Discussion on the environmental impact of plastic manufacturing
Plastic products in the process of use in addition to scattered in the city streets, tourist areas, water bodies, highways and railways on both sides of the pollution caused by “visual pollution” pollution, there is also a potential danger. The plastic structure is stable, and not easy to be degraded by natural microorganisms, in the natural environment for a long time without separation. This means that plastic waste, if not recycled, will become a permanent pollutant in the environment and continue to accumulate, causing great harm to the environment.
Plastic products are non-toxic, but because recycling equipment is not perfect, the process is simple, and many manufacturers do not have a legal business license, resulting in the reproduction of plastic products at a temperature of 65 ° C, the toxic substances will be precipitated and infiltrated into the food, the liver, kidneys, reproductive system, and central nervous system and other important parts of the human body will cause harm.
In addition, plastic waste in landfills not only occupies a large amount of land but also does not restore the occupied land for a long time, which affects the sustainable use of land. Plastic waste that ends up in domestic waste does not decompose for 200 years if it is landfilled. It is extremely harmful to the soil, changing its acidity and alkalinity, affecting the absorption of nutrients and water by crops, and leading to a reduction in agricultural yields. As for plastic products discarded in water or on land, not only do they affect the environment, but they can also cause death if passively swallowed. This upsets the ecological balance.
Strategies and technologies adopted by Daoben Machinery to reduce carbon footprint
Approximately 95% of the PCF from plastic iniection machine is generated during the use phase. However, the actual level of emissions during daily use depends on many factors. The main determinants are the choice of polymer, product design, and mould design. A key parameter is the specific energy requirement, i.e. the ratio of energy consumption divided by output, expressed in kWh/kg. As a rule of thumb, the shorter the cycle time and the greater the weight per mould, the lower the specific energy requirement and the better the CO2 equivalent.
The specific energy requirement is strongly influenced by the type of drive, i.e. whether it is electric, hybrid, or hydraulic. Other influencing factors include whether single or dual-circuit pump technology or hydraulic accumulators are used and whether options such as servo-electric metering or ejection are included.
Any feature that enables synchronised, dynamic and fast movement, and therefore shorter cycle times, contributes to the carbon footprint of the use phase. The same applies to screw diameter and installed power: the higher the weight per mould, the lower the power consumption and the better the carbon footprint. Overall, machines and equipment tailored to specific needs and processes can significantly reduce energy requirements. Daoben supports its customers in this area with its extensive application and process engineering expertise and the benefits of modular machine technology.
For plastic iniection machine, a meaningful carbon footprint can be calculated “from production to end-of-life”. At the manufacturing stage, raw materials have about ten times more impact on a product’s carbon footprint than electricity consumption. Local supply chains, a high degree of vertical integration and the use of renewable energy can have a positive impact on the carbon footprint.
As the PCF at the use stage depends on many factors, individual case studies are required. Typically, the specific energy requirement of plastic molding machines decreases as their utilisation increases. In addition, electric plastic molding machines produce around 50% less CO2 emissions than hydraulic machines, although the exact amount depends on the equipment and material throughput. The goal for the future is to be able to determine a scientifically sound overall LCA for plastic iniection machine, which will require more effort.
Efficiency improvements for energy and material savings
The power consumption of injection moulding mainly consists of three systems: power drive, cylinder heating, and plastic drying and heating. The above three power consumptions account for about 95% or more of the total energy consumption of injection moulding processing, which is the main direction of research, development and application of energy-saving technologies.
In the past, injection moulding processing mostly used the hydraulic system of the quantitative pump, the oil pump motor provides a constant flow rate at a constant speed, and the excess oil pressure is returned to the tank through the relief valve, i.e. high-pressure throttling, so the oil pump motor consumes more ineffective energy. During the holding pressure and cooling, pick-up phase, the injection moulding machine is in a stationary waiting state with virtually no flow and pressure requirements, but the motor of the metering pump system is continuously discharging oil into the oil circuit. Due to the presence of system back pressure, more power is unnecessarily consumed, resulting in a waste of electrical energy and an energy loss of 25% to 80%. In order to reduce the inefficient consumption of electricity, frequency conversion technology, variable pump technology and other transitional approaches to technology appeared one after another.
After 10 years of development of energy saving technology, the current mainstream technology and products are servo energy saving systems, including hydraulic servo and all-electric servo. Servo system has excellent performance such as energy saving, precision, stability, fast response, etc., with high cost performance, almost all the main products of plastic iniection machine manufacturers are servo-driven energy-saving systems, and the market application volume reaches more than 90%. And the terminal injection moulding factories also gradually complete the application of servo energy-saving technology through the energy-saving technological transformation, and the energy-saving technology can be generally adopted and accepted.
The role of sustainable practices in the future of manufacturing
At present, the market requirements for plastic products are becoming increasingly stringent, “green smart manufacturing” has become a strong voice of the times. From the industry as a whole, after several rounds of technology and environmental protection policy elimination, the current market active plastic iniection machine manufacturers are very much focused on the development of a new generation of high-tech equipment, through the intelligent control, to meet the current production of high-precision product requirements.
The traditional injection moulding machine adopts hydraulic transmission, which has the characteristics of high environmental pollution, high noise and high energy consumption. Such plastic molding machines not only have serious energy loss, but also have greater adverse factors to the environment. However, its manufacturing cost is low and maintenance is relatively convenient, so it is the type of injection moulding machine with the highest market share at present.
However, 80% of mainstream injection moulding machines have been retrofitted with energy-saving auxiliary equipment, from low-energy heating coils to servo-intelligent control systems, and from core components to design processes, each module has been carefully optimised, and the performance of the whole machine has been further improved. It can be said that sustainable development has become a symbol of the new era, and is also an important factor that today’s moulding machinery manufacturers need to consider when planning future models.
