AntistaticcoverallIt is applicable to petroleum, petrochemical, chemical, refining and other industries and has the ability to prevent electrostatic accumulationSpecial work clothes。It is a kind of work clothes sewn according to the specified style and structure with anti-static fabric as the fabric to prevent the accumulation of static electricity on the clothes.(GB12014-2009Anti static clothing, 3.1 Definition of anti-static clothing)
Anti static fabric is made by mixingConductive fibreSpinned yarn or embedded conductiveFilament weavingThe formed fabric can also be treated with anti-static properties.(GB12014-2009 anti-static clothing, 3.2 definition of anti-static fabric)
Anti static clothing (GB12014-2009) is defined as anti-static work clothes suitable for use in places where electrostatic accumulation may cause electric shock, fire and explosion.[1]
Chinese name
Antistatic clothing
Scope of application
Petroleum industry, mining and metallurgy industry, chemical industry
Anti static work clothes are used to preventElectrostatic accumulation, work clothes made of anti-static fabric.Antistatic fabric is mixed in at roughly equal intervals or evenly during spinningConductive fibreOr anti-staticSynthetic fibreOr a fabric mixed and interwoven by both.Conductive fiber refers to the use of metal ororganic compoundOfConductive materialOr fibers made of sub conductive materialsVolume resistivityρ v~is between 104~109 Ω/cm.According to the distribution of conductive components in the fibers, conductive fibers can be divided into three types: uniform conductive components, conductive components covered and conductive components composite.
staychemical fiberAntistatic work clothes made by adding conductive fiber into the fabricPower extinctionIt is based on two mechanisms of charge leakage and neutralization.When grounded, the static electricity on the fabric will be removed from the conductive fibercorona discharge In addition to being neutralized, it can also go to the ground through conductive fiberDischarge；When it is not grounded, the weak corona discharge of conductive fiber is used to eliminate electricity.
Super clean fabric
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ESD Garments
Anti static for anti-static work clothesUltracleanFabric is often called "conductive silk".In fact, this statement is not strict. According to its own technical characteristics, conductive silk can be divided into anti-static (ESD)Clean Room(Clean Room), only conductive silk suitable for clean rooms can be called anti-static super clean fabric.What isAnti static fabric？The fabric after anti-static processing can be called anti-static fabric.The anti-static processing methods of fabrics usually include:
① The fabric is treated with antistatic finishing agent;
The mechanism of the first two methods is to improve the fabricregain, LowerInsulation, AccelerationElectrostatic leakage。So if youDry environmentThe processing effect is not durable or significant, and is usually applied to ordinary clothing fabrics.Only the third method can solve the electrostatic problem of textiles in a lasting and efficient manner, so it is widely used in the production of anti-static work clothes.The fabric is treated with antistatic finishing agent.
Anti static fabricIt can be woven fabric, such as conductive silk, anti-staticT/C fabric, orKnitted fabric, such as anti-static knitted glove cloth, anti-staticKnitted underwearEtc.The anti-static fabric must conform to the general use of textilestechnical standardIn addition, it must have good anti-static performance to meet the needs of product production and safety.For technical requirements, please refer to GB12059-89 Performance of Antistatic Synthetic Fiber Silk Fabric for Electronic Industry
The difference between anti-static super clean fabric and ordinary anti-static fabric mainly lies in the concept of "super clean".The anti-static super clean fabric must have the following three characteristics at the same time:
Anti static function: static electricity will absorb dust, and make the absorbed dustWind drenchingIt is not easy to be blown away.Therefore, the primary feature of anti-static super clean fabric is its anti-static performance.At the same time, this anti-static property must be durable and efficient, and will not be significantly weakened due to daily washing and friction.
The fabric itself does not generate dust: since it is worn in the clean room, it is required that the fabric should not become a source of dust in the clean room, which determines that the super clean fabric can only be chemically synthesizedLong fibreTo produce.But cotton, linen, silk and other naturalShort fibreIt cannot be applied to super clean fabrics, although these materials can make the fabrics more wearable.At the same time, the selectedchemical filament The amount of dust generated should also be strictly controlled.Generally speaking,Total extinctionPolyester filamentIt is not suitable for weaving anti-static super clean fabrics.Because the polyester productionMatting agent—Titanium dioxideWill becomePollution source。
The fabric should have good dust filtering property: the dust in the clean room mainly comes from the indoor flowing air and the indoor human body.When the equipment conditions are determined, improving the cleanliness means that the tiny dust generated by the human body should be controlled in the clothes to the maximum extent, so that it can pass through the fabric and enter the air.This is the so-called high dust filtration rate of fabrics.Improving the dust filtration rate is at the expense of the fabricAir permeabilityAt a cost, soKnitted fabricLoosely woven fabrics are not suitable for clean rooms.
