SEMINAR VI - THE " NEED TO KNOW"
ON MOLDING AND MOLD DESIGN

John Klees Enterprise, Inc. - 125 Caldonia Drive - Candler, NC  28715
Phone: 828.667.0580  -  Fax: 828.667.0830  -  E-mail: jklees@johnklees.com

This two day, total 16 hours, course offers a concise review of the essentials one ought to know when dealing with the injection molding processes. Emphasis is on obtaining a condensed overview on rheology, molding machinery, cycle elements, energy transfer (heating, cooling, thermal expansion) need to know of runnerless tooling and mold base, cavity, core and slide alignments.

This fact-filled presentation is considered a general overview and "wrap-up", which combines the highlights of our other injection molding and tool design programs. It is a fast-paced compact seminar covering methods generally known, yet less understood. This seminar reveals why many innovations should or have become the industry standard.

This course is intended for those individuals who like to "brush up" on their overall knowledge in the injection molding field. It is not a beginners seminar, therefore a sound knowledge and understanding of the injection molding process is a prerequisite.

At this seminar you will....

• Understand polymer flow and behavior and learn about the heat content of plasticized materials.
• Witness several mold filling scenario's and observe crystal structure and spherulites growth.
• Understand the effect of molding conditions and wall thickness on mold shrinkage.
• Learn how to interpret the molding machine specifications.
• Come to know the high dynamic forces on a mold and hot runner system (which just appear to be a static assembly).
• Apprehend heat coefficient versus flow of the cooling media.
• 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     Plastic flow and behavior:

• Overview of thermoplastics, amorphous and crystallinity materials, polymerization process and intermolecular forces.
• Polymer flow and mold filling studies.
• Viscosity versus shear rate.
• Crystal structure & spherulites growth during the cooling process.
• Shrinkage from mold dimensions of molded plastics.
• Discussion on computer aided mold filling analysis.

II     Cycle elements

• Dependent and independent variables.
• Hydraulic pressure versus cavity pressure.
• Intensifying ratio, shot weight and plasticizing capacity.
• Clamping mechanism (parallelism of the platen, tie bar elongation).

III     Mold types 

• Two plate mold; Stripper plate mold; Three plate mold; Stack mold, etc.

IV    Cam Actions

• Projected areas on the slide, and resultant forces projected against the clamping mechanism.
• Slides and cam activation, sliding mechanisms, etc.

V    Hot runner systems

• Advantages and disadvantages of hot runner systems.
• Annular versus cylindrical flow in runnerless tooling.
• Application of heating elements; power requirements and thermocouples.
• Calculations required in order to install the correct capacity heating element(s).
• Gating methods and material suitability.
• Thermal conductivity of tool steels and other non-ferrous materials used in the mold making industry.
• Coefficient of thermal expansion of materials used in the mold making industry.
• When, why and where to use insulator sheets.
• Mechanical stability of the mold base and components.

VI     Mold base alignment

• The application, position, and alignment of parting line interlocks.
• Guided ejector mechanism.
• Cavity - core alignment.

VII     Cooling theory

• Cooling system(s) for the injection molding shop.
• Basic water cooling theory and energy removal.
• Importance of metering the cooling media.
• Discussion on computer aided mold cooling analysis.

VIII     Mold cooling circuits

• Uniform heat transfer circuits.
• Applications of cooling inserts, baffles, bubbles and heat pipes.
• Typical common errors in cooling line layouts.

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