1. Ensure Nomex Felt is Centered
- Align the felt to the center: Start by positioning the heat transfer felt in the center of the machine. This step is crucial to avoid uneven heating or tension as you proceed with the shaping process.
2. Check Equipment Preparation
- Verify guide rollers are parallel: Next, ensure that all the guide rollers are properly aligned. This alignment guarantees the felt will run evenly without shifting during the process.
- Ensure uniform heating roller temperature: It’s equally important to check the temperature distribution of the heating rollers. Make sure the heat is evenly distributed to guarantee consistent results across the felt.
3. Heating Process
- Gradually heat the machine: Begin by gradually heating up the machine while keeping the felt moving. This helps the felt adapt to temperature changes and prepares it for the shaping process.
- Understand the maximum operating temperature: The heat transfer felt can withstand temperatures up to 240°C. However, keep in mind that during the first month of use, the felt will experience a 3% lengthwise extension and widthwise contraction, which is entirely normal.
4. Pre-Run and Shaping Method
(Follow the machine and Nomex felt manufacturer’s manual)
Now, proceed with the pre-shaping using the following temperature and time settings:
- Low Speed:
- 120°C: Heat for 2 hours
- 140°C: Heat for 2 hours
- 160°C: Heat for 2 hours
- Middle Speed:
- 180°C: Heat for 2 hours
- 200°C: Heat for 3 hours
- High Speed:
- 220°C: Heat for 4 hours
- 230°C: Heat for 2 hours
- 220°C: Heat for 2 hours
Cool the felt to 220°C: Once the heating process is completed, allow the felt to cool down to 220°C. This step helps ensure the tension between the center and the sides of the felt is evenly balanced.
5. Shaping Considerations
- Do not use the pressure roller: During the shaping phase, avoid using the pressure roller. The felt should have just enough tension to rotate smoothly with a slight tightening. If the felt shifts slightly, simply run it in the opposite direction to correct it.
6. Adjustments After Shaping
- Finish shaping before adjusting off-track felt: Complete the shaping process before making any adjustments to the felt if it goes off-track.
- Do not loosen the felt belt during the first week: For the first week of operation, keep the felt belt securely tensioned to ensure it stays in place.
- Shutdown the machine: After the temperature drops below 100°C, you can safely turn off the machine.
7. Additional Notes
- Strictly follow temperature and time guidelines: Be sure to adhere to the recommended temperature and time settings. Deviations may affect the final shaping quality.
- Minimize tension fluctuations: Avoid making unnecessary changes to the tension during the shaping process. This will help the felt stay stable and perform optimally.
By following these steps, you will effectively shape the heat transfer felt, ensuring it performs well in future production stages while maintaining its stability.
