Sheet Die Head Cleaning and Maintenance
Sheet die heads are among the most critical components in production. While benefiting from their high production efficiency, it is also necessary to carry out necessary cleaning and daily maintenance so that the die head can perform its work to the best of its ability.
Core Requirements for Operators
- Operators must fully understand the function of the sheet die head, and know the impact of temperature changes, die hole or adjusting rod adjustments on product quality. They also need to pay attention to the source of faults.
- Operators must understand the importance of maintaining good contact between the heater and the sheet die head, and be able to judge whether there is a fault on the production line and where the fault is. For example, when the extruder extrudes intermittently, do not continuously adjust the choke block of the slit die head.
- Operators must be able to judge whether the inlet pressure exceeds the limit based on the measurement results. Note that the die lip or choke block cannot be adjusted quickly, but should be adjusted moderately in the adjacent area, otherwise the bolts and choke block may be damaged.
Daily Cleaning and Maintenance Precautions
- Only scrapers made of soft materials (copper, brass, soft aluminum) can be used to remove the melt in the die lip, so as to avoid scratching the die lip. The width of the sheet die head die lip gap should also be measured with soft materials such as brass gauges. Even the slightest scratch will cause stripes on the extrudate and reduce product quality.
- When the die head needs to be replaced frequently, it must be operated by designated personnel. These personnel must be familiar with the structure and function of the die head, have detailed instructions (drawings, assembly instructions, parts list) at hand, and it is best to have experience in disassembling, inspecting and installing new die heads before use.
Standardized Disassembly, Cleaning and Maintenance Specifications
- Disassembly, cleaning, repair and maintenance of sheet die heads shall be carried out at a designated location, which shall be far away from the production site, clean and padded with corrugated plates. A small crane shall be equipped for use. When manually lifting, the iron chain of the pulley block often damages the die head; to avoid this risk, hemp rope can be considered for use. The work site shall also be equipped with various tools (screwdrivers, torque wrenches), soft shovels (bronze, copper, soft aluminum), cleaning and polishing materials. If possible, a die head preheater shall also be provided, which can greatly shorten the time for replacing the die head.
- Check the heater and ensure it is equipped with a certain number of heating wires and control systems.
- If the sheet die head needs to be thoroughly cleaned, the main bolts of the die head must be loosened, but not removed. The die head is still connected to the extruder, and only those related to the flow channel need to be loosened.
Key Safety Reminders
- Never use hard metal tools to clean the die lip surface.
- Always follow the correct sequence when disassembling and reassembling die components.
- Keep detailed records of all maintenance work for future reference and traceability.
