Newsflash

The drive for lightweight materials to reduce overall cost and environmental impact for automotive manufacturers is nothing new.  Fuel economy attracts car buyers too. That is how majority of steel parts have been replaced in F-150 pickup truck by aluminum parts, reducing overall weight over 500 pounds. Then there are alloys, carbon fiber and plastics composites.The ambition for lighter vehicles did not stop with alloys (magnesium, aluminum), and/or composites (glass, carbon fibers).  Recently, Japanese researchers at Kyoto University led by Professor Hiroaki Yano along with its industrial partners (Denso Corporation and Daikyo-Nishikawa Corporation) reported that they were developing cellulose nanofiber based materials for automotive as well as aircraft parts to reduce environmental footprint while increasing product performance.Inevitable questions are: 1) would these materials be cost effective? 2) What would be the service life of these products compared to the current ones? 3) How about the parts’ safety in situations like crash or fire?A final question that an automaker has to ask is: what would be the pay back time to replace current production line (machinery) to CNF based plastics line?Reference: https://www.japantimes.co.jp/news/2017/08/15/business/researchers-japan-use-wood-make-cellulose-nanofiber-auto-parts-stronger-lighter-metal/#.WbAIKeTXuUm...
We know polycarbonates mostly from its use in plastics water bottles, safety goggles, smart phones, structural panels (glazing) and the list goes on.  A quick look at Wikipedia gives a spectrum of applications.However, polycarbonates have its weaknesses along with the BPA (bis-phenol) controversy. Polymers such as polysulfates and polysulfonates have similar if not better mechanical properties than polycarbonates.  The issue has been how reliably scale-up the manufacturing process of polysulfates and polysulfonates?“Click chemistry” is a concept in organic chemistry by which highly reactive reactions provide high yielding products and require little to no purification.  The concept was introduced by Nobel Prize winner Professor K. Barry Sharpless in 2001.A recent work published in Nature Chemistry, by a team of researchers from The Scripps Research Institute (La Jolla), Lawrence Berkley National Laboratory (Berkley), California and Shanghai Institute of Organic Chemistry & Soochow University, China claimed that reduced cost of catalyst, product purity, and by-product recycling make their work ready to move from laboratory research to industrial process.Chemists are at work indeed!References:https://en.wikipedia.org/wiki/PolycarbonateK. Barry Sharpless et al; Nature Chemistry, 2017 DOI: 10.1038/nchem.2796...
In a recent The Atlantic interview Bill Gates made a wish on an energy miracle, “Here’s a source of energy that is cheaper than your coal plants, and by the way, from a global-pollution and local-pollution point of view, it’s also better”.  The race is on to find that source. One such energy source is solar energy. We all know that solar energy can be harnessed to generate thermal energy or electrical energy for use in the residential and/or in the commercial applications.  Any material that can store Solar Thermal Energy is called Solar Thermal Fuel (STF).  The quest to harvest solar energy, store the same and use it when needed has been the focus of research in industry and academia alike. For the first time, Professor Grossman’s team at MIT, Cambridge (USA) has come up with a new approach which uses polymer Solar Thermal Fuel (STF) storage platform utilizing STF in its solid-state.  According to the published article, researchers stated, “Closed cycle systems offer an opportunity for solar energy harvesting and storage all within the same material. This approach enables uniform films capable of appreciable heat storage of up to 30 Wh kg?1 and that can withstand temperature of up to 180 °C.”How the STF process works?Certain molecules (chemicals) can have 2 different stable structural forms. These structures are called conformations.  When original molecular conformation is exposed to sunlight, the molecule gets charged and the original conformation changes to the other and stay in that charged conformation for a long period.  The charged molecule snaps back to their original shape (conformation), when triggered by a very specific temperature or other stimulus generating heat in the process. Currently, developed polymeric film can release heat about 10 degree C above the surrounding temperature. Film property improvements are underway. German auto company BMW, has sponsored this research. Where the potential application lies - your guess is as good as mine.References:The Atlantic, p 56, November 2015Zhitomirsky, D., Cho, E. and Grossman, J. C. (2015), Solid-State Solar Thermal Fuels for Heat Release Applications. Adv. Energy Mater., 1502006. doi:10.1002/aenm.201502006...
