The "one mold porous" technology, commonly referred to as the "porous mode," is an advanced extrusion process that significantly improves yield, production efficiency, and profile quality. This method is energy-efficient, labor-saving, and cost-effective, aligning with national energy-saving policies and playing a crucial role in promoting sustainable development for enterprises.
1. **Mold Design and Manufacturing**
To achieve optimal results in the design of "one mold porous" molds, it's essential to consider the strength of the steel material and avoid excessively large or small hole spacing. It is recommended to arrange the holes horizontally based on symmetry. If vertical placement is necessary, the holes should be staggered. High-precision mold processing equipment is vital to ensure mold qualification. For instance, CNC machining centers are ideal for processing shunt holes and welding chambers, while slow wire cutting is used for cavities to guarantee verticality, parallelism, and surface finish.
2. **Extrusion Production Process Control**
2.1 **Process Parameters**
2.1.1 **Bar Temperature**
For multi-hole flat molds, the bar temperature is typically maintained between 390–480°C. A ladder-type cooling method is used, starting from the upper limit and gradually decreasing by 10°C per stage until reaching the lower limit. For porous split molds, the bar temperature range is generally 430–500°C, following a similar control method.
2.1.2 **Mold Temperature**
The normal mold temperature should be controlled between 430–480°C.
2.1.3 **Barrel Temperature (Material Gall Temperature)**
The barrel temperature is usually kept within 410–440°C, and can be set higher depending on production conditions.
2.1.4 **Outlet Temperature**
The outlet temperature should be maintained between 520–580°C. If it's too low or high, it may affect the hardness and quality of the final product.
2.2 **Process Operation Specifications**
2.2.1 **Aluminum Rod Heating**
Aluminum rods are heated using a bar furnace with zone-controlled heating. To ensure even warming, the heating is usually controlled from high to low, adjusting the temperature settings according to the number of sections in the furnace.
2.2.2 **Mold Heating**
Mold heating time is typically limited to 6 hours. The mold, along with the die pad and die set, should be heated evenly without overheating, which could damage the surface quality of the profiles. When placing the mold in the furnace, it should be positioned away from the walls and fan vents, with at least 5 cm clearance between molds. The furnace must remain clean to prevent dust contamination during heating.
2.3 **Extrusion Process Control**
2.3.1 **Time from Mold Removal to Extrusion**
The time between removing the mold from the furnace and extruding the material should not exceed 3 minutes to avoid uneven material flow.
2.3.2 **Front Rod Handling**
The front rod should not be left unextruded; instead, short rods of 200–300 mm should be used.
2.3.3 **Extrusion Speed Adjustment**
Initially, the extrusion speed should be slow, then gradually increased once the material flows smoothly.
2.3.4 **Discharge Port Setup**
High-temperature pads should be used at the discharge port to prevent scratches. Graphite plates should separate each profile to avoid rubbing and deformation.
2.3.5 **Traction Force Adjustment**
Intermittent adjustment of the traction force ensures dimensional accuracy. Tension should be increased initially and reduced once the material flows normally.
2.3.6 **Extrusion Speed**
Under normal conditions, the output speed should be maintained between 30–40 m/min.
2.3.7 **Quenching Process**
Quenching must follow the alloy state requirements, either air-cooled or water-cooled.
2.3.8 **Production Interruptions**
If production stops due to equipment failure, the mold must be reloaded into the furnace if the downtime exceeds 3 minutes. The mold temperature should be kept above 500°C. To protect the mold and profile quality, it is recommended to unload the mold after delivery and reload it later. Reinstalling a cooled mold can cause profile defects and mold damage.
2.4 **Outlet Profile Temperature and Speed Control**
2.4.1 **Adjust Bar Temperature Based on Outlet Profile Temperature**
The aluminum bar temperature should be adjusted accordingly to maintain the desired outlet profile temperature.
2.4.2 **Control Outlet Profile Temperature**
The outlet profile temperature should be between 520–580°C. Temperatures below 520°C may result in insufficient hardness, while temperatures above 580°C can cause overheating.
2.4.3 **Visual Inspection After Discharge**
If the discharged material appears black, the rod temperature and extrusion speed should be immediately reduced to prevent excessive heat.
2.4.4 **Operator Monitoring**
Operators must continuously monitor the rod temperature, outlet profile temperature, profile surface, and equipment operation. Any abnormal situation requires immediate shutdown to prevent mold damage and reduce maintenance costs.
3. **Extrusion Equipment for “One Mold Porous†Technology**
Achieving the “one mold porous†technique requires not only a stable extruder and high-quality mold but also advanced supporting equipment such as double tractors with flying saw machines, mold heating furnaces, long spindle furnaces, and heat shear technologies. These components are essential for maximizing efficiency and ensuring consistent output quality.
4. **Conclusion**
With continuous improvements in extrusion processes, the "one mold porous" technology has significantly enhanced production efficiency and yield. However, due to differences in equipment, mold materials, and extrusion methods across companies, the development and application of this technology may vary. Despite these variations, its benefits in terms of energy savings, cost reduction, and sustainability make it a promising approach for the future of the aluminum industry.
Self-Aligning Ball Bearing,Automatic Self Aligning Bearing,Self Aligning Bearing,Automatic Self-Aligning Bearing
Shanghai Yi Kai Cheng bearing Co., LTD , https://www.ykchbearing.com