Meaning
Tooling classifications developed by the Society of the Plastics Industry specify the requirements for moulds designed for high-volume production. Building an SPI Class 101 mould requires the use of hardened steel cavity inserts and robust guidance components capable of running over one million cycles. This specification ensures that the tooling survives high-speed, continuous production without significant wear.
Tooling Specification
Moulds of this class utilize expensive materials such as stainless steels or tool steels hardened to at least 50 Rockwell C. High durability components in an SPI Class 101 mould include guided ejector plates, wear plates on slide mechanisms, and hard-plated slide surfaces. This design limits maintenance intervals.
Economic Justification
High initial tooling cost is offset by the low unit cost achieved through automated, long-term production. Part dimensions are held consistently over millions of shots. Scrap rates are low.
Moulding Performance
Cycle times are minimized through the use of highly engineered cooling channels, including conformal cooling and copper alloy inserts in areas of heat concentration. Tooling built to SPI Class 101 standards prevents part defects like warping or sink marks through superior thermal management. Rapid and reliable ejection is achieved through the use of hard, polished ejector pins and air assist valves, ensuring that the press runs continuously with minimal operator intervention.
