We all know that in the production of aluminum profiles, profit = sales minus production costs.The total cost of aluminum profile is divided into fixed cost and variable cost.Fixed costs such as plant rent, depreciation of machinery, etc.It’s fixed.And variable costs have a lot of flexibility.
In the case of the same aluminum profile sales price, the higher the cost of aluminum profile, the lower the profit.At present, under the harsh environment of rising raw material prices, rising workers’ wages, appreciation of RMB, rising energy prices, increasing tax burden and so on, the competition in the same industry has entered the “white-hot” today.The time has come for fine cost control.
Cost control is the key that the enterprise manages and the core.Only by constantly find the weak link, mining internal potential, can use all the means and way to reduce costs, full participation, start from the details, starting from reducing waste, aluminum fine to the implementation of cost control, can effectively broaden the space of enterprise survival, improve the enterprise management status, make the enterprise sustainable development, and is in an impregnable position.
Aluminum profile cost control is based on the value chain as the guide, the cost control is divided into design cost, procurement cost, manufacturing cost, sales cost and service cost.Because cost control involves a wide area, content is much.I will talk about how to improve the rate of finished products from the point of view of manufacturing so as to reduce production costs.
Through data analysis and practice, it has been proved that improving the yield of aluminum alloy profiles is one of the most direct and effective ways to reduce the production cost. Taking the extrusion workshop as an example, the production cost of aluminum materials will be reduced by 25-30 yuan per ton if the yield is increased by one percentage point, and the reduced part is the net profit of the enterprise.To improve the extrusion yield, the task of production is to reduce the extrusion waste.
How to improve the yield of aluminum profiles to reduce aluminum waste, improve productivity, and reduce the production cost of aluminum profiles, we summarized the extruded wastes:
The waste of aluminum extruded profiles can be divided into two categories: geometric waste and technical waste.Geometric waste is an unavoidable waste product of aluminum alloy profiles during extrusion.Such as the extrusion of residual material, stretching products at both ends of the chuck, the size of the material is not enough length of the length of the material abandoned, cut the necessary sample, the shunt combined die in the shunt chamber of the remaining aluminum block, ingots and products cut the size of the material of the saw-blade consumption of aluminum chips and aluminum ingots consumed during mold test.
Technical waste is the waste produced by unreasonable technology, equipment problems and improper operation of workers in the process of aluminum alloy profile production.Different from geometrical waste products, it can effectively overcome and eliminate the generation of technical waste products through technical improvement and strengthened management.Technical waste can be divided into:
Tissue waste products: overburning, coarse grain ring, coarse grain, tail shrinkage, slag inclusion, etc.
Mechanical properties unqualified waste: strength, hardness is too low, do not meet the national standards; or plastic is too low, not enough softening does not meet the technical requirements.
Surface waste products: layers, bubbles, extrusion cracks, orange peel, tissue clauses, black spots, longitudinal welding line, transverse welding line, scratch, metal pressing, etc.
Geometric dimension waste products: wave, twist, bend, plane clearance, size out of tolerance, etc.
Rate of finished products division of labor sequence rate of finished products and comprehensive yield.
Process finished aluminum ratio generally refers to the main process, usually based on the workshop as a unit for calculation.Casting process (casting workshop), extrusion process (extrusion process), oxidation coloring process (oxidation workshop), powder spraying process (spraying workshop).It is defined as the ratio of the qualified output of the workshop to the input of raw materials (or semi-finished products) in the workshop.
The rate of finished products is related to the quality of equipment, ingot quality, product structure, frequency of change of varieties and specifications, advanced degree of technology, enterprise management level and quality of operators and other factors.
The key to improve the yield of aluminum alloy profiles is to reduce and eliminate waste products.Geometric waste is unavoidable, but it can be minimized.Technical waste is a human factor, which can be eliminated on a case-by-case basis or minimized.Therefore, effective control and improvement of the yield of extruded products can be adopted.
