Process: WI-DYG-009 Author: A
Document type: WI-Work Instruction Reviewer: B
Title: VISUAL COLOUR ASSESSMENT PROCESS Approver: C
PURPOSE
1.0 PURPOSE
This document describes the processes required to guarantee the highest degree of accurate visual colour perception is achieved and to coordinate the process between the three departments.
2.0 SCOPE
This process covers all areas where colour viewing is carried out for colour approval;
Laboratory team members.
Dye house team members.
Finishing team members.
QAD team members.
3.0 APPLICABLE REFERENCE/DOCUMENTS
3.1 Munsell 100 Hue Test The process of testing all personnel for known colour blindness related issues. This is carried out for those whom are involved with the colour approval process.
3.2 TTD-001 Colour Measurement The physical process required to accurately measure colour for the colour approval process.
3.3 TTD-002 Colour & Metamerism Technical Training Document used for educating staff whom are involved with colour matching and the colour approval process.
3.4 WI-EPY-DYG-020 Internal Colour Pass/Fail Procedure An internal procedure used to streamline the colour approval process by using both the digital colour approval process and visual.
3.5 TCD-EPY-DYG-001 Light Cabinet Light Source Calibration Register A Technical Control Document (TCD) used to monitor and control of the regular and systematic change of the light sources.
3.6 TCD-EPY-DYG-002 Light Cabinet Tube Cleaning Register A Technical Control Document (TCD) used to control the systematic process of cleaning the light sources in the light cabinet (light tubes).
4.0 APPLICABLE SAFETY PRECAUTIONS & DOCUMENTATION
4.1 No Smoking
Smoking is not permitted on the production floor.
1.0
5.0 EMPLOYEE QUALIFICATIONS
All staff are to undergo the Munsell 100 Hue test. Any personnel who fail this process are not permitted to visually asses colour.
Approved personnel are to undergo rigorous training on colour approval and colour perception routines for a minimum of 6 months before being given full authority.
6.0 EQUIPMENT USED / APPROVED MATERIALS
6.1 Munsell 100 Hue Test
6.2 Verivide Light Cabinet
6.3 DataColor Conditioning Cabinet
6.4 Standard Air-Conditioner/Humidity Conditioning Unit.
6.5 DataColor Spectrophotometer.
7.0 RESPONSIBILITIES
Position/s Responsibility
Supervisor, Assistant Manager and DH Manager. Colour Assessment of production batches
Supervisor, Assistant Manager and DH Manager. Development of addition recipes for failed batches
Supervisor, Assistant Manager and DH Manager. House Keeping of Light Cabinet
QAD Manager, DH Manager & Laboratory Manager Munsell 100 Hue Test of appropriate staff.
8.0 PROCEDURE
8.1 The observer is not permitted to wear clothes which are bright in colour.
8.2 The room ambient light should be low.
8.3 The room temperature and humidity should be 20°C +/- 2°C and the humidity should be 65% +/- 2%. A chart should be maintained to control the room environment.
Temperature Control Limits Relative Humidity Control Limits
20°C +/- 2°C 65% +/- 2% Rh.
8.4 Before visual inspection is to begin the tube lights should be given 10 seconds to reach optimum temperature performance. Once the 10 second period is complete the viewing process may begin.
8.2 At all times the observer is to ensure their hands are clean and free from sweat, soil, colorants or any other foreign materials that could pollute the samples and standard.
8.3 The Supervisor removes any foreign materials from the light cabinet (the cabinet is to be empty at all times) and carries out a quick visual assessment of the light cabinet checking for defects, failure in switches and the illuminant calibration sheet for expired tubes.
illustration 1.0
The above illustration (1.0) shows the incorrect method of Light Cabinet conditions. The cabinet should be free of items at all times ready for colour review.
7.0
Incorrect application shown in the above Light Cabinet. The Light Cabinet should be free from all obstruction for viewing purposes.
8.3.1 If the light cabinet looks in disrepair or is damaged in any way, he is required to report this directly to the Dye House Manager.
8.3.2 The Dye House Manager is required to communicate with the AGM of Dyeing and Finishing, who is to organise repairs or maintenance of the light cabinet.
Illustration 2.0
Illustration 2.0 shows the degree of wear from placement of folders, materials and abrasive items. This example shows that a repaint of the surface is required. VeriVide use N5 (lighter in depth) or N7 which is available for purchase.
