Aluminum extrusion profile manufacturing can be a tricky business for newcomers. Although the aluminum extrusion profiles market is booming globally, there are many pitfalls in the newcomer profile manufacturers’ path to profitability.
Even the few profile manufacturers that have achieved profitability have yet to reach their full potential. The Achilles heel for most of them is the high production costs compared to aluminum profile yield.
Like other enterprises, aluminum extrusion profile manufacturers need to keep their production costs low while increasing their yield to become profitable. In most instances, a 1% increase in aluminum profile yields translates to a $5 to $10 drop in production cost.
The reduced portion of the production cost leads to higher net profits. The most effective way of enhancing aluminum profile yield is minimizing extrusion scrap (the remnants products of the extrusion process).
Extrusion scrap can be classified as physical scrap or technical scrap. Physical scrap is the inevitable scrap created during the extrusion process. It includes:
● The residual extrusion material
● Necessary cutting samples
● Mold test aluminum billets
● Chip scraps from cutting aluminum billets and profiles
● Aluminum stuck in the porthole die
On the other hand, technical scrap is the avoidable scrap created during the extrusion. Technical scrap can result from:
● Improper operations by workers
● Equipment issues
● Unreasonable technology
Although physical scrap is unavoidable, the focus should be on minimization. Conversely, technical improvements and management strengthening can help effectively eradicate technical scrap. Here are nine ways to address physical and technical extrusion scrap to boost aluminum profile yield.
1. Use High-Quality Aluminum Billets
Billets are the primary raw material in the extrusion process. Therefore, the billet quality will massively impact the efficiency and profile yield of the entire extrusion process. High-quality billets should have a uniform structure with small grains. It shouldn’t have any segregation, blowhole, slag, cracks, or defects.
A top-quality billet with all these characteristics will require a reduced extrusion force and increased extrusion speed. As a result, the internal quality of the extruded profiles will be enhanced. Additionally, the extruded profiles will be less likely to develop surface defects like bubbles, scratches, cracks, holes, and pits.
Poor-quality billet with slag inclusion can be very problematic. Even though the smaller slags can be expelled through the mold working belt’s slits, they can still cause marks on the extruded profile surface, thereby creating scrap. The larger slag typically blocks the mold belt slits, making them difficult to eliminate.
Consequently, the mold could stop midway during the extrusion, or the profile being extruded could crack. Changing the mold would be necessary to resolve the issue, negatively impacting the yield.
2. Select the Appropriate Aluminum Billets Length for Extrusion
Picking the appropriate billet for extrusion means there will be less scrap. The expected length on the extruded profiles should be calculated from the billets before extrusion and not from the profiles after extrusion.
You should know that long-billet heating ovens paired with hot log shears produce significantly fewer aluminum chips and scraps than short-billet heating ovens. This is because mold use alters the furnace’s wall thickness, increasing the flexibility and accuracy of billet length control, thereby significantly improving yield.
Reliable data shows that utilizing long billet heating along with hot log shear can boost the aluminum billets’ yield rate by 4% and entire production efficiency by 2-3%. After extruding aluminum profiles severally, add a 5–10-millimeter length increases to the previous production billet length last entered onto the mold card. After that, make the necessary slight adjustments to the billet length to make the second billet even more precise.
The problem is most aluminum profile manufacturers don’t follow the correct approach to calculating billet length during the initial mold production stage. Rather, once they utilize the long-billet furnace fitted with hot log shear, they disregard the billet length calculation and move forward with the extrusion process.
The operators have to leverage their experience to measure the first billet. It often takes up to 3 billets to establish the billets’ precise length. During this entire process, the production efficiency and yield diminish as a significant amount of scrap is generated.
3. Optimize Mold Design, Manufacturing, and Testing
How much resources and time are utilized in your mold design, manufacturing, and testing?
Improving your undertaking of these three mold stages is critical to increasing the yield. For instance, your final die acceptance test likely uses 1 to 3 billet pieces, cutting the yield rate by 0.5% to 1%.
Suppose you have improper mold design practices and a low manufacturing level; the mold testing will have to be repeated 3 to 4 times, meaning the yield rate would fall by 2% to 5%.
Additionally, repeated mold testing would lengthen your extrusion line’s production cycle, leading to massive losses. Keep in mind that the more mold testing, the greater the amount of aluminum turned to scrap, resulting in lower yield rates. Mold repair can help mitigate some yield rate loss from repeated mold testing. Steller shaping and durability standards should be maintained during mold repair.
Consider adopting the modern “zero test mold” concept in your aluminum profile extrusion. It dictates that once the mold is manufactured, there’s no need for mold tests. Production on an aluminum extrusion machine can commence immediately with no hindrance.
The “zero test mold” concept leverages computer simulation design software and finite element analysis for mold design and mold testing. An automatic machining center does the mold cavity processing.
The whole mold processing undertaking is a high-precision operation to get high-quality molds. As a result, the extrusion machine’s qualified rate is maintained at over 90%, and the yield rate rises by 2% to 6%.
4. Beefing Up Production Records and Mold Management
Having accurate and updated original production records and mold cards is crucial. The original production records must indicate the precise weight, length, and quantity of billets. In the upcoming production, you can rely on the recorded information for decision-making.
On the other hand, each mold card must indicate details of mold nitriding and mold maintenance. It must also show the production conditions for each mold batch.
Adopting computerized data management is the most straightforward to beef up your production records and mold management. You should also make sure that your staff is adequately trained on how to use the new computerized data management system properly.
