PETform's Manufacturing Practices
Stack Parts & Hot Runner Components-
Cores, Neck Rings, Cavities & Gate Inserts are manufactured exclusively using Bohler-Uddeholm's Stavax ESR Supreme (Corrosion resistant martensitic stainless steel) steel.
Stack parts are rough machined, stress relieved & vacuum hardened to 50-52 Rockwell by Bohler-Uddeholm.
Final dimensions are machined only after hardening to nullify any changes in dimensions during hardening.
All mating surfaces (tapers and faces) are cylindrical / surface ground for high precision and long life.
Manufacturing is conducted in a temperature controlled room.
Each component is measure in-process by work-probing systems.
Each component is measured post process by highly accurate measuring instruments & gauges in a temperature controlled (standard) room.
Tolerances on critical dimensions is maintained within +/- 3 microns.
Mould base plates, hot runner manifold & backing plates are rough machined and stress relieved before finish machining. This is to ensure that the dimensions of the plates do not change over time.
At PETform, finish sizing, drilling & boring is done by jig boring class machines* only and never general precision CNC machining centers.
In process gauging is used for eliminating errors and holding close tolerances.
All plates are inspected on CMMs in temperature controlled (standard) rooms before assembly.
* jig boring machines are geometrically much more accurate than standard precision CNC machining centers. Jig borers have geometrical accuracies similar to measuring machines. The axes on jig boring machines are significantly straighter and the axis are more square in relation to each other (3 to 4 axis) than standard precision CNC machining centers commonly used by virtually all preform mould manufacturers.