A Triangular Symbol Made of Three "Chasing Arrows"
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A triangular symbol made of three "chasing arrows" containing a number in the middle and special letters on the outside is used to identify the different types of plastic. The following are the letters of identification and their meaning: 1. PETE - Polyethylene Terephthalate - PETE is most often used for cooking oil bottles, soft drink bottles, and peanut butter jars. 2. HDPE - High Density Polyethylene - HDPE is commonly used for milk jugs and detergent bottles. 3. PVC - Polyvinyl Chloride - PVC is used for plastic pipes, water bottles, outdoor furniture, shrink-wrap, liquid detergent containers, and salad dressing containers. 4. LDPE - Low Density Polyethylene - LDPE is often used for trash can liners, dry- cleaning bags, produce bags, and food storage containers. 5. PP - Polypropylene - PP is used for drinking straws and bottle caps. 6. PS - Polystyrene - PS is used to make packaging pellets, commonly referred to as "Styrofoam peanuts." 7. OTHER - Plastics listed in the OTHER category are any not listed in the first six categories. Certain types of Tupperware and other food storage containers commonly fit within the OTHER category. The many different types of plastic has made recycling plastic difficult, particularly because the process of sorting plastics cannot be automated. In fact, recycling plastic is labor intensive since reading the special triangular symbol can only truly identify most plastic items. Biodegradable Plastic Currently, there is research taking place in the area of biodegradable plastic. The goal is to develop a type of plastic that can naturally break down from exposure to sunlight. By mixing starch with the plastic, it can be made to degrade more easily. It does not, however, cause the plastic to break down completely. A genetically engineered bacterium capable of synthesizing biodegradable plastic has also been developed. This material, however, is quite expensive to create at this point. Currently, BASF does make a biodegradable polyester called Ecoflex that is used for food packaging applications. Unfortunately, carbon gets locked up in these biodegradable plastics and is released into the atmosphere as carbon dioxide. Another downside to these biodegradable plastics is that they require sunlight to degrade. Therefore, this type of plastic really only helps with roadside litter. Plastics buried in landfills will not receive the sun they need to degrade and, therefore, can still last for decades. While there are still many questions left unanswered when it comes to the environment and plastic, it is clear plastic is here to stay for a very long time. 9 June 2010 MUSCAT -- On the occasion of World Environment Day, celebrated recently, Oman Plastic Industries began the manufacture of Oxo-Biodegradable plastic bags for the first time in Oman. Oman Plastic Industries is officially certified by the Directorate-General of Specifications and Measurements of Oman to manufacture the oxo-biodegradable plastic carry bags, after completing the necessary test run with the co-ordination of the local distributors of the d2w additive in Oman. Oxo-biodegradable plastics, with a pre-programmed life, significantly reduce the harmful effect on the environment. At the end of its useful service life, they degrade in the environment by a combination of oxidation and biodegradation. During its service-life, strength and other qualities are the same as ordinary plastics. The plastic eventually breaks down to water, carbon dioxide, biomass and trace elements, on land or sea, in the light or dark, in heat or cold. It leaves no fragments or methane or harmful residues thus avoiding pollution and damage to the environment and wildlife. Oxo-Biodegradable plastics do not need a highly-microbial environment to degrade. It will happen even if the plastic is left in the open or in the sea. Ecomagination from GE - with innovation, there will be more clean water for everyone The plastic is made oxo-biodegradable with the addition of d2w additive when the plastic product is being manufactured. d2w products have been available for more than four years and are now used in more than 50 countries by major retailers, hotel groups, food manufacturers, etc. The additive does not have any toxic effect and is totally soil safe as per the ATM D 6954 -- 04 Standard which tests plastics that degrade in the environment by a combination of oxidation and biodegradation. The world produces and uses 20 times more plastic today than it did 50 years ago. Ordinary plastics can take up to 400 years to break down. Given plastic is a fundamental part of our day-to-day lives, it is time to move on to a more earth-friendly product like degradable plastic. "With the technology now available in Oman, it empowers retailers and organisations who think 'Green' to show their care for the environment," says Tariq Ali Mirza, Managing Director of Oman Plastic Industries. By Staff Reporter HDPE Plastics Ubiquitous in every day life and accounting for the bulk of material used to create milk bottles, laundry