Improve the design level and material performance

Benchmarking international standards &nbsp，Improve the design level and material performance—GB 20653-2020 Interpretation of the standard of High visibility Warning Clothing for Occupational Protective clothing

Zhang Mingming, China Work Safety Research Institute   Jia Jia of 3M China Co., LTD

1 Revision Background  

In recent years, as the country and society pay more and more attention to occupational safety, the application of occupational high visibility warning clothing and protective clothing with high visibility warning function is increasing.  At the same time, with the increase of people’s traffic and outdoor activities, the general improvement of personal safety awareness and the diversification of clothing aesthetic design, the design, material and technical requirements of high-visibility warning clothing for occupational use have been more and more referenced for non-occupational clothing.  

GB 20653-2006 High Visibility Warning Clothing for Occupational Use has gradually become the main basis and reference for the design, production and inspection of reflective function of warning clothing for various industries in China (industrial production, transportation, rescue, etc.) and ordinary clothing (outdoor, cycling, school, etc.) since its release and implementation, and has become the basic standard of visibility clothing in China.  It is an important personal protective equipment foundation to ensure the safety of all kinds of personnel in China.  In order to adapt to the application environment and objective requirements at home and abroad, the latest development and changes of the standard system and related technologies (ISO20471:2013 “Warning Reflective Clothing. Test Methods and Requirements Standard” has been widely used for reference), the relevant standards need to be revised and improved.  

GB 20653-2020 High Visibility Warning Clothing for Occupational Use of protective clothing is based on the 2006 version,  Reference has been made to ISO 20471:2013, Reflective Clothing for Warning use: Standards for Test Methods and Requirements (revised version of EN471:2003, Special High Visibility Warning Wear – Test Methods and Requirements) and ANSI/ISEA 107:2015, Update of High Visibility Safety Clothing and Accessories Standards.  In addition, the revision of GB 20653-2006 “High visibility Warning Clothing for Occupational Use” is made by taking full account of the implementation and application feedback.  

2 concept of high visibility warning suit  

High visibility warning clothing is mainly made of fluorescent materials and reflective materials by special design. Usually, fluorescent materials are used as the base cloth, and strong reflective materials are glued or sewn on it.  

On the one hand, the “high visibility” function of high visibility warning clothing is to make use of the “warning” function of fluorescent materials with high visual sensitivity to human, so as to ensure that the wearer can be easily identified from the complex environment under various natural lighting conditions (such as day, dusk, dawn, fog, haze or rainy day).  On the other hand, the reverse light reflection effect of reflective materials on irradiated light is utilized to make the wearer reflect light after being irradiated by lighting light in a dark environment, thus greatly improving the possibility and timeliness of its discovery and recognition.  Regardless of natural light during the day or light at night (or dark background), the high visibility warning clothing can highlight the wearer’s visual presence to warn others and avoid accidents.  

Fluorescent materials, generally using fluorescent dyes on ordinary textile fabrics (such as polyester, acrylic, cotton or blended) dyeing treatment.  Compared with ordinary textile fabrics, fluorescent color absorption uses more visible spectrum and lower wavelength (such as ultraviolet light), and the reflectivity of fluorescent fabrics is up to 200%~300%(ordinary bright fabrics can only reflect 90% of the color at most). Therefore, fluorescent materials are more eye-catching under the same light.  

Reflective materials, it is through will have a certain refractive index and the back of the reflective layer of glass beads processing in different cloth based materials, or in PVC template pressing and other ways to form a microprism structure, so that reflective materials can reflect light under the irradiation of the light.  Compared with ordinary textile fabrics, its special lies in that it has a high reverse reflectance to irradiation light, and forms a reverse reflection “passive light source” when receiving light irradiation.  

At present, many countries and regions, including the United States, the European Union, Japan, Brazil, Australia, Canada and so on, have issued standards for warning clothing, or directly reference ISO standards, and mandatory use in some fields  

3 Environmental risk level and High visibility warning clothing The application of site warning clothing is to improve the visibility of the wearer and reduce safety risks caused by low visibility.  Therefore, the design and related requirements of warning clothing must be consistent with the existing environmental risks.  In visibility less risky environment, homework personnel and related personnel should wear high grade high visibility warning clothing: in the medium or low risk environment, homework personnel or related personnel should wear of the middle or lower level warning clothing (e.g., with strong visibility function of clothing, with some visibility part or design of clothing).  Therefore, environmental risk level and the relevant factors (locomotive speed, warning uniform staff participation, weather conditions, ambient lighting conditions, operational complexity, the complexity of the background environment, vehicle activity and other related factors, the influence factor of any change may cause the risk level of different), also must be warning clothing design are important factors to consider.  In order to facilitate environmental risk analysis and guide the design of various levels of warning clothing,  GB 20653-2020 “High Visibility Warning Clothing for Occupational Use of Protective clothing” has been modified to refer to Appendix A of ISO 20471:2013 “Reflective Clothing for Warning: Test Methods and Requirements”, which is used as the information Appendix F “Environmental Risk Level and guidance for design of visibility clothing” for reference.  

