotation-molded, like outdoor furniture. Thermosetting polymers cure by crystallizing, so once they are cured they cannot be melted and reused in the same form. Often, they are in the form of glues and used produce plywood or fiber board. They are also used in combination with glass and carbon fibers to make high strength, cured reinforced plastic products like motorcycle helmets or ski poles.

Biopolymers are polymers that biodegrade. They can come from either renewable natural or synthetic materials. Depending on the application, biodegradability might not be ideal or practical in use. Biodegradable polymers can come from starch, sugar, cellulose, or petrochemical based synthetics. We looked closely at corn based polylactic acid polymer (see linen-impregnated with PLA and a piece of PLA glue below). This study will explore creative possibilities and limitations of using conventional and emerging biopolymers combined with bast fibers in composites.

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PLA/ biopolymer

WHAT IS PLA?

Poly(lactic acid) or polylactide (PLA) is a biodegradable, thermoplastic, aliphatic polyester derived from renewable resources. PLA can be produced from corn starch (in the United States), tapioca products (roots, chips or starch mostly in Asia) or sugarcanes (in the rest of world).

At the moment, PLA is usually made in two stages. First, a source of starch or sugar, which could be an agricultural byproduct, is fermented to produce lactic acid-the same substance made by the body during exercise, only in this case it comes from the bacteria exercising themselves in the fermentation process.

In the second stage, lactic-acid molecules are linked into long chains, or polymers, in chemical-reaction vessels, to produce PLA. Due to the complicated process of making PLA, it is currently more expensive than other polymers, however, there are other manufacturing technologies currently being developed, to ease and simplify this process.

Like the petroleum-based biodegradable polyesters, PLA has many of the same undesirable mechanical properties, such as low heat deflection temperature. The polymer is also very brittle and has a low-melt strength leading to difficulty in processing. Consequently, most commercial applications using PLA require a synthetic rubber and/or acrylic additive to compensate for these deficiencies.

PLA is a sustainable alternative to petrochemical-derived products, since the lactides from which it is ultimately produced can be derived from the fermentation of agricultural by-products. PLA is more expensive than many petroleumderived commodity plastics, but its price has been falling as production increases.

The demand for corn is growing, both due to the use of corn for bioethanol and for corn-dependent commodities, including PLA.

At the moment, PLA is usually made in two stages. First, a source of starch or sugar, which could be an agricultural by-product, is fermented to produce lactic acid-the same substance made by the body during exercise, only in this case it comes from the bacteria exercising themselves in the fermentation process. In the second stage, lactic-acid molecules are linked into long chains, or polymers, in chemical-reaction vessels, to produce PLA. Due to the complicated process of making PLA, it is currently more expensive than other polymers, however, there are other manufacturing technologies currently being developed, to ease and simplify this process.

Like the petroleum-based biodegradable polyesters, PLA has many of the same undesirable mechanical properties, such as low heat deflection temperature. The polymer is also very brittle and has a low-melt strength leading to difficulty in processing. Consequently, most commercial applications using PLA require a synthetic rubber and/or acrylic additive to compensate for these deficiencies.

PLA is a sustainable alternative to petrochemical-derived products, since the lactides from which it is ultimately produced can be derived from the fermentation of agricultural by-products. PLA is more expensive than many petroleum-derived commodity plastics, but its price has been falling as production increases. The demand for corn is growing, both due to the use of corn for bioethanol and for corn-dependent commodities, including PLA.

WORKING WITH PLA

PLA has similar mechanical properties to PETE polymer, but has a significantly lower maximum continuous use temperature. PLA can be formed by blow molding, injection molding, sheet extrusion, or thermoforming. It can also be blended with some petroleum-based polymers to improve heat resistance. Potential for compostability is lost, but that is not a drawback for objects that would not have been reasonably expected to be properly composted.

Polylactic acid can be processed like most thermoplastics into fiber (for example using conventional melt spinning processes) and film. In the form of fibers and non-woven textiles, PLA also has many potential uses, for example as upholstery, disposable garments, awnings, feminine hygiene products, and diapers. It has also been used in France to serve as the binder in Isonat Nat'isol, a hemp fiber building insulation.

PLA is currently used in a number of biomedical applications, such as sutures, stents, dialysis media and drug delivery devices. It is also being evaluated as a material for tissue engineering.

Because it is biodegradable, PLA can also be employed in the preparation of bioplastic, useful for producing loose-fill packaging, compost bags, food packaging, and disposable tableware.

