A Japanese eyewear retailer rejected a shipment of 2,000 EVA eyeglass cases last spring over something most factories never measure: the lining had left a haze on anti-reflective lens coating after a two-week contact test. We ran the same test here, switched to a low-lint velvet at 180 g/m², and the case passed. That order moved to Gaobu in April and has reordered three times since.
What an eyeglass case actually has to do
The job is smaller than a tool case and fussier. A glasses case has to hold a 140 to 155 mm frame without pressing on the bridge, survive being sat on inside a bag, and not scratch the lenses it is protecting. Our EVA eyeglasses cases run 4 to 5 mm of EVA at 0.20 to 0.22 g/cm³ with Shore C hardness around 55 to 60, molded as a clamshell with a slight hip so the shell resists collapse under a 70 kg load. Softer and it slumps; harder and the shell transmits the impact straight into the frame.
The interior does the delicate work. Die-cut foam holds the frame in a shaped cavity, or a soft velvet pocket is used for customers selling sunglasses with wide temples. Lint is the failure mode people miss. A cheap flocked lining sheds fibres that end up on the lens, so we specify a low-lint velvet and run a tape-pull test on every incoming lot. Zippers are YKK, cycle-tested to 5,000 operations, and the pull is set back from the hinge so it cannot press on the temple when the case is closed.
Forty-plus countries, three very different specs
Export now covers more than 40 countries, with North America, Europe and Japan taking most of the volume, and the specifications are not the same. European buyers ask for REACH declarations and, increasingly, recycled content in the shell. Japanese buyers care about dimensional accuracy and packing: a case 2 mm over the stated size generates a defect report, and the polybag has to be folded a particular way. US buyers want a hangtag with a UPC and a case that survives being thrown into a gym bag.
Certification paperwork follows the shipment: ISO 9001 for the quality system, RoHS and REACH test reports from CTI on the materials, and SGS factory audit documentation for buyers who need it. One boundary is worth stating plainly. Medical device work is governed by ISO 13485, a separate system we have not certified to, so our medical and insulin cooling cases are built to customer specification and tested to the customer's protocol rather than sold as certified medical packaging.
Capacity and how orders run
The plant is 10,000+ m² with six lines and a little over 100 people, and eyeglass cases share the molding bays with tool, earphone and tablet case work. MOQ is 500 pieces per shape, with 1,000 and 3,000 as the price tiers. Sampling takes about three days for a standard clamshell, longer when the customer wants a custom zipper pull, a printed logo on the shell, or a foam cavity cut to a specific frame.
The current development is a slim case for reading glasses that has to close flat at 22 mm while holding a 148 mm frame. The mold trial is set for the week after next, and the first question on the bench will be whether the bridge clears the foam when the case is squeezed at the hip.