Table 1 is the risk analysis of high-risk environment, clothing grade and influencing factors of design. Risk levels of various environments are simply rated and divided, and typical places are listed.  In the table, speed classification is mainly based on different speed limit rules of European countries. Speed above 60km/h generally belongs to motorways and country roads, 30-60km /h is most urban roads, and speed below 30km/h is the requirement of general residential areas and industrial parks.  In Table 1, passive road users mainly refer to those who do not actively participate in vehicles and traffic activities in the traffic place and focus on other jobs other than traffic activities, such as road maintenance personnel and relevant personnel in emergency situations:  Active road users refer to people who actively participate in traffic activities and pay attention in traffic places  

People in traffic activities, such as pedestrians and cyclists in traffic places.  

According to the above classification and analysis, operating personnel and emergency rescue personnel in highway and track environment, airport ground operation personnel;  Public road operators, traffic command, construction and survey personnel, express delivery, takeaway delivery and representative driving personnel, etc., parking lot, service area, warehouse and road operators within the factory area are all personnel with high visibility risk, and they should wear level 3, 2 and 1 high visibility warning clothing respectively when working.  

High visibility warning clothing is mainly used for “poor visibility of high-risk environment”, a lower risk for visibility of “visibility of medium and low visibility risks” environment, strong visibility by wearing clothing or with a visibility of decorative clothing to ascend in personnel safety (standard appendix F,  Risk analysis and design guidelines for high visibility clothing are also provided), which can even be extended to daily life or outdoor activities.  

4 high visibility warning clothing type design  

Corresponding to the applicable environmental risk level, only three fluorescent colors with higher visual sensitivity are specified for occupational high visibility warning clothing: fluorescent yellow, fluorescent orange and fluorescent red;  However, clothing in medium risk environment can use more colors of fluorescent fabrics, including fluorescent yellow, fluorescent green, fluorescent yellow-green, fluorescent orange, fluorescent red, fluorescent pink and other colors.  

In terms of design requirements, compared with clothing in medium-risk environments, high-visibility warning clothing for occupational use emphasizes more on the coverage area and area of the wearer’s body by visible materials, the 360° surround design of torso and limbs by visible materials, and the recognition of the wearer’s outline.  Simultaneously meets the day and night visibility requirements (fluorescent materials and reflective materials are available).  

The area of the visible materials on the clothing directly determines the intensity of reflected light and visual sensitivity. Therefore, different areas of the visible materials on the warning clothing will produce different degrees of warning, which means that the possibility and duration of the wearer of the warning clothing will be different.  Therefore, different use areas of visible materials (base materials, reflective materials, composite performance materials) on a single piece or single set of clothing correspond to different product grades (level 1, Level 2 and Level 3) of occupational high visibility warning clothing, which are respectively suitable for different risk levels in different application scenarios in high visibility high-risk environment.  

GB 20653-2020 “High Visibility Warning Clothing for Occupational Use of Protective Clothing” follows the contents of GB 20653-2006 “High Visibility Warning Clothing for Occupational Use”.  It is consistent with or equivalent to EN 17353:2020, Test Methods and Requirements for Clothing with Enhanced visibility in Medium Risk Environments, and ANSI/ISEA 107:2015, Update of High Visibility Safety Clothing and Accessories standards.  However, GB 20653-2020 “High Visibility Warning Clothing for Occupational Use of Protective Clothing” provides relevant specific requirements for the measurement basis of using area and assessment requirements of grade, which makes the rating more maneuverable and clearer.  If the measurement area is increased, the minimum design size of clothing should be selected, and all zippers, buckles and other fasteners should be buckled to the minimum position;  No pattern, print or label of any kind shall be counted “.  

