Color matching plastic materials

Is the color standard based on the same material as the desired match demands The color match becomes very difficult if the color standard is based in a plastic material that is different from the desired match plastic. A Pantone standard, an opaque painted paper, is still frequently used as a color standard. However, a Pantone paper standard does not address the issues of opacity, gloss, and texture, which are essential to color matching plastic materials. Similarly, painted metal color standards possess gloss levels that often exceed the range capable for most polymers. This factor also further complicates a visual color match in plastic materials with lower gloss. Thus, if possible, secure the color standard in the same material that the match is desired. 

There are many available methods for mixing colorants into plastic materials. Choosing a laboratory method that will most closely match the production process is ideal, but not usually the norm. Colorant dispersions in plastic materials determine the perceived color. Thus, choosing a consistent, reliable mixing method that closely mimics production dispersions is critical to a good visual color match. 

There are systems that precisely dispense up to four material components into a mold. The plastic is dispensed up to 6 lb/sec with a reported accuracy of 0.02 lb. The system works as the feeder automatically reads a barcode. The barcode is matched to a dispensing recipe and then the required amounts of color and plastic powder are dispensed. The system is capable of holding more than 65,000 recipes. 

It is very important to understand the plastic material before starting a color match Know the polymer, its limitations, processing conditions, physical properties, and other attributes. The more information known about the polymer, the more assured and defined is the visual color match. 

The character of AR/TS is changing. Materials, equipment and applications are all increasingly sophisticated. There is more need for expert personnel, yet flexibility and breadth of outlook are required to cope with new situations. How does one predict the weatherability of plastics when twenty years service is the objective The organizers of a 1967 symposium on the subject felt obliged to conclude that after a century the problem is still far from a satisfactory solution (9). How does one predict with reliability the hazard to a large population of a new food additive or soap bacteriostat over a long period of time How does one deal with subjective properties of chemicals such as taste and flavor The synthetic sweeteners in use today have all been discovered accidentally is this the way to run a chemical business How are reluctant old timers weaned from visual color matching to computers ... 

The automotive indushy is an extremely competitive market for the injection molding industry. Automotive manufacturers are reducing the number of supphers which produce components for their vehicles. To stay competitive, injection molders need to be proactive in both technology and pricing. Interior trim is a very competitive market for the injection molding industry. Much of the interior of an automobile is comprised of plastic parts molded from many different materials. The variety of plastics used in interior trim makes it very difficult for the assembler to obtain color match between all components. Each type of base resin requires a different formulation of colorant to achieve the same finished color. This problem is further complicated by the addition of additives such as UV stabilizers, lubricants, fillers, etc. Other problems include molding faults such as flow lines, weld lines, sink, splay, and blush... 

The other approach is to embed the hygroscopic perchlorates in a plastic material, which thus becomes fuel, binder, and protective coating and also opens the way for new production techniques. This scheme has been tried as shown in a U. S. patent for lithium perchlorate embedded in nylon for the purpose of formulating high-energy propellants, and it is applicable to colored flame production. A similar idea is incorporated in another U. S. patent that deals with colored flame matches or more exactly match splints made from cellulose acetate in which the perchlorates of copper or strontium perchlorate, dissolved in triethanolamine, are dispersed. Again, the color effect is most pleasing, but the technique seems to have remained confined to laboratory samples. 

Rosin type (sample) n. Sample of rosin, or a mold of thermosetting plastic material, used as an unofficial standard in grading rosin. Such sample shall be so selected, sized and surface-finished that it will have the form of an approximate 7/8in. cube with at least two opposite faces having smooth parallel surfaces and shall have a color when viewed through these faces which matches within rather narrow tolerances the color of the corresponding official government standard. 

Each plastic part must be strong while not exceeding final weight requirements. It was also critical that they can withstand attack from a whole host of specified chemical compounds. To ensure these needs are met, PTA provided extensive chemical resistance data on numerous materials and supplied sample plaques of multiple materials in various wall thicknesses used for testing. It was also required that the plastic parts be produced with a color shift of no greater than a AE of 1. PTA successfully matched two colors in multiple materials and finishes while still adhering to the color considerations. 

It becomes increasingly apparent that color in foods will be measured in one of two ways by abridged spectrophotometry, or by direct color measurement, preferably in terms of the 1931 C.I.E. conventions in either the original C.I.E. color space or one of its more useful transformations. One may also anticipate increased use (when applicable) of carefully prepared plastic material standards which can be cleaned and polished as often as necessary, for nonmetameric matches delimiting tolerances acceptable in a given color grade for a food. 

Paradoxically, exact color matches are at the same time very coimnon and very rare. They are common in the sense that any two sections of the same uniformly colored surface or material will usually match physically and therefore also visually. Otherwise, exact color matches are rare. For example, samples of paints of the same name and specification, intended to match, seldom do so exactly if drawn from separate batches. Pigments of identical chemical specification generally do not cause surfaces to match if they are ground to different particle sizes or suspended within different binders. Physical matches of different materials, such as plastics and fabrics, are usually impossible because differing binders or colorants must be used. 

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