Reducing geometric waste is an important prerequisite to improve the yield of finished products
Measures to reduce geometric waste
Correct choice of ingot length is the main measure to reduce the process waste.The length of the ingot is not calculated after extrusion, but calculated after extrusion.
Now most enterprises use the long rod hot shear aluminum rod heating furnace, compared with the short rod heating furnace, reduce the loss of aluminum chips, because of the change of mold wall thickness, the casting length control is more flexible and accurate, greatly improve the yield.But many enterprises in the use of long rod hot shear furnace, ignore the calculation of casting length, and directly hand over the work to the operator to control.And the operator is often based on experience under the first bar, observe the length of the material, if the difference is large, continue to adjust, usually need about 3 bars to get the accurate length.In the process, a lot of waste has been produced, which reduces both the production efficiency and the yield.
The correct approach is that the length of the ingot is calculated by the process control department during the initial production of the mold. When the mold is produced on the machine for many times, the length of the rod recorded on the mold card is slightly increased by about 5-10mm, and the length of the material is observed when the material is produced.Fine tuning if there are differences.So the second rod is very accurate.According to some data, the yield of finished products can be increased by 4 percentage points by using long hot shears, and it is completely feasible to increase the yield by 2 to 3 percentage points in actual production.
In addition, the number of fixed length or product length, in order to ensure the smooth extrusion function under the premise of extrusion.When the length of the cold bed is long enough, increase the length of the fixed size or the length of the products as much as possible, that is, the longer ingot may be chosen.It is also an effective method to reduce the percentage of geometric waste and increase the yield of finished products.
Measures to improve the rate of finished products from the technical level
It is an important technical measure to improve the rate of finished products to improve the level of mold design and manufacture and to reduce The Times of mold test.Generally not this test mold cost 1-3 ingots, so that the yield reduced 0.5-1%, due to the design of the mold, low manufacturing level, some products to repair mold, mold 3–4 times or even more times to produce finished products, immaterially reduce the yield of 2–5%, which will not only cause economic losses, but also due to repeated test mold, will extend the production cycle.
Modern mold zero test concept, that is, after the mold is manufactured, there is no need to test the mold, you can directly on the machine to produce qualified products.Using simulation design software, finite element analysis, design can be completed in the computer.It can also be tested by computer simulation.Mold cavity processing is completed in the automatic machining center, the processing of the whole mold is high precision, so the quality of the mold is very high.On the machine pass rate in more than 90%.It can increase the yield of finished products by 2-6%.
Appropriately increase the extrusion coefficient of aluminum to improve the yield
Each aluminum factory has a series of machines, each factory according to the extrusion ratio of the product, the length of the cold bed, the outer section of the product, the length of the extrusion cylinder diameter, to determine the product on the corresponding machine production.Practice has proved that the same specifications of products, put in different tonnage extrusion machine production, because of the different extrusion coefficient, the structure of the product performance and production efficiency has a great impact, its yield will also produce differences.When the extrusion machine tonnage is larger, the extrusion coefficient is larger, the finished product rate is higher, and the extrusion cost is close to.
Improving the quality of ingot is the premise of improving the yield
Ingots are the raw materials of extrusion production. Ingots have uniform structure, fine grains, no slag, pores, segregation, cracks and other defects, which can not only reduce the extrusion pressure, improve the extrusion speed, and improve the internal quality of products.And can reduce the product surface bubbles, pores, scratches, cracking, pitting and other defects.Smaller slag inclusion can be discharged through the slit of the mold working belt, but it will cause pear marks on the profile surface, resulting in a certain length of waste.The larger slag inclusion will be stuck in the slit of the working belt and cannot be eliminated, which will cause mold plug or products cracking and replace the mold, which will seriously affect the yield.Use corresponding pads when stretching and straightening to reduce the cutting length of head and tail material.
Profile in stretch straightening, many enterprises do not design the corresponding cushion, especially some large hanging profile and hollow profile.As a result, the deformation of the head and tail of the profile is too large, and the deformation part must be cut off when sawing the finished product.This has resulted in a decline in the rate of finished products.