Because our country has not formulated the corresponding super clean fabric orClean clothesTherefore, the selection of anti-static super clean fabrics can only be made by the application units according to the requirements of the operating environment or after testing or experience.A competent user can spend hundreds of thousands to purchase a complete set of equipment. In an environment with the same cleanliness as the actual application environmentISO StandardsTest each batch of clean clothes.Most users can only choose by experience (including others' experience).To learn how to choose super clean fabrics correctly, you must first understand some basic knowledge about fabrics.
Woven fabric is made up of yarns in warp and weft directions with specific arrangement densityorganization structureIt is interwoven.Generally speaking, it refers to what materials are used, how many rows are tight, and what patterns are woven.In order to weave anti-static super clean fabric, you must also addConductive fibre。Here, yarn, (warp and weft) arrangement densityFabric weaveAnd conductive fiber are the four elements of anti-static super clean fabric.Choosing anti-static super clean fabric is to compare the four elements of fabric according to the cleanliness requirements of the operating environment.
If the resistance is the same, select the one with stable resistance value;
Pay attention to whether the fabric is added during finishingAntistatic agent(Applicable to only longitudinal additionConductive fibreConductive silk, commonly known asStriped cloth）The method is to use the surface resistance tester to measure the longitudinal and latitudinal resistance respectively. If the resistance is the same, it means that the antistatic agent is added, then the measured resistance does not represent the true level.
seeMicrostructure: Use a high-power magnifying glass to see the cloth surface quality, compare the gap size between the fibers (related to the dust filtering rate), and see whether there isAttachment(Related to the amount of hair dust), check whether the fibers are arranged neatly and tight (for example, if the tightness is inconsistent, some fibers that are loose during wearing and washing are easy to abrade, and will be dusty when wearing later).
inspectConductive fibre: Conductive fiber is the key raw material in anti-static super clean fabric. Checking conductive fiber is to see whether conductive fiber is added according to specifications and what kind of conductive fiber is added.
The inspection method is: use scissors to carefully cut the fabric along the edge of the black conductive fiber, and separate the black conductive fibermagnifierObserve whether there is one or several relatively thick fibers, and useSurface resistance testerMeasure the resistance of the separated conductive fiber.Take out several pieces in succession, and you can basically judge each piece of fabricBlack silkWhether they all contain conductive fibers.(The conductive silk is carbon organic conductive fiber, which is black or gray, generally about 20D, between 1F and 6F. In order to meet the strength requirements when weaving, it is necessary to combine a common black or whitePolyester fibre）。
1. All clothes shall be made of anti-static fabric, and lining is generally not used.When the lining must be used, the exposed area of the lining shall not exceed 20% of the inside area of all clothing.
Anti static coat (blue)
2. According to the static electricity of different processing objects in different placesSensitivity, different grades ofAntistatic clothAnd anti-static work clothes.
3. The washing of work clothes should be carried out in a simple way as far as possible, and the work clothes should not be washed by strong mechanical and chemical operations.
4. It is forbidden to attach or wear any metal objects on the anti-static work clothes.
5. It is not allowed to put on or take off work clothes at the site where electrostatic sensitive products are operated (the work clothes shall beLocker RoomChange clothes).All buttons of the work clothes shall be buttoned up, and the work clothes shall not be in a state close to undressing.
6. Several pieces of anti-static overalls purchased in batches shall be randomly selected to test the charge before wearing.After a certain period of wearing, especially when the wearer feels electric shock when undressing, the retest shall be carried out.
Performance test
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1. Purification performance test For the pollution particles attached inside and outside the clothing of anti-static work clothes used in the clean room, the following four methods are used to determine:ASTMF-51 method (microscope method), F-51 repairsEvidence method（Counting method），HELMKERotating drum method(Roller method, equivalent to ASTM test method) andvibration test Method (vibration method).