PLA is used as a feedstock material in 3D printers such as Reprap and Makerbot..

PLA has similar mechanical properties to PETE polymer, but has

TEMPERATURE LIMITS

The maximum continuous use temperature of PLA, before temperature-driven loss of mechanical properties becomes excessive, is that of 50 °C. The definition of excessive can vary between industry sectors, but exceeding this temperature will not necessarily cause degradation of the material.

Melting onset of PLA, the temperature at which some constituents of the material begin to melt, is 160 °C. However, the heat deflection temperature, also known as "heat distortion temperature," of PLA is 65 °C. This is significant because it reflects the of retention of mechanical strength at elevated temperatures. It is used primarily for material comparison, but the exact value may be useful in design if referenced to guidelines (e.g. relating deflection temperature to thermoforming mold temperature).

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WHAT IS PLA?

PAPER

Paper is perhaps the first bio-composite, originally made by the Egyptians from papyrus. Papyrus stems were disassembled, laid flat, woven in strips at right angles, and then hammered to join the strips by softening the cellulose polymer. Today's paper is made by smashing fibers with water into a pulp and then organizing the fibers onto a screen (flat) or shaped over a form until it dries. Common fibers used are wood, cotton, hemp, and linen. This process makes use of the natural polymers in the fibers to hold the fibers in a new (random) orientation.

Other polymers are sometimes added to paper to change its character (say, adding plastics to increase water resistance used in packaging). Opportunities for using paper exist for designers who want to make forms from alternative natural fiber papers (such as bast). They can also consider replacing petro-chemical based polymers with biopolymers. If polyethylene used in coated papers was replaced with a biopolymer, it could reduce plastic scraps in trash and compost. Coating paper with natural vegetable wax could be an alternative.

PLYWOOD

Plywood is one of the most commonly used man-made composites. Technically, plywood is a composite made from bidirectionally oriented reinforcement fibers set in a glue resin polymer. Designers can consider substituting the inner plies with bast fiberboard cores, adding fiber textiles as reinforcement inside traditional plywood, as well as substituting biopolymer glues for traditional formaldehyde based resins. Columbia Products, a major producer of plywood in the U.S. is now using soy based glue for its plywood.

The natural properties of fibers in wood cause the width of a solid wood plank to change considerably depending on the ambient humidity (wood moves across the grain). The composite plywood takes advantage of the one way available to cabinetmakers to stop wood from moving. Sliced thin enough, the strength of the glue becomes stronger than the fibers' ability to expand and contract. Thin slices of wood are called veneer and sold in sheets. Plywood panels are made by stacking these thinly sliced sheets of wood (veneer), alternating the grain direction 90 degrees between each layer to create large dimensionally stable flat panels.

Plywood panels were developed as an alternative to traditional frame-and-panel construction. Until plywood was perfected, carpenters made furniture from wood panels slotted into grooves. Panels floated within dimensionally stable frames. Before plywood, this was the only reliable method of constructing long lasting furniture, as the structure was designed to allow wood to move without compromising the strength of the joints. Plywood makes it possible for designers to use large stable panels without the need for a frame.

In the 1950s, glue polymers were quickly developing, and designers began experimenting with the forming possibilities available in plywood. Designers began making organically formed shapes by laminating veneer. Veneer layers are stacked with glue in between, then the entire stack is pressed over a form until it cures and holds the shape as a composite. Since the grain follows the form, this construction is stronger than simply cutting the shape from a solid log (where grain will sometimes be oriented in the short direction and can break easily). U.S. designers, Charles and Ray Eames, for example, developed strong plywood splints during World War II whose organic shape conformed to the human body for maximum support. They later used these experiments to develop an organically shaped plywood chair. Compare opportunities in plywood from an exhibition catalog of the Eames' work (plate 6) versus an early Finnish-made solid wood chair carved from a single log (plate 7).

FIBERBOARD

Similar to plywood, fiberboard composites were developed for more specialized uses or cost requirements. They are most commonly made from randomly oriented chipped or ground wood fibers set in urea formaldehyde resin polymer. Particle board (low density), medium density fiber boards (mdf), and oriented-strand boards are short fiber versions of plywood. They were developed to be used as substrates (under a skin). While they are consistent in color and density, they are most commonly covered by finish, veneer or plastic laminate. One fiberboard (Masonite) is made solely from wood chips -blast steamed, heated and pressed into boards. It is a hardboard panel that relies on the wood's natural cellulose to bind the fibers, the same as paper.

