Application
UV-Stabilizer-Masterbatches prevent or terminate oxidation of plastics by UV-light: acting by absorption of energy, deactivating by-products of oxidation, decomposition of by-products. Some types also offer functions as antioxidants, too.
Effect
Ultraviolet light and the simultaneous influence of oxygen (photo oxidation), considerably damage unstabilized thermoplastic resins. Depending on the polymer decrease of optical, mechanical and physical properties happens: loss of surface shine, surface rips, de-chalking, yellowing, discolouring, embrittlement, deterioration of the mechanics, etc. light stabilizer agents delay or prevent the photo oxidation in different ways.
UV-absorber filter the ultraviolet part of the light. Thereby the energy of the absorbing light is transformed into heat. The strength of the UV-absorption depends on the concentration of the active substance and the wall thickness of the final product. Generally, this does not provide the plastic surface with any protection. UV-absorber can protect filling goods against UV-light.
HALS-additives prevent the formation of aggressive photo oxidation products on the surface, as well as in deeper lying layers. Thereby an optimum protection, virtually independent from the wall thickness of the final product is obtained. The concentration of the additive in the end product is the measure of the life of the product.
Beside the photo oxidation, thermoplastics are subject to the attack of oxygen in the presence of heat (thermo oxidation). Products, which are exposed to direct sunlight, are heated according to their colour up to more than 50°C. Therefore, some of our UV-Masterbatches are combined with thermo-stabilizers, which simultaneously increase the effect of the UV-stabilizers.
Halogenous flame-retardants disturb the effect of HALS-stabilizers. In these cases a detailed consultation is necessary.
Additives
UV-Absorbers e.g. benzophenones, benzotriazoles
UV-Stabilizers e.g. hindered amines (HALS)
Polymer stabilizers Antioxidants for synergistic effects
Dosage
The dosage of UV-stabilizer-batches depends on many factors: type of plastic, cross-section or layer thickness of the finished parts, fillers and pigments, orientation and crystallinity, as well as the geographic area of application. The UV-radiation energy, which hits the surface of the product, is measured in kLy (kilo Langley): 1 kLy = 1 kcal/cm² = 4.2 kJ/cm². The annual dosage of the radiated amount of energy corresponds in Central Europe to ca. 70-80 kLy, in Southern Europe to ca. 100-120 kLy, and in the USA to ca. 120-160 kLy.
Quality
Our Masterbatches are well formulated to the special demands of the individual requirements.
Granules: strand-cut or round pellets
Compatibility to the following polymers:- PE-LD, PE-HD, PE-LLD
- PP, PP-homo, PP-copo, PP-random
- EVA, EBA , Universal
- PS and Styrenics (ABS, SAN …)
- PC
- PA 6, PA 6.6, PA 11, PA 12
Food contact approval
In general, nearly all of the active agents are admitted within the usual dosage, according to the BfR-recommendations.
The particular data can be taken out of the product information sheets.
Approvals of other authorities, especially FDA- and EC-approvals are present in most cases and are available, if required.
Do you have questions or do you need detailed product information?
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