(1) ASTM-F-51 method (microscope method) test probe is equipped with filter diaphragm,Direct connectionThe air flow through the suction metering pump is 28L/min.During the test, the air passes through the test cloth, the hair dust particles contained in the air are captured on the filter membrane for the test, and the dust is observed and counted with a 400 times microscopeNumber of particles。 Read 0.5-5 and more than 5 particles on the filter membrane.A 3.08mm grid is printed on the filter membrane to read the number of particles in a grid.
(2) ASTM-F-51 revised method (counting method) is used to make air pass through the test clothParticle counterDetermine the size and number of dust particles.Place the sample on the beltMetal meshOn the bench of, usesampler (replaced by a 47mm filter bracket) contact suction, and the amount of air passing through is 28L/min.
（3）Barrel rollingHelmke Drum TestInternal rotation, sample dust particles from the grain bucketParticle counterDetermined after measuring the number of particlesCleanlinessLevel of.The size of the rotating drum is 43cm × 33cm, there are 4 blades on the inside of the barrel, and the number of revolutions of the barrel is 10 rpm.
(4) The vibration method puts the sample in the chamber, produces particles through vibration and torsion, and uses the particle counter to measure.At the same time, the particles with large size (more than 25) are trapped on the filter membrane and the number of particles is read out.The air volume is 3.5 feet/minute (0.099 m/mim), and the vibration frequency is 150 times/minute.
At present, ChinaClean work clothesDust freeperformance testing Not yetnational standard, refer to Japan AirClean AssociationJapanese industrial standards studied by special committeesJIS-B-9923, and American IES standard RP-CC-003-87-T.For the evaluation of dust-free performance, various industries caninternational standardAccording to ISO/TC209Clean workshopStandards, which are used in combination with their respective cleanliness levels.
Antistatic performance testing Antistatic performance is an important characteristic of anti-static work clothes, especially inmicroelectronicsSuch industries have more stringent requirements on the anti-static performance of clothing.test methodCan be based onNational Standards of the People's Republic of ChinaGB/T12703-91 Test Method for Static Electricity of Textiles, because the cloth used for clean work clothes is polyester woven with conductive wiresFilament fabricTherefore, only triboelectrification voltage (method B), charge surface density (method C) and triboelectrification of work clothes (method E) in this standard are suitable for anti-static performance testing of clean work clothes.In addition, it can also refer to the national standard of the People's Republic of China GB/T12059-89 Performance and Test Methods of Synthetic Fiber Antistatic Silk Fabric for Electronic Industry.
(1) Friction electrification voltage method The test principle of this method is to make the sample rub with the standard cloth under a certain tension condition, and the maximum voltage andAverage voltageEvaluate the friction electrification relationship between the wearer and the coat.The method is to clamp 4 samples (2 warp and 2 weft, size 4cm × 8cm)drum(outer diameter 150 ± 1mm, width 60 ± 1mm)（nylonorPolypropylene）Friction, test the charged voltage of the sample within 1minMaximum（V）。
(2) Charge surface density methodlay down a conditionUsed after rubbing with nylon standard cloth in a specific wayFaraday cylinderTest its charge, that is, charge surface density.
Selection
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（1） Technology and performance of anti-static work clothes
Relevant technologies andperformance index For details, please refer to the national standard Anti static Work Clothes (GB 12014-1989).
（2） Use and management of anti-static overalls
The anti-static work clothes are not always worn. If they are not worn properly or washed for many times, their electrostatic conductive function may be reduced and cannot meet the safety requirements. Therefore, the following items should be noted when wearing and keeping them:
(1) All clothes shall be made of anti-static fabric, and lining is generally not used.When the lining must be used, the exposure of the lining shall not exceed 20% of the inside area of the whole clothing.
(2) Different grades of anti-static cloth and anti-static work clothes shall be selected according to the electrostatic sensitivity of different processing objects in different places.
(3) It is forbidden to attach or wear any metal objects on the anti-static work clothes.
(4) It is not allowed to put on or take off work clothes at the site where electrostatic sensitive products are operated (it should be changed in the designated changing room).All buttons of the work clothes shall be buttoned up, and the work clothes shall not be in a state close to undressing.
(5) The work clothes should be washed in a simple way as far as possible, either machine wash or hand wash, and the water temperature should be 30-600 ℃coverallThe immersion time should not exceed 3h when washed by strong mechanical and chemical operations.