In a recent The Atlantic interview Bill Gates made a wish on an energy miracle, “Here’s a source of energy that is cheaper than your coal plants, and by the way, from a global-pollution and local-pollution point of view, it’s also better”.  The race is on to find that source. One such energy source is solar energy. We all know that solar energy can be harnessed to generate thermal energy or electrical energy for use in the residential and/or in the commercial applications.  Any material that can store Solar Thermal Energy is called Solar Thermal Fuel (STF).  The quest to harvest solar energy, store the same and use it when needed has been the focus of research in industry and academia alike. For the first time, Professor Grossman’s team at MIT, Cambridge (USA) has come up with a new approach which uses polymer Solar Thermal Fuel (STF) storage platform utilizing STF in its solid-state.  According to the published article, researchers stated, “Closed cycle systems offer an opportunity for solar energy harvesting and storage all within the same material. This approach enables uniform films capable of appreciable heat storage of up to 30 Wh kg?1 and that can withstand temperature of up to 180 °C.”How the STF process works?Certain molecules (chemicals) can have 2 different stable structural forms. These structures are called conformations.  When original molecular conformation is exposed to sunlight, the molecule gets charged and the original conformation changes to the other and stay in that charged conformation for a long period.  The charged molecule snaps back to their original shape (conformation), when triggered by a very specific temperature or other stimulus generating heat in the process. Currently, developed polymeric film can release heat about 10 degree C above the surrounding temperature. Film property improvements are underway. German auto company BMW, has sponsored this research. Where the potential application lies - your guess is as good as mine.References:The Atlantic, p 56, November 2015Zhitomirsky, D., Cho, E. and Grossman, J. C. (2015), Solid-State Solar Thermal Fuels for Heat Release Applications. Adv. Energy Mater., 1502006. doi:10.1002/aenm.201502006...
Reliable and high performance lithium ion batteries commonly known as LIBS are highly sought after product by industries. We all have heard stories about laptops, electric vehicles, airplanes catching fires due to LIBS. Underlying problem is the battery overheating. Preventing batteries from overheating is crucial to the public safety.  Now a team of researchers at Stanford University designed a thermo-responsive (heat sensitive) plastic composite film made from polyethylene and spiky nickel microparticles coated with graphene which shuts down the battery if the temperature is too high.         In a recently published work led by Yi Cui and Zhenan Bao of Stanford University, USA concluded “Safe batteries with this thermoresponsive polymer switching (TRPS) materials show excellent battery performance at normal temperature and shut down rapidly under abnormal conditions, such as overheating and shorting.” How practical this design approach is? Time will tell.References: Y. Cui, Z. Bao et al Nature Energy vol.1, Article number: 15009 (2016); DOI: 10.1038/nenergy.2015.9Chemical & Engineering News, Page 7, January 18, 2016...
In aviation industry, the focus is how to improve fuel safety and handling. Mike Jaffe and Sahitya Allam gave their perspective on safer fuels by integrating polymer theory into design (Science, 350, No. 6256, p. 32, 2015).Mist (generated from the fuel) is much more flammable than the liquid and that is why anti-misting kerosene interferes with mist formation when a low percentage of a polymer is added into it.  The problem however, is that the polymer chain undergoes scission during handling and can’t assist in suppressing mist formation. The answer comes from a recent paper published in the Journal Science by Professor Julia Kornfield and her cross-functional team at Caltech, Pasadena, USA. The group designed a megasupramolecules having polycyclooctadiene backbones and acid or amine end groups (telechelic polymer) which is short enough to resist hydrodynamic chain scission while protecting covalent bonds through reversible linkages. Yes, polymers can be designed to suit our societal needs including aviation fuel safety.Reference: M-H Wei, B. Li, R.L. Ameri David, S.C. Jones, V. Sarohia, J.A. Schmitigal and J.A. Kornfield; Science, 350, (6256), pp. 72-75 (2015)...
At the TED conference, Carbon3D, a Vancouver based company touted a radical 3D printing technology and named it CLIP or Continuous Liquid Interface Product. CLIP grows parts instead of printing them layer by layer. It harnesses light and oxygen to continuously grow objects from a pool of resin.  The result: make commercial quality parts at game-changing speed.  CLIP is 25 to 100 times faster than traditional 3D printing technique.  To make the point, Carbon3D web site provides a head-to-head comparison of CLIP to Polyjet, SLS and SLA.[Press release: March 16, 2015, Vancouver, Canada.  www.carbon3D.com]...
