Static electricity causes serious consequences across a wide range of industries. Whether it is film sticking to rollers, dust accumulating on freshly printed films, or sparks in volatile environments, electrostatic charges can disrupt production, damage equipment, and endanger operators. Therefore, it is crucial to install static control devices on the shop floor to ensure the safety of people and assets as well as to enhance production efficiency and product quality.
Causes and effects of static charges
There are four main causes of static charges.
1. Contact induced charge generation: electrons can be exchanged between materials on contact; materials with weakly bound electrons tend to lose them while materials with sparsely filled outer shells tend to gain them. This is known as the triboelectric effect.
2. Charge induced due to separation: a charged object brought close to an electrically neutral object causes a separation of charge within the neutral object. Charges of the same polarity are repelled, and charges of the opposite polarity are attracted.
3. Pressure induced charge generation: applied mechanical stress generates a separation of charge in certain types of crystals and ceramic molecules.
4. Heat induced charge generation: heating generates a separation of charge in the atoms or molecules of certain materials.
Effects of static charges
Static charges can result in various safety, productivity, and quality-related issues. The following are some of the most common problems they cause:
How do static eliminators work?
Static eliminators emit positive and negative ions, which are directed towards the charged surface. The ions interact with the charges on the material and the ions, and the static charges neutralise each other.
Types of static eliminators
- Active static eliminators (AC and DC type)
- Passive static eliminators
- Air-based static eliminators
1. AC static eliminators: ideal for short to medium range
AC static eliminators are active ionising bars powered by alternating current, designed to emit a stream of positive and negative ions. As charged materials pass under the bar, the ions neutralise the charges built up on the surface.
These AC static bars are ideal for:
- Short to medium discharge range (10-100mm)
- Medium to high-speed applications
2. DC static eliminators: ideal for high-speed and long-distance applications
Unlike AC and DC static eliminators emit positive and negative ions simultaneously, making them more effective for high-speed and long-distance applications
These DC static bars are ideal for:
- Long range applications (100-500mm)
- Complex special applications such as winders, unwinders, and coating
3. Passive dischargers: a reliable low-cost solution
In passive electrostatic discharge systems, grounding enables the natural movement of charges between a charged body and the earth, preventing static build-up.
Common forms of passive dischargers include:
- Carbon brushes
- Semi-conductive bristles
Passive static dischargers are particularly useful where static build-up level is low to moderate and can be managed through simple dissipation mechanisms.
4. Air ionisers: targeted static removal for 3D geometries and long-range applications
For three-dimensional parts and long-distance applications that require directed airflow, air-based static eliminators—commonly known as air ionisers—are a practical solution. These systems use compressed air or fans to deliver ionised air streams to neutralise charged surfaces.
Types of air ionisers include:
- Ionising air guns
- Ionising nozzles
- Ionising blowers or knives
Air ionisers are especially beneficial in:
- Plastic moulded component manufacturing
- Cleanroom applications
- Medical packaging lines
- Printed circuit board (PCB) cleaning
They serve dual purposes—neutralising static electricity and removing dust or fine particles from surfaces before further processing or packaging. This makes them a popular choice in pharmaceutical, electronics, automotive component manufacturing, and packaging lines.
Choosing the right static elimination solution
When selecting a static control device, consider the following:
- Material type: Is it conductive or insulating?
- Speed of operation: High-speed lines require active ionisation
- Surface geometry: 2D surfaces like webs need bars; 3D parts need air ionisers
- Environment: Explosive zones need ATEX-certified products
AxisValence is committed to aiding safety, health, and environment on the shop floor. Under its flagship brand “Valstat,” AxisValence offers a wide range of electrostatic control devices across industrial applications.