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SPI Class 101 Mold Guideline for Manufacture EVCO Plastics USA

Specification Number T-101 Rev: 0

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Cycles: One million or moreDescription: Built for extremely high production. Machine size is 400 ton or less. This is the highest priced mold and ismade with only the highest quality materials.

General Specifications

1. Evco to approve mold design prior to start of construction.2. Mold to have adequate channels for temperature control.3. Wherever feasible, all details should be marked with steel type and Rockwell hardness.4. Customer name, part number, and mold number should be stamped on all molds.5. Mold and large components should have adequate provision for handling, e.g., eyebolt holes.6. Threads of eyebolts to be English.

Design1. Detailed mold design required.2. Mold base to be minimum hardness of 280 BHN.3. Molding surfaces (cavities and cores) must be hardened to a minimum of 48 R/C range. All other details, such as slides,

heel blocks, gibs, wedge blocks. Etc. should also be of hardened tool steels.4. Steels moving against one another should be dissimilar and have a hardness differential of at least 4 Rockwell C.

5. Ejection should be guided.6. Slides must have wear plates.7. Temperature control provisions to be in cavities, core and slides wherever possible.8. Over the life of the mold, corrosion in the cooling channels decreases cooling efficiency thus degrading part quality and

increasing cycle time. It is therefore recommended that plates or inserts containing cooling channels be of a corrosiveresistant material or treated to prevent corrosion.

9. Water inlets and outlets must be labeled.10. Parting line locks are required on all molds.11. A Mold flow analysis is done to determine gate location and vents.12. SPI standard knock out pattern with provision for flush mounting of knock out bars.13. All molds will be built with the ability to use magnetic platens for mold clamping. If an insulator plate is used then a

steel plate will be required behind it for magnetic clamping.

Mold sampling and tryout 1. The mold is to be sampled with the exact material specified.2. The estimated Cycle time is to be used if practical.3. Scientific injection molding practices will be followed during the mold sample.4. The mold must be run for a minimum of four continuous hours without breaking cycle.5. Mold to be tested for adequate cooling during the sample.6. During the sample each shot must fall freely from the core or allow for robotic removal.7. During the four hour run 32 shots must be bagged and serialized then sent to EVCO Plastics for a statistical capability

study.

Quality and workmanship1. An accepted tolerance on a mold is normally 50% of the part tolerance. This gives the mold builder and the molder equal

tolerance to compensate for their variations in construction and molding.2. Mold must be sealed to prevent coolant leakage. Test at 100 PSI for one hour on the bench and test for a minimum of 4

hours at normal plant operating pressure under a normal cycle.3. Flash specification is 25% of the part print requirement at 95% part fill.4. Preliminary venting should be based on a mold flow analysis.5. Final venting will take place after first shots as directed by Evco Engineering.6. A full layout of all part dimensions must be submitted per standard EVCO Plastics format.7. Steel dimensions of major characteristics shall be reported on standard Evco Plastics format.