Keep every O-ring size, compound and cure date on record against its shelf life.

A seal plant makes small parts in very large variety. An O-ring is described by inside diameter, cross-section and compound, while a rotary lip seal has a metal case, a spring and a rubber lip. A hydraulic seal set has a rod seal, a wiper and a wear ring, and customers range from machine builders to distributors with thousands of sizes on shelves. Variety is the whole difficulty.

Rubber ages. Old stock is a liability. Software for seal makers therefore treats cure date and shelf life as part of the product record. Planners see which sizes are low and which compounds are due for mixing, while quality staff see hardness and compression set by lot before anything is bagged. Dispatch sees the lot and cure date to print on each bag, so the label a customer reads matches the batch that left the press room.

A distributor or a machine builder orders by catalogue size, compound and colour, often in hundreds of lines on one order. Standard sizes come from stock. Missing sizes are put on a moulding plan, which groups orders by compound so a mixed batch is used while it is fresh. Moulds hold many cavities, and one tool may serve several neighbouring sizes, so the planner must know which insert sits in which press this week. Most lines ship from shelf.

Compound is mixed and tested for hardness and cure curve, then presses mould the rings and operators remove flash by running parts through a trimmer or a deflashing machine. Cord-spliced rings are cut and joined for sizes with no mould, and lip seals have metal cases bonded or assembled with springs in their own cell. Samples go for hardness, compression set and dimension checks. Parts are packed in labelled bags, counted by weight or by hand, and stamped with lot and cure date. Nothing leaves without a date.