Manufacture production moulds — Occupational Awards Limited End-Point Assessment Manufacturing & Engineering Revision
This subtopic covers the practical skills and theoretical knowledge required to manufacture production moulds used in the sanitary ware industry. Learners
Topic Synopsis
This subtopic covers the practical skills and theoretical knowledge required to manufacture production moulds used in the sanitary ware industry. Learners will develop proficiency in mould making from design interpretation to final finishing, ensuring moulds meet quality and production standards for the casting of ceramic sanitary products.
Key Concepts & Core Principles
- Slip casting: The process of pouring liquid clay (slip) into plaster moulds to form hollow shapes, which is the primary method for producing complex sanitary ware items.
- Glaze application and firing: Understanding how glaze composition affects finish and durability, and the importance of controlled kiln temperatures (typically 1200-1300°C) for vitrification.
- Quality control and defect identification: Recognising common faults like pinholes, crazing, or warping, and using inspection tools such as micrometers and gauges to ensure dimensional accuracy.
- Raw material properties: Knowledge of clays, feldspar, silica, and other additives, and how their proportions influence plasticity, shrinkage, and final strength.
- Health and safety in ceramics: Safe handling of silica dust, proper use of PPE, and adherence to COSHH regulations when working with glazes and kilns.
Exam Tips & Revision Strategies
- Always reference the specific sanitary ware product requirements (e.g., shape, undercuts, draft angles) when justifying mould material and design choices.
- Use clearly labelled diagrams or photographs to illustrate the stages of mould assembly and reinforcement in written assessments.
- In practical tasks, continuously check critical dimensions at each stage (e.g., after each plaster pour) to avoid cumulative errors and ensure final mould accuracy.
- When responding to quality-related questions, refer to industry standards and tolerances for sanitary ware moulds to demonstrate applied knowledge.
Common Misconceptions & Mistakes to Avoid
- Incorrect plaster/water ratio leading to weak, porous, or brittle moulds that fail during casting.
- Failure to apply sufficient release agent to the pattern, causing damage to both pattern and mould on separation.
- Neglecting to reinforce high-stress areas of the mould, resulting in distortion or breakage under casting pressures.
- Inadequate cleaning and preparation of pattern surfaces, leading to surface defects transferred to the mould and ultimately the ware.
Examiner Marking Points
- Award credit for correctly identifying and justifying mould components (e.g., case, cope, drag, cores) based on product design.
- Credit for demonstrating accurate measurement and mixing ratios for plaster, resin, or other mould materials.
- Evidence of using appropriate PPE and following COSHH assessments during all stages of mould manufacture.
- Award credit for conducting thorough inspection and recording dimensional conformity using appropriate tools (vernier, templates).
- Credit for explaining how to diagnose and rectify common mould defects (e.g., air bubbles, weak sections, warping).