Self-healing plastics has been around for a while. Applications include self-healing medical implants, self-repairing materials for use in airplanes and spacecrafts. Even scientists have made polymeric materials that can repair itself multiple times. A recent report in Science describes a significant advance in self-healing plastics. The authors describe a product that mimics how blood can clot to heal a wound. When the plastic is damaged a pair of pre-polymers in channels combines and rapidly forms a gel, which then hardens over 3 hours.The authors demonstrated that holes up to 8 millimeters wide can be repaired. The repaired parts can absorb 62% of the total energy absorbed by undamaged parts.  Science never stops.Reference:S. R. White, J. S. Moore, N. R. Sottos, B. P. Krull, W. A. Santa Cruz, R. C. R. Gergely; Science, Restoration of Large Damage Volumes in Polymers, Vol. 344 no. 6184 pp. 620-623; (9 May 2014). ...
Knowingly or unknowingly, flexible electronics has become a part of our daily life.  Transparent conductive films (TCFs) are used in mobile phones, tablets, laptops and displays.  Currently, Indium Tin Oxide or commonly known as ITO is the material of choice.  But use of ITO has some major disadvantages and these are brittleness, higher conductivity at greater transparency, and supply of Indium.  This is where non-ITO materials come into play. Based in St. Paul, Minnesota (USA), Cima NaoTech’s uses its SANTETM nanoparticle technology, a silver nanoparticle conductive coating which self-assembles into a random mesh like network when coated onto a flexible substrate such as PET and PC.  According to a recent press release, the company stated SANTETM nanoparticle technology enabled transparent conductors in a multitude markets from large format multi-touch displays to capacitive sensors, transparent and mouldable EMI shielding, transparent heaters, antennas, OLED lighting, electrochromic and other flexible applications.  Cima NanoTech is working with Silicon Integrated Systems Corp. (SIS) of Taiwan and using its highly conductive SANTE FS200TM touch films to develop large format touch screens.References: Press release, San Diego, June 03, 2014; www.cimananotech.com ; http://www.cimananotech.com/sante-technology ; http://www.sis.com/...
In an article appeared today (January 29, 2014) in The Guardian newspaper, Stuart Dredge wrote, “From jet parts to unborn babies, icebergs to crime scenes, dolls to houses: how new technology is shaking up making things”1. Mr. Dredge was speaking about 3D printing technology.  The heart of this technology is the 3D printer itself. Stratasys, a company headquartered in Minneapolis, USA is the manufacturer of 3D printers.  It recently announced the launch of Color Multi-material 3D Printer, the first and only 3D printer to combine colors with multi-material 3D printing.  According to the press release2, by using cyan, magenta, and yellow, multi-material objects can be printed in hundreds of colors.  The technology is based on proven Connex technology.  While the base materials are plastics and elastomers, they can be combined and treated to make finished products of wide ranging flexibility and rigidity, transparency and opacity.  Designers, engineers and manufacturers can create models, mold, and parts that match the characteristics of the finished production part. This includes achieving excellent mechanical properties.  According to the manufacturer, print job in the newly revealed printer can run with about 30 kg of resin per cycle and prints as fine as 16 micron layers for models.  No wonder why some call the new Color Multi-material 3D printer a groundbreaking stuff.References: 1. www.theguardian.com.technology/2014/jan/29/3d-printing-limbs-cars-selfies (January 29, 2014)2. http://investors.stratasys.com/releasedetail.cfm?ReleaseID=821134 (August 3, 2014)...
Instead of stitches or skin staples, doctors use skin glue to close wounds. The glue joinsthe edges of a wound together while the wounds heal underneath. Most of the timeskin glue is used for simple cuts or wounds. According to the paper published inScience Translational Medicine, there are no clinically approved surgical glues thatare non-toxic, bind strongly to tissue, and work well in wet and highly dynamicenvironments within the body. This is the reason why this published work is promisingwhere infants born with heart defects would benefit tremendously. Researchers at the Brigham and Women’s hospital in Boston have engineered ‘bio-inspired’ gluethat can bind strongly to tissues on demand, and work well in the presence ofactively contracting tissues and blood flow. The authors of the paper show howthe glue can effectively be used to repair defects of the heart and blood vessels during minimally invasive procedures. [References: P. J. del Nido et al; Sci. Transl. Med., DOI: 10.1126/scitranslmed.3006557; See also, www.geckobiomedical.com/news/gecko-biomedicals-co-founde.html]...
