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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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