Optimization of phase morphology of ABS to control the gloss level for Sheeting application
25 August, 2020
The surface roughness of thermoplastic parts is an important characteristic as it affects the optical behavior and the aesthetics. In some plastics products, such as optical discs, the surface roughness must be kept to a minimum, because minute roughness in the Nano-meter range would cause noise. In other areas of plastics application, such as the board panels of automobiles, the surfaces must have a rough texture without shiny areas and the gloss must be low and kept within a narrow range. For this particular type of product, the accomplishment of these specifications will reduce the specular reflections from external lights that might disturb the driver visibility and also create a comfortable environment in the interior of the car/truck.
Surface gloss is a subjective impression created by the light flux reflected by a part. It may be quantitatively assessed with a glossmeter that, for a specified angle, measures the fraction of light flux reflected in the specular direction when the specimen is illuminated by a parallel light beam. Spectrophotometers operating in the reflection mode and diffractive optical sensors have also been used to study the gloss differences of injection moulded plastics products. Nevertheless, the gloss meter is still the more common and suitable instrument for measuring gloss in the industrial environment. Gloss varies with the refractive index of the polymer, the angle of incidence, and the topography of the surface. Additives such as particulate inorganic fillers create surface roughness and are effective agents to reduce gloss. The topography and consequently the gloss of injection moulded parts depend on the mould finish and also on the replication accuracy. Studies were published showing that the processing parameters may affect the gloss of injection moulded parts.
Additionally Some OEM’s have specified a 2.0 or lower sixty degree Gardner gloss level for most first surface interior components that are moulded in colour (MIC) and without paint or a secondary finishing process such as a vinyl wrap. Due to this directive the need to develop low gloss material have become an important issue for material developers. This has arisen to find suitable additive to achieve low gloss ABS from the High gloss ABS. This project will aim to find such suitable additive or to optimise process to achieve low gloss level in sheet extrusion grade.
Surface gloss is a subjective impression created by the light flux reflected by a part. It may be quantitatively assessed with a glossmeter that, for a specified angle, measures the fraction of light flux reflected in the specular direction when the specimen is illuminated by a parallel light beam. Spectrophotometers operating in the reflection mode and diffractive optical sensors have also been used to study the gloss differences of injection moulded plastics products. Nevertheless, the gloss meter is still the more common and suitable instrument for measuring gloss in the industrial environment. Gloss varies with the refractive index of the polymer, the angle of incidence, and the topography of the surface. Additives such as particulate inorganic fillers create surface roughness and are effective agents to reduce gloss. The topography and consequently the gloss of injection moulded parts depend on the mould finish and also on the replication accuracy. Studies were published showing that the processing parameters may affect the gloss of injection moulded parts.
Additionally Some OEM’s have specified a 2.0 or lower sixty degree Gardner gloss level for most first surface interior components that are moulded in colour (MIC) and without paint or a secondary finishing process such as a vinyl wrap. Due to this directive the need to develop low gloss material have become an important issue for material developers. This has arisen to find suitable additive to achieve low gloss ABS from the High gloss ABS. This project will aim to find such suitable additive or to optimise process to achieve low gloss level in sheet extrusion grade.