Warning clothing is characterized by enhanced visibility to increase the perceived distance of the wearer.  Studies have shown that fluorescent warning clothing is 5.5 times more visible than regular clothing.  For example, a cyclist wearing a warning suit can be perceived at 670m, while a cyclist wearing normal clothing can only be perceived at 120m.  But being perceived and being recognized are at a different level, and car drivers are better off if they can recognize you as a cyclist at an early stage  

Plan your movements.  Therefore, in order to increase the ease of identification, design requirements such as layout and size of visible materials on the warning clothing must also be made clear.  

According to the different parts of human body covered by warning clothing, GB 20653-2020 High Visibility Warning Clothing for Occupational Protective Clothing partially adjusts the design types of warning clothing, and summarizes them into five types, each of which provides detailed provisions on the layout, specification and size of visible materials.  

1) Warning clothing (such as vest and sleeveless jacket) covering only the upper body and torso;  

2) Warning clothing (such as jacket, shirt/coat, T-shirt, etc.) covering parts including upper body, torso and arms;  

3) Warning clothing mainly covering legs (such as pants, suspenders, etc.) :  

4) Warning clothing (such as sleeveless overalls) covering parts including upper body and legs;  

5) Warning clothing (such as overalls) that can cover upper torso, arms and legs.  

GB 20653-2020 “High visibility Warning Clothing for Occupational Use of Protective clothing” refers to the five styles of ISO 20471:2013 “Reflective Clothing for Warning: Test Methods and Requirements”. Short-sleeved work clothes (such as T-shirts) are added according to the actual application, and the covering parts include warning clothing for upper body and legs.  Compared with GB 20653-2006 “High Visibility Warning Clothing for Occupational Use”, for vest and sleeveless short coat, it is clearly required to have at least one reflective belt across the shoulder seam, from the shoulder seam to the chest and back  

Extend at least 15cm or connect with the reflective band on the trunk;  Removed the strap that is rarely used in the real environment and cannot ensure effective visibility (the strap work clothes are only made of reflective materials, which does not meet the minimum area requirements of high visibility warning clothes, and the visibility of the bottom clothes of the strap cannot ensure its due visibility).  

5 Material performance requirements  

For reflective materials, refer to IS020471:2013 Warning Reflective Clothing. Test Methods and Requirements  GB 20653-2020 “High Visibility Warning Clothing for Occupational Use of Protective Clothing” has unified provisions on the minimum reflective coefficient of single performance reflective materials (equivalent to grade 2 of reflective materials in GB 20653-2006 “High Visibility Warning Clothing for Occupational Use”), no classification provisions.  

1. The durability requirements of reflective materials should be consistent with GB 20653-2006 “High Visibility Warning Clothing for Professional Use”. It is necessary to inspect the reverse reflection performance of samples after wear-resisting, flexure resistance, low temperature bending, temperature change, washing, dry cleaning and rain test.  

2. For wear resistance test, martindale method is required, according to GB/T 21196.2-2007 “Textile Martindale method of fabric wear resistance determination part 2:  Specimen damage determination of inversion model test, the diameter of 140 mm reflective material is fixed on the ground (heads), wool fabric fixed on the sample clamp, abrasive test 9 kPa downward pressure, wear and tear after 5000 cycles (a complete Li Sha shavings graphics including 16 laps of friction, wear for a loop),  Test the reflection coefficient of the sample, according to whether meet the requirements of standard 6.2.2-6.2.4 to determine the results  

3. For flexure resistance test, according to GB/T 12586-2003 “Rubber or plastic coated fabric flexure destructive determination” method A, the reflective tape sample made into (37.5±1)mm wide, 125mm long sample, folded twice into A 12.5mm wide sample, folding process to ensure that the coating outward-facing,  Mount to fixture for flexure test.  After the specimen has completed 7500 cycles of flexure, the result is determined by whether it meets the requirements of retroreflection coefficient in standard 6.2.2-6.2.4.  

4. For low temperature bending test, according to GB/T 18426-2001 “Rubber or plastic coated fabric low temperature bending test” requirements, cut 25mmx100mm reflective tape sample 3 pieces (in general, the length of the sample and the radial parallel to the coated fabric), the sample at (-20±2)℃ for placing and folding,  Under the condition of (20±2)℃ and relative humidity of (65±4)%, the humidity was lowered for at least 2h, and then the reflection coefficient was tested. The results were determined as above.  