Stability of organic electronics in water is a major research challenge. For this reason,organic electronics has yet to see any sensing application in aqueous environment.However, as understanding of underlying mechanism of stability aspect is becomingclearer, new developmental efforts to make water compatible organic polymer devicesare taking place. Recently, Professor Zhenan Bao’s group in the department of chemical engineering at Stanforduniversity revealed in a paper published in the journal of Nature Communications thatsolution- processable organic polymer could be stable under both in freshwater andin seawater. Developed organic field-effect transistor sensor is able to detect mercury ionsin the marine environment (high salt environment). Researchers believe that the work hasthe potential to develop inexpensive, ink-jet printed, and large-scale environmental monitoring devices. [References: O. Knopfmacher, M.L. Hammock, A.L. Appleton, G. Schwartz, J. Mei, T. Lei, J. Pei,and Z. Bao; Nature Communications, 5, 2954, January 6, 2014; DOI: 10.1038/ncomms3954]...
Insulin, the wonder medicine for diabetes was discovered about a century ago.Since insulin does not get into the blood stream easily, diabetes patients oftenhave injected themselves with insulin. Now a group of scientists led by Dr. Sanyog Jainat the Center for Pharmaceutical Nanotechnology of National Institute of Pharmaceutical Education and Research in Punjab, India has designed a polymerbased package for oral insulin administration. The package design addresses two major obstacles, 1) digestive enzymes must notdegrade insulin prior to its action and 2) the insulin gets into the blood stream.The package contained folic acid functionalized insulin loaded in liposomes.To protect the liposomes (lipids or fat molecules) they were alternately coated withnegatively charged polyacrylic acid (PAA), and positively charged poly allylamine hydrochloride. Studies were conducted to compare the efficacy of bothdelivery systems: designed polyelectrolyte based insulin and standard insulinsolution. Effects of oral administration lasted longer than that of injectedinsulin, authors reported in a recent article in Biomacromolecules. [Reference: A.K. Agarwal, H. Harde, K. Thanki, and S. Jain; Biomacrmolecules, Nov. 27, 2013;DOI: 10.1021/bm401580k]...
Research in the area of stretchable electronics is heating up!  Thanks to polymers. Led by Professor George M. Whitesides of Harvard University (USA), a team of researchers have demonstrated in a recently published paper in Science that ionic conductors can be used in devices requiring voltages and frequencies much higher than commonly associated with devices using ionic conductors.  The team showed for the first time that electrical charges carried by ions and not electrons, can be utilized in fast-moving, high voltage devices.As a proof of concept, the authors of the study built a transparent loudspeaker that produces sound across the full audible range i.e., 20 Hz to 20 kHz.  Components [such as VHB 4910 tape (acrylic tape with PE liner), polyacrylamide hydrogel containing NaCl electrolyte] used for the high speed, transparent actuators are described in the paper.Tissues and cells are soft and require stretchable conductors for biological systems. Many hydrogels are biocompatible which makes this work particularly an important one. The design of gel-based ionic conductors is highly stretchable, completely transparent and offer new opportunities for designers of soft machines.   [Reference: C.Keplinger, J-Y. Sun, C.C. Foo, P. Rothemund, G.M. Whitesides, and Z. Suo; Science, 341 (6149), pp. 984-987 (2013); DOI: 10.1126/science.1240228]...
Interweaving biological tissue with functional electronics, one can make bionic ears.  NASA has tested 3D-printed rocket engine part.  Then why not 3D print yourself?Well, Twinkind, a German start-up company is now offering enthusiasts statues of themselves for display.  How this works?  A full body scanner takes an image of the customer’s body, transfers the file to the printer after which 3D printer laser sinters a composite powder layer by layer into the customer image.Can we dare to say that Madame Tussauds wax figure of Voltaire can now be 3D printed in polymers soon!  [Reference: www.twinkind.com ]...
Polymer membranes have become a leading contender in numerous separation processes.  Be it in gas (air, hydrogen etc.) or be it in water purifications (salinated water, waste water etc.).  Not only polymer membrane technology helps reducing the environmental impact but also it is cost-effective.  Fracking in shell gas is one of many examples. New advances in drilling technology (such as horizontal drilling) have led to new hydraulic fractures called fracking.  Hydraulic fracturing requires about 2.5 to 5 million gallons of water per well.  Water management and its disposal are major costs for producers.One major challenge, however, of the membrane technology is the fouling (damage caused by contaminants) mitigation.  This has been recently studied by a group of researchers from University of Texas at Austin led by Professor Benny Freeman to address efficiency and reuse of water for fracking in shale gas plays.Researchers modified polydopamine coated UF (ultrafiltration) module by grafting polyethylene glycol brushes onto it.  The result is more hydrophilic surfaces which in turn improved cleaning efficiency relative to unmodified modules. The coating improves the membrane life, and can easily be applied to membrane surface by rinsing it through the recycling system.[References: D.J. Miller, X. Huang, H. Li, S. Kasemset, A. Lee, D. Agnihotri, T. Hayes, D.R. Paul, and B. Freeman; J. Membrane Sci., 437, pp. 265-275 (2013); Also see www.advancedhydro.net ]...