The cushion can be made of hardwood or aluminum blocks. The design minimizes the size of the cushion and increases its versatility.For the long wall and closed section of the profile, straightening in the closed cavity into the pad but also put the support frame in the part of the wall.Thus, the deformation in the length direction is reduced.Fixtures must be designed, managed and guided by special personnel.
At the same time, in order to prevent the phenomenon that workers are not willing to use the cushion because of the trouble, we must establish the reward and punishment mechanism that the rate of finished product is linked with the wage.
Strengthen the management of extrusion die and original production record of aluminum profile.
The mold card and the original production record are very important. The mold card must be able to truly show the nitriding situation of the mold, the maintenance situation and the material situation. The original record must be able to truly show that the support weight, casting length and quantity provide a reliable basis for the next production.
Now many enterprises have also realized computerized data management, but there is still a long way to go in the actual use.
Reduce geometrical waste by using press-free afterextrusion
The fixed pad is fixed on the extrusion rod without residual extrusion, and the two are modified to a certain extent.When the extrusion cylinder does not retreat, the pressure pad is also easy to separate from the ingot.The next ingot is then pushed directly into the extrusion cartridge.Extruded with the remainder of the previous ingot, thus avoiding the need to shear each ingot once.According to the quality requirements and order quantity to determine the number of casting shear press.Usually 40-50 pieces are cut at a time.
Optimize the extrusion process of aluminum profiles to reduce technical waste
There are many aspects affecting the extrusion process of technical waste, which covers the whole extrusion production process.Mainly include: ingot quality, process temperature, extrusion speed, extrusion tools, dies, transfer loading and unloading, aging treatment, etc.In addition to the development of advanced, scientific production technology, but also the correct strict implementation of operating procedures, improve the workers’ proficiency and sense of responsibility.
As far as possible to reduce the variety of production per shift, it is best to arrange only 3-5 varieties per shift, to improve the production of a single set of molds.The more varieties on the machine, the more mold aluminum will be taken away, the lower the yield.
The effect of mould on the yield is mainly in two aspects: new mould test and the use of production mould
The more times the mould is tried, the more aluminum the mould is taken away, and the lower the yield.So we must improve the design and production level of the mold.
Mold production should be carefully maintained, reasonable nitriding, timely maintenance.Ensure each time on the machine qualified rate is high.Good molding and high durability.If each shift due to mold maintenance unqualified, resulting in 3-4 varieties on the machine production failure, the rate of finished products will be reduced by at least one percentage point.
Aluminum extrusion tools include: extrusion cylinder, extrusion rod, extrusion pad, die pad, etc.Mainly to ensure that the extrusion cylinder, rod, mold three concentric.Secondly, reasonable maintenance of the extrusion cylinder, correct heating, to ensure that the end surface of the cylinder is smooth.Eliminate all kinds of extrusion cylinder and die with bad phenomenon.Clean up the residual aluminum in the inner wall of the extrusion cylinder regularly, check whether the inner hole wall is damaged, use the die pad correctly, and improve the support strength of the die.
Extrusion temperature, extrusion speed and cooling three, on the product structure, mechanical properties, surface quality has a great impact, will also affect the yield.In addition, the three will affect the length of the product, the casting rod temperature is high, the extrusion speed is fast, the cooling rate is low, will make the length of the product after extrusion increase, the growth rate can be up to 0.5% – 1%, also affects the linear density of the profile, so the stable process can improve the yield.
Improve the subsequent extrusion process to avoid technical waste.Extruding the subsequent process of transport, mainly pay attention to the profile of the scratch scratch.
One die porous extrusion can improve the yield of finished products.
For some products suitable for multi-air extrusion, as far as possible using porous extrusion, not only can reduce the extrusion coefficient, reduce and pressure, but also can improve the yield.Under the condition that the technical waste is zero, the yield of the double hole extrusion can be increased by 3% ~ 4% than that of the single hole extrusion.
