Decorating plastic product

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. 

Due to the self-releasing properties of almost all materials (which are rotation-ally processed), a subsequent decoration of products with screen printing, painting, and placement of stickers is often very difficult. Preparation of the plastic product is possible, but very complex. For some time now, there are specially developed possibilities for decorating plastic products using mold-in-systems. 

Plastic products are made by a variety of basic manufacturing processes. As an example a major method such as extrusion has subdivisions that include profile, pipe, tube, film, sheet, coating, post forming, etc. equipment In injection molding there are subdivisions such as coinjection, gas assist, foam, inmold decorating, etc. equipment. There are literally hundreds of processes used with only about the dozen, as reviewed in this chapter, that are principally used (2). 

Many plastic products are decorated to make them multi-colored, add distinctive logos, or allow them to imitate wood, metal and other materials. Some plastic products are painted since their as-molded appearance is not satisfactory, as may be the case with reinforced, filled or foamed plastics. Painting or coating is also for product protection. The following section will discuss some of the secondary operations frequently used with plastics. Since plastics vary widely in their ability to be machined and to accept finishes,... 

This is a one step economical process for selectively transferring a high quality image to a plastic product. A heated die transfers the pattern from selected transfer tape to a flat plastic surface. Lettering or decorative designs can be transferred in pigmented, wood grain, or metallic finishes. 

Sublimation (diffusion) printing is a textile process in which color patterns in dry die crystals are transferred from a release film to the fabric under high heat and pressure. The process has been adapted to plastics. The equipment used is very similar to that used for hot stamping. Under heat and pressure, the dye crystals sublime (go directly to the vapor phase from the solid phase without melting) and the vapor penetrates the plastic product. As a result, the decoration is very durable and wear resistant. It is also cost competitive against other processes such as two-step injection molding or silk screening. 

The increasing use of plastics as construction materials has led to a renewed interest in decorative finishes for plastic products. There are a wide variety of secondary operations that can be used for adding decoration to molded parts. Progress is also being made in providing decorative surfaces in the mold itself. The first use of this is in woodlike panels for wall decoration and furniture parts such as cabinet doors. 

Although pearlescent pigments are commonly known for their decorative enhancement to plastic products, the pigments can now be used in a functional... 

Use Applications are as a backing for plastic film padding for surgical dressings, diapers, sanitary napkins drapes and other decorative textile products filtration shoe liners industrial wiping and... 

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 flame treatment, plastic objects such as bottles and film are passed through an oxidizing gas flame. Momentary contact with the film causes oxidation of the surface, which makes it receptive to material used in decorating the product. 

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. 

The finishing of plastics includes different methods of adding either decorative or functional surface effects to a plastic product (Tables 9-5 and... 

Priming involves the application of a coating on the surface of the plastic product to promote adhesion or to prevent attack by the solvents in a subsequent protective or decorative coating. In some cases priming can be done after cleaning. In others, it must be done after pretreatment. 

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