is part of the Division of Informa PLC
This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.
By Anja Oltmanns, Head of Sales and Technical Service Compounds, Antistatics, Nonwovens, BASF Polyurethanes GmbH
We are all familiar with the crackling sound and one's hair standing on end when taking off a synthetic sweater - which is at worst mildly discomforting. In industry however, the electrostatic charging of plastics can cause the failure of electronic components and computer chips and is even capable of igniting combustible gases, vapors and dusts. On the surface of a polymer, which is at first electrically neutral, charge may be generated by contact with another surface and subsequent rapid separation. Without suitable dissipation, this charge can neutralize in an uncontrolled and abrupt fashion. To address this problem, BASF has developed an antistatic thermoplastic polyurethane (TPU) granulate under the Elastostat brand. Elastostat is available as a masterbatch. The material is part of the Elastollan product range that has been embodying BASF Polyurethanes' TPU expertise for over 30 years.
New fields of application for TPU
Plastics with defined electrical properties are capable of dissipating electrostatic charge in a controlled and permanent way. The decisive characteristic for assessing the electrostatic charging or discharging of a material is its surface resistivity. TRBS 2153 (German technical rules for operation safety "Preventing ignition risks resulting from electrostatic charging") defines a material's electrostatic properties in terms of its conductive, dissipative and insulating capacities. A material with a surface resistivity of less than 106 Ohm is said to be conductive. Such materials are capable of rapidly dissipating generated charges, and this can cause damage to sensitive electronic components. Materials with a surface resistivity greater than 1012 Ohm are defined as insulating. Most plastics are insulators that are easily electrostatically charged by friction. Owing to their very low conductivity, the applied charges can remain on their surfaces for a long time and electric charging of several thousand Volts (on synthetic sweaters, for example) are therefore possible. Materials with a surface resistivity of 106 to 1012 Ohm are termed dissipative and are known as intrinsic dissipative polymers (IDPs). The new antistatic additives cover the range of IDPs.
The new TPU masterbatch opens up major fields of application, particularly for industrial packaging made of polyolefin resins. Antistatic treatment is an absolute must for containers in which combustible liquids or certain powdered products that generate dust are transported. These packages include big bags and plastic drums or cans. Such materials are also transported in intermediate bulk containers (IBCs). In their most common form, IBCs consist of a polyethylene inner container, a tubular metal outer frame and a pallet. Moving forward, such containers, which are used for chemicals, foods, cosmetics and pharmaceuticals, will be able to be produced more easily and at lower cost. The TPU additive could also be used in pipelines, hoses and conveyor belts to prevent the electrostatic charging of the transported material.
Another application sector is the automotive industry, which is increasingly demanding dirt-insensitive materials. Plastic surfaces in vehicles are also susceptible to electrostatic charging. An elevated surface tension can cause the materials to attract dust and dirt particles. The antistatic masterbatch can be used in both film extrusion and injection molding to significantly reduce the surfaces' dust effect. The possible applications here are mainly in the vehicle interior, e.g. in linings, covers, instrument panels, headliners, sun visors and seat covers.
A third field of use comprises packaging and transport systems for electronics. Electronic components have to be protected particularly well, as peak voltages can cause damage when rapidly discharged. Electronic components can also be damaged by electrostatic charging. Packages treated with the new antistatic masterbatch provide a high level of protection from both risks. Such packages include transport trays and tablets for small electronic parts like microchips as well as air bubble film bags and resealable bags for mobile phones, circuit boards, drives and other electronic devices.
Elastostat from BASF Polyurethanes is a highly specialized easy-to-process product with an excellent price/performance ratio. The exceptional properties of Elastostat are its permanent antistatic effect, mechanical properties like improved impact resistance, and compatibility with non-polar polymers. In extensive tests, BASF's experts have demonstrated both its antistatic effect and compatibility. The homogeneous polymer matrix shows no tendency to delaminate. The test results are also promising in terms of its mechanical properties. BASF further adapts the performance profile of the antistatic TPU to customer applications and requirements and thus develops tailor-made solutions in partnership with the customer.
More information about text formats