An eye mask is a large-curve soft silicone part that fits the face; comfort depends on the conformal curve and hardness. The mold focus is conformal parting, soft-hard composite and venting.

Design Highlights

Conformal parting: the parting surface follows the curve transition, avoiding visible flash on the contact surface;
Soft-hard composite: for a rigid frame plus soft sealing edge (or two-shot/overmolding), solve the bond strength and locating;
Venting: vent inserts or vacuum venting at dead corners such as the nose bridge and cheekbones;
Uniform wall thickness: gentle transitions on the curved surface to avoid local shrinkage and flow marks;
Ejection: flexible ejection to protect the sealing edge.

Process

Mold temperature 170~200C; hardness commonly Shore A 20~40. Use fit, flow-mark appearance and wearing pressure marks as criteria; a 3D scan of the first article is recommended.

Common Defects

Poor fit: curve shrinkage or uneven wall thickness;
Flow marks or bubbles: unbalanced filling and insufficient venting;
Heavy pressure marks: hardness or edge-radius design issue.

Delivery

Design, machining and trialing of eye mask molds, with soft-hard composite structure advice.