One molding rack in Dongguan can hold shells that look nearly identical from five meters away. Open them and their purposes separate quickly: a red first-aid organizer, a velvet-lined headphone case, a game console carrier, and a slim eyewear shell. EVA, or ethylene-vinyl acetate, gives designers a shared structural platform, but each application changes the lining, hardness, opening angle, retention method, and verification plan.
Different contents create different interiors
Medical and first-aid organizers favor visibility and wipeable surfaces. Mesh zones, elastic loops, and color coding let users find a vial, swab, or small device without emptying the case. Projects associated with a medical device may need documentation aligned with the device manufacturer's ISO 13485 system, but that does not mean the case factory itself holds ISO 13485. LIANPING operates an ISO 9001 quality system and can work from an agreed material and inspection specification for custom medical EVA cases.
Audio products need surface care and cable control. A headphone cavity should support the headband without flattening the ear cushions, while a separate recess prevents a plug from rubbing against the cup. Velvet or fine jersey lining suits finished surfaces; elastic mesh suits detachable leads. For compact earbuds, the zipper and puller can dominate the case weight, so a lighter molded profile and shorter opening route often feel better than simply increasing shell thickness.
Applications also change the outer construction
Game console cases need clearance above joysticks and shoulder buttons. A soft flap can separate the screen from cartridges without adding hard pressure points, and a zip pocket should be loaded during the close test. Eyeglass cases use a much smaller radius and can rely on a slim PU or textile surface. Pencil cases tolerate frequent opening, ink marks, and uneven contents, making zipper routing and cleanable lining more important than a complex precision cavity.
These examples can be compared across LIANPING's EVA case categories, yet density and hardness still follow the payload. Common sheet density runs about 0.15–0.25 g/cm³, with Shore C 40–70 covering soft organizers through firmer equipment shells. Fabric lamination, molded ribs, wall depth, and sewing structure alter the final stiffness. A number on a material sheet is only the starting point.
Compliance is application-specific too. RoHS and REACH may be requested for electronics or EU programs, CA Prop 65 may appear in a North American material brief, and EN 71 can apply to certain children's products. The buyer must identify the market, product classification, and restricted-substance list. LIANPING can source and document materials to an agreed brief using CTI or SGS reports where specified, but a material report should not be presented as a finished-product certification.
Custom orders begin at 500 units, and a straightforward sample can usually be prepared in about three days. The factory's six lines handle cutting, compression molding, sewing, lamination, packing, and full inspection. On the rack this morning, the headphone shell has been released to sewing, while the game case remains at the bench until its lid pad clears both joysticks by another 3 mm.