During the processing of polymers, several selected substances are added to optimize specific properties<\/strong>, because only after the incorporation of an additive can a polymer fulfill those requirements. Supplementation of polymers with additives is quite common.<\/p>\n Additives can include:<\/p>\n Antimicrobiological substances<\/strong><\/p>\n<\/li>\n Antistatic agents<\/strong><\/p>\n<\/li>\n Flame retardants<\/strong><\/p>\n<\/li>\n Fillers<\/strong><\/p>\n<\/li>\n Lubricants \/ dispersing agents \/ release agents<\/strong><\/p>\n<\/li>\n Nucleating agents<\/strong><\/p>\n<\/li>\n Stabilizers<\/strong><\/p>\n<\/li>\n Blowing agents<\/strong><\/p>\n<\/li>\n Plasticizers<\/strong><\/p>\n<\/li>\n<\/ul>\n There are principally two methods<\/strong> of adding additives:<\/p>\n As a component of a color batch<\/strong><\/p>\n<\/li>\n As a separate additive batch<\/strong><\/p>\n<\/li>\n<\/ol>\n Some additives must be incorporated by the polymer manufacturer<\/strong> due to the high concentrations required. For example, certain grades of polymers, such as glass fiber-reinforced types<\/strong>, contain up to 55\u201360% filler<\/strong>.<\/p>\n It is also common for customers to request the incorporation of an additive into the color preparation, for instance, a stabilizer to improve the light fastness<\/strong> of the plastic article.<\/p>\n A combination of color plus additive<\/strong> in one batch can sometimes be problematic:<\/p>\n Space in the formulation:<\/strong> Additives take up space in the recipe, reducing the concentration of colorants, especially for very intensive colors. This may require a higher addition<\/strong> of the color batch for the final product.<\/p>\n<\/li>\n Color of additives:<\/strong> Some additives are not colorless, so they must also be colored, increasing the total amount of colorant needed.<\/p>\n<\/li>\n<\/ul>\n Some additives are marketed as pre-made batches<\/strong>, so it is worth evaluating whether two separate batches<\/strong> (color batch + additive batch) or a combined batch<\/strong> is more economical.<\/p>\n Additives can be inorganic<\/strong> or organic<\/strong>.<\/p>\n<\/li>\n Interactions<\/strong> between additives and colorants may occur and can be either positive or negative.<\/p>\n<\/li>\n The primary function of an additive is to optimize a specific property<\/strong> of the polymer.<\/p>\n<\/li>\n This requires tailor-made substances<\/strong> for each polymer type, depending on its chemical structure, which results in a large variety of additives<\/strong>.<\/p>\n<\/li>\n<\/ul>\n Antimicrobiological Substances<\/strong><\/p>\n Tests have shown that bacteria and fungi<\/strong> can settle on plastics and even penetrate the polymer surface<\/strong>. Consequently, mechanical cleaning alone is insufficient<\/strong> to remove them.<\/p>\n To prevent harmful contamination, an antimicrobiological substance<\/strong> can be added to the polymer. This supplementation serves as an additional precautionary measure<\/strong> and does not replace standard hygiene practices<\/strong>.<\/p>\n Fields of Application<\/strong><\/p>\n Examples include:<\/p>\n Characteristics of Effective Antimicrobiological Substances<\/strong><\/p>\n Antimicrobiological substances used in polymers are well-known compounds<\/strong> previously applied successfully in disinfectants for many years.<\/p>\n A substance is suitable for polymer application if it meets the following requirements:<\/p>\n Example:<\/strong><\/p>\n Antistatic Agents<\/strong><\/p>\n Many polymers have good electrical insulating properties<\/strong>, which makes them susceptible to static electricity accumulation<\/strong>.<\/p>\n Static electricity is generated when two materials with different electron affinities<\/strong> are rubbed together. This can involve two polymers or different types of materials. Friction shifts the natural balance of electrons:<\/p>\n When such materials come into contact with a conductive material<\/strong>, a discharge (spark)<\/strong> occurs. Dry conditions<\/strong>, particularly in winter, increase the risk of static buildup.<\/p>\n Mechanism of Antistatic Agents<\/strong><\/p>\n Antistatic agents reduce static electricity by forming a very thin layer of humidity<\/strong> on the polymer surface, making it partially conductive<\/strong>.<\/p>\n Fields of Application<\/strong><\/p>\n Practical Considerations<\/strong><\/p>\n Problems related to static electricity during polymer coloring can be solved by adding 0.1\u20130.3% antistatic agent<\/strong> to the color preparation.<\/p>\n It should be noted that several dispersing agents<\/strong> also exhibit a side effect of antistatic activity<\/strong>.