Extrusion speed is an important process parameter in the extrusion process, which is related to the quality of products and production efficiency.Extrusion speed is not like to master the process temperature, a kind of alloy a heat treatment process can basically select a temperature, and the extrusion speed is a very empirical process parameter.Different alloy profiles with different sections have different extrusion speeds. The same product is affected by temperature changes in the extrusion process, and the extrusion speeds are different before and after the extrusion.To correctly control the extrusion speed, it should be:
Skillfully and flexibly grasp the range of extrusion speed of various alloys, various sections (including wall thickness), and pay attention to the impact of the extrusion speed on aluminum profiles, such as surface quality, molding degree, etc.
Familiar with the ability of extrusion equipment to control extrusion speed.Some extruders have constant extrusion control and PLC control, some have only PLC control, and some have neither.When a given extrusion speed, some extruders can begin to press the speed of extrusion, with the gradual reduction of the billet in the extrusion cylinder, extrusion pressure is reduced, the outflow speed of the product will be faster and faster, sometimes make the product after the crack.Therefore, it is necessary to adjust the extrusion speed.Only by understanding the state of the equipment can the extrusion speed be properly adjusted and controlled.
Understand the impact of different molds on extrusion speed.Generally speaking, the extrusion speed of flat die (solid profile) is higher than that of split die (hollow profile).But the same kind of mold, the same section shape of the product, because of the design and manufacturing level is different, the extrusion speed is different.In particular, the section has wall thickness difference, or the semi-hollow profile with an opening, which has a great relationship with the mold. Only a certain extrusion speed designed by the mold is the best. The speed is too fast or too slow, and it is easy to produce twisting and opening and closing.
Reduce waste generation by strengthening initial inspection and process inspection
The outer dimension of aluminum waste products, such as wall thickness out of tolerance, twisting, plane clearance, opening or closing, etc., mainly depends on the first rod after the mold test by the host hand in the discharge inspection and the quality inspector in the tensile inspection to prevent the generation of such waste products.The general wall thickness tolerance should be controlled from the negative tolerance, because with the continuous production of products, the wall thickness of products will gradually become thicker due to the gradual wear and tear of the mold.For large wall profiles, when drawing and straightening to carefully check the drawing, control a reasonable amount of stretching.
Surface waste such as scratches, orange peel, tissue, black spots, bubbles, often not all of the root products appear.It is necessary to check each other through the host operator, the quality inspector and the sawing process of the stretching finished product, and jointly supervise the removal of the waste products on the surface.
If the quality inspector does not find scratches on the discharge table, and finds scratches on the finished products when sawing, it is necessary to check from the conversion process of the cold bed to see if some parts of the transport belt, digger and so on are hard and prominent, resulting in scratches.
Quality management is the management of the whole staff and the whole process. Each process must have a good quality, so that self-inspection, mutual inspection and special inspection can be combined, so as to effectively eliminate the technical waste in the bud.Artificial control and improve the yield.
Through the above measures can reduce the geometric waste, it can be seen that the reduction of geometric waste is an important technical management measures for enterprises, which has great significance for high economic benefits.
To improve the yield of aluminum extrusion billet is to complete and meticulous work process of extrusion production, not only the technical aspects should be in place, but also the management aspects should be in place.There is still a lot of room for China’s aluminum profile enterprises to improve the yield, the yield will be a continuous process, improve the yield and improve product quality, output is closely linked.Is an enterprise technology and management level of the comprehensive embodiment.
Improve the yield of oxidized colored aluminum
The yield of oxidation is the yield of one production, that is, the yield of one production without rework. According to the production practice, the cost of reworked profiles is 3 times that of non-reworked profiles, and the surface quality of profiles can not be guaranteed.Of course, the quality of oxidized products starts from the casting workshop. Due to space restrictions, the following is a brief talk about some details that should be paid attention to in the oxidation production process.