Even with modern technology helping with your record management, the human element can cause inaccurate or outdated record keeping. Therefore, it’s vital to create a company culture where the necessary records are updated as promptly and precisely as possible.
5. Use Aluminum Extrusion Coefficient to your Advantage
Most aluminum extrusion profile manufacturers have several extrusion production lines at their facility. If you are such a profile manufacturer, then you should be using the aluminum extrusion coefficient of each production line to your advantage.
Unless all your extrusion machines are of the same model, each production line will have a varying diameter of the extrusion cylinder, the length of the cooling bed, the extrusion ratio of the product, and the outer circle of the aluminum profile.
Therefore, some extrusion profiles will be more suitable for extrusion on a particular production than others. Extruding each profile design on the most suitable production line will give you a higher aluminum extrusion coefficient and greater production efficiency, bringing forth a higher aluminum profile yield.
6. Embrace Remnant-Free Extrusion to Eradicate Physical Scrap
Although remnant-free extrusion seems like a big new invention, it has existed for a while. It refers to no billet butt being left on the extrusion cylinder after each extrusion. To start taking advantage of remnant-free extrusion, you will need to make a few adjustments to your extrusion machine.
These adjustments are fixing the dummy block against the extrusion ram and altering their normal operation. The new operation mode should allow for the dummy block and aluminum billet to be easily separated without the extrusion container retreating.
This way, before the previous billet is fully extruded, the next billet can be placed in the extrusion container to be extruded together. As a result, the extrusion will proceed continuously with no physical scrap. Remnant-free extrusion can work with up to 50 billets being fed into extrusion containers back-to-back, depending on the profile quality requirements.
7. Streamline the Extrusion Process to Eradicate Technical Scrap
Technical scrap can be generated across the extrusion process. It is primarily brought about by billet quality, extrusion speed, process temperature, extrusion tools, molds, and aging heat treatment. You must optimize your extrusion process to abolish technical scrap. Start by tweaking your production processes to be more advanced and scientific - no more guesswork.
Establish and enact accurate and strict operating procedures to boost staff proficiency. Reduce the variety of profile specifications extruded per shift. Try to stick to 3 to 5 profile specifications per shift to maximize each mold set’s output and increase yield.
Additionally, ensure that extrusion tools like container, ram, and die have three concentric points. The extrusion container should be properly maintained with correct heating and cleaning to preserve a flat surface. Keep an eye on the extrusion speed, extrusion temperature, and profile cooling, as they not only affect aluminum profile quality but also profile yield. Excess aluminum billet temperature and speed coupled with a low cooling rate can improve the yield.
While extrusion temperature can be easy to get right since it’s determined by the type of aluminum alloy, extrusion speed is more challenging to master. Besides the type of aluminum alloy, extrusion speed is also influenced by mold design. Proper extrusion speed control should involve skillfully paying attention to how it influences the extruded profile’s shape, quality, etc.
8. Make the Anodizing Production More Detailed
Your anodizing production should have a one-time production yield, meaning there’s no need to redo the profile anodizing. Data indicates that production costs for profiles with an anodizing rework are three times greater than non-reworked profiles.
To ensure that your anodizing work needs no rework, there are several best practices you must implement. Firstly, frequently tighten the screw between the conductive beam and the hanging beam. Always confirm the hanging rod’s rigidity before binding aluminum profiles. The hanging rod should be replaced promptly as needed as it corrodes, becoming smaller and weaker with time.
Aluminum profiles should be tightly tied to the handing rod so they don’t fall into the tank. If the profiles fall into the tank, they could make contact with the poles, causing the power supply to short-circuit. Use thick aluminum wire (3 millimeters) to bind large profiles and thin aluminum wire (2 millimeters) for medium and small profiles.
The wire’s annealing hardness should be ½ ~¾, or you can instead use a clamp. Adequately tighten the rework profiles before oxidation. Use a vise to tap each profile’s end to remove any film on the contact before inserting them in the oxidation tank to promote stellar electrical conductivity.
After oxidation, immediately remove the profile tips from the oxidation tank to prevent unwanted coloring on one end. Pay special attention to the pH requirements of each tank. The first washing tank should be 0.8 to 1.5 after oxidation and 1.5 to 2.5 after coloring. Furthermore, the second washing tank should be 2.5 to 3.5 after oxidation and 3.5 to 5.0 after coloring.
9. Strengthen the Entire Process Inspection
Tight controls should be in place throughout the whole extrusion process, from selecting the proper billets to delivering the extruded profiles to clients. How thoroughly the first aluminum billet inspection is conducted will determine how scrape is created.
Scrap created from twisting, wall thickness, flat clearance, and opening or closing intolerances can be eliminated if the inspection by the main operator focuses on upholding precision throughout the extrusion process.
Wall thickness tolerance can be managed through negative tolerance. The wall thickness of the products often increases as the die gradually wears down with continued profile extrusion.
Large cantilever profiles must be carefully analyzed against drawings during inspection. Confirm there's a reasonable amount of stretching with no scratches, orange peel, or die lines.
A combination of self-inspection and mutual-inspection has to be carried out by the machine operator and quality inspector as part of quality control.
Once you optimize your aluminum profile yield, you can become the globally renowned aluminum extrusion profiles manufacturer want.
Keep in mind that having reliable aluminum extrusion machinery is crucial for any aluminum profile manufacturer to unlock its full success. You can rely on Wangeshi aluminum extrusion equipment to get unrivaled efficiency, top-class profile quality, and unbeatable profile yield.