To lower the cost of loader products, we aim to reduce cutting and blanking expenses by improving the utilization rate of essential materials such as cooling water pipes, electrodes, vortex rings, nozzles, nozzle caps, protective caps, and vortex gas caps during plasma cutting and blanking.
With increasing market competition, cost-effective products have become the first choice for customers. However, the cost of producing a product, which includes raw material cost, energy consumption, employee salaries, equipment depreciation, and manufacturing cost, is also increasing. As a result, there is less and less room for the company’s profits to rise.
Figure 1 illustrates the composition of product cost.
To respond to the company’s call to “strengthen cost control” and increase profits, it is urgent that we reduce the cost of equipment consumables.
Fig. 1 product cost composition
As low-value consumables constitute a significant part of the manufacturing cost, enhancing their utilization rate is a way to increase profit margins.
In plasma cutting, cooling water pipes, electrodes, vortex rings, nozzles, nozzle caps, protective caps, and vortex gas caps are essential materials.
Optimizing the usage of these materials can lead to a certain degree of profit improvement for the product.
Loss classification of plasma cutting head
After analyzing the consumption of low-value plasma consumables in June, it has been concluded that the consumption of electrodes and nozzles is the highest.
To understand the reasons behind the high consumption of these two consumables, measures will be taken to improve their utilization and reduce their consumption.
The electrode’s primary damage form is depression, as shown in Figure 2a.
The main damage forms of nozzle cap and vortex gas cap are burn, hole out of round, and an increase in hole diameter, as shown in Figure 2b.
The nozzle’s primary damage forms are hole out of round, burn, and an increase in hole diameter, as shown in Figure 2c.
The protective cap’s primary damage forms are deformation, scratch, and overdenture, as shown in Figure 2d.
The vortex ring is mainly broken, while the cooling water pipe’s primary damage form is burning out with the gun.
Fig. 2 Damage of plasma cutting head components
Damage causes and improvement measures of plasma cutting head
First, let’s consider the number of perforations required for blanking programming.
During the blanking process, each piece must be perforated before the material can be arranged according to the shape of the part.
If you want to increase the service life of the electrode, the number of perforations and cutting length should be reduced. However, the cutting length is directly related to the product design and cannot be changed arbitrarily. Therefore, our focus will be on reducing the number of perforations.
The conventional cutting procedure requires the gun to be started once for each closed contour. Therefore, studying how to combine several contours for cutting can significantly reduce the number of perforations.
The improved blanking and cutting procedure is depicted in Fig. 3.
Fig. 3 Blanking and cutting after improvement
Secondly, the pressure in the plasma pipeline is insufficient. This directly affects the quality of the plasma cutting torch and limits the distance that the cutting head can cut. As a result, there is an increased risk of collision damage to the cutting head.
To remedy insufficient pressure, the pump can be configured to increase the internal pressure of the pipeline, which in turn reduces the loss of the cutting nozzle.
By implementing the above measures, the loss of the cutting nozzle can be significantly reduced, as shown in Figure 4.
After two months of implementing these improvements, the consumption of plasma cutting head consumables continued to decrease.
Fig. 4 Loss trend of plasma cutting head
During the blanking and hole cutting process, waste material often falls onto the grid and can cause the cutting gun to drop and damage the motherboard or cutting nozzle. To improve this situation, we have implemented the following measures:
Firstly, when cutting a hole, a plane falling probe automatically adjusts the height. However, this can cause issues when cutting small holes as it is easy to bump the probe.
To address this problem, we have established a small hole database that allows the automatic height adjustment command to be disabled during hole cutting. By doing so, the probe will not fall, reducing the risk of damaging the cutting gun.
After analyzing the causes of plasma cutting head parts loss, the main factors influencing it have been identified: number of perforations, closed contour, pipeline pressure, and cutting size.
By implementing appropriate and effective measures, the loss of plasma cutting head parts can be significantly reduced.