(7) Several pieces of anti-static overalls purchased in batches shall be randomly selected to test the charge before wearing.After a certain period of wearing, especially when the wearer feels electric shock when undressing, the retest shall be carried out.
(8) WearingAnti static clothingMust be consistent with that specified in GB 4385Anti static shoesWear it together.Wear anti-static shoesConductive shoeShould not wear insulatedWoolThick socks and insulated insoles.The place where anti-static shoes are used should beAnti static floorThe place where conductive shoes are used shall be conductive ground.In addition, the resistance test shall be carried out once during the threading process, generally not more than 200h.
(9) Anti static work clothes must be strictly in accordance with labor protection articlesLife cycleReplace it to prevent its anti-static function from weakening after repeated washing and failing to meet the requirements.The specific requirements are: the first configuration is for each personSpring 2 setssummer wear2 setswinter clothes1 set, 1 pair of summer shoes, 1 pair of winter shoes, 2 summer hats and 2 autumn hats.Replace the anti-static work clothes andWork shoesFor example, 1 set of spring and autumn clothing is replaced every two years, 1 set of summer clothing is replaced every year, 1 set of winter clothing is replaced every four years, 1 pair of summer shoes is replaced every year, and 2 sets of summer hats are replaced every two years.
Choose anti-static work clothes with certain anti-static performanceDurabilityTherefore, the selection of anti-static work clothes should also be based onWorkplaceThe appropriate anti-static work clothes shall be selected according to the washing requirements determined by the pollution of.
Anti static work clothes are used in fire and explosion places, so anti static work clothes with flame retardancy should be selected to provide more reliable protection for workers.Anti static work clothes used by gas station operators and similar types of work should also be oil proof.
CottonThe made work clothes have the effect of preventing static electricity, but may not meet the requirement that the charged charge of a single garment required by the anti-static work clothes is less than 0.6 μ C. Especially after washing, due to the selection of detergent and other reasons, the effect of preventing static electricity will declineCotton fabricThe anti-static work clothes made must be careful, especially in dry areas in the north.
Quality verification
When selecting anti-static overalls, you should ask the supplier for a test report and check the test reportProduct characteristics, production batchdate of manufacture, and theswatch Whether it is consistent with the supplied products.Since the structure of anti-static overalls is closely related to their anti-static effects, attention should be paid to the following when checking the ordered anti-static overalls:
1. Buttons, zippers, hooks, trips and other accessories of work clothes should preferably be made of plastic, nylon and other non-metallic materials.If you chooseMetal accessoriesTry it on to ensure that the metal accessories are not exposed when wearing and engaging in various activities.
2. Look at the back of the work clothes, pockets, welts, reinforcement cloth, etc., and it is better to use the same anti-static fabric;useOther materialsThe exposed area shall be less than allAnti static clothingLess than 20% of the exposed area.
3. Made for cold protection and warmth preservation or other special requirementsCottonThe cotton inner sleeve and full lining of full lining work clothes shall be detachable.
4. Check the anti-static fabric. For the same type of conductive fiber, the higher the density, the better its anti-static performance.
national standard
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Standard scope
This standard specifiesAnti static clothingOftechnical requirement, test methods, inspection rules, identification, etc.This standard is applicable to electric shock, fire andExplosion hazardous areaWear anti-static clothing.The anti-static clothing defined in this standard is not applicable to anti power voltage.Standard No:GB12014-2009 ChineseStandard name: Anti static clothing (instead ofStandard No: GB 12014-1989 Anti static Clothing)
Definition of terms
The following terms and definitions are applicable to this standard.Anti static clothingelectrostatic accumulation , work clothes made of anti-static fabric according to the specified style and structure.The antistatic fabric shall be blended intoConductive fibreThe spun yarn or woven fabric embedded with conductive filament can also be treated fabric with anti-static property.Conductive fiber is made of conductive material of metal or organic matter or electrostatic dissipative material in whole or in part.Static Dissipative Materials Surface resistivityMaterials larger than or equal to 1 × 10 ^ 5 ohm, but smaller than 1 × 10 ^ 11 ohm.The surface resistivity characterizes the surface conductivity of objectsphysical quantity。Point to point resistance is applied between two electrodes on the material surface within a given timeDC voltageAnd theDC currentRatio.
technical requirement
(1) Fabric: - Appearance quality: the fabric shall be free of damage, spots, dirt or other defects that affect the anti-static performance of the fabric-Test parameters: the fabric is tested by point-to-point resistance method, and the technical parameters are shown in the table below.
