What is an ESD foil bag and what types are available?

ESD packaging also includes the so-called ESD foil bag. It is available in many different versions – depending on the intended use.

ESD film bags are used as packaging for electronic devices or parts thereof to protect them from static electricity. Depending on the design, ESD bags offer protection against electrostatic charging or direct discharge and protect against dust and, in some cases, water vapor and gases.

The reason why ESD film bags have antistatic properties is an additive in the plastic. This additive prevents static electricity from being generated when the ESD packaging bag is used, for example through friction. The plastic used is therefore only slightly chargeable.

For example, LDPE (low-density polyethylene) is used. At the same time, ESD bags are usually also dissipative.

However, there are also ESD bags that both dissipate static electricity and also have a shielding function. This means that the packaged items are not only protected against charging, but also against the discharge of any electrostatic fields. These static ESD film bags are also known as shielding bags, metallized shielding bags or “static shielding bags”, which translates from English into German as “Statischer Abschirmbeutel”. Shielding foil bags are comparable to a Faraday cage. The inner area of the cage is shielded from static electric fields that occur outdoors.

Dissipative Pink-Poly Bag (antistatic ESD bag)
The often pink-colored antistatic ESD bags made of LDPE are capable of dissipating static electricity. These dissipative flat bags are used, for example, to prevent electrostatic charging in the event of friction between the films or on other materials in the environment. Pink poly bags do not provide shielding from discharges that occur outside the bag. Strictly speaking, it is therefore not an ESD bag. This is because ESD stands for “electrostatic discharge”. These antistatic flat bags therefore do not provide a Faraday cage.

Tubular film
There is also antistatic tubular film made from LDPE on a roll. The advantage of tubular film is that you can adjust the length of the packaging individually and then weld the film at the open ends.

Permanently dissipative ESD bags
There is a special version of dissipative packaging bags that is permanently dissipative. The protective effect of these bags is therefore maintained indefinitely, as the antistatic agent does not diffuse.

Static shielding bag (static ESD shielding bag)
The shielding bags, which are used not only for electrostatic discharge but also for shielding against external charge currents, are usually made of metallized polyethylene. They usually have a bluish or silver color. The metallized shielding bags are suitable for both storage and transport.

ZipTop or OpenTop
ESD bags are available with and without a pressure closure, also known as a zipper closure or ZipTop. Thanks to the zipper closure, the respective ESD bag can be closed at the open point and opened again. Bags without such a closure are called OpenTop, which means that these bags can be welded and closed in this way.

Bubble wrap bags
The pink poly bags and the shielding bags are also available as bubble wrap bags.

Moisture barrier bag (MBB)
And then there is the moisture barrier bag, also known as a dry bag. These shielding bags usually have a multi-layer barrier layer. This is intended to prevent moisture and gases from penetrating the inside of the bag (corrosion and therefore moisture protection). These barrier bags are suitable for storing components for long periods of time or for transporting particularly sensitive items, for example overseas.

ESD gusseted bags
So-called ESD gusseted bags can be used as ESD bin liners, for example, by slipping the open end of the gusseted bag over the edges of a crate

ESD side gusset bags
So-called ESD side gusset bags can be used as ESD bin liners, for example, by slipping the open end of the side gusset bag over the edges of a crate.

Antistatic cover film
Antistatic cover films are suitable as dust and dirt protection for covering machines in an EPA zone due to their size, which can be several meters in some cases.

Conductive bubble wrap
And instead of bubble wrap bags, you can also simply buy bubble wrap on a roll. This conductive, dissipative bubble wrap can also be welded in some cases.

ESD foil bags are available in different sizes. Before purchasing ESD bags, you should therefore consider which objects you want to use the bags for and determine the size of these objects. The ESD film bag must be larger – sometimes by a lot – than the object to be packaged, provided that the object expands its volume in all three dimensions, i.e. in height, width and depth. In this case, the ESD film bag becomes noticeably narrower in width and height.

For example, if you want to send an electrostatically sensitive electronic component, you should not send it in a pink-colored bag to protect it from static electricity, as these are often not dissipative enough with a small amount of antistatic agent to prevent the build-up of charges or dissipate them.

Instead, you should use an ESD bag with a shielding function or additionally wrap the dissipative packaging with a conductive, or even better, shielding material.

Pink-colored, dissipative packaging materials should therefore primarily be used within the electrostaticprotected area (EPA). Shielding effect against electrostatic discharge is only required if the enveloping packaging does not provide a shielding effect and the components are located outside the EPA.