Silicone cases turning yellow in bulk? 168h anti-yellowing + 0.1% defect rate

Bulk quality control and zero yellowing solution, full-process control of silicone case anti-yellowing

Bosses engaged in wholesale of digital accessories and brand OEM (Original Equipment Manufacturing) have once faced situations where million-level orders of silicone cases became unsalable due to batch yellowing. When the products were put into the warehouse, their color was pure and uniform, but yellow spots and color deterioration appeared in a short time. This not only led to concentrated returns from downstream customers but also directly damaged the brand reputation. In fact, by mastering the three-fold control of “raw materials + craftsmanship + testing”, it is possible to achieve 168-hour anti-yellowing performance and an ultra-low defect rate of 0.1%, thus stably ensuring the delivery quality!

First step: Upgrade raw materials to block the source of yellowing! Before customizing silicone cases, it is necessary to use high-purity silica gel with a platinum vulcanization system, adding 0.3%-0.8% UV stabilizers and antioxidants. This can improve the anti-yellowing performance by 80% compared with ordinary materials. Reject recycled materials and inferior color masters. The color master should be a special anti-yellowing type for silica gel, and the addition amount should be controlled within 5% to avoid irreversible yellowing caused by damage to the silica gel cross-linking structure.

Second step: Control the craftsmanship to avoid yellowing due to over-vulcanization! Strictly control the vulcanization temperature at 160-180℃, and adopt a gradient heating mode (preheat at 150℃ for 5 seconds first, then heat up). The risk of yellowing will increase by 30% for every 10℃ increase, so over-vulcanization must be firmly prevented. Thoroughly clean the mold before production to remove residual release agent. New molds need to be baked at 200℃ to remove oil, preventing surface yellow spots caused by impurity migration.

Third step: 168-hour aging test + strict inspection before delivery! Sample 15% of each batch, and conduct a 168-hour anti-yellowing test under the environment of 60℃ with UVA-340 light source in accordance with the standard of GB/T 16422.3-2014. Only those with a yellowing index (YI value) increase not exceeding 2.3 are considered qualified. At the same time, inspect the uniformity of appearance color, eliminate any products with slight yellow spots, and strictly control the defect rate within 0.1% to ensure that the delivered silicone cases have no hidden danger of yellowing.

Whether you are a digital accessory wholesaler, a brand OEM factory, or a purchaser focusing on light-colored/transparent products, are you worried that the batch yellowing of silicone cases will delay the delivery schedule and cause after-sales disputes? Click on the online customer service or call directly, inform us of the purchase quantity and product requirements. We provide full-process anti-yellowing control services, support the verification of 168-hour anti-yellowing test reports, and offer small-batch trial orders to help you deliver stably and eliminate after-sales concerns!