Flexible electronics can change the way we use electronic devices.  It is a term used for assembling electronic circuits by mounting electronic devices on a flexible plastic. A recent review article captured the advancement of CNT and graphene based flexible thin film transistors from material preparation, device fabrication to transistor performance control compared to traditional rigid silicon1. Silicon is used almost exclusively in electronic devices.Now Prof. Ali Javey led a team at the University of California, Berkley to develop a printing process to make nanotube transistors at room temperature with gravure printer.  The plastics used is polyethylene terephthalate (PET). The device exhibited excellent performance with mobility and on/off current ratio of up to ~9 cm2/ (V s) and 105 respectively.  Also, maximum bendability is observed.  The paper authors conclude that this high-throughput printing process serves as enabling nanomanufacturing scheme for range of large-area electronic applications based on nanotube networks2. References:1. D-M. Sun, C. Liu, W-C. Ren and H-M Cheng; Small, DOI: 10.1002/smll.2012031542. P.H. Lau, K. Takei, C. Wang, Y. Zu, J. Kim, Z. Yu, T. Takahashi, G. Cho, and Ali Javey; Nano Letters, 13 (8), pp. 3864-3869 (2013); DOI. 10.1021/nl401934a...
Drinking coffee from paper cups are as common as drinking water from plastics bottle. The issue however, is recycling of disposable cups. The disposable cups are made up of 90-95% of high strength paper (fibers) with a 5% thin coating of plastic (PE).To address the recycling issue, James Cropper Speciality Papers of UK have developed a process which involves softening the cup waste, and separating the plastic coating from the fiber.  After skimming off the plastic, remains are pulverised and recycled, leaving water and pulp behind.  According to the company news release, the high grade pulp is reused in luxury papers and packaging materials.An innovative approach to address a common problem.[Reference: www.jamescropper.com/news ]...
A search for an alternative to rigid silicon wafers gave birth to the area of flexible or bendable electronics. Research has been intense for the past few years in the area flexible electronics as it opens up multitude of new applications. Polymers play an important role to exciting field of flexible electronics.In a recent research report, a team of scientist led by Prof. Ali Javey of University of California, Berkeley (USA)  has shown for the first time user-interactive electronic skin or e-skin can conformally wrap irregular surfaces and spatially map and quantify various stimuli through a built-in active matrix OLED display.  Three electronic components namely thin film transistor (uniform carbon nanotube based), pressure sensor, and OLED arrays (red, green, and blue) are integrated over a plastic substrate.  Spin coated and cured polyimide on a silicon wafer is used as the flexible substrate.  Details are in the paper.This work essentially provides a technology platform where integration of several components (organic and inorganic) can be done at a system level on plastic substrates. According to the paper, this e-skin technology could find applications in interactive input/control devices, smart wallpapers, robotics, and medical/health monitoring devices.    [Ref: C. Wang, D. Hwang, Z. Yu, K. Takei, J. Park, T. Chen, B. Ma, and Ali Javey; Nature Materials, Published online July 21, 2013; DOI: 10.1038/NMAT3711]...
Recent buzz in the technology world is 3D printing.  Researchers to designers are creating new products everyday using 3D printing technology.  Even eBay has unveiled its services to those looking to make their own creations using 3D printing App.Since ages composites have played a crucial role in our society. Inspired by natural (biological) composites such as bone or nacreous abalone shell, researchers from MIT (USA) and Stratasys have developed composite materials that have fracture behaviour similar to bones.  Using computer model with soft and stiff polymers, the team has come up with a specific topological arrangements (hierarchical structures) of polymer phases to boost the mechanical behaviour in the composites.Interestingly, the team has been able to manufacture (thanks to 3D printing) a composite material that is more than 20 times larger than its strongest constituent.  The referenced paper showed that one can use computer model to design composite materials of their choice, tailor the fracture pattern and then use 3D printing technology to manufacture the composites.[Ref: L.S. Dimas, G.H. Bratzel, I. Eylon, and M.J. Buehler; Advanced Functional Materials, Published online June 17, 2013; DOI: 10.1002/adfm.201300215]...