<\/p>\n The main compounds used as antistatic agents include:<\/p>\n Fatty acid esters<\/strong><\/p>\n<\/li>\n Ethoxylated fatty acid esters<\/strong><\/p>\n<\/li>\n Alkylamine derivatives<\/strong><\/p>\n<\/li>\n Ethoxylated alkylamine derivatives<\/strong><\/p>\n<\/li>\n Alkylsulfonates<\/strong><\/p>\n<\/li>\n<\/ul>\n The antistatic effect works by forming a very thin layer of humidity<\/strong> on the polymer surface. This requires the migration of the antistatic agent<\/strong> to the surface.<\/p>\n In partially crystalline polymers<\/strong>, the required concentration is 0.1\u20130.5%<\/strong>.<\/p>\n<\/li>\n In amorphous polymers<\/strong>, a higher concentration of 1.0\u20131.5%<\/strong> is needed.<\/p>\n<\/li>\n<\/ul>\n Migration is not limited to the outer surface; it can also occur internally<\/strong>, which may result in contamination of the filled product<\/strong>.<\/p>\n Use of antistatic agents in consumer goods<\/strong>, especially those in contact with food, cosmetics, or other sensitive products<\/strong>, is subject to legal regulations to ensure consumer safety<\/strong>.<\/p>\n Germany:<\/strong> All plastic items in contact with food, packaging for food, smoking materials, household products, cosmetics, and items in prolonged skin contact are regulated. Only approved antistatic agents<\/strong> within defined concentrations are allowed (e.g., ethoxylated alkylamine derivatives up to 0.15% in the final product).<\/p>\n<\/li>\n United States:<\/strong> Only FDA-approved antistatic agents<\/strong> may be used in consumer goods.<\/p>\n<\/li>\n<\/ul>\n Many antistatic agents are liquid at room temperature<\/strong> or have melting points below polymer processing temperatures<\/strong>, such as ethoxylated alkylamine derivatives and ethoxylated fatty acids.<\/p>\n Incorporating a liquid antistatic agent into a solid color preparation requires special precautions<\/strong>, especially at higher concentrations.<\/p>\n<\/li>\n Frequently used liquid antistatic agents are commercially available as solid concentrates<\/strong>, either:<\/p>\n Absorbed on a highly absorptive carrier like silica, or<\/p>\n<\/li>\n As a highly concentrated batch<\/strong><\/p>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n These solid concentrates are preferred because they do not cause problems during production<\/strong> of solid color preparations.<\/p>\n Most polymers are more or less combustible<\/strong>, and high standards in fire protection<\/strong> necessitate the use of flame retardants. To comply with regulations, polymers must often be equipped with a flame retardant.<\/p>\n Flame retardants are commonly used in:<\/p>\n Electrical\/electronic appliances:<\/strong> TV compounds, fuse boxes, switches, plugs, etc.<\/p>\n<\/li>\n Interior decor of public transport:<\/strong> Buses, railways, airplanes<\/p>\n<\/li>\n Building protection:<\/strong> Interiors and exteriors of airports, railway stations, and similar structures<\/p>\n<\/li>\n<\/ul>\n In the past, chlorinated and brominated substances<\/strong> were preferred due to their effectiveness at relatively low concentrations.<\/p>\n<\/li>\n However, they released gaseous halogen hydrides<\/strong> during fire, which, combined with water, were highly corrosive and could destroy sensitive electronic components<\/strong>, often causing more damage than the fire itself.<\/p>\n<\/li>\n As a result, halogenated flame retardants have lost importance<\/strong> in recent decades.<\/p>\n<\/li>\n<\/ul>\n Modern flame retardants are halogen-free<\/strong>, but:<\/p>\nCommon Additives<\/h3>\n
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Methods of Incorporation<\/h3>\n
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\nConsiderations for Combining Color and Additives<\/h3>\n
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\nNature and Function of Additives<\/h3>\n
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Antistatic Agents (Continued)<\/h3>\n
Primary Compounds Used<\/h4>\n
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Concentration and Polymer Type<\/h3>\n
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Regulatory Considerations<\/h3>\n
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Practical Considerations for Incorporation<\/h3>\n
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Flame Retardants<\/h3>\n
Fields of Application<\/h3>\n
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Evolution of Flame Retardants<\/h3>\n
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Modern Flame Retardants<\/h3>\n
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