At this seminar you will....

• Understand the basis of rheology and what this means to product design and development
• Learn points to be considered when analyzing part function versus screening candidate materials.
• Broaden your understanding of the relationship between product design, mold design, mold making and the molding operation.
• Discover design techniques which will aid the ease of assembly.
• Hear how to avoid typical plastic product design flaws.
• 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   Introduction to Polymer Chemistry

• Definition of plastics, petrochemical source, classification of plastics.
• Thermoplastic and thermosetting materials.
• Elements, atomic weight and energy bonds, monomers, polymerization, macromolecules.
• Linear polymers with carbon and other atoms in the backbone.
• Molecular weight distribution.
• Polymer flow and variables in molecular orientation.
• Homopolymers, copolymers and terpolymers.
• Elastomers, alloys, additives, reinforcements and fillers.
• Crystal structure and spherulites growth during the mold cooling process and its influence on product's rigidity, toughness, elongation and dimensional behavior.
• Gating and cooling influence or effect on the part's geometry.
• Understanding the hygroscopic polymers.

II     Principle properties of plastic

• Tensile strength, elongation, impact strength (Izod, charpy, fallingdart), tensile impact.
• Designing for impact resistance.
• Measuring shrinkage from mold dimensions of molded plastics. Deviations from assumed shrinkage: environmental dimensional change. Processing conditions and post-molding shrinkage. Mold and manufacturing tolerances.
• Tolerances standards and practices of plastic custom molders.
• Deflection temperature, compressive properties, flexural properties, melt index, flammability.

III     Plastics Additives

• Additives: Antimicrobials, Antioxidants, Blowing Agents, Colorants, etc.
• Fibers: Aramids, Carbon fibers, Glass fibers.
• Fillers: Glass fillers, Mineral fillers.
• Lubricants: Graphite powder, PTFE, Silicone fluids.

IV     The Injection Mold and Molding machine

• The injection molding machine: injection unit, clamp mechanism, and machine specifications.
• The injection mold: Type of molds with some examples.
• The effect of machine setup parameters versus product quality.

V      Plastic Product Design Evaluation

• Designing for uniform wall thickness and wall thickness transitions; corner designs; rib designs; gussets; strengthening members; holes and counter bores.
• Designing with parting line considerations and draft angles in mind.
• Coring techniques and design locations for part ejection (ejector pin, blade and sleeve marks).
• Designing for screw, rivets and fasteners assembly techniques.
• Undercuts, threads and twist lock devices.
• Design techniques whereby the mold uses "by-pass shut-off" instead of cam and sliding actions.
• Aesthetics: surface finishes, flow and weld lines, sink marks, voids, and airtraps.

VI     Snap joint techniques

• Flexible design techniques: Distortion snaps, press-fit assembly, snap-fits, snap-hook designs, cantilever snap-joints, annular snap-joints, latches, permanent snap design and twist snaps.
• Living hinges and hinge designs.

VII     Other joining techniques

• Ultrasonic welding, vibrational welding, spin welding, hot plate welding, staking an swaging.

VIII     Design - General

• Essential information to be agreed upon by product designer and mold designer.
• Test your knowledge of plastic part design.

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