Technical Training on Plastics and Tooling

Class overview

Robust molding process: Training covers what is a robust molding process. What is part to part consistency, run to run consistency, tool consistency.

Plastics raw material basics: Family of polymers. Understanding commodity plastics, engineering plastics, specialty plastics. Polymer pyramid. Amorphous and semi-crystalline plastics, their property, and behaviors.

Plastics raw material selection: In-depth understanding of various polymer grades, selection based on application requirements. Eg:- Flaimmablity, chemical resistance, thermal performance, outdoor weathering, water contact, etc..

Plastics raw material advanced: Understanding of homopolymers, blends, copolymers. Datasheet interpretation of polymers and understanding properties in detail.

The manufacturing process and machine: Introduction to the different plastic manufacturing processes, Injection molding machines in detail. Injection molding machine screw, heating principle, typical damages in the machine screw. Clamping unit and clamping calculations. Shot size consideration. Molding machine selection guidelines.

Material preparation: Storage of raw material, transport, mixing, and pre-drying. Importance of pre-drying, consideration for different polymers, over-drying and its adverse effect, cumulative drying time for various polymers. Methods of drying and different types of equipment. Signes of undried material, moisture absorption facts, moisture analysis.

Process establishment: Procedure to establish and fine-tune molding, mold qualification flow chart. Understanding fill, pack, switchover point. Understanding pressure drop in the feed system.

Tool design: Different types of injection molds. Feed design and sizing, runner balancing, nozzle sizing, cold slug, types of gate, deriving gate size by understanding material shear rate, injection time, pressure drop in the feed system, gate freezing time. Gate positioning and number of gates. Runner cross-section and gate type correlation. Cooling system and thermal stability in a mold. Mold insulation. Air venting based on different polymers and their positioning. Key mold design tips for engineering plastics.

Troubleshooting: Molding defects and solution. Different types of injection molding defects such as silver streaks, diesel effect, weld lines, pin marks, gate blush, record grooves flash, shot shot, blisters, jetting, sink marks, warpage, black specks, scoring. Detailed understanding of molded-in stress, part failure due to molded-in stress, and solution. Nozzle effect on resin, attending hangouts, and degradation due to injection molding machine nozzle.

Product design: What is a good part, plastic part design principles, guidelines for designing various features like ribs, bossed, etc.. Draft angel. Understanding flow length of different polymer grades, dimensional stability, and achievable tolerance for different polymer compounds.

Application development: Detailed understanding of various polymer applications such as antistatic, ant- fog, fire retardant, water management, outdoor, thermally conductive, EMI shielding, Painting, plating, medical bio compactable applications, lubricating and low friction, aerospace, etc..