2019年11月1日星期五

Disposable Chopsticks Life Cycle

Chopsticks are an important component of Asian culture since they are the utensil of choice for meals, and the popularity of disposable chopsticks has increased because of to-go restaurants. Today, chopsticks are commonly used around the globe, even though they originated from Asia.  The modernization of chopstick manufacturing is the result of increasing demand for these commonly used utensils; however, the production of disposable chopsticks consequently leads to the waste of raw materials and uses potentially harmful chemicals.

The lifecycle of disposable chopsticks from its creation to commercial distribution starts at the harvest of raw materials, resulting in a devastating impact on the surrounding environment by processes such as deforestation. By understanding the processes behind harvesting the raw materials used in the production of disposable chopsticks, we will have a better understanding of what steps are needed to limit the harmful effects of large-scale manufacturing on the environment.

The production of disposable chopsticks begins with the destruction of forests to harvest timber. Disposable chopsticks are primarily composed of aspen wood, but other organic materials such as bamboo, oak, and cedar are commonly used in the production of chopsticks. The woods used must have certain properties such as hardness and imperviousness to water in order to be used for chopstick composition. However, this process causes severe deforestation, as the 50 billion chopsticks produced from China cut down over 20 million trees. A mixture of heavy machinery and chainsaws are used to both cut down the trees and load the timber onto trucks to have the wood transported to a mill to be processed.

The machinery requires lots of fuel in the form of gasoline to power the chainsaw and heavy machinery. For trees on level ground, diesel-powered tractors are used to transport the fallen trees onto trucks for loading. Other machinery, like telescoping hydraulic yarders, are used for steep slopes in order to effectively collect the most amount of trees. If the trees are on level ground, the wood is dragged directly to the loading trucks. In contrast, if the trees grow on uneven ground, the wood is raised in the air and guided by guide wires to the loading trucks. The fuels are necessary to power the machines are extracted from crude oil fracked from oil-rich locations such as the Middle East and then processed into gasoline or diesel fuel to power the vehicles and tools necessary to cut down the trees.

The wood is then transported to sawmills where they are milled, steamed, and cut into the familiar chopstick shape. The milling of the wood consists of cutting the logs into small blocks to prepare for steaming so the wood will be easier to peel into longboards in later parts of the manufacturing process. Cutting and shaping the wood involves using a bandsaw, usually with a carbon steel blade. The carbon steel blade consists of material primarily comprised of iron and copper, but also has trace amounts of other elements such as chromium, cobalt, nickel, and titanium. These elements are smelted in blast furnaces to expel any impurities and input carbon to create a strong blade that will cut through wood with ease.

The blocks of wood are steamed in a steam box, made of a material that ranges from treated wood to PVC pipes. Steam boxes made of PVC are really made of vinyl chloride monomer, a synthetic material created by combining chlorine obtained through electrolysis of salt and ethylene in a reactor at high temperatures. The PVC steam boxes are attached to a steam generator, which uses water pumped through tubes made of alloy 600, a non-corrosive nickel-chromium-iron solid alloy. This alloy is created by combining the elements together at a very high temperature in a furnace.

This results in a product that is capable of withstanding high heat so water can be heated while traveling through the furnace without compromising the structural integrity of the metal itself. The water is heated in the tubes and produces steam that is injected into the steam box containing wooden planks. By steaming the wooden planks, they are making the wood more flexible and easier to peel. They are peeled using a veneer peeling machine equipped with a carbon steel blade, resulting in logs that are cut into thin boards, usually about 5 millimeters thick. These planks of wood are then cut again using a heat stamp that cuts the final shape of the chopsticks.

These chopsticks are then put into a chemical bath, but the process itself remains unknown to the public as the Chinese national standards have no record of this process, and companies withhold the details of this information in their manufacturing. In 2010, the Chinese government-imposed limits on chemical usage in chopsticks, but these limits were never strictly enforced. China’s lenient quality inspection has led to many chopstick manufacturing plants to operate with little to no scrutiny for the chemical treatment of its products.

Through alternative sources of experiments from other companies and individual investigators, chopsticks have been known to be treated with low levels of sulfur dioxide, hydrogen peroxide, sodium sulfite, and mold inhibitors. The U.S FDA restricts sulfur dioxide in fresh food to be 10 parts per million but does not impose that restriction on preserved or non-digestible products. Most of these factories are small workshops in remote areas, safe from any prying eyes and investigation by authorities. This reduces the restriction placed on these factories due to the lack of an effective quality control department to oversee production. Non-restrictive practices such as this give the chopsticks a yellow tint, indicating that those chopsticks are linked to excessive sulfur mixed into the wood.

Based on reports done at small-scale chopstick factories, we assume this chemical treatment occurs after the wood has been cut into the final shape. There is a report depicting a large chemical bath, assumingly sulfur dioxide based on the description of a yellow liquid, with bundles of finished chopsticks being soaked in this bath. Sulfur dioxide is a waste product from processes such as burning fossil fuels and smelting mineral ores, where is then captured and used as an aqueous solution to treat the wood. This process requires a metallic sulfide, which comes from hard rock mining of metals in sulfide ores. The sulfide ores are extracted from mines in the form of minerals such as copper sulfide, iron sulfide, and silver sulfide and then smelted in factories to burn off the sulfur to purify the desired mineral. Instead of letting the sulfur dissipate into the air and cause harmful toxic effects, the gas is captured and liquefied by using ice and salts as well as high pressure to create an aqueous sulfur dioxide solution.

These finished chopsticks are then shipped out on cargo ships running mainly on heavy fuel oil. These tanker ships are some of the largest air polluters, using the lowest grade oil that contains the most amount of sulfur, causing enough pollution equivalent to the emissions of 50 million cars. They use crude oil that is hardly refined, often waste oil after other fuels like diesel and heating fuels are created. The chopsticks then are offloaded onto heavy and medium-duty trucks, using diesel or regular fuel to transport the chopsticks to the desired location.

Most of these chopsticks are used once then disposed of when most wooden disposable chopsticks are compostable and can go in green bins. The end of the lifecycle of disposable chopsticks usually landfill, as very few chopsticks are reused in any way but new innovative and creative ways are currently being devised in order to minimize the waste created by chopsticks. In a few instances, people use creative methods to build sculptures and artwork to raise awareness of the environmental impact disposable chopsticks have on forests.

However, there are new ideas to reduce waste by using wasted chopsticks to create biofuels. Companies are experimenting by using potassium carbonate to liquidate the chopsticks into a bio-oil with characteristics similar to diesel while being more efficient to heavy oil. These ideas, however, result in severe pollution like carbon dioxide and nitrous oxide, so scientists are continuing to work on a way to utilize chopsticks effectively while minimizing the pollutants released from it.

The lifecycle of the chopstick is one that is severely wasteful, and the environment is paying the price, as well as possibly our health. Chopsticks use around 4 million trees each year in China alone with the majority of them ending up in a landfill since they are rarely recycled. Due to the leniency of health and safety policies of these rural chopstick factories, we don’t know the quantity or type of chemicals used to coat these chopsticks; instead, we rely on individual investigators to deduce the composition of the chemical baths used.

However, there is starting to be a shift in people carrying their own personal reusable pair of chopsticks, usually made of metal, bamboo or plastic. This change is a gradual one, and there are still over 50 billion chopsticks produced each year in China, resulting in not only the waste from creating the product but also from using fuels to transport them all around the world via plane, boat, and trucks.

没有评论: