Thermoplastic polyurethane surfaces can become tacky as temperature rises. Sheets may block during storage, stick to masking, adhere to plugs or molds, or pick up texture and contamination from contact surfaces. Behavior varies widely by hardness, chemistry, surface treatment, and grade.
The stage where sticking begins should be identified. Blocking before heating is a storage or interleaf problem; plug adhesion occurs during forming; mold sticking appears during cooling and release. Surface temperature, contact time, finish, moisture condition, and approved release strategy should be checked for the exact grade.
Storage, separation films, drying where specified, contact materials, and tool temperature should follow supplier guidance. Unapproved release agents can interfere with bonding, printing, or appearance. The process should minimize unnecessary hot contact rather than relying on more eject force.