Useful antistatic TPU launched

BASF’s new granulate Elastostat provides a permanent antistatic effect and is easy to process while opening up large fields of applications

01 August 2013

BASF has developed for the first time an antistatic thermoplastic polyurethane (TPU) granulate which for the time being goes under the Elastostat brand name in the TPU portfolio. 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.

The exceptional properties of Elastostat are
its permanent antistatic effect, mechanical
properties and compatibility with
non-polar polymers

In a presentation, Anja Oltmanns, head of sales and technical service compounds, antistatics, nonwovens, BASF Polyurethanes GmbH, explained that most polymers have insulating properties and are therefore susceptible to electrostatic charging. These materials can now be rendered antistatic through the addition of Elastostat, which has the edge over existing solutions in that its antistatic effect is permanent and does not require any specific ambient conditions such as a certain atmospheric humidity. What is more, the product is easy to process. The material is highly compatible with standard plastics like polyethylene (PE), polypropylene (PP), polystyrene (PS) and ABS. Simply mixing it with the polymers yields high homogeneity and thus eliminates the need for elaborate compounding. For the plastics-processing industry, this is of great significance, because usually no liquid additives are processed. 7.5 to 15 volume per cent of the antistatic TPU masterbatch is added. The properties of the matrix materials are scarcely affected and, thanks to the additive’s neutral colouration, the material can be dyed in any desired colour.

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 chargings 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 large fields of application, particularly for industrial packaging made of polyolefins. The TPU additive could also be used in pipelines, hoses and conveyor belts to prevent the electrostatic charging of the transported material.

The masterbatch also has applications in the automotive industry. Another field of use comprises packaging and transport systems for electronics.

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