5. For temperature change test,  The main method is to take two reflector strips of 100mm in length and 50mm in width (if the width is 25mm, take four strips) and place them successively under the condition of (50±2)℃ for 12h, and then immediately place them under the condition of (-30±2)℃ for 20h, and then dehumidification at (20±2)℃ and relative humidity of (65±4)% for at least 2h;  Finally, the back of the reflective tape was pasted and spliced into a sample of 100mmx100mm to test the reverse reflection coefficient of the sample, and the result was determined as above.  

6. For fluorescent materials, occupational high visibility warning clothing is limited to three fluorescent colors: fluorescent yellow, fluorescent orange and fluorescent red, and corresponding chromaticity coordinates (X, Y) range and minimum brightness factor (βmin) are given.  For fluorescent fabrics used in high visibility warning clothing, x and Y parameters must conform to a certain chroma area, and must meet the requirements of minimum brightness factor (βmin).  

7. For the base material (fluorescent) and non-fluorescent material, these two materials constitute the outer body of the warning suit, and the area used on a single suit is relatively large.  In order to ensure that the fluorescent materials and reflective materials of clothing keep good visibility during the whole wear life, it is required that the base materials (fluorescent) have good color fastness index (discoloration), and the base materials (fluorescent) and non-fluorescent materials have good color fastness.  

8. For the technical requirements of color fastness to perspiration, water washing, dry cleaning, hypochlorite bleaching and heat pressing of base materials and non-fluorescent materials, GB 20653-2020 “High visibility Warning Clothing for Occupational Use of Protective clothing” has been partially adjusted.  Considering that the discoloration performance of non-fluorescent materials is not related to safety, even severe discoloration will not affect the safety, but for base materials and non-fluorescent materials, if the color is contaminated with fluorescent or reflective materials, it will affect, and the color fastness should not be reduced due to different aging tests.  Therefore, GB20653-2020 “High visibility Warning Clothing for Occupational Use of protective clothing” refers to ISO 20471:2013 “Warning Reflective Clothing. Test Methods and Requirements” to adjust the relevant indicators: for non-fluorescent materials, remove the requirement of color change performance;  The color fastness to perspiration, washing and dry cleaning should be adjusted from grade 3 and 4-5 in GB 20653-2006 “High Visibility Warning Clothing for Occupational Use” to no less than Grade 4, so that the uniform color fastness should be  

It also facilitates standard implementation and application.  

GB 20653-2020 High Visibility Warning Clothing for Occupational Use of Protective Clothing has been modified to meet the technical requirements for mechanical properties of base materials and non-fluorescent materials based on actual application:  

1) As for the breaking strength, the method of breaking strength and the ratio of fabric g/w (the original standard requires a value greater than or equal to 2) is not convenient to use, and the requirement of 400 N is too high (some sports clothing fabrics may fail the test).  In order to adapt to the expansion of application fields and fabric types of warning clothing, the standard value of breaking strength should be appropriately lowered. Therefore, GB 20653-2020 High-visibility Warning Clothing for Occupational Use of Protective clothing should delete the requirement of ratio according to ISO20471:2013 Warning Reflective Clothing. Test Methods and Requirements standard.  And adjust the breaking strength value should not be less than 100N.  

2) For tearing strength, considering the expansion of application scope and material types of high visibility warning clothing, some thin and comfortable fabrics have low strength.  GB 20653-2020 “High visibility Warning Clothing for Occupational Use of protective clothing” refer to IS020471:2013 “Warning Reflective Clothing: Test Methods and Requirements standard” to appropriately reduce the tearing strength value of coated cloth and composite cloth to no less than 20N.  

3) For bursting strength, due to the different equipment used in different laboratories, the sample size is not the same, and the results are similar, so two kinds of sample gauge and corresponding methods are reserved;  Due to the strong strength of some light and comfortable fabrics, the top breaking strength is unified with ISO 20471:2013 “Warning reflection. Test Methods and Requirements standard”.  The new GB20653-2020 “High visibility Warning Clothing for Occupational Use of Protective clothing” shall be revised accordingly according to reference, and adjusted to: bursting strength shall not be less than 100 kPa(test area: 50C ㎡), or bursting strength shall not be less than 200 kPa(test area: 7.3c㎡).  

9. Regarding the chemical safety of clothing materials, GB 20653-2020 “High Visibility Warning Clothing for Occupational Protective Clothing” refers to GB 18401-2010 “National Technical Code for Basic Safety of Textile Products” and puts forward the technical requirements of pH and formaldehyde content of base materials and non-fluorescent materials, and provides clear testing methods.  

