Why is plastic recycling important?
Plastics are a waste that make up a high percentage of waste due to increasing consumption. Before entering into this discussion, it is not bad to have an overview of the uses and properties of these materials and their origin for introduction. Plastics are materials that are widely used in the packaging industry due to their ease of molding and forming, and sometimes due to their high strength, high thermal stability, high toughness and corrosion resistance, in the production of parts for the automotive, electronics and aircraft industries, and Even astronautics and rocketry are used. That is, from handbags and plastic containers to engineering gears, car bodies, wire and cable covers, hall flooring and medical equipment, etc. are used. Therefore, for the above reasons, they are a good alternative to metals. At the same time, their waste is increasing day by day.
In general, waste plastics in Iran are produced from three sources. Municipal, industrial and hospital waste, so that according to the statistics obtained from the analysis of municipal waste, these materials constitute about 15% of municipal waste and the most source of plastic waste is municipal waste that is purchased and recycled by the owners of this industry. Placed.
Industrial waste, known as machine foot waste, is sold by manufacturers or re-crushed by mill and reused on the production line with new materials. Provided that the product is not consumed by food or high physical and mechanical properties such as strength and impact resistance, etc. are not desired.
Waste plastics from hospitals such as serum, syringes, etc. are also incinerated or disposed of by incinerators.
Why do we recycle plastics?
There are many reasons for recycling plastics: the construction of new petrochemicals and as a result the production of more plastics, more consumption due to the urban phenomenon for example disposable food containers and also more consumption due to use in various industries, non-decomposition and durability in Nature for at least 300 years and the creation of environmental pollution and the most important factor, namely the increase in the price of new petrochemical materials due to the elimination of subsidiaries of energy carriers and also increase in world prices, etc. has led to more and more acceptance of recycled materials and granules. In terms of price, the price of recycled granules is usually about 30% lower than new petrochemical granules. In fact, the reason for the development of the recycling industry in the world, in addition to the discussion of the environment, is that valuable products can be obtained from materials that are lower in price than new, and this creates added value. Fortel, for example, increased sales of its products from 3 million to 30 million in seven years by producing PET recycled fibers. The company claims to have the highest consumption of recycled bottles and also collects raw materials from different countries. Fortunately, there are successful examples of this type in our country.
Benefits of recycling
- Less waste is burned or buried.
- Less energy and raw materials are needed to produce waste materials than new ones.
- Reducing waste and reusing it reduces environmental pollution.
Problems with recycling plastics and how to fix them
As you know, the presence of heat and the phenomenon of degradation during the production of recycled materials has caused these materials to have lower properties than new. In fact, the depolymerization agent reduces the molecular mass of these materials and therefore can not be used recycled granules alone to produce high quality products and also due to contaminants in food packaging and cosmetics and overnight.
In Iran, in addition to the above problems, the lack of standards and supervision for recycled materials leads to the production of low quality products and harmful to health. For example, it has even been seen that unfortunately, profiteers in deprived areas have used recycled materials in the production of baby glass nipples, which has caused pests in infants. Lack of devices that can produce products with good quality is another problem of this industry. According to my observations, most of the devices have minimal facilities, and at the same time, the hand-held devices are mostly second-hand and old, and they do not use enough water even during the washing process, so it is difficult to enter the recycling workshop.
But the solutions that can solve the problems of recycled materials are:
- Use relevant and up-to-date technologies. For example, to produce soft drink bottles from recycled bottles, a technology such as (B to B) can be used, which can be used again to produce soft drink bottles due to the elimination of microbial contamination.
- Mix with new ingredients or add additives
- He designed the product to have more strength, for example, he chose a thicker product wall.
- Choose a manufacturing process that fits the type of product. For example, it is used in the production of products whose color does not matter much, and because a mixture of several plastics is generally recycled, the final color will be dark green or black, which is even for light-colored products, such as containers made of polyethylene. Dyes can be added to cover the main color of the product.
- Quaxterone process in the production of products in which recycled plastic is extruded between new materials and, for example, multilayer sheets in which the middle layer of recycled polyethylene terephthalate and the bottom and top layers of the new material are extruded. This technology is being purchased by the private sector in Iran. It should be noted that all recycled plastics are used in injection molding, compression molding, extrusion and blowing, calendering, thermoforming and rotational molding.
- Sandwich injection molding is another technique for recycled plastics whose inner core is recycled material and the outer layer is new material.
Recycling industry in Iran is one of the young industries and is of special importance due to economic issues. But in the meantime, monitoring and standards are needed to create more value-added products. In general, for investment and entrepreneurship, in addition to environmental issues, it has economic attractiveness, which can be achieved with the necessary reflection and research and consultation with a specialist. In the following articles, recycling methods and its differences and related technology and devices will be discussed.