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Illustration 3.0
Dye house teams are required to monitor the number of hours the tubes have been in operations. When the hours exceed 2,000 hrs the tubes require changing with new tubes and a record retained of the time, date and who changed the tubes with expected hours for next change.
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8.4 Upon receiving the fabric sample and production Batch Card from the production personnel, the supervisor is to check the sample corresponds with the correct Batch Number and dyeing history card.
8.5 When viewing colour, the comparing “dyed” samples are to be of equal size and shape. The batch is to be cut into a size and shape which is identical to the standard.
8.6 Once the samples are prepared the samples are to be placed inside the DataColor Conditioning Cabinet for 30 minutes. Once the samples are placed in the cabinet side by side the Supervisor is to press the “START” time on the timer for 30 minutes.
The samples are not to cross over or rest on other samples.
The conditioning cabinet settings should be set to 21C and 65% humidity.
8.7 When the alarm sounds after 30 minutes the Supervisor is to fold the standard and batch so they both have the same number of layers.
8.8 Place the Standard and batch on a clean flat surface see illustration 4.0, or the 45 degree resting panel according to these steps;
illustration 4.0
8.8.1 Fold the fabric so both samples are of equal number of layers/thickness, typically 2-4 layers is sufficient see illustration 9.0.
8.8.2 The fabric does not overlap but touch side by side illustration 5.0.
8.8.3 The Warp and Weft are both facing in the the same direction.
8.8.4 The fabric is of the same size and shape see illustration 8.0 & 9.0.
8.8.4 The same “face” of the fabric is facing forward “outward” towards the observer see illustration
9.0.
illustration 5.0
Do not cover the fabric samples or lie them over each other.
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illustration 6.0
Do not have contrasting colours on the surface of the fabric.
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Illustration 7.0
Samples should be folded a minimum of 2 times (x2) and a maximum of 4 times (x4).
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Illustration 8.0
Samples are required to be of the same diameter and shape.
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Illustration 9.0
This format is correct, the samples are of similar size, layer and the Warp and Weft and face are all coordinated for viewing assessment.
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8.9 When viewing colour, the observer is to communicate using the following textiles terms see illustration 7.0;
Lightness: Light/dark
Chroma: Bright/dull
Hue: Yellow/Blue – Red/Green (opposite sides of spectrum).
illustration 7.0
8.10 The observer is to use D65 as the viewing light source by selection on the VeriVide light cabinet.
8.11 The observer is to review the colour within a 3-5 seconds for colour approval.
8.8.1 The sample is to be viewed within 3 minutes of removal from the conditioning cabinet. If the sample is out of the cabinet more then 3 minutes the colour is no longer stable and must be placed inside the cabinet for a further 30 minutes for conditioning.
8.12 The Observer (Supervisor) is to use the pass/fail rules to determine whether the batch is a “pass” or “fail”.
8.13 If the batch is “Passed” the Supervisor stamps the batch card with the dye house approval seal and processes the batch to the Finishing team for extraction or slitting.
8.14 If the batch is “Failed” the Supervisor then develops an “addition” of dyes to be added to the batch following the “Reprocessing” Work Instruction or to the laboratory for manual recipe development.
9.0 TERMS AND ACRONYMS
Acronym Term
Munsell 100 Hue Test A strict process that tests the observers colour perception/accuracy.
Verivide Cabinet A Cabinet made to represent an a-chromatic environment for colour viewing using specific light sources.
DataColor An industrial company based in the United States who is responsible for developing colour measuring devices as well as other textiles hardware.
Reprocessing Or “addition” is the process caused from quality failure in the dye house causing the batch to receive further processing to correct the failure.
Lightness A description used to identify the degree of depth to a colour, thin/light or heavy/dark.
Chroma The degree of saturation of colour from dull to bright.
Hue The degree to which a stimulus can be described as similar to or different from stimuli that are described as red, green, blue, and yellow"
10.0 REVISIONS
10.0 OUT OF CONTROL ACTION PLAN (OOCAP)
In the event that a sample and standard are out of the conditioning cabinet for more then 3 minutes the samples are to be introduced to the cabinet for a further 15 minutes or more before colour perception is again permitted.
11.0 REVISIONS
This section will record and date each version and revision of this document
Revision Date Author of Change What Alterations were Made
1 25/02/2020 A Document of Origin
Signature
Author: A
Reviewer B
Approver C