Test items
technical requirement
Grade A
Level B
Point to point resistance/Ω
1 x 105---- 1 x 107
1 x 107---- 1 x 1011
(2) Clothing: - Appearance quality: there should be no damage, spots, dirt and other defects that affect the wearing performance-Structural style:Clothing structureIt shall be safe and sanitary, which is conducive to the normal physiological requirements and health of Japanese people;Clothing shall be easy to wear and take off and adapt to physical activities during operation;Clothing styleIt shall be concise and used.According to the use requirements-Sewing: the sewing line of each part is straight, neat, flat and firm.The upper and lower tightness shall be appropriate, and there shall be no needle skipping, and there shall beRetuned needle-Test parameters: anti-static clothing is chargedCharge quantitySee the following table for the technical parameters of the method test.
Test items
technical requirement
Grade A
Level B
Charged charge/(μ C piece)
<0.20
0.20 ---- 0.60
(3) Washing:Anti static clothingAnd fabrics must be washed as required before testing.
curing
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Packaging, storage and transportation
During transportation, it shall be noted that the anti-static work clothes must be covered, and the package shall not be damaged to prevent exposure to the sun and high temperature;It is strictly prohibited to useHand hookDrag.
Anti static work clothes should be stored in a dry and ventilated warehouse to prevent mildew and deterioration.When storing, keep away from the ground and wall for more than 200mm, and leave everythingfeverMore than 1m.Avoid direct sunlight and do not place in the open.
Anti static overalls are best usedNeutral detergentWhen washing, do not mix with other clothes. Use hand washing or washing machine soft washing procedures to avoid conductive fiber breakage.The washing water temperature should be below 40 ℃ for rinsingNormal temperature clean water。Washing timeAs short as possible, but must be fully rinsed to remove residual detergent.Do not use anti-static overalls with flame retardant and oil resistant propertiesbleaching powder、Organic solventDecontamination.
Cleaning specification
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(1) Newly sewnClean work clothesIt can be washed directly. If oil stains are found on the recycled clean work clothes, they should be carefully removed before washing.
(2) Scratches, damages andBuckleetc.AccessoriesInspect and repair, replace or scrap the defective ones.
(3) Must be used in theClean RoomClean, dry and pack in a clean room with high cleanliness.
(4) Wet typeDry cleaningThe water used should be filtered, and the solvent should also be distilled and used less than 0.2 at the point of useμmThe pore size of the filter membrane can be filtered more than once as required.
(5) To removeWater solubilityAfter the pollutants are washed with clean water, the final washing is carried out with solvent to remove oily pollutants.
After drying, it shall be folded in the clean room dedicated for washing and put into a clean polyester bag or bone bag. According to the requirements, it can be double-layer packaging or vacuum plastic packaging. The packaging material should preferably be the material with good anti-static property.Because the folding process is most prone to dust, the folding process must be carried out in a high-level purification space.
Wear attention
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1. Anti static work clothes must comply with the requirements of GB4385Anti static shoesWear it together.
2. Prohibited inAnti static clothingAttach or wear any metal objects.Tools that need to be carried should be anti-static and antistaticelectric sparkFunction;Metal tools shall be placed in the anti-static work clothes, and metal parts shall not be exposed.
4. Zaiqiangelectromagnetic environment Anti static work clothes shall not be worn in areas with high-voltage bare wires nearby.
service life
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The anti-static work clothes are damaged and the suture is brokenMildewIf the conductive fiber is broken, or the washing resistance time specified by the anti-static grade has been reached, it shall be scrapped in time.The user unit shall sample and submit for inspection the anti-static work clothes whose service life reaches half of the service life or the storage life reaches one year. The products whose anti-static performance is lost after detection shall be scrapped in a timely manner in a whole batch to ensure the qualified use of the products.
Mainly used in factory industries such as electronic communication, ESD product manufacturing, assembly workshops andComputer Room, protect the product from damage and prevent the instrument fromElectrostatic interferencecauseMisoperation。
It is mainly used in electronics, medicine, food, bioengineering, etcproduction environment In addition to the above b anti-static functions, it can also avoid the entry of micro dust due to electrostatic dust collection or shielding human bodyworking space, Impactproduct quality。
