Continuous improvement is one of the most important parts of manufacturing. This case study shows how customer feedback helped us further improve our quality control process and deliver more reliable eyewear.
The Challenge
Approximately one year after delivery, one of our Australian optical retail chain customers contacted us regarding several acetate optical frames.
Out of a shipment of 700 pairs, 71 pairs developed green copper corrosion inside the transparent acetate temples after long-term storage in a basement warehouse.
Although the issue affected only a small portion of the shipment, we immediately treated it as a priority.
Overall frame with the affected temple area highlighted
Our Response
Our priority was not to determine responsibility—it was to solve the customer’s problem as quickly as possible.
We asked the customer to return all 71 affected pairs, and we manufactured 71 brand-new replacement frames at our own expense.
By acting quickly, we helped the customer continue serving their own customers with minimal disruption while reinforcing the trust we had built together.
Close-up of the affected temple
Root Cause Analysis
After receiving the returned products, our engineering and quality teams conducted a detailed investigation.
We found that the corrosion resulted from a combination of factors:
- Residual acidity within certain acetate material batches.
- Long-term exposure to moisture in the customer’s basement storage environment.
Although the storage conditions accelerated the reaction, we believed there was still room to further strengthen our own manufacturing process.
Turning Feedback Into Improvement
Instead of stopping at product replacement, we upgraded our quality control procedures.
ncoming Material Verification
Every incoming acetate batch is now subject to additional material stability verification before entering production.
Intelligent Drying System
We also invested in a new intelligent drying system to better control moisture before production.
The equipment provides more stable temperature and humidity control, helping improve the long-term stability of acetate materials throughout manufacturing.
Intelligent drying system installed in our factory.
Intelligent Drying Process
The Result
The customer received 71 newly manufactured replacement frames, allowing them to continue their business without interruption.
More importantly, the improvements introduced after this project have now become part of our standard manufacturing process.
Today, every acetate project benefits from:
Our Commitment
Every piece of customer feedback is an opportunity to improve.
At Timing Optical, quality is not simply about delivering products—it is about continuously improving our materials, processes, and manufacturing systems to build stronger long-term partnerships.
Because reliable manufacturing is built on responsibility, transparency, and continuous improvement.
Looking for a Reliable OEM & ODM Eyewear Manufacturing Partner?
If you’re looking for a manufacturing partner who values transparency, accountability, and continuous improvement, we’d be happy to discuss your next eyewear project.
Timing Optical
OEM & ODM Eyewear Manufacturer Since 2008