Manufacturers are experimenting with using other chopped plant fibers for these composites, as the fibers needed can be short or even ground. Waste fibers from agricultural processes are a focus, as they are inexpensive and the individual plant fibers are often stronger than wood fibers. Bast fibers used for these composites can either be made from plants grown specifically for fabric fibers (long fibers) or from agricultural waste (short fibers). Below left is the Compos Chair designed by Samuli Namanka (plate 8) and developed with manufacturer Piiroinen in 2009. It is made from a cast fiberboard composite of waste flax fibers (leftover from linseed oil production that would otherwise be burned) set with polylactid acid (or PLA), a polymer made from corn starch.

REINFORCED PLASTICS

Reinforced plastics in household products are commonly made from petro-chemical based plastic polymers combined with glass, carbon, or aramid fibers (man-made but not petro-chemical based). The fibers are placed into the polymer by various means. One, they can be mixed into the polymer in its liquid state then pressed into sheets or injected into a form. Fibers will be randomly oriented in sheets or, in the case of injection molding, fibers will orient themselves generally in the direction of the material flow while being injected into the mould. In another process, woven textiles are saturated with polymer and then allowed to stiffen.

Reinforced plastics were developed in the 1940s as a replacement for formed metal. Plastic polymers used in plastic composites are grouped into thermoplastic or thermosetting types, as described in the polymer section.

The advantage of thermoplastics is they can be melted and reused, though less easily if reinforced with fibers. Some thermoplastics (such as PLA can be recycled in combination with the fibers in a closed loop. Further studies are needed to determine how much the fibers deteriorate or get shorter with each reuse. Common thermoplastics used in household product composites are polypropylene, polyethelene, polyamide (nylon), polyethylene terephthalate (PET), acrylic, polyvinyl chloride, polystyrene, polytetrafluoroethylene ("Teflon"), and acrylonitrile butadiene styrene (ABS).

Common thermosets used in composites are often in the form of glue, like urea resin, polyurethane, epoxy, polyester, and vinylester. Advantages of thermosets is that they take a form permanently and will not burn or melt. They are malleable until they cure and then hold their final form by cross-linking. Since they cannot be melt-ed after curing, they can not be recycled unless ground as filler. Advantages are they have a smooth surface finish and can be melted down to use again and again without degrading. Sometimes they are less heat resistant and can deform if they get too hot. One early reinforced modern plastic was actually made using natural fibers. Phenolic ("Bakelite") is a thermoset created in the 1940s made from layers of paper or cloth (such as cotton or linen) impregnated with phenol and formaldehyde.

Later reinforced plastics evolved to use man-made fibers as they were developed with specialized characteristics that could be controlled in a laboratory.

Two classic chairs made from fiberglass reinforced polyester are Charles and Ray Eames Shell Chair (made from fiberglass reinforced polyester, a thermosetting polymer) and Verner Panton's (plate12) entirely plastic fiberglass reinforced polypropylene chair made from thermoplastic polypropylene reinforced with fiberglass, a thermoplastic polymer. Designers must choose the orientation of the fibers within reinforced plastics depending on the forces placed on a product. Longer fiber (used most commonly for woven textiles) are stronger than short fiber randomly-oriented fiber structures, but random orientation gives more opportunity for organic form. As the tensile strength of some bast fibers is comparable to glass fiber, opportunities exist for designers to use bast fiber textiles or randomly-oriented needle-punched (felted) fibers as a replacement for glass, carbon, or aramids ("kevlar"). Contrast the Panton and Eames chairs to Light Light, designed by Albert Meda in 1987 (plate13, left). It is made from woven carbon fiber saturated with thermosetting polyester. The epoxy-saturated aramid fiber chair Knotted Chair (plate 14, above) was designed by Marcel Wanders in 1995.

Bast fiber alternatives were used by Francois Azambourge, who worked with a producer to develop a composite for his Lin 94 chair in 2008. The final design is cast from a composite of flax, 80% plant-based/epoxy resin. He chose flax because it is lighter than glass fiber and requires less energy to produce than both carbon and glass fibers.

