Thread Damage is a common issue in manufacturing and handling processes, leading to costly rework, scrap, and customer dissatisfaction. This article explores the common causes of thread damage and outlines effective strategies for minimizing its occurrence.
Common Causes of Thread Damage
Thread damage can occur at various stages of the manufacturing and handling process. A comprehensive study examining a specific case revealed several key areas of concern:
1. Degreasing Process:
The initial degreasing process, where parts were dumped into a rotating basket filled with cleaning solution, was identified as a potential source of thread damage. The rough handling and contact between parts during this process contributed to nicks and imperfections in the threads.
2. Bin Transfers:
Transferring parts between bins at different stages of the process, including from the cleaning basket to material bins and then into feed boxes, created further opportunities for thread damage. Each transfer involved the risk of parts colliding with each other or the container walls.
3. Part Drops:
A significant drop of approximately four feet from the oven into the customer’s bin after coating and drying was another major contributor to thread damage. The impact of the fall caused significant damage to the delicate threads.
Effective Strategies to Minimize Thread Damage
Addressing the identified causes of thread damage led to the implementation of several preventative measures:
1. Eliminating Degreasing:
By arranging for parts to be delivered “dry,” the degreasing process, a major source of damage, was eliminated. This change significantly reduced the risk of early thread damage.
2. Streamlining Bin Transfers:
Providing dedicated process bins to the customer eliminated the need for multiple bin transfers. Shipping parts directly in these designated bins minimized handling and reduced the potential for damage during transfer.
3. Minimizing Impact Forces:
To mitigate the damage from dropping parts, several adjustments were made:
- Protective Linings and Chutes: Feed towers were lined with plastic, and chutes were installed to reduce the impact of parts falling into the tower from the bin.
- Padding: The vibrating bowl and feed track were padded to cushion the parts and prevent damage during movement.
- Controlled Descent: A chute was placed at the end of the oven to provide a controlled descent into the shipping bins, minimizing the impact force.
Residual Thread Damage and Conclusion
While these improvements significantly reduced thread damage, it’s important to acknowledge that eliminating all damage is often impossible, especially when handling large quantities of small parts. Despite best efforts, some residual damage may still occur. However, by addressing the key sources of handling damage, a substantial reduction (as much as 95%) in thread damage is achievable. This case study highlights the importance of thoroughly analyzing the entire manufacturing and handling process to pinpoint and address the specific causes of thread damage. By implementing preventative measures tailored to these causes, manufacturers can significantly improve product quality, reduce waste, and enhance customer satisfaction.
