OBJECTIVES
· Describe the cause of injection moulding defects and types of defects.
· Understand principles of polymer properties and characteristics
· Describe basic mould construction
· Differentiate filling stage and packing stage
· Apply techniques in mould rheology for polymer flow behaviors.
· Determine holding phase sequencing and variation in parameter setting occurs during processing.
TARGET GROUP
Personnel dealing with customers on daily basis.
Technician / Supervisor/Quality Control/ R&D Engineer/ Lecturer/Instructor
TRAINING METHODOLOGY
Classroom and practical
TRAINING PROGRAM OUTLINE
1. Plastics materials properties and characteristics.
· Different types of molecular shape.
· Different types of molecular arrangement.
· How molecular shape and arrangement affect properties of plastics.
· Molecular chain behavior during cooling for crystalline and amorphous plastics.
· How melt flow affect plastics materials properties.
(Hands on Practice using injection machine)
· Basic Fluid Flows & Flow Phenomena
2. The Construction of Injection Moulds
· Runner system layout
· Gating system
· Imbalance cavity filling
· Clamping force
3. Polymer Drying
3.1. Why Dry Plastic Pallets?
3.2. Moisture Problems
· Machine Processing Problems
· Cosmetic Problems
3.3. Hygroscopic Polymer
3.4. Non-Hygroscopic Polymer
4. Variation and changes in Processing Parameters
· Injection stage – optimize filling stage (Hand on practice)
· Injection Speed
· Injection Pressure
· Holding stage – optimize packing phase (Hand on practice)
· Barrel Temperature & melt temperature
5. Trouble Shooting
5.1. Problem Solving ( Using software simulation)
5.2. Solutions
· Fast Results
· Slow Results
6. Types of Defects6.1. Definition of appearance and dimensional defects
6.2. Processing Defects-Definitions, Causes & Solutions
· Drooling
· Short shots
· Slow Cycle Time
· Flashing
· Crazing, Stress Whitening
· Delaminating
· J-Hooks
· Jetting
· Dimension Unstable
· Silver streaks
· Warpage / deformation
· Non visible / Internal Part Defects
· Voids