How to specify medical device assembly gloves without buying the wrong cleanroom product: filament yarns, 13 to 18 gauge liners, PU coatings, ESD test methods, inner-bag controls, AQL inspection and honest factory limits.
Start With the Device Risk, Not a Glove Catalogue
Medical device assembly gloves should be specified from the component risk, not from a glove catalogue page. A line clipping together non-sterile plastic housings, tubing sets, diagnostic cartridges or pouch packs usually needs low lint, good fingertip feel, clean packing and traceable lots. That is not the same job as a sterile surgical glove, and it is not always the same as an ISO Class 5 cleanroom glove. If operators touch implant parts, fluid-path components after final cleaning, optical windows or sterile barrier contact surfaces, the glove must be qualified inside the buyer's contamination control plan, alongside wipes, trays and bags under ISO 14644-1, ISO 14644-5 and the site's bioburden rules. In factory quotation work we split these requests into 3 practical groups. The first is controlled handling: 13, 15 or 18 gauge white or grey nylon 6, nylon 66 or polyester filament liners with PU fingertip or PU palm coating. The second is ESD-sensitive assembly: usually 15 gauge nylon plus carbon conductive yarn, with PU coating and test requirements such as EN 16350 or ANSI/ESD STM11.11. The third is true cleanroom or sterile consumable supply: washed, particle-tested, double-bagged or sterilised gloves with documented cleanroom packing. GloveMark can manufacture low-lint knitted PU and ESD PU gloves and pack them with lot control. We do not claim a normal knit-and-dip line in Yiwu is a validated sterile cleanroom glove plant.
Low Lint Starts With Filament Yarn and Controlled Coating
Lint is not fixed by printing low lint on a polybag. It starts with the liner yarn. Spun cotton inspection gloves are soft and cheap, but loose cotton fibre is a poor choice around adhesive windows, small seals, transparent housings and optical sensor areas. Continuous filament nylon 6, nylon 66 or polyester sheds less because the yarn is not made from short fibres twisted together. For most assembly benches, 15 gauge is the balance point: thin enough for 2 to 4 mm clips and O-rings, stronger than many 18 gauge styles, and less bulky than 13 gauge. Use 18 gauge only when dexterity is more important than abrasion life. Use 13 gauge when operators handle larger trays, metal fixtures or carton work. Coating choice also changes lint risk. Uncoated knit fingertips can leave fibre on textured ABS, PC, PP or silicone parts. PU fingertip coating gives the cleanest touch where operators handle small components and need less sweat buildup. PU palm coating improves grip on trays, pouches and cartons but adds more coated area. Nitrile micro-foam grips oily metal better, but the open foam texture can hold dust after reuse, so we do not push it for clean medical benches unless the process has oil or coolant residue. During sampling, add a simple shop-floor lint screen: rub 5 glove fingertips for 10 strokes on black acrylic, clean glass or the actual component, then compare against the approved sample under fixed lighting. It is not IEST-RP-CC005 particle testing, but it catches bad yarn, dirty dipping lines and careless packing before bulk production.
ESD Gloves Only Work Inside an ESD System
ESD medical device assembly gloves are useful for diagnostic readers, sensor modules, pumps, battery packs, flex circuits and PCB-loaded subassemblies. The glove alone does not make a station safe. Operators still need grounded wrist straps or footwear, ESD mats, controlled carts, correct ionisation where needed and humidity control. If the bench, floor and operator are not grounded, a carbon-striped glove becomes a visual comfort item, not a control measure. The common construction is 15 gauge nylon knitted with carbon conductive yarn, usually visible as black or grey stripes at 5 to 10 mm spacing, then coated with PU on the palm or fingertips. The black stripe is not proof. Put the test method on the purchase order. EN 16350 is often requested for protective gloves used where electrostatic properties matter; it sets vertical resistance below 1.0 x 10^8 ohms under defined conditions. Electronics teams may instead request ANSI/ESD STM11.11 surface resistance, often with a buyer range such as 10^6 to 10^9 ohms. Some factories quote ESD from an old internal meter reading with no conditioning. That is not enough for a regulated device line. Coating layout matters. A thick full palm PU layer can reduce practical discharge through the working fingertip, especially when the conductive yarn is buried under coating. For small circuit handling, many buyers choose PU fingertip coating or a thin palm dip rather than a heavy coated palm. Ask for readings from the liner area and the coated contact area, and test after conditioning because humidity can change results. If you require EN 61340-5-1 compliance at the line level, state that separately from the glove item.
