Wesel, Germany - Additives supplier BYK has launched what it claims is a unique group of processing additives to improve compatibility and processability of foam systems.
BYK points out that incompatibility and separation are "familiar phenomena in today's foam formulations." To make speciality foams such as super-soft and viscoelastic grades, for example, requires components of different chemical compositions and polarity, which are of either limited solubility or complete incompatibility, the company added. Hence the need for BYK's six new additives (see below) to help overcome the incompatibilities between various raw materials in the formulation.
Processability during foam production presents another major challenge, and additives which help here include:
•Anti-sedimentation/flotation additives, for example, to prevent the sedimentation of calcium carbonate and melamine powder or the flotation of ground PU foam or polyethylene powder. This is achieved by means of thixotropy and the build-up of a slight yield value in the polyol.
• Anti-cold-flow additives improve the dimension stability of the foam and thus reduce the cold flow effect.
• Hydrophilic additives to influence the water-absorbing properties of polyether/polyester foams, so increasing the water receptivity and the absorption rate of the foam.
• Viscosity modifiers improve the flow behaviour and 'pumpability' of higher viscosity polyols or systems, especially at lower temperatures. The additives are 100% isocyanate reactive.
Compatibilisers: BYK-P 9900, P 9901, P 9902, P 9903, P 9904, P 9905
Anti-sedimentation/anti-floating additive: BYK-P 9906
Anti-cold-flow additive: BYK-P 9910
Hydrophilicadditive for polyether/polyester foams: BYK-P 9911
Viscosity reducer forpolyols/foam systems: BYK-P 9915