6 Other Parts  

Regarding the logo of warning clothing, compared with GB 20653-2006 “High Visibility Warning Clothing for Occupational Use”, GB 20653-2020 “High Visibility Warning Clothing for Occupational Protective Clothing” adds two vertical reflective strips connecting shoulder and horizontal reflective strips in the logo drawing;  At the same time, GB 20653-2020 “High visibility Warning Clothing for Occupational Use of Protective clothing” on reflective materials  

The reflective performance of materials has been uniformly stipulated without classification. Therefore, the grade identification symbol (Y) of reflective materials has been deleted simultaneously in the product identification part, and the grade identification symbol (X) of warning clothing has been retained.  

GB 20653-2020 “High Visibility Warning Clothing for Occupational Protective Clothing”, the sample washing methods of warning clothing are more diverse, allowing customers to choose by themselves according to different material properties, according to relevant washing standards, and make relevant marks and instructions on the product manual.  When testing institutions conduct tests, washing treatment should be carried out in accordance with the washing method recommended by the warning clothing manufacturer as far as possible.  Considering that there may be industrial washing methods for warning clothing in practical application, GB 20653-2020 “High Visibility Warning Clothing for Occupational Use of Protective Clothing” has added industrial washing methods and the arrangement of reflective tape during industrial washing (as an information appendix D).  In the part of washing and dry cleaning pretreatment, gb20653-2020 “High Visibility Warning Clothing for Occupational Use of Protective Clothing” has updated the washing standard and corresponding procedures according to the actual domestic application.  At the same time, considering the particularity of some warning clothing fabrics, there may be some special requirements on washing, therefore, according to ISO 20471:2013 “Warning Reflective Clothing: Test Methods and Requirements standard”,  GB 20653-2020 “High Visibility Warning Clothing for Occupational Use of Protective Clothing” stipulates that the cleaning method shall be carried out in accordance with the method recommended by the manufacturer (e.g. GB/T 19981.2-2014 “Professional Maintenance, Dry cleaning and Wet Washing of Textile Fabrics and Clothing part 2:  GB/T 8629-2017 “Household Washing and Drying Procedures for Textile Testing”, ISO 15797:2004 “Textile Materials. Industrial Washing and Finishing Procedures for Garment Testing” or other equivalent methods).  If the cleaning procedure is not clear, when the care label indicates that the warning clothing is suitable for washing, the procedure specified in GB/T 8629-2017 Household Washing and Drying Procedure for Textile Tests shall be carried out, and a complete washing cycle shall include washing and drying;  When the care label indicates that the warning clothing is suitable for dry cleaning, the procedures specified in GB/T 19981.2-2014 “Procedures for Professional Maintenance, Dry Cleaning and Wetting of Textile Fabrics and Garments” shall be applied.  

Compared with the previous version of the standard, the new standard is more clear on washing and dry cleaning, and the number of cleaning has been specified.  If the manufacturer does not declare, it shall be cleaned for 15 times.  In addition, terms and definitions of GB 20653-2020 High Visibility Warning Clothing for Occupational Use of Protective Clothing have also been partially improved.  Gb20653-2006 High Visibility Warning Clothing for Occupational Use terms and definitions of several materials and clothing (such as high visibility warning clothing, fluorescent materials, base materials, etc.) are not directly and clearly related to each other.  GB 20653-2020 High Visibility Warning Clothing for Occupational Use is modified and improved based on international standards such as ISO standard and ASTM and gb20653-2006 High Visibility Warning Clothing for Occupational Use by implementing feedback, making it more clear, definite, easy to understand and clear boundaries between various materials.  For example, for “high visibility police  

The garment is clearly defined as “specially designed and manufactured using fluorescent and reflective materials” and is further stated to be suitable for “high-risk environments with poor visibility” to distinguish it from the “medium and low risk” environment in Appendix F, “Environmental Risk Levels and Guidance for Apparel Design of Visibility”.  At the same time, the term and definition of “non-fluorescent material” are added for the non-fluorescent material and non-reflective material that may exist on the high visibility warning clothing, and the complete concept of several materials of high visibility warning clothing is given before the standard technical content, which is easy to understand the standard text.  In addition, to facilitate the understanding of reflective materials, reference  

The existing standard (JT/T 688-2007 Terms of Retroreflection) introduces the term of “retroreflection”, and standardized and unified the relevant terms and definitions in appendix C of the previous version of the standard, so that there will be no disagreement or inconsistency in the application process.