What is a static shielding bag?
A static shielding bag is a bag made of polyethylene terephthalate (PET) material. It is like a plastic bag, but its shape may take a bubble-wrapped or a foam look. Based on the content packed in the bag, the static bag may be silver, pink or black. Static shielding bags are designed using the Faraday Cage principle that eliminates non-static electric fields. Additionally, the bag has a thick layer to protect the equipment from mechanical damage. The static shielding bag is also known as an anti-static bag.
Why do we use antistatic bag?
You have probably bought electronic and wondered why it had been wrapped with a static bag. A lot of electronics are delicate and stand a chance to be destroyed by electrostatic discharges. The static electricity can make the electronics useless by causing major damage to microprocessors or the component’s internal circuitry.
The most common factor that causes the build-up of static electricity is tribocharging. The latter can be defined as a form of contact electrification, where materials get charged by coming into frictional contact with other materials.
Static bags are, therefore, critical in ensuring the components are not destroyed. The Dissipative anti-static bags and Static-Shielding bags are the most common static shielding bags although most people refer to them in one category of “Anti-static bag.”
Dissipative anti-static bags
The dissipative bag is mainly made of pink or black polyethylene plastic material. Polyethylene plastic does not hold or create any form of charges meaning if anything external rubs against the contents in the bag, the tribocharging effect does not occur. Therefore, no static charge occurs. In the transport of products the polyethylene plastic bag isn’t only used as a bag but to also create a poly-foam or polyethylene bubble wrap for additional protection of the packaging.
Although these bags are perfect in the prevention of static building, they do not protect the equipment from direct static discharge. They are, therefore, only used for components that are not affected by static discharges but could be brought in an environment where static build-up discharge could affect more sensitive components.
These bags are heavier and bulkier than the dissipative anti-static bags as they have multiple layers of different materials. Static-Shielding bags cause a Faraday cage effect for the electronics inside them. As a result, the products are completely protected from building up static electricity and a direct electrostatic discharge. The bags are, therefore, used to carry sensitive products that could be destroyed by electrostatic discharge.
The first layer of the bags is created using dissipative polyethylene plastic similar to those of dissipative anti-static bags. This prevents a build-up of static electricity that could result in the movement of products in the bag, as well as provide them with a comfortable surface to sit on. The second layer is made of aluminium which forms a protective layer against electrostatic discharges. The layer acts as a conductor that safely takes and grounds the static charges around it ensuring the contents inside the bag remain intact.
The third layer of the bag is made up of a type of polyester with a dissipative coating like the one on the polyethylene plastic. The layer adds an extra coating for the bag to protect it and its insides by protecting the middle layer and preventing a build-up of static charges outside the bag.