ABSTRACT
Coffee shop is one of most popular catering restaurants, people would stay there to read the books, browsing the internet and meet their friends. Coffee is the popular beverages around the world because of its stimulating and refreshing properties. More than 400 billion cups of coffee are sold each year. The consumption of coffee bean was around 9.9 billion kilogram in 2018. However, the thousands tones of plastic waste were produced after the customers enjoyed a cup of coffee. During the coffee-brewing process, a lot of spent coffee grounds (SCG) wastes were generated because a small number of compounds were extracted from the coffee bean. The 50% dry mass of SCG mainly consists of polysaccharides, cellulose and hemi-cellulose. As SCG contains several organic compounds that are detrimental to the environment, it will cause pollution to the soil if we use it as compost and thus disposed of in landfills. As over thousand tons of SCG were generated every day, it can be used as a cheap and reliable source of renewable and recycled materials. Many researchers considered to convert the different compositions of SCG into useable materials. The consumption rate of coffee has been increasing and many spent coffee grounds (SCG) waste has been generated. As SCG contain many different organic compounds, it may cause negative impact to the environment when disposed of in landfill. Several recycling strategies were developed for converting SCG into different materials, including agriculture fertilizers, construction materials, adsorbent materials and fuels. During the recycling processes, chemical extraction method is used to remove the oil from SCG. The SCG is then mixed with polymeric materials to extrude to three-dimensional (3D) printing filaments. Some researchers found that the tensile strength of composite materials is improved. The domestic users of additive manufacturing technologies such as primary and secondary schools users are encouraged to the SCG-recycled 3D printing filaments. The development of these biodegradable 3D printing filaments is beneficial both economically and environmentally. In the chapter, the global consumption rate of coffee will firstly be discussed and how it polluted the environment. Secondly, the different coffee oil extraction methods and their yield rate will be compared. Thirdly, the pre-treatment and mixing processes of green composite 3D printing materials filaments will be explained. Finally the testing result will be showed.