Packing Controls Prevent Most Avoidable Complaints
Many rejections on medical device assembly gloves are not about the PU formula. They are loose threads, carton dust, mixed sizes, oil marks from handling, unsealed inner bags or wrong lot codes. For controlled handling, bulk loose packing is risky. A practical packing format is 10 pairs per PE inner bag, 100 pairs or 200 pairs per export carton, with size, item code, lot code and quantity printed on each inner bag. Individual pair bags are useful when one operator takes one pair into a controlled station, but they add cost, plastic waste and packing time. Do not bring export cartons into a clean or controlled side unless the site's SOP allows it. Cartons pick up dust during palletising, container loading and warehouse storage. The cleaner method is to open cartons outside, wipe or transfer sealed inner bags, then issue gloves by batch. If the buyer needs double-bagging, specify inner bag material thickness, for example 0.04 to 0.06 mm PE, seal type, label position and whether the outer bag must carry the same lot code. A useful lot code should trace knitting date, yarn lot, dipping line, curing shift and packing batch. A real batch may be knitted over 3 to 5 days, dipped through one PU line, cured in a tunnel oven, then packed 2 days later. If a customer reports tacky PU, fibre shedding or size mixing, that code lets us isolate curing temperature, packing table contamination or operator error. For pre-shipment inspection, many importers use ANSI/ASQ Z1.4 or ISO 2859-1, commonly AQL 2.5 for major defects and 4.0 for minor defects. For this category, add special checks for foreign matter inside inner bags, coating transfer, open seams at fingertips and size marking accuracy.
Colour and Branding Must Not Add Contamination
White gloves are common because dirt shows quickly, but white also creates false complaints when cartons, pallets or warehouse benches are dusty. Grey nylon hides minor transit marks while still looking controlled. Blue can help visual control because fibres or glove pieces stand out against white trays or clear parts. Do not assume blue means detectable. Normal nylon PU gloves are not metal detectable unless a detectable yarn or insert system is specified and validated by the buyer's detection equipment. Branding should stay away from the working surface. Heat transfers, silicone grip prints and large ink logos can crack, rub off or change grip after repeated flexing. For medical device assembly gloves, we prefer no decoration on the palm and fingertips. If private label is needed, use printed inner bags, carton labels or a small woven cuff label that does not touch the component. Any cuff label should be checked for loose yarn ends and edge fray. Do not print ink across the back of the hand unless rub-off has been checked by a dry and wet crocking test or the buyer's own wipe test. Size control is better done with cuff overlock colours and bag marking. A common sequence is white for S, green for M, brown for L and black for XL, but we will follow the buyer's SOP if it is already used on site. Custom liner colour, private bag printing or non-standard size ratio normally needs 3,000 to 5,000 pairs per size. Stock white 15 gauge PU fingertip or PU palm styles can sometimes be sampled and trialled at lower quantities, but custom yarn dyeing, carbon yarn layouts and special bags cannot be run economically at a few hundred pairs.
Specify the Factory Limits Before You Issue the PO
GloveMark's suitable range for medical device assembly gloves is knitted nylon, polyester and nylon-carbon liners in 13, 15 and selected 18 gauge, with PU fingertip, PU palm or light nitrile coating. We can control yarn selection, knitting gauge, dipping coverage, curing, size sorting, inner-bag packing, carton labelling and pre-shipment inspection. Standard sample development is usually 7 to 12 days when yarn and coating are available. Bulk lead time is normally 4 to 7 weeks after sample approval and packaging artwork confirmation. If the order uses custom dyed filament yarn, carbon yarn spacing or double-bagged private label packing, allow extra time before production booking. Commercially, FOB Ningbo or FOB Shanghai is the cleanest Incoterm for most importers because the buyer controls freight, insurance and destination compliance. EXW Yiwu is possible but usually inconvenient for overseas buyers. DDP can be arranged through freight partners for some markets, but the buyer must still confirm PPE classification, medical device accessory status if claimed, import duty code and local labelling rules. A 40 ft high cube container can hold a large quantity of light PU gloves, but most first orders ship by LCL or air carton because size trials and line approval matter more than container efficiency. We should not be treated as the direct source for sterile surgical gloves, chemo-rated disposable gloves, validated ISO Class 4 cleanroom gloves, endotoxin-controlled gloves or gamma-sterilised packed gloves unless the project is routed through a specialised partner with the correct cleanroom, sterilisation and test documents. If your RFQ needs extractables, non-volatile residue, ion content, endotoxin limits, sterility assurance level or USP testing, state it before sampling. If the real need is controlled handling of non-sterile components, a well-specified 15 gauge low-lint PU or ESD PU glove is often the more honest, lower-cost answer. Approve it with fit trials by size, fingertip shedding check, grip on the actual component, ESD readings where required and one carton-level packing inspection before mass production release.
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