Wood-plastic composites (WPC) may be one of the most dynamic sectors of today’s plastics industry.  Since my last article about Wood-Plastic Composites (WPC) in March 2004 a lot has happened:

-        Figures have been released showing increased demand from US$ 750 million in 2002
         to S$2.1billion by 2004 and predicting a demand of US$ 3.5 billion by 2009.
-        Primary markets are for decking and railing but fencing is starting to be commercialised
-        Industry associations have been formed (NADRA, CFDA)
-        Products are being marketed as  "low maintenance" instead of "no maintenance"
-        Entry of the "big boys" (Louisiana-Pacific (LP), Alcoa, Dow, Weyerhaeuser)
-        Second-generation technology (oriented WPCs) is now commercial and rapid growth is
         expected in the next few years
-        Agricultural fibres (wheat straw, soy straw and corn stover) are new cellulosic fillers,
         which will augment and/or replace the supply of wood fibres for WPCs.
 
University researchers have taken keen interest to study WPC products.  Results are often found in polymer/plastics related conferences1-3.  The intent of this article is to update the readers on the market trends and the future of WPC technology. 
Market Trends
Construction is the major market for WPCs, with decking and fencing accounting for 2/3 of the market. WPCs accounted for 25% of the $3 billion market in 2006 for North American sales of residential decking. And Wood still has 70% of the market, vinyl has only 4% and other plastics and metal contribute the remaining 1%. 

In 2004, the main manufacturers of decking were Trex (34%), TimberTech (11%), LP (11%), AERT (6%), Fiberon (5%), and Epoch (5%).  But at this time composites only provided about 10% (368 Million Lineal Feet) of the 3.5 billion lineal foot decking market.  Decking has become so important in the market that it now boasts it own trade show (DeckExpo), magazine (Deck Builder) and trade association (NADRA – North American Deck & Railing Association).

Fencing is about to take off.  The $5.5 billion North American market for fencing is dominated by chain link fence. WPC fencing is barely on the charts but several WPC manufacturers (Trex, Fiber Composites, TimberTech, AERT, Composatron, Royal, Heartland Biocomposites, and Woodguard) have announced fencing products – primarily residential privacy fencing which accounts for 80% of the residential fencing market.  The American Fence Association (AFA) who runs the annual trade show FenceTech, have formed another trade association, CFDA (Composite, Fence & Deck Association) and published a new magazine Deck World

The biggest change on the manufacturing scene is the addition of very large companies to the current list of about 50 manufacturers. The first was Louisiana-Pacific (LP) with their "Weatherbest", followed by Alcoa with their Alcoa Home Exteriors division (Oasis).  A year ago, Dow chemical announced its arrival with the introduction of their "Symmatrix" decking line.  In October 2006, Weyerhaeuser purchased PSA Composites LLC; the company that pioneered the second-generation oriented WPCs, and is planning to manufacture a low-density material, which is twice as strong, and half the weight of the first-generation WPCs.