detergent bottles, and margarine tubs, it may surprise some readers to learn that HDPE plastic actually begins life as thick black crude oil pumped out of the ground. HDPE plastics are produced from a component of crude oil, naphtha, which is cracked (heated at very high temperatures) in order to extract the ethylene gas which is released when the chemical structure of naphtha deteriorates. The ethylene gas is then polymerized, a process which involves the free gas particles joining together to produce long chains of ethylene molecules. There are many different types of polyethylene. HDPE is a particular type of polyethylene with a very dense linear structure which gives it an increased tensile and molecular strength. HDPE is normally defined as being polyethylene with minimum density of 0.941 grams per cubed centimeter. Within the category of HDPE plastics, molecular weights range from 100,000 to 500,000, which is where the great variance in HDPE grades arises. Common grades of HDPE plastics include blow molding grade HDPE plastics, injection molding grade HDPE plastics, film grade HDPE plastics, and pipe grade HDPE plastics. Each of these grades have slightly different physical properties, the most notably important one being MFI, or melt flow index. Melt flow index describes how quickly the HDPE plastic flows when in liquid form, applications such as pipe making and blow molding require a highly viscous slow flowing HDPE plastic, whereas injection molding requires a quickly flowing HDPE resin. HDPE plastics were first invented in the 1950¶s, though it took some time to discover ways to reliably produce large amounts of homogeneous HDPE, as the processes under which HDPE is produced must be tightly controlled in order to produce the different grades of HDPE. Ethylene naturally polymerizes at high temperatures and pressures, but it is not commercially viable to operate facilities under these conditions. So instead, catalysts are used to lower the temperature at which polymerization will take place, and also direct the type of polymer which results. HDPE¶s largely linear structure with little molecular branching is commonly produced by Zeigler-Natta catalysts, or chromium catalysts. HDPE lends itself well to recycling, and a great deal of reprocessed HDPE, recycled HDPE, and regrind HDPE is available on the market. The bulk of recycled HDPE plastics are post consumer scrap reclaimed from kerbside recycling programs. Millions of tons of HDPE plastic milk bottles and other household vessels are collected and recycled every year. For the most part, recycled HDPE plastics are equally as useful as virgin HDPE plastics, though they may not be used in food contact applications. There is some risk that contaminants found in the scrap HDPE from which recycled HDPE is made may pass through the various cleaning and filtration steps and degrade and contaminate the end product. If one is dealing with a reputable supplier, and the specific application is not overly intensive, recycled HDPE is an economically sound alternative to virgin HDPE plastic. Plastics can be biodegradable because they are already made by chemical reaction. Plastics are derivatives of hydrocarbon. And only those things can be biodegrade those are related to living organisms like paper, fruits waste ,skin or even cloth INTRODUCTION: During the past 25 years, plastic materials have gained widespread use in the food, clothing, shelter, transportation, construction, medical and leisure industries. Plastics offer a number of advantages over alternative materials ± they are lightweight, extremely durable, and relatively unbreakable. However, plastic materials also have several disadvantages, one of the largest being that plastic does not break down in the environment. Materials such as wood and paper are subject to breakdown from microorganisms (biodegradation). Plastics are composed of petroleum-based materials called resins (e.g., polyethylene, polypropylene) ± materials that are resistant to biodegradation and because of this resistance, plastics that are disposed of in landfills will remain in their original form in perpetuity. Every year, large volumes of plastics are disposed of in U. S. landfills ± in 1995 alone, an estimated 20 million tons of plastic products were disposed of in landfills. TYPES OF BIODEGRADABLE PLASTIC 1) Starch based plastics: These are 'compostable' plastics made from various food substances and they compostable because they will completely biodegrade within 4 months in a commercial composting plant. Please be aware that they do not decompose in a home composting facility because elevated heat is required to compost them. PLA is the best known type. The largest manufacturer of starch based plastic is reported as saying that they will create methane if placed into the anaerobic zone of landfills. This kind of plastic is best suited for composting in commercial composting facilities where food and garden waste are composted but undesirable in landfills. 2) Oxo-biodegradable conventional plastics: These are conventional plastics with an additive added to them that cause them to biodegrade.