The screw between the hanging rod and the conductive beam should be often tightened. Before tying the material, we should first check whether the hanging rod is fixed loose. If it is slightly loose, it should be tightened in time.Another corrosion, hanging rod will become smaller, need to be replaced in time, because its conductive area is small, easy to cause heat, at the same time to tie, prevent the profile falling into the slot caused by pole, short circuit damage to the power supply.
At the same time fall into the profile of the tank should be cleaned out in time, such as the alkali washing tank into a profile, it will soon corrosion, the experiment proved that the alkali consumption is equivalent to the alkali washing of 50-100 root of the profile of the alkali consumption.Falling into the coloring tank or sealing tank, due to corrosion, the tank will accumulate a large number of aluminum ions, affecting the service life of the tank liquid.
Binding material with aluminum wire with two kinds of specifications is good, aniseed to choose coarse aluminum wire, medium and small material is used in fine aluminum wire, can be used 2mm and 3mm, or 2.2mm and 3.2mm two kinds of specifications, aluminum wire annealing hardness takes 1/2~3/4 is good.At present, a lot of enterprises have been converted to jig.
Before hanging into the oxidation tank to tighten each profile;The rework material before the oxidation of the material, to use pliers to beat the end of the profile to make it shift before the material, so that the contact without film, to ensure good conductivity.
Type material hanging into the oxidation tank and coloring tank conductive seat should pay attention to the right, otherwise prone to Yin and Yang complexion difference.
After the end of the oxidation power is suspended in time, stay in the oxidation tank for a few minutes will affect the sealing hole, will also make the speed of coloring;After oxidation, it is lifted and tilted in the air for too long. One end of the acid reducing solution is darkened because of the pore expansion of the oxide film, and color difference at both ends is easy to appear.
The pH value of the four water washing tanks before and after the coloring tank should be kept relatively stable. The pH value of the normal four water washing tanks is controlled as follows:
The pH value of the first water bath after oxidation: 0.8~1.5
The pH value of the second water bath after oxidation: 2.5~3.5
The pH value of the first water bath after coloring: 1.5~2.5
The pH value of the second wash tank after coloring: 3.5~5.0
Under normal circumstances, a certain amount of overflow water is opened during production, and the inlet valve is closed in time when production is stopped. It should not drain or add water in the whole tank. If the water stays in the first washing tank after oxidation for a few minutes, the coloring speed will be accelerated, and if the water stays in the second washing tank, the coloring will be slowed down.
For the production of light-colored imitation steel material, the method of coloring is generally adopted first, then back to the standard color plate.Because of the color difference of imitation steel coloring time control range is very small (only 2~3 seconds), and using the fading rule can have 10~15 seconds of color control time, and unified fading is also conducive to the same background color, for imitation steel fading and complementary colors are color tends to turn green, and one-time coloring tends to be red.
Type material hanging from the coloring tank and the first washing tank after coloring after hanging do not stop empty time is too long, otherwise the profile surface will appear ribbon, uneven color and drainage end of the white phenomenon, should be slightly on the color of the next wash in time, accurate color should be in the second wash after.Generally speaking, for imitation steel material, such as contrast template color red, it shows that the coloring time is not enough to complement the color;If the color is yellow, it has been colored, according to the color depth, you can choose to recede in the coloring tank or in the first washing tank after coloring.
Adding method of drugs in the coloring tank: stannous sulfate and nickel sulfate must be dissolved in the tank, and the coloring additive must be dissolved in pure water (pure water is soluble). It must be noted that the solid additive can be poured after completely dissolved, and the concentrated sulfuric acid can be poured directly into the coloring tank.
The temperature, time and water quality of hot water washing before electrophoresis must be guaranteed. If residual SO42- in the oxide film hole is not washed, yellowing and opacity of the paint film are likely to occur after electrophoresis and baking.Under normal circumstances, the hot water temperature is controlled at 60~70℃, and the hot water washing time is 5~10 minutes.
Post time: Mar-26-2021
