DSM enhances processing window for polyamide

Improved crystallisation properties ensure an extended processing window, providing opportunities in designing co-extruded multi-layer and monolayer film structures.

The firm said Polyamide 6 (PA6) has good barrier properties and mechanical strength but the high crystallization rate can limit its processing window.

Processors have to compromise on productivity, or get improved processability by blending the PA6 with more expensive amorphous polyamides or polyamide copolymers, reducing cost-effectiveness of the film, said DSM at K Show in Dusseldorf.

Akulon XS crystallizes much slower in the film bubble than conventional PA6.

Barrier film layers​

Many barrier films are coextruded on blown film lines and structures with seven, nine and 11 layers are now common.

Royal DSM said though slower crystallization creates larger crystals expected to produce a less clear film, tests on full-scale production lines show that there is virtually no discernible difference in the optical properties made with a benchmark film-grade polyamide and Akulon XS.

The film is more stretchable, so less force is needed to achieve the same blow-up ratio (BUR), or the same force can be used to produce a bubble with a BUR between 7 and 10% higher.

DSM also provides a service to optimize film structure designs which predicts the barrier properties of different film structures, after retort processing, and enables blown film producers to find the optimal layer structure and processing conditions for Akulon XS.

Customers for food packaging include VF Verpackungen and Wipack.

DSM approves bio-based BDO​

The firm also announced it had tested and approved bio-based BDO (1,4-butanediol) made with Genomatica’s process, for use in their Arnitel ThermoPlastic Copolyester (TPC).

Used as a raw material, BDO made from Genomatica's process is able to increase Arnitel's bio-based content up to 73%.

DSM plans to start transitioning its Arnitel portfolio to this new BDO, as soon as supplies are readily available from one of the producers that Genomatica licenses to use its BDO process.

Arnitel Eco already has a bio-based content of 22-53% depending on the hardness. The introduction of BDO made with Genomatica's process will increase the bio-based content up to 73%.

It is used for food packaging films and soft touch applications in consumer electronics.