COMPOSITE TEXTILES

Textiles and filaments can be combined with polymers to create textiles with improved characteristics, such as tear resistance, water repellence, shape-holding, translucency, or elasticity. Fibers can be woven into textiles and impregnated with polymer, mixed with fibers and sprayed in a random orientation, or mixed with polymer as needle-punched felt and heated to hold shape. The structural textile for hot air balloons needs to hold air as well as let some air pass through, be flexible, and have a very high tensile strength. The fabric is generally made from either nylon or polyester with polyurethane as a sealer (polymer) with the addition sometimes of neoprene or silicone and various ultraviolet inhibitors. A characteristic of linen woven textiles are their crispness, which means they holds shape well. Opportunities exist for using fabrics as structural or sculptural textiles, as Rachel Philpott does in her textile design (plate17) or Mika Tolvanen does in his recycled PET felt basket (plate16).

In some applications, the fiber filament is also a self-bonding polymer. George Nelson's Bubble Lamp (plate15) and also the Taraxacum Lamp by Achille and Pier Giacomo Castiglioni, for example, use nylon as both fiber/polymer to create a light diffusing elastic textile, spraying it onto a rotating steel frame in layers until the frame is covered in semi-solid fiber. The fiber/polymer then tightens as it cures to form a translucent, strong, flexible, and prestressed textile over the steel armature. The same idea is used in spray on fabric developed by Dr. Manel Torres (fabric is formed by the cross-linking of various fibers sprayed directly onto the human body or used in any application where spray fabric is appropriate, and it is available in varying colors, textures, and properties. An advantage of this composite is its easy repairability. The customer can repair by simply spraying on more fiber. ISO Standards: They are standards that many companies try to meet in order to better their business, quality, and service. ISO standards simply said are a set of international standards that can be used in any type of business and are accepted around the world as proof that a business can provide assured quality.

ISO standards play a huge role in raising levels of quality, safety, reliability, efficiency and interchangeability -as well as in providing such benefits at an economical cost.

ISO is the world's largest developer of standards, and this means they reach far beyond simply the technical world. ISO standards also have important economic and social repercussions, which mean they effect even that which is far from technical.

What are some of the benefits:

1. They provide governments with a technical base for health, safety and environmental legislation. They can do this by setting specific guidelines, which the government can then implement into inspections and safety specifications, and can do so at minimal cost and minimal risk as these standards have been tested and set by ISO.

2. They are useful for structuring and starting new technical companies. By knowing the standards that other companies are meeting, new companies can emerge competitively as they too can meet these internationally known and respected standards.

3. ISO standards are a shield, or a safeguard to consumers, and users in general, of products and services. ISO standards are simply a way of ensuring a certain quality of life is maintained.

4. ISO standards are a safety net. Things for well, have less problems and security issues when there is a specific standard of quality they must meet.

ISO standards are there to make the development, manufacturing and supply of products and services more efficient, safer and cleaner, which benefits all.

www.ISO.org

IVN Naturtextil

Used mainly for fashion and shoes made out of natural fibres.

Publisher of the IVN label is the "Internationale Verband der Naturtextilindustrie" (IVN) -international association of the natural textile industry. Interested producers will send them a proposition after which the company will be controlled regarding the delivery of goods, as well as social-and environmental standards. After fulfilling those criteria, the producer will be certified for one year terminable.

Criteria: You get certified with the "IVN NATURTEXTIL BEST" if your products and fibres are produced following the highest environmental and social responsible factors. E.g.: 70% to 95% of the fibres needs to be from controlled ecological farming, prohibit the use of polluting production-and upgrade methods as well as deny special substances like formaldehyde, metal complex colours and synthetic colours with an AOX-level over 5%. Separate storing form conventional produced items. Social responsibility including deny child-and forced labour, discrimination and guarantee regulated working hours. the shoe BOOTY/ SHOE In the light of developing a sustainable shoe, the Hemp Booty was created. Firstly a "last" (wooden show form used to mold a shoe to a determined size) was used to follow the contour of the shape and used the "resist" method (creating a whole boot using the last as a mold). The contouring of the Booty was done directly on the last, using a mat of Hemp and PLA with heat and placing wax paper on top of the mat. When the desired shape for the base of Booty was done, then it was taken off the last. Following the base more matting was added. The heel was made with urea, formaldehyde resin (the resin will be substituted with vegetable wax), and hemp fibers. It was then casted at 170-degree heat, using a carton mold, finally chiseling it to the desired shape. Finally the heal was added to the Booty, gripped by using pure PLA sheets. In conclusion the Booty was designed as a starting point, where eventually it can become a reality. It is a "work in progress" Inspired by the huge amount of paper waste that results from the packaging and advertisement industry, we wanted to try for ourselves and put to new use this waste and explore its suitability for quality packaging. Through research, we discovered that hemp and flax fibers have a higher content of cellulose than wood, which is the primary base in paper production, and they therefore serve as suitable replacements for wood fiber. This allows paper produced from flax and hemp fibers to be recycled more times than that produced out of wood. This would save resources and energy invested in deforestation, which in itself is very damaging to the environment.

