What is an Antistatic bag?
An antistatic bag is a shipping bag for electronic devices which can be damaged by electrostatic discharge. Static travels around the bag and dissipates before it has a chance to damage contents when shipping or storing. These plastic bags have a distinctive color (silvery for metalized Mylar and other similar plastics, pink or black for polyethylene). The polyethene bags may also take the form of foam or bubble wrap, either as sheets or bags.
How anti-static bags are made
Traditionally, static-shielding bags are manufactured by depositing a thin metal coating such as aluminum over an antistatic polyester film substrate. The metallized layer protects the devices in the bag from electrostatic fields; the insulative layers prevent direct contact with potential ESD hazards. At the low end are amine-free, polyethylene film bags that are transparent or pink in color, referred to as antistatic or pink poly.
Types of Antistatic bags
Flat Anti-Static Poly Bags
Protect electronic components from static build-up. Constructed from pink anti-static polyethylene film that keeps products clean and moisture free. Normal static protection where Faraday Cage protection is not required. 4 and 6 mil bags meet full static decay requirements of MIL-PRF-81 705D Type II and also EIA-541. These transparent pink bags are good for easy identification and are also wrinkle resistant bags.
Gripseal Antistatic bags
The same properties as the flat Pink Poly Bag plus the security and convenience of a zipper top. The zipper top closes securely to protect against damage from dust and moisture.
Anti-Static Bubble Bags
Anti-Static Bubble Bags that provides excellent protection against static discharge for circuit boards, relays, switches, resistors, controls and other static sensitive electronic components. Industrial bubble coated with a nylon barrier provides outstanding cushioning. Pressure sensitive lip covered with release paper allows for easy closing.
Anti-Static Poly Tubing
Make your own anti-static poly bags. Excellent resistance to static discharge. Static dissipative, non-corrosive pink polyethylene is heat sealable. Seal with Poly Tubing Sealers.
How to measure Zipper Anti-Static Bags?
Benefits of Anti Static Bags
- Simple design and construction
- Low cost
- Eliminates the problems of static damage and prevents the generation of static electricity
- Antistatic agent or material on/in film
- Surface resistance is less than 1012 ohms/sq.
- Perfect for packging, storing and shipping non-sensitive and sensitive electronic components and easy to indentify
Question & Answer about Anti Static Bags
Question. I have two questions about one material. Anti-stat bags.
1. How effective are anti-stat bags with a relative humidity of less than 20 % and temperatures as high as 110 degrees Fahrenheit.
2. How do you put a spec on an anti-stat (ohms/sq. etc.) bag to ensure maximum protection and re-use?
Answer.The clear static dissipative polyethylene (PE) that high quality vendors use in their bags is far superior than the "topically treated washed" pink poly products.
1. perform a resistance test on the bag film to < 1x10^11 ohms @100 volts [using two five pound electrodes and megohmeter per esd s11.31-1994 and esd ds20.20-1998]
2. perform a tribocharge test, yielding static decay of less than or equal to 140 milliseconds, per FTMS 101C, Method 4046
Question. What is the recommendation or guidelines in determining when Anti Static shielded bags are no longer any good, i.e. crinkled or have small puncture holes, and put out of service?
Answer.All your answers are in the MIL-B-81705C Standard document. Specifically, an anti-static shielding bag (type III) wouldn't be good if it meets any of the following conditions:
- the bag delaminates as defined in section 18.104.22.168 in MIL-B-81705C
- has a static decay rate exceeding 2.0 seconds
- does not attenuate EMI at least 10 dB
- punctures over 6.0 lbs
- doesn't shield an ESD event under 30 kilovolts
- and has a surface resistivity greater than 1x10^12 ohms/sq both inside and out and less than 1x10^5 ohms/sq on the inside.
Generally a shielding bag might still shield if it has crinkled or has small holes because of the Faraday effect, but it is safer to discard these bags and be incorrect on the conservative side. It costs more to test and qualify the bag then to replace it.
Because we mentioned antistatic grip seal bags and antistatic bubble bags we thought these websites to be useful for more information about each of the bags.
Please visit www.resealable-bags.co.uk for grip seal bags.
Please visit www.discountbubblebags.co.uk for bubble bags.