Innovation in plastics decoration and surface treatment strives towards providing an ever increasing all-round sensory experience. Within the physical limits imposed by different processes (e.g., contact or non-contact, point, linear, single side contact or full immersion) many diverse aesthetic effects, appealing to any of the senses (visual, tactile, olfactory, taste, or auditory), can be produced or influenced in plastics through one or more of the processes involved. Often several different technologies can be used to produce the same effect to varying degrees of efficacy. Their sensory effects are described in descending order of importance, and refined into a list of 10 categories for describing the primary intent of patents.
As well as selective coating deposition, and the decreasing attention to 3D, tactile and depth effects over the three year period used for sampling. Whereas overall there is a heavy bias towards surface quality improvement, 3D, tactile and depth effects, and metallic or reflective effects (between them representing the major focus of two-thirds of all patents), five other categories still show a significant patent count.
1 Introduction to Decorative Effects
1.1 Three-dimensional, Tactile and Depth Effects
These popular effects can be visual and non-tactile, tactile only, or a combination of visual and tactile effects. They constitute one of the most sought-after goals in plastics’ decoration and surface treatment.
Transparency is a measure of the portion of unabsorbed light that passes through a material or coating. Matte surfaces reduce clarity by introducing haze. Haze in a translucent material will reduce distinctness of an image (DOI) seen through the material. Some polymer resins, inks and coatings are required to be clear and transparent. ‘Water-whiteness’ is a term that is used to describe colourless transparency. Polypropylene (PP) can be improved, for example, by adding clarifying additives. In decorative terms, good transparency provides an impression of depth.
Visual 3D effects can be achieved by the simple assembly of components that are translucent and optionally decorated. In the field of decoration and surface treatment, methods include depth effects obtained by applying a thick translucent film over a decorated substrate, with optional decoration or coating to enhance the effect, a gradated magnetic orientation of pigments in a coating, or the use of lenticular or holographic effects via moulding, embossing