Dow Corning (Midland, Michigan / USA; www.dowcorning.com) has launched a flame-retardant additive for use in PA compounds at this month’s “Chinaplas” (www.chinaplasonline.com) trade fair in Guangzhou / China.

The Dow Corning "43-821" additive is said to address the problems associated with using high levels of traditional flame-retardant additives, such as organic phosphorous. Although organic phosphorous additives are a popular choice, Dow said they have a major drawback in that the high loadings (up to 20%) required to meet regulatory requirements can cause mechanical properties to degrade and result in high corrosion.

The 43-821 additive can be used at levels of just 1 - 2%, restoring the resin’s key mechanical properties, minimising corrosion and lowering compound costs by 10% or more.

“Not only does this new product optimise highly filled, flame-retardant PA compounds, but it also delivers cost advantages in three major ways: by reducing the required amount of organic phosphorous additive; by delivering high performance at very low loadings and by avoiding the need for over-engineered inherently flame-retardant materials,” explained Christophe Paulo, Dow Corning’s global segment leader for plastics solutions.

According to the US company, tests have shown that 30% glass-filled PA compounds incorporating 13% by weight of aluminium phosphinate and 2% by weight of the Dow Corning 43-821 additive meet requirements for the plastics flammability standard, UL-94 V-0 at 1 mm.

Glass-reinforced PA 6 and PA 6.6 compounds are widely used in electrical/electronic applications in the automotive and appliance industries. Dow said the PA additive is the first in a totally new product family.