DSM AKULON® PA6 OUTPERFORMS PA66 FORMULATIONS

The choice of a polyamide (PA) thermoplastic for an engineering application, particularly between PA6 and PA66, often focuses on heat aging or strength and stiffness—and cost. Akulon® PA6 from DSM Engineering Plastics offers performance equal to or better than many competitive PA66 formulations, with significantly better price/performance when processability is factored in.

PA6 and PA66 are generally chosen for high stiffness and strength at temperatures above 100°C, or for high impact resistance at low temperatures, 23°C (or even down to -40°C). Stiffness and strength for conventional PA6 and PA66 formulations, as well as dimensional change after uptake of water, are comparable. However, in comparison with competing PA66s, Akulon PA6, shows:

• better retention of strength both at ambient temperature as well as above 100°C after heat aging,

• higher impact resistance at low temperatures (even in dry, as-moulded state) and

• much better processability, measured both in lower processing costs per part and in more favourable processing parameters: a broader processing window, better surface appearance, and higher weld strength.

Tensile strength (TS) at 23°C for Akulon PA6 after heat aging is well above 140 MPa, compared to a typical PA66 value of ~90 MPa, or 155% higher TS for Akulon. TS of Akulon versus typical PA66s at 170°C after heat aging is 160% higher (80 MPa for Akulon; 50 MPa for PA66). Figures are for 30% glass-reinforced formulations for all types and are based on internal testing at DSM; figures are values after heat aging at 170°C for 5000 hours.

As with all polyamides, Akulon PA6 absorbs moisture reversibly from the environment until it reaches equilibrium. Although PA6 absorbs more moisture than PA66, especially under high humidity, the resulting dimensional changes between the two are similar. With PA6 there is some reduction of the glass transition temperature with uptake of water and a consequent lowering of stiffness and strength at room temperature, but most applications call for elevated temperatures, and above 100°C, parameters affected by water show minimal change from as-moulded values.

DSM Akulon PA6 formulations include neat; high stiffness (30-40% glass reinforcement); higher stiffness (>50% glass); Ultraflow™ with 50% better flow than regular materials; Ultralas™ for laser welding or laser marking; high-burst, impact-modified for splinter-free performance as low as -33°C; ultraviolet (UV)-stable; and blow mouldable grades. Akulon is also available in film grades.

Typical applications include under-bonnet automotive components and assemblies including air cleaners, intake manifolds and engine covers; automotive appearance items such as door handles; electrical components such as connectors, junction boxes, and terminal blocks; power tool and lawn and garden enclosures and housings; a wide variety of sports equipment, including ski bindings and inline skates; and a broad range of appliance and building and construction applications.