Today, all walks of life are pursuing “sustainable development” from fishery, home furnishing to energy and construction. In fact, from a narrower perspective, machining in the manufacturing industry has been pursuing some form of sustainability. Processing high-quality products with competitive prices can make manufacturers profitable, thereby maintaining the continuous operation of the enterprise.
To Throughout history, manufacturers have been trying to find ways to make the machining process more efficient and cost-effective, including continuous development of advanced and precise production machinery, improved cutting tools, and optimization of the entire cutting system. Specific strategies include high-speed machining, high-feed machining, high-performance machining and digital machining. To recently proposed a sustainable machining plan, which aims to reduce the consumption of raw materials, energy use and waste generation throughout the product life cycle, so that it can at least reach a level that is balanced with the earth’s carrying capacity. Usually, discussions on sustainability focus on macro-global environmental issues, while ignoring basic elements such as price, cost, customer satisfaction, process knowledge, and reliability. When it comes to the sustainability of machining, true success begins with simple, straightforward steps and analysis.
01. Sustainable pricing
Setting sustainable prices for goods or services is a challenge that every business faces. The price must be sufficient to cover costs and generate profits, but must attract customers in market competition. If the customer thinks the product is value for money, the manufacturer has room to set a higher price.
On the other hand, if pressure from customers and competitors leads to underpricing, profit margins will be affected. When the price is lower than the production cost, it will cause losses. If competitive pressures make prices too low, then product designers and processors must find cheaper, faster, and better production methods to cut production costs and maintain sustainable profit margins.
02. Invisible costs
In many companies, the profit and loss threshold is actually not clear. This is because the true cost itself is not clear. There are some hidden, ignored or unknown factors that are not included in the cost. Typical invisible costs include unplanned shutdowns, non-conforming parts and broken tools. These costs are considered unrepresentative or not “real” enough. This attitude or way of thinking that turns a blind eye to certain cost factors is not limited to production personnel, but may also exist in the entire company.
To achieve a sustainable cost structure, invisible costs must be visualized. Manufacturing personnel must check and evaluate the processing and the structure and flow of activities within the organization as a whole to discover hidden costs.
03. Customer satisfaction
Customer satisfaction is a key element of sustainable economic development. What customers care about is when the order will be delivered. In the minds of customers, the “delivery time” is calculated from the time the order is placed. And the delivery time is not just production time. If it takes three weeks to process a part, but two weeks before and after the management activities, the workshop must frankly inform the customer that the delivery time is five weeks. Metal cutting equipment suppliers, including Seco Tools, provide tool inventory management, tool identification and machine tool monitoring systems that enable workshop personnel to track customer operations and maximize workshop capacity to meet delivery targets and maintain customer satisfaction.
04, waste and measurement
Efficient manufacturing can minimize the waste of time, energy and raw materials. The waste products (such as chips, cutting oil and coolant, etc.) generated during the machining process involve more complex issues. Manufacturers are accustomed to regard waste as an inevitable product in the production process, and believe that this situation is difficult to change, so little investment in this area.
In order to effectively reduce waste and save resources, it is necessary to fully understand the characteristics of the workpiece material and the processing technology. This means that we need to accurately measure the key parameters of the processing technology and clarify the processing results.
To be truly accurate, we should try to avoid the use of rounded numbers. For example, integers usually represent estimates and cannot fully present the actual situation, and will hinder the effective determination of the result when we make adjustments. If a workshop claims its production efficiency is “above 60%”, is it 61% or 95%? After all, both figures are higher than 60%. Similarly, information such as “cutting speed of about 200 m/min” is not reliable enough. The actual value may be 195 m/min or 206 m/min, rather than an integer estimate.
In one case, a workshop owner was convinced that his factory’s time utilization rate was 70% (integer). However, after careful calculation, it was found that the actual utilization rate was only 34%. The reason is that only one out of every three machines in the factory is working and the other two are idle. Therefore, the estimation of the person in charge of the workshop is meaningless.
06, reliable processing technology
The sustainable process is reliable and predictable, and can minimize energy waste. Unreliable processes can lead to rework or scrapping of parts, as well as waste of raw materials, energy and labor due to unqualified products.
To Similarly, from a sustainability perspective, work in process (WIP) is essentially a waste. From an economic point of view, work in progress represents a waste of money, time and space. In addition, the stored semi-finished products may be damaged when moving in the logistics system. Therefore, the work in process in the workshop should be reduced as much as possible.
07. Reduce energy consumption
Throughout history, the manufacturing industry has always achieved greater results with less energy consumption. For example, in the early 1980s, the power of machine tools in many workshops was 70 kilowatts or more. Today, milling machines with a power of 7 kilowatts can provide a productivity that is higher than those of milling machines with ten times the power. Sustainable processing can minimize the energy consumption per cubic millimeter or cubic inch of material. Minimizing energy consumption will naturally reduce energy waste and make the processing more environmentally friendly.
08. Maximize efficiency
Figure 3 shows the power consumption of a five-axis machining center in one working day (the data is collected from a machine and can be used for general reference). Surprisingly, most of the energy used by this machine is not consumed by the spindle. Spindles and shaft drive motors usually consume only 30% of the energy, while various cooling systems consume 44%, and the rest is consumed by pumps, transformers, machine controls, and other systems. Therefore, most other systems of the machine tool continue to consume energy when the machine tool is not performing cutting operations.
Efficient use of energy can significantly increase product output with a small increase in overall energy use. Assume that in the first scenario, the actual processing of a workpiece takes one hour. Through programming, the setup and waiting time takes 6 hours, and the machine tool will produce two workpieces within 8 hours. When the machine tool is cutting, the energy consumption can be regarded as 100% or a nominal unit. Cutting operations consume 20% of energy, while the machine tool consumes 80% of energy units when it is not cutting.Therefore, the total energy consumption of the machine tool per day is 6.8 units, and the output is two workpieces.
In the second scene, the process is analyzed and the focus is on how to reduce wasted time. Through analysis, the idle time can be shortened to 5 hours, a 16.5% reduction. Now there are three hours of cutting time and three workpieces can be produced. The total energy consumption per day is 7 units, which is 3% higher than the first scenario.
In the first scenario, it takes 3.4 energy units to produce a workpiece, while in the second scenario, the production of each workpiece requires 2.2 energy units. In the second scenario, the energy consumption of each workpiece is reduced by 36%, while the daily energy consumption is only increased by 3%. The production of three parts in the first scenario requires the machine to run longer and consume more energy. This shows that sustainable processing does not necessarily aim to consume less energy, but to do more work with the consumed energy.
For a long time, manufacturers have pursued economic sustainability by processing high-quality products with competitive prices to support and maintain their business development. Economic sustainability includes many aspects, but in general, these components are fundamental and straightforward. Most importantly, economic sustainability means that manufacturers need to realistically and accurately assess waste in all aspects of the production process and take reasonable countermeasures.
The problems that manufacturers solve in the process of achieving economic sustainability also enable them to cope with and reduce the impact of their business on the environment, and achieve sustainability in a global sense.
Post time: Feb-09-2021