Decorating Plastics

The decorative plastic laminates widely used for countertops and cabinets are based on melamine—formaldehyde resin (see Laminates). Several layers of phenohc-saturated kraft paper are placed in a press and a sheet of a-ceUulose paper printed with the desired design and impregnated with melamine—formaldehyde resin is placed over them. Then a clear a-ceUulose sheet, similarly impregnated with the resin, is placed on top to form a clear, protective surface over the decorative sheet. The assembly is cured under heat and pressure up to 138°C and 10 MPa (1450 psi). A similar process is used to make wall paneling, but because the surfaces need not be as resistant to abrasion and wear, laminates for wall panels are cured under lower pressure, about 2 MPa (290 psi). 

Decorative laminates made of particleboards with outer decorative plastic layers such as PVC and so on. 

L. K. Sharpies, Conference on Printing and Decorating Plastics, The Plastics Institute, Bristol, 1968. 

With metallizing decorative plastic parts and automobile plastic reflectors, a good film quality is required but also important and decisive are low expenses of the coating process. Metallization of such parts is often done in horizontal cylindrical coaters with the evaporation sources in the cylinder axis and the substrates arranged around them on planetary axes as can be seen in Fig. 64. 

Commercial techniques for decorating plastics are almost as varied as plastics themselves. Depending on end-use applications or market demands, virtually any desired effect or combination of effects, shading of tone, and degree of brightness can be imparted to flexible or rigid plastics products. 

In high quality decorating and coating operations, the costs of untreated static can be tremendous. Some plants expect scrap rates to be around 10 percent and price their products accordingly. Much, but not necessarily all, of that 10 percent can directly be attributed to static, and, if the proper equipment is employed, scrap rates can be significantly lowered. Nobody who decorates plastic is immune to static bottle printers, painters of automotive parts, hot stampers of toothbrushes, pad printers of cellular phone buttons or coaters of lenses, they all can be affected. 

In a typical plant, people play the blame game decorators blame molders and molders do the best they can to keep the products clean. However, all of the processes incorporated into manufacturing and decorating plastic products leave lots of static and its related problems. 

Uses Urethane-acrylic in clear coatings for paper and wood laminates, adhesives, metal decorating, plastics Features Exc. flexibility, toughness, abrasion resist. 

Decorating n. The processes used for decorating plastics are defined under the following headings ... 

As with adhesive bonding, surface treatment emd cleanliness is of primary importance when decorating plastic parts. Prior to decoration, the svirface of the plastic part must be cleaned of mold release, internal plastics lubricants, and plasticizers. Plastic parts can also become electrostatically charged and attract dust. This could disrupt the even flow of a coating or interfere with adhesion. Solvent or destaticizers may be used to clean and eliminate static from plastic parts prior to decorating. Cleaning of the plastic part requires an understanding of the plastic material to be cleaned and the effect of the solvents and processes on that plastic. 

Painting of plastic parts is fully addressed in another chapter of this book, and the reader is referred there for details on the painting processes and materials used. In this section, some of the fundamentals of painting will be reviewed from a perspective of decorating the plastic part. Small-volume processes will be emphasized because these processes are usually most conducive to the flexibility (changes in color or design, short lead time, etc.) needed in decorating plastic parts. 

Edward A. Muccio, Finishing and Decorating Plastic Parts, Plastic Part TechnoU, ASM International, Materials Park, Ohio, 1991. 

Figure H.4 Hot stamping machines for (a) flat and (b) round plastic parts. (Ref Muccio, E.A., Finishing and Decorating Plastic Parts , Plastic Part Technology, ASM International, Materials Park, OH, 1991)...

Engineering plastics can be flexible and offer advantages such as transparency, self-lubrication, economy in fabricating, and decorating. Plastics are electrical non-conductors and thermo insulators. Plastics are considered to be competitive primarily with metals. Compared to metals, plastics are easier to fabricate and low cost. Plastics can be pigmented in a wide variety of colors. 

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