Q&A: Developments in Plastics Decoration
A resource sponsored by SPEs Decorating & Assembly Division
by Paul Uglum, technology advocate, fabrication engineering
Peugeot Exalt concept car showing the use of natural materials.
Bentley offers a vehicle with real stone trim.
There are many reasons for plastic decoration and, to some extent, the term is a misnomer. We apply secondary operations to plastic parts to add value. That value can take the form of improving the appearance, and therefore increasing the desirability and perceived value of an object, but it also can take the form of improved performance in the environment in which it will be used. So, the purpose of decoration should be to create a visually exciting object both promotes the brand image of the company and creates a sense of value. Since plastics decoration is used in so many industries, ranging from packaging and consumer products to telecommunications and automotive, the requirements for both appearance and function vary widely. Even with this variety, there are underlying trends that exist across our industry.
How do I find out what design trends are?
So, how does one find out what the design trends are that drive decoration choices? This is not a small question since developing and implementing a decoration process involves a significant investment in equipment and human capital. A wrong choice can consume resources and make it more difficult to compete.
A first step is to know what is going on in the industry: The quote requests you receive, conferences and trade journals are a good starting point. Then, look to other industries. Beauty Packaging, Appliance Design, Wards Automotive and many other trade journals can give a more complete picture of what people want. Take a look at tradeshows, especially those that show concepts and new products. Auto shows and the Consumer Electronics Show (CES) are good examples. Various color specialists put out palettes that define color trends. Some industries respond quickly to these, and others are more conservative and slower to adopt change. One caution: Color has cultural meaning, so if your product is global, it is important to understand regional preferences.
Industrial designers tend to be very good sources of information because they have an understanding of both the past and current trends. In a recent article in Appliance Design, Bill Dorr, the director of industrial design at Design Concepts, published an article titled Understanding and Using Emerging Aesthetic Design Trends. It outlined a number of trends that I have seen across many industries. Two were particularly interesting: Real Materialism and Organic Textures and Patterns.
Real materialism is about the application of real wood, metal or carbon fiber instead of the substitutes because of the higher perceived value of actual materials.
How do I achieve real materialism in decorated plastic?
There are characteristics and appearances of plastic that are honest and fundamental characteristics of the material. High-gloss piano black would be an example of this. Beyond that, plastic often is the substrate for other materials.
Wood is a good example of how real materialism is finding a market. There are several reasons for this general trend, including a push for green materials, its texture and its high perceived value. So, how do you apply wood to plastic, and where is it used? Years ago, Yamaha developed a process where thin wood was laminated to metal, then formed and insert molded. The wood surface then was sealed, stained and sanded just like solid wood, before being shaped with a plunge router. This technique was used in both instrument and high-end automotive interior applications. Since then, companies like Quin and others have insert-molded wood veneer with a clear plastic top layer. Others, like Mono, have both insert-molded veneer with a backing and directly applied finished veneer to plastic. Real wood is finding its way into a wide range of applications in cosmetic packaging, cellphones and automotive.
Other real material applications include insert-molded metal-first surfaces and leather. Both can be applied after molding and, in some cases, insert molded. Insert molding tends to be somewhat problematic, but it has been used for smaller parts like key fobs, cameras and cellphones. Like leather, fabrics also can be in-molded.
Some applications of real materials include the use of more exotic or difficult-to-process options. Real cut crystal has been used in applications ranging from cosmetic packaging through automotive interiors. Real polished stone surfaces have been applied to interior surfaces on very high-end vehicles, like Bentley.
It is clear these processes are used because there is a market for real materials. Real carbon fiber is interesting since it is usually used in a composite with a plastic resin. Most of the printed versions fail to look real since they lack the depth of image. There now are some versions of imitation carbon fiber that consist of dyed glass fiber imbedded in clear plastic that can be insert molded and has an appearance identical to carbon fiber. These materials have found use in weight-sensitive applications like cellphones but have not had the advertising value of real carbon fiber.
How are texture, patterns and feel achieved in plastic decoration?
Tactile and visual features add a lot of value to a part. For some time, in applications ranging from telecommunications to automotive, soft-feel coatings have been perceived as adding significant value. The recent trend has been to improve the durability of these coatings to improve performance and life.
Texture is interesting because it has visual and tactile characteristics. It is an area that has seen significant growth both in desirability to consumers and in the range of manufacturing processes available.
The explosion of new processes has been driven by demand and advances in technology. Ultra-fast laser pulse width has allowed direct texturing of tools. This has been used to apply very fine and reproducible textures and textures that can transition from one pattern to another. This was not possible or at least not as repeatable with chemically etched textures. Taiyo has taken advantage of this to make very intricate textures in plated plastic parts. The company has developed back-lit and non-backlit chrome appearances that were not possible previously.
Even coated (painted) surfaces are seeing an explosion of new techniques to apply textures. Tacia (Cubic) introduced a hydrographic (water dip process) coating capable of texture. Akzo Nobel has developed a printing and painting process capable of making intricate textures. Rayn Technologies has developed a process that allows laser texturing of painted or printed surfaces. Digital ink jet allows direct printing of patterns and textures to plastic substrates.
In-mold decoration also has seen advances. The pressures involved in in-mold decoration can wash out printed textures. One solution to this is the 3D overlay method (TOM) developed by Fu-se Vacuum Forming of Japan. With this process, the applique is applied under low pressure, which preserves the surface texture.
How do I pick the best process for my product?
Given the options, it can be difficult to choose the best process. The first step is to understand what the customers goals are. What appearance do they seek? What is the environment the decorated part needs to survive in its use and to satisfy the customer? The next step is to spend some time learning the advantages and constraints of each process. Determine how well it fits into your plant and your manufacturing plans for the future. One thing is clear: There are many more processes and technologies available today than there were even two years ago.