Finishing materials by chemical conversion processes
URN: SEMMPF333
Business Sectors (Suites): Materials Processing and Finishing Suite 3
Developed by: Enginuity
Approved on:
2020
Overview
| This standard identifies the competencies you need to carry out chemical conversion coating activities to various substrates, in accordance with approved procedures. You will be required to access the appropriate specifications, to check that these are the current issue and to extract all necessary information in order to carry out the chemical conversion coating operations. You will be expected to prepare and adjust the processing solutions to give satisfactory coatings at optimal productivity levels. You will be expected to identify any coating defects and to carry out the necessary actions and adjustments to equipment and coating solutions in order to correct them. You will need to carry out tests on the components to ensure that the conversion coatings meet the specification requirement. Your responsibilities will require you to comply with organisational policy and procedures for the conversion coating activities undertaken and to report any problems with these activities or with the materials and equipment used, that you cannot personally resolve, or are outside your permitted authority, to the relevant people. You will be expected to work with a minimum of supervision, taking personal responsibility for your own actions and for the quality and accuracy of the work that you carry out. Your underpinning knowledge will provide a good understanding of your work and will provide an informed approach to applying chemical conversion processes and procedures. You will understand the chemical conversion process and its application, in adequate depth to provide a sound basis for carrying out the activities, correcting faults, and ensuring that the finished components are to the required specification. Your knowledge will also include effluent treatment for the waste streams from the coating processes and associated pre-treatments. You will understand the safety precautions required when carrying out the chemical conversion coating operations. You will be required to demonstrate safe working practices throughout, and will understand the responsibility you owe to yourself and others in the workplace and towards the environment. |
Performance criteria
You must be able to:
| 1. work safely at all times, complying with health and safety legislation, regulations, directives and other relevant guidelines 2. follow relevant job instructions and specifications 3. ensure the material surfaces to be treated are prepared for the finishing operations 4. check that the finishing equipment and treatment solutions are set up and maintained at required operating conditions and levels 5. carry out finishing according to operating procedures and to meet specifications 6. check that the treated workpiece achieves the required characteristics and meets the finishing specifications 7. deal promptly and effectively with problems within your control and report those that cannot be solved 8. ensure that work records are completed, stored securely and available to others, as per organisational requirements 9. leave the work area in a safe condition on completion of the activities, as per organisational and legal requirements |
Knowledge and Understanding
You need to know and understand:
| 1. the types of specifications that are used during the coating activity 2. the specific safety precautions to be taken whilst carrying out the activities (including any specific legislation, regulations or codes of practice relating to the activities, equipment or materials) 3. the health and safety requirements of the work area and the activities, and the responsibility these requirements place on you 4. the hazards associated with the activities, and how to minimise them and reduce risks 5. the personal protective equipment and clothing (PPE) to be worn during the activities 6. how to assess component suitability for chemical conversion coating (to include methods of handling, methods of pre-treatment, the most efficient and appropriate method of application) 7. the properties of various conversion coatings 8. how to identify conversion coating specifications, or customer specific requirements and advise on the process to give the desired results for specific substrates 9. the importance of keeping constituent elements within controlled limits when substrates are formed from alloys (aluminium, manganese, zinc castings) 10. the non-chromate systems that are available as substitutes for traditional techniques and their importance in reducing health risks and environmental impact 11. the basic principles of operation of the chemical conversion process plant and equipment used 12. advantages and disadvantages of work placement methods, jigs, baskets, wiring, trays 13. how to set up and check that the chemical conversion plant, equipment and solutions are fit for purpose 14. how to clean, activate and rinse substrates and check the surface condition prior to the conversion process 15. how to make up conversion coating solutions and pre-treatment solutions, safely and correctly 16. how to dispose of spent solutions and clean out process tanks, safely and correctly 17. how to carry out effluent treatment 18. how to carry out the chemical conversion process and the sequence of operations that are required 19. the importance of agitation to prevent uneven deposits and temperature layering, and the various means of achieving this 20. how to identify and correct any chemical conversion processing faults 21. methods for checking coated surfaces for visual defects and other specified characteristics 22. how to remove poorly applied coatings without damaging substrates 23. how to test coated components for specification requirements 24. the extent of your own responsibility and to whom you should report if you have problems that you cannot resolve 25. how to access, use and maintain information to comply with organisational requirements and legislation |
Scope/range
| 1. Finish materials, using the chemical conversion process, carrying out all of the following: 1. use the correct issue of process and other related specifications 2. adhere to health and safety regulations, systems and procedures to realise a safe system of work ensure that the equipment is correctly prepared for the coating operations 3. ensure that any meters and gauges to be used are within their calibration periods 4. clean all tools and equipment on completion of the coating activities 5. complete the production documentation (condition/pre-treatment of substrates, coating material preparation, equipment settings, confirmation of standard of finish) 6. leave the work area in a safe and clean condition 2. Carry out chemical conversion coating activities on one of the following materials: 1. electroplated zinc 2. magnesium alloy 3. copper 4. mechanically plated zinc 5. aluminium 6. other material substrate 3. Use one of the following methods for locating/processing the components: 1. wiring 2. specialised jigs 3. barrels 4. baskets 5. trays 6. other specific method 4. Measure and correct two of the following chemical conversion processing conditions: 1. concentration of conversion coating solutions 2. temperature of solutions 3. contaminant levels in conversion coating solutions 4. pH (acidity/alkalinity) of solution plus two more from: 5. total and free alkalinity of cleaners 6. effectiveness of acid activation 7. contamination levels in cleaners 8. effectiveness of rinsing 9. temperature of cleaners 5. Carry out two of the following activities: 1. prepare conversion solutions from basic salts 2. clean out process tanks correctly 3. dispose of spent solutions safely 6. Make corrections for two of the following faults: 1. colour or brightness of conversion coating is unsatisfactory 2. coating is dried too rapidly, leading to incorrect colour or cracking 3. conversion coating forms unevenly 4. reaction occurs too rapidly or too slowly 5. coating adherence is unsatisfactory 7. Check the coated components for two of the following characteristics: 1. evenness of the conversion coating 2. colour and brightness 3. evidence of nodules or blisters in the substrate 4. evidence of substrate attack by conversion coating or pre-treatment 5. corrosion resistance 6. adherence of coating 8. Check coatings applied to components comply with one of the following quality and accuracy standards: 1. military or aviation standards 2. current industry standards and codes of practice 3. international standards 4. company standards and requirements 5. customer standards and requirements ** ** |
Scope Performance
Scope Knowledge
Values
Behaviours
Skills
Glossary
Links To Other NOS
External Links
Version Number
2
Indicative Review Date
2023
Validity
Current
Status
Original
Originating Organisation
SEMTA
Original URN
MPF3.33
Relevant Occupations
Engineering and Manufacturing Technologies, Manufacturing Technologies, Process Operatives, Process, Plant and Machine Operatives
SOC Code
8115
Keywords
Engineering; manufacturing; processing; finishing; coating; chemical conversion; process; materials