The biggest change in advertising is the marketing of WPCs as "low maintenance" instead of a "no maintenance" material.  To stop the growth of lichen or other microorganisms on WPCs, periodic washing is advised.

Doors, windows, siding, roofing, and trim are being developed for other residential construction markets.  Doors and windows have been available for some time. The other products are in various stages of product development and market introduction.

Non-construction markets that are of growing importance are docks, landscape architecture and bridges. Everarch has recently made a major step forward with structural WPCs, building and installing several pedestrian bridges for walking trails, golf courses and municipal parks.
Government Interest
An indication of government interest in this area is provided by recent announcements: 
-       In the United States, an article reported that the U.S. Department of Agriculture and the U.S. Department of Energy have granted $790,000 to Louisiana State University at Baton Rouge, LA to make natural fiber-reinforced plastic composites.  The LSU project, led by Dr. Qinglin Wu, will use recycled plastics and wood or other agricultural fibers.  The market identified for the results of this work is the construction market.
-       In the United Kingdom, the Department of Trade and Industry is providing £278,000 funding towards the £777,000 Combine project to develop plastics durable enough for car doors and boat-hulls which are light-weight, but environmentally friendly.  The 2½ year project will develop prototypes using natural fibres and bio-plastics.  The companies involved in the U.K. are NetComposites and Aptiform.
-       In Canada, there is interest and support at both the federal and provincial government levels.  At the federal level, Agriculture & Agri-Food Canada announced a new program to focus on commercialization of new agri-based products.  The $134 million funding is to get ideas from the drawing board into the market.  Bioproducts are especially identified.
-       The Ontario government is funding Renewable Auto Technologies.  The $5.9 million investment in the Ontario Bio-Car Initiative is a research project to turn Ontario’s harvest (wheat, corn, soybeans and forest biomass) into viable materials for the auto industry. Four Ontario universities involved in the research program (Guelph, Toronto, Waterloo and Windsor).
 
The Technology Evolution
Polyethylene is the dominant resin used in WPCs but PVC and polypropylene are used and are expected to become more important in the future. 
The primary process technology for WPCs is extrusion using either single-screw or twin-screw extruders. The resulting WPC profile is typically a deck board (1" x 5 ½"), with a density of 1.1 to 1.2 g/cc, a flexural strength (MOR) of 3,000 to 3,700 psi. while a flexural modulus (MOE) of between 300,000 and 600,000 psi. 
The use of Injection moulding to process WPCs is becoming more common. It is being used to make accessories like railing post caps and trim pieces.  Injection molding uses WPC with a maximum content of 40% wood fibre whereas the extruded product can contain 50 to 60%. 
Specialised equipment has been recently been developed to process WPCs, since the available process equipment had its limitations.  B&P Process Equipment of Saginaw, MI have made a major step forward in extrusion technology with the development of a twin-screw co-rotating extruder that produces pressure without the need for a secondary device such as a single-screw extruder or a gear pump.  Cincinnati Milacron is marketing this TE series of extruders.  Krauss-Maffei, have recently introduced an injection moulding compounder, with a twin-screw extruder mounted on an injection-molding machine that ram injects the output of the extrusion compounder.  This development is illustrated with a WPC injection molded pallet.  More about extrusion machine and its manufacturers have been described elsewhere4.  
Second-generation WPC technology
In this new development, orientation is used to increase the thermoplastic polymer's properties enormously, in a similar way to that achieved in a one dimensionally oriented monofilament fishing line, biaxially oriented polypropylene film, or natural products such as wood, where uniaxial-oriented, bulk orientation gives greater physical properties in the direction of the grain than across the grain. 

Second generation WPC products include oriented polypropylene that has a draw ratio of 12:1 providing a flexural strength increase from 7,000 p.s.i. to 40,000 p.s.i. – 6 times increase; and a flexural modulus increase from 270,000 p.s.i. to 1,100,000 p.s.i. – a four-fold increase. 
PSA Composites developed this technology and Green Forest Engineered Products (GFEP) in Nevada, MO was the first licensee.  GFEP now manufactures a line of products, specialising in fence posts used for electric fences for rotational grazing.  Instead of becoming the second licensee, Weyerhaeuser, the forest products giant, purchased PSAC and in the near future is planning to manufacture low-density composites, that are twice as strong and half the weight of first-generation WPCs.

