MoldMaking Technology

DEC 2018

Advertising in MoldMaking Technology offers

Issue link:

Contents of this Issue


Page 9 of 50

8 MoldMaking Technology —— DECEMBER 2018 EAB A mold design can be like a soup. The designer has ensured that the move- ments that the part geometry requires are designed (the meat), the gates are properly placed to fill the part (the vegetables) and that the mold fits in the press (the broth). But, has the designer checked that the cavity and core blocks have the proper number of screw holes to retain them in the base, or whether there are any? Having a proper mold-design review and checklist can and will save time to market by ensuring that the designer has even accounted for the small potatoes, or the design details. Oakley has developed an extensive mold- design checklist. Here are some top items. Mold designers check that: • The mold fits in the desired press. (The designer checks water lines, hot sprues or heater rods and wires, injection locations and mold height mini- mum and maximum to clear all press tie or safety bars.) • The gate sizes and locations are correct. (They should be 50 to 80 percent of the part thickness at the gate location.) • The runners are properly sized. (Working from the part, the runner adjacent to the part should be no smaller than the maximum part-wall thickness and each branch should be sized up by multiplying 1.259 to the previous branch.) • Venting has been addressed. (The designer starts with a ring vent on the Z pull- er, which is the first cold slug and initial point to remove unwanted out-gas- sing. It is self-cleaning with every ejection cycle with a natural dynamic vent.) • Cooling lines, heater rods and oil lines are adequate and appropriate for the plastic material. • The part remains on the proper side of the mold for ejection. (The designer reviews the part draft and slide delays to help.) • Mold components are poka-yoked (mistake-proofed), or they are keyed for proper assembly and timing (or both). • The leader pins are taller than any other mold components above the parting line to keep the insert interface safe from misalignment. • Parting-line side or taper locks are in place to protect shut offs (if necessary), or inserts or blocks are designed with interlocking features to protect deli- cate interlocking features. • The mold components are made from proper materials to accommodate plastic part requirements, and the component Rockwell hardness ratings differ by more than two points to ensure that interfacing components do not gall. • The slides are held effectively in the open position. (The designer checks whether a heal lock can be used as a kick-back feature to place the slide back into the open position if it is moved or whether springs are required.) • The slide or the lifter travel (or both) is enough to clear when the part is ejected. Mold Design Checklist Gerardo Miranda (Jerry) Global Tooling Manager Oakley Foothill Rand, California 949-900-7785 EDITORIAL ADVISORY BOARD (EAB) The EAB enhances the standing of the publication and strengthens its professional integrity through the active involvement of its members. The Board represents all aspects of the mold manufacturing industry with a balance of moldmakers, molders, OEMs and academia, and various moldmaking segments and job functions. A member is selected based on his or her experience and knowledge of the mold- making industry to serve a three-year term. Kylee Carbone Director of Talent Development Westminster Tool Plainfield, Connecticut 860-564-6966, ext. 244 Will J. Cipkar Technical Sales Crest Mold Crest Thermal Technology (CTT) Division Ontario, Canada 519-737-1546, ext. 117 Andrew Garstkiewicz Senior Advanced Manufacturing Engineer GE Appliances, a Haier company Louisville, Kentucky 502-387-1259 Ryan Katen President and General Manager Micro Mold Company Inc. Erie, Pennsylvania 814-838-3404, ext. 238 Tim Krieger President Krieger Craftsmen Inc. Grand Rapids, Michigan 616-735-9200 Gabe Meldrum Plant Manager International Mold Corp. Clinton Township, Michigan 586-783-6890 Gerardo Miranda (Jerry) Global Tooling Manager Oakley Foothill Rand, California 949-900-7785 Francine Petrucci President BA Die Mold Aurora, Illinois 630-978-4747 Ryan Pohl Founder Praeco Skills LLC Grand Rapids, Michigan 616-951-2133 Rich Stueber Engineering Manager NyproMold Instructor, Lake County Community College Clinton, Massachusetts 847-855-2252

Articles in this issue

Links on this page

Archives of this issue

view archives of MoldMaking Technology - DEC 2018