Course content for Injection Moulding for Quality Engineers – Online Delivery

Injection Moulding for Quality Engineers – Online Delivery

 Duration: 9 x 1 hour sessions delivered over 3 days – 10am to 1pm each day with short breaks each hour

This course content is designed for QA Engineers who have not had previous formal moulding training. Attendees be given a thorough introduction to the moulding cycle, a short overview of plastic materials from a moulding and mould design point of view, and a detailed overview of troubleshooting.

Practical sessions will be delivered using an injection moulding simulator – setting up the process from a blank program to understand the parameters that make up the moulding cycle, troubleshooting moulding defects and reviewing quality/ defect issues.

Course content – 9 one hour sessions:

Session 1. Analysis of the Moulding Cycle – Injection, Holding, Plasticising, Decompression, Mould Opening, Mould Closing, Ejection

Session 2. The Injection Mould – Sprues, Runners, Gates, Hot and Cold runners etc.

Basic Mould Design and how poor design can lead to defects

Mould Cooling, Venting, Gate position and size, Mould Balance

Clamping Requirements vs part size (projected area)

Basic Part Design – Wall thickness, flow ratios, ribs and bosses, draft angles etc.

Session 3. Navigating injection moulding machines – layout of control panels, location of important parameters, what data to collect etc

Session 4. Troubleshooting: Analysis of Injection Moulding Faults (short shot, flash, sink marks, burn marks, weld lines, high gates, gloss inconsistency and other surface defects (drag marks, air hooks, etc), as well as dimensional control.
This session will concentrate on how to use data to find the root cause of part defects, and developing logical troubleshooting methods.

We will concentrate on building an understanding of troubleshooting with an in-depth explanation of what’s happening to the material and the many ways defects can be avoided.

Session 5. Understanding pressure curves – how to analyse the injection stroke, injection pressure and injection speed curves to understand what is happening inside the mould. Using injection/ holding profiles is covered in this session with a full run through an optimisation process using screenshots of every change made on a hard-to-fill and poorly vented training mould.

Session 6. Plastics Materials: Processing of various thermoplastics, Correct material handling & preparation, processing factors relating to different thermoplastic materials.

Amorphous vs Crystalline materials – Understanding shrinkage, warpage, impact strength, sink marks, dimensional control, surface gloss, chemical resistance, creep/ tensile strength.

Session 7. Overview of the Scientific Injection Moulding (SIM) process optimisation procedure for a new mould which most Irish injection moulding companies currently use

Process variables & how they influence part quality/product consistency
Screw rpm speed calculation for different polymer materials and screw sizes
Barrel temperature and mould temperature selection – consideration of material manufacturers guidelines as well as mould specific requirements

Optimisation trials for Back Pressure, Decompression Distance to reduce shot to shot variation

How to optimise the Injection Speed by creating an Injection Rheology Curve
Profiled injection speeds – how and why they are used to correct defects and achieve cycle time reduction
Holding pressure optimisation and holding pressure profiles
Explanation of how process parameters interact and affect each other and which parameters to change for a given part defect
Different methods of measuring/ benchmarking shot-to-shot consistency

Session 8. Injection Moulding Process Simulator

This session will use an injection moulding process simulator (PICAT) to practice troubleshooting defects and work around other issues that arise during the troubleshooting process. A number of defects will be worked on during this session

Session 9. Case Studies and final review

Practical examples of defects – real life case studies of a number of different samples from troubleshooting work completed will be shown and discussed. The attendees will be given an overview of the problem and the information that was available, then they are challenged to come up with a step by step procedure to diagnose the root cause and correct the defect.

Review of course content and Q&A