Manufacturing with other processes
While the orientation process has not yet been commercially applied to processes other than thermoplastics extrusion, a number of applications are under development

·       A new company, MKM AutoTech, has been formed in Canada based in Guelph, Ontario with the explicit purpose of developing and commercializing injection moulding of oriented thermoplastics.  The company is currently working with three injection moulding manufacturing companies and plan to work with several companies who are injection moulding automotive parts. The company will also be taking advantage of funding from the Ontario Government as well as newly formed Ontario BioAuto Council.

·       A sheet of low-density embossed WPC sheet (12" x 5 ½" x ¼") has been thermoformed into a tray with the retention of the low-density and the embossed wood grain.  This demonstration shows that thermoforming is possible.  Efforts are currently underway to obtain support from commercial thermoforming processors to make demonstration parts for the automotive and packaging industries.
·       Hydroforming is a steel-forming process where high-pressure water is used to form steel pipes into automotive parts such a car and truck chassis.  Recently work at McMaster University under the direction of Dr. Mukesh Jain, has progressed to show that hydroforming of oriented thermoplastics, has reached “Proof of Concept”.  The next stage will involve making automotive parts to show that this technology is practical and economic.

The Challenges and the Future of WPCs
Wood K Plus provided a world market overview of the production of WPC in 2005 at the Bordeaux WPC conference in March 2007.  It showed North America produced 700,000 tons of which WPC, 80% was growth from the last 5 years.  Europe was next with 100,000 tons all of which 100% was growth from the last 5 years.  Similarly with neither China (50,000 tons) nor Japan (40,000 tons) produced any WPC 5 years ago.  Obviously, the availability of fibre for WPCs is a major issue.
The question of fiber availability was addressed by a report sponsored by the U.S. government entitled "Forest and Agricultural fiber resource availability", (April 2005).
This report estimates that the total resource potential is1366 million dry tons per year.  Of this, the forest resources are 368 (roughly 1/3) and the agricultural resources 998 (roughly 2/3).  Agricultural fibres should be a major raw material in the future because agricultural fibre sources can provide comparable physical properties and they are usually closer to the market than forestry fibre sources and transportation costs are a major part of the cost of this raw material for the WPC manufacturers and poses additional challenge.  Rice hulls are already being used as a substitute for wood fibre in WPCs currently being manufactured.  Heartland Biocomposites have recently announced the first commercial use of APCs (Agricultural fibre/Plastic Composites).  The company is using wheat straw and recycled plastics in their production plant in Torrington, WY for the production of fencing, decking and sheet products.
Among others current development activities include the use of nano-fillers, bio-resins and thermosetting systems.  These works are in the early stages of commercialization.  From this short update, it should be evident that orientation of thermoplastics will be a major element in the ongoing dramatic growth of thermoplastic composites as illustrated by WPCs and APCs.  These will be described at a later date.  Keep tuned.

References
  1. S-K Yeh, K-J. Kim, and R.K. Gupta; Cincinnati, ANTEC 2007, p. 2235
  2. L.M. Matuana and O. Faruk;             Cincinnati, ANTEC 2007, p. 1248
  3. J. Muzzy, X. Xu, and A. Ragauskas; Cincinnati, ANTEC 2007, p. 2240
  4. R. Stewart; Plastics Engineering, 63 (2), pp.22-26 (2007)
Frank Maine,

Frank Maine Consulting Ltd., 71 Sherwood Drive, Guelph, Ontario N1E 6E8 Canada

Dr. Maine is an organic chemist with a B.Sc. and an M.Sc. in Engineering Chemistry from Queen's University and a Ph.D. in organic chemistry from Cambridge University. He held various positions in government laboratories and in industry in various areas of plastics engineering. He was Manager of Research and Development at Fiberglas Canada.

 
Dr. Maine is actively involved in the commercialization of oriented plastics. Currently, he is working with a group of companies that are developing and commercializing oriented thermoplastic and composite products including woodfibre/plastic composites. He has given numerous presentations and is often sought speaker in WPC technology including being Conference Chair of the Executive Conference Management Annual Conference on WPCs.

 
Previously, he was the Member of Parliament (Canada) for the Guelph riding of Wellington from 1974 to 1979.
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