Mold-in color

There is Europe s plastic skin, 2-seat coupe, called the Smart car with molded-in color that virtually eliminates painting. The idea was to eliminate the need for three coats of paint and reducing both cost and emission problems, Project started in 1994 via a joint venture of Daimler-Benz in Stuttgart, Germany, then known as Mercedes-Benz, and the Swiss watchmaker SMH AG in Biel. They created a... 

Another consideration is the ability of a material to provide a surface that is compatible with the requirements of the application a smooth finish for extruded profiles, molded-in colors, textured surfaces, etc. The compatibility of the major processes with in-mold coating and other insert-surfacing materials, and their compatibility with surface decoration secondary processes, could also be important. 

Various types of surface finishes are available for plastics and RP products, such as smooth, textured, molded-in color, and inmold coating. A textured product surface can be obtained through either a textured mold cavity or a postmold paint process. The former method is the most commonly used. A... 

There may be a requirement for surface finish, molded-in color, textured surface, or other conditions the plastic material is to meet (Chapter 2). The different processes may be able to provide only one surface to be smooth or both sides are smooth. Important that smooth be identified since it has many meanings to different people. Surface finish can be more than just a cosmetic standard. It can also affect product quality, mold cost, and delivery time. The Society of Plastics Engineers/Society of Plastics Industries standards range from a No. 1 mirror finish to a No. 6 grit blast finish. A mold finish comparison kit consisting of six hardened tool steel pieces and associated molded pieces is available through SPE/SPI. 

There may even be some new opportunities under this law, as plastics processors who now paint or otherwise use a solvent-based coating on their products may be forced to stop coating and use molded-in color. 

The aluminum die-cast deck of a mower tractor has been replaced with PC/PBT alloy incorporating molded-in color, saving 3.6 kg of weight and 25% of cost. The same material finds application in tractor hoods. PC/ABS has also been used on the inlet of a vacuum/chipper. Important properties for these applications can be summarized as resists breakage scratch resistance UV resistance injection moldability... 

PBT/copoly(ether-ester) elastomer blend molded parts exhibit excellent surface finish and good paint adhesion without the need for primers. About 3 kton/y of this blend is being used for painted, flexible bumper fascias in selected luxury model cars in the USA. Because of the excellent surface esthetics of the blend, molded-in colors are also being evaluated to reduce the painting costs. Lower levels (< 20%) of copoly(ether-ester) elastomers have also been blended with PBT for high impact strength molding resin applications (Celanex , Hoechst-Celanese). 

There is considerable competition between materials in automotive markets. For example, a major shift is taking place from polyurethanes to TPO for bumper fascia. The TPOs, with molded-in color capability, light weight, relatively low cost, and ease of recycling, are poised to capture a large share of the fascia market both in North America and Europe. A significant cost saving is possible with a TPO fascia, especially if it is not painted. A polyurethane fascia, by contrast, must always be painted, which adds some 60% to the cost of a fascia. 

Engineered polypropylenes have gained rapid acceptance in the automotive marketplace over the last eight years. There are several reasons for this. Polypropylene is light in weight, chemically resistant, recyclable, has favorable NVH characteristics, and lower raw material cost versus most competitive materials. Another key attribute is good weatherability and the potential for molded in color . These combined properties can lower system costs versus competitive materials, especially those which require painting. 

Polymers are painted because this is frequently a less expensive process than precolored resins or molded-in coloring. They are also painted when necessary to provide UV protection. However, they are difficult to paint, and proper consideration must be given to the following ... 

The floor console of the 1994 Chrysler Neon was the first unpainted polypropylene floor console used by a U.S. manufacturer [3]. Besides achieving cost reduction, the significantly lighter part eliminated the need for paint and its associated environmental burdens. The part was also of the same material as the IP and pillar trim, allowing for a large amount of a single material to be harvested from the interior of the vehicle. This helped to make end-of-life recycling more economical. The 1996 Ford F-150 also used a molded in color PP console with all of the parts made fi om PP [3]. The console was attached to the vehicle with two bolts that were easily accessible. 

In the early 1990s unpainted plastic mirror housings started to appear in automobiles. The optional electric mirror on the 1991 Chevrolet Blazer and GMC Jimmy was molded in color with polycarbonate and poly(butylene terephthalate) blend (PC/PBT). The technology was a joint development between GE Australia... 

An excellent example of a compatible system is the 1997 Buick Park Avenue bumper/fascia system. The fascia is a TPO material and the energy absorber is PP foam snap fit to the aluminum bumper beam. Signal markers and trim strips are also snap-fit for easy removal. Therefore, a large amount of compatible material can be quickly removed from it for recycling. There has been a trend toward molded-in-color fascias on certain types of vehicles. These not only reduce mass but also eliminate the environmental burdens associated with painting. Molded-in-color fascias have been used on a variety of small cars and some sport utility vehicles. 

Polymers can be molded in color, which can eliminate the need for painted parts. Eliminating paint is particularly desirable as it reduces air emissions of volatiles and aerosols associated with painting. Eliminating paint also makes the parts easier to recycle. Also, molding plastics require less energy... 

In interior trim, doors A, B, and C pillars quarter panels and consoles are all molded of PP. Different types of resin are used depending on the requirements, but the choice is almost always an impact copolymer. Most often, the parts are produced with molded-in color, even though sometimes the parts are painted for perfect color matching and appearance. For interior trim, resins yielding low gloss parts are desirable because reflections are reduced, the visibility of knitlines and mold imperfections is minimized, and low gloss parts have less of a plastic appearance. 

However for intermediate compositions (32-50% in CHDM) they formed homogeneous mixtures above an upper critical solution temperature (UCST) that rendered a miscible metastable phase upon quenching. A thermodynamic analysis of the USCT-type behavior demonstrated that the bare interaction energy for each pair of blends, was positive and increased with the content of 1,4-CHDM units in the copolymer (140). Commercial PEj.C -T/ PC blends (Ektar DA series, Eastman Kodak) have been used in lawn and garden equipment, floor care appliance parts, sterilizable medical equipment, etc. In these applications, a beneficial combination of clarity, toughness, chemical resistance, heat, UV and gamma radiation resistance has been profited. Molded parts made of these blends generally showed excellent surface finish and hence molded-in-color could be used (141). 

Various types of surface finishes are available for plastics and composite parts, such as smooth, textured, molded-in color, and in-mold coating. A textured part surface can be obtained through either a textured mold cavity or a postmold paint process. The former method is the most commonly used. A wide variety of texture designs is available. The surface smoothness, and to some degree the texture, of a plastic or composite is as dependent on the materials used in it as on the surface of the cavity. For example, certain textured surfaces can be obtained only if the proper steel or metal is used in the mold cavity. Also, with any mold the proper cavity steel based on the plastic processed will significantly reduce its wear and tear and extend its useful life [11, 12]. 

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