PROTOTYPES/ paper+packaging

In our paper experiment, we used recycled newspaper and flax and hemp fibers. The pulp was made by mixing these ingredients in a blender with water. Afterwards, we poured the pulp on a screen to dry with the aid of sponges, and we further allowed the fibers to set and harden into paper. Through trial and error, we discovered that the lesser amount of fibers used resulted in a more flexible paper. However, the fibers increased the strength of the paper, and in industrial paper production, the required machinery would refine them for higher quality products. Such products are available on the market, but only on a very small scale. flax fiber panels

In this same spirit, I explored opportunities for replacing glass fiber with strong, renewable bast fiber to create similar formed components. I chose flax fiber, as I have ready access to both the short waste fiber and textile in Finland. I took a profile from common fiberglass roofing panels (which gain rigidity from both fiber reinforcement and being formed into engineered shapes). I made a mold over which I could vacuum form samples of this shape from different combinations of fibers and polymer. Because I was unable to obtain adequate PLA or soy resin, I produced my test samples from urea resin polymer and varied only the fibers.

In this same spirit, I explored opportunities for replacing glass fiber with strong, renewable bast fiber to create similar formed components. I chose flax fiber, as I have ready access to both the short waste fiber and textile in Finland. I took a profile from common fiberglass roofing panels (which gain rigidity from both fiber reinforcement and being formed into engineered shapes). I made a mold over which I could vacuum form samples of this shape from different combinations of fibers and polymer. Because I was unable to obtain adequate PLA or soy resin, I produced my test samples from urea resin polymer and varied only the fibers.

RESULTS

1 layer of nonwoven mat (randomly-oriented short fibers) impregnated with resin:

• Complicated to obtain even thickness when making thin formed sheets.

• Mold should be 2 part (male/female) for even surface finish on both sides.

• Can be sanded and painted if desired.

• Not as strong as impregnated woven fibers, but much less expensive material cost.

• Can use waste fibers from linseed production that would otherwise be burned.

• If made w/ thermoforming resin (such as PLA), it can be melted, including fibers, and reused to make the same composite in a closed loop. This type can also biodegrade.

• If made w/ thermosetting resin (such as soy-based glue), composite cannot be reused in closed loop production but can be biodegradable. 84 85 5 layers of woven textile (bi-directional long fibers) impregnated with resin:

• Longer fibers made a strong, still flexible, composite in length and width.

• Woven textile sheets are easier to assemble into even layers when pressed.

• Linen textile is expensive.

• Textiles cannot be extracted for reuse in closed loop production.

• If made with PLA or soy resins, biodegradation is a possibility.

• Can be sanded and painted if desired..

• Can be covered with a "skin" of veneer or textile if desired.

• Textile sheets can be alternated with wood veneer layers to create a plywood composite.

The look and feel of linen composite is limiting aesthetically, so I experimented with possibilities for adding a "skin" of wood or needlepunched linen felt (undyed and dyed). Since it can be sanded, painting the composite is also a possibility. However, because of its strong texture, the woven composite would require use of filler to obtain a professionally smooth surface finish. Wood fibers are strong in length but tend to crack along the grain. Bi-directionally woven linen textile inserted between the wood layers adds stability perpendicular to the wood fibers while still being thin enough to take a form (unlike a stiff layer of wood veneer oriented perpendicular to the curved shape). It also allows the plywood to flex without breaking across the width. Shaping the bottom layer adds thickness needed to keep the shelf straight when weight is applied, lighter than a solid plywood panel of the same thickness. Aesthetically, wood has a warm, familiar look and feel. The linen/wood composite can be sanded and finished the same as conventional plywood. Cost of materials and production would be higher, but the expense might be appropriate where thinness is desired for elegance or to reduce weight.

Shelf weighs 1.5 kilos and flexed just 7mm with 50 kilograms of weight in center.

wood + linen plywood composite 86 87