This three day, total 24 hours, seminar projects concise technical and expert insight for everyone involved in the injection molding industry. It provides a unique understanding of the molding operation to all levels of personnel involved in injection molding. It is recommended for management, purchasing, technical representatives, mold procurement personnel, tool makers, tool designers, molding supervisors, press operators, technicians, and quality insurance personnel.

At this seminar you will....

• Understand the scientific method as a fundamental approach;
• Understand the basics of rheology, what it means to product design, to mold design, and to the molder;
• With the help of a video, witness how a polymer flows and orients into the mold;
• Learn points to be considered in selecting an injection molding machine;
• Comprehend the advantages of microprocessors, learn how process setup can be used repeatedly without adjustments;
• Learn why a close loop system is not smart enough to compensate for poorly trained operating personnel;
• Receive a source of technical information tempered with a considerable amount of practical material;
• Receive and comprehend more information, allowing one to communicate efficiently, leading to improved production of better quality products at a reasonable cost;
• Be satisfied with what you learned, regardless of whether you are involved in plastic product design and development, mold design, mold manufacturing or molding;
• Receive a comprehensive custom-developed instruction manual, provided only to participants of this seminar, which will serve as a valuable source in the future.

Seminar Outline

I    Plastics

• Introduction to polymer chemistry from monomer to macro molecules, intermolecular forces, molecular weight distribution.
• Molecular orientation and flow into the mold and mold filling analysis.
• Shear rate, shear stress and plastics viscosity versus plastics velocity.
• Gate location(s) versus orientation, weld lines, mold venting and shrinkage.
• Shrinkage versus wall thickness and mold temperature.
• Homopolymers, copolymers and terpolymers, crystalline and amorphous materials, crystal structure and spherulites growth during the mold cooling process and its influence on product rigidity, toughness and elongation.
• Understanding hygroscopic polymers and drying procedures.
• Understanding the General Test Methods of Plastic: tensile, melt-index, impact strength, etc.

II    The Injection Molding Machine

• Injection molding machine terminology. Development of the injection unit. The reciprocating screw. Importance of screw design, L:D and compression ratio considerations, mixing screws. Check valve assemblies, nozzle and nozzle adapters and application of shut-off valves.
• Hydraulic injection pressures versus plastic pressure (intensifying ratio), injection speed, packing and holding pressure and time, cushion control, temperature set-up parameters, back pressure control and screw R.P.M. Gas assist injection molding.
• Vented screw and barrel, functional zones of the screw, starve feeding versus flood feeding.
• Toggle, hydraulic and hydro-mechanical clamping mechanisms, clamp unit specifications, parallelism of machine platen, wrap around, machine levelness, and tie bar equalizing procedure. Two-platen clamping technology and tiebarless machines. Ejector mechanism.
• Standard S.P.I. core pull sequences. Machine and cycle efficiency factors.

III    Microprocessors

• Process-control, clamp set-up, ejector set-up, injection velocity profile, holding pressure profile, cavity pressure profiles (cavity pressure sensors), temperature set-up, process-timers, extruder R.P.M. and back pressure.
• Process optimization

IV    Auxiliary and Ancillary equipment

• Granulators, dryers, conveyors, lift and take-off devices, robots, mold heaters, chillers.

V    Basic Evaluations prior to Mold Design

• Evaluating the plastic product design: wall sections, bosses ribs, material selected and tolerances used.
• Projected area and clamping force requirement.
• Shot weight of the molding.
• Shrinkage from mold dimensions of molded plastics. The effect of molding conditions and wall thickness on mold shrinkage.

VI    Mold types

• Two and three plate molds.
• Stripper plate molds, unscrewing molds.
• Stack molds, interchangeable mold base and prototype molds.

VII    Cooling process

• Cooling characteristics, Reynolds Numbers, flow of cooling media and lay out of cooling channels.

VIII    Molding problems and possible solutions

• Failure analysis for injection molding
• Surface imperfections, warpage, voids, sinks, etc.

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