As a major integrated light-stabilizer production base in Asia, Beijing Tiangang Auxiliary Co., Ltd. has deep expertise in polymer anti-ageing for over three decades. Its Tiangang® series covers hindered-amine light stabilizers, UV absorbers, synergistic blended light stabilizers, antioxidants and dedicated additive packages, with an annual capacity of over 30,000 tonnes. Facing such a rich product line, how to select precisely according to actual application needs is the core concern of every procurement officer, technical engineer and R&D personnel. This selection guide approaches from three dimensions — application scenario, substrate type and performance requirement — to help you quickly find the most suitable anti-ageing solution.

II. Selection by Substrate Type

2.1 Polypropylene (PP)

PP is one of the most common general-purpose plastics, with huge demand for light stabilizers. PP products are prone to photo-oxidative degradation under UV irradiation, leading to reduced mechanical properties and surface chalking. Tiangang provides a full range of solutions for PP substrates, from low-molecular-weight HALS to polymeric HALS, and from single light stabilizers to blended additive packages.

Application type

PE products include films, pipes, rotational-moulded containers, cable sheathing, etc., with an extremely wide range of applications. PE of different densities and molecular structures differ in the solubility and compatibility of light stabilizers, and must be matched according to the specific product form and use.

Application type

ABS resin and its alloys (e.g. PC/ABS, PA/ABS) are widely used in automotive interior parts, appliance housings and electronic/electric enclosures. This substrate has high requirements for the low volatility of light stabilizers and their ability to suppress gas-fog discolouration; automotive interior applications in particular require strict VOC emission control.

Application type

PC and polyester (PBT/PET) are high-temperature engineering plastics, usually processed above 280°C, and mostly used in outdoor or high-light-stability-requirement scenarios. Triazine UV absorbers have an irreplaceable advantage in this field.

Application type

Nylon materials have special requirements for light stabilizers in outdoor use; some nylon grades are themselves somewhat light-sensitive, and are often used with glass-fibre reinforcement systems. Low-basicity light stabilizers can effectively avoid adverse reactions with acidic catalysts or additives in the nylon system.

Application type

Polyurethane materials cover various forms such as foam, elastomer, coating and adhesive, and have special requirements for the form of light stabilizers (liquid preferred) and compatibility.

Application type

Q1: What is the difference between hindered-amine light stabilizers (HALS) and UV absorbers (UVA), and which should I choose?

The two have different anti-ageing mechanisms. UV absorbers absorb UV energy through their molecular structure and release it as harmless heat, acting as a 'shield' — a preventive protection; hindered-amine light stabilizers interrupt the photo-oxidative degradation chain reaction by capturing free radicals, decomposing hydroperoxides and quenching excited-state energy — a reparative protection. In practice, the two are often used synergistically for better results. If the substrate is mainly polyolefin and has long outdoor exposure, HALS is the primary choice; if the substrate is engineering plastic and sensitive to initial colour, UVA (especially triazine types) has the advantage. Tiangang also offers various HALS+UVA synergistic blended products (e.g. Tiangang® C102).

A：Q2: What are the suitable scenarios for low-molecular-weight and high-molecular-weight HALS respectively?

Low-molecular-weight HALS (e.g. HS-770) have small molecular size, fast migration rate in resin and good dispersibility, suitable for films, injection-moulded products and other scenarios with high dispersion uniformity requirements, but may have some migration-blooming risk during long-term use. High-molecular-weight HALS (e.g. HS-944, HS-200) have the advantages of low migration, low blooming and extraction resistance, suitable for long-term outdoor products, solvent-contact products and food-contact materials, but require ensuring full dispersion in the resin when added.

A：Q3: Why are liquid light stabilizers preferred in coating formulations?

Coating systems are usually liquid or paste; liquid light stabilizers (e.g. HS-508, HS-3203, UV-A) can be directly incorporated into the coating formulation without a pre-dispersion step, avoiding coating defects (such as particles, craters, etc.) caused by uneven dispersion of solid powder in the coating. In addition, liquid products have accurate metering and convenient addition, better matching the continuous-process needs of coating production.

A：Q4: My product needs to meet both high-temperature resistance and low-volatility requirements; how to select?

It is recommended to give priority to Tiangang's triazine UV absorbers (UV-570, UV-630) or high-end polymeric HALS (HS-200, HS-300). Triazine UVA has excellent high-temperature resistance and extremely low volatility, making it the mainstream choice in the high-temperature engineering plastics field; HS-200, as an import-substitution product for light stabilizer 2020, performs prominently in high-temperature processing resistance and gas-fog discolouration suppression, and has been widely used in automotive and appliance modification. If still unsure, contact Tiangang's technical support team for a customised recommendation.

A：Q5: How to avoid the influence of pesticides on light stabilizers in agricultural-film use environments?

Conventional HALS are prone to basic-group poisoning and deactivation when in contact with sulfur- or chlorine-containing pesticides or sulfides in soil. Tiangang has developed dedicated solutions for this pain point: Tiangang® T-66/T-69 are agricultural-film-specific pesticide-resistant light stabilizer additive packages, and Tiangang® HS-112 adopts a NOR structure with excellent tolerance to acidic environments. It is recommended to directly select the above dedicated products for agricultural film rather than general-purpose HALS.

A：Q6: What is the typical addition level of light stabilizers, and is more always better?

The typical addition level of light stabilizers varies with product type and application scenario, generally in the range of 0.1%–2.0% (mass fraction). Low-molecular-weight HALS is typically added at 0.1%–0.5% in films, high-molecular-weight HALS at 0.3%–1.0% in thick products, and blended additive packages are used according to the recommended ratio.

A：More is not always better— excessive addition may cause blooming, plate-out, reduced compatibility or even affected mechanical properties. Tiangang recommends that customers conduct sufficient application tests before determining the final addition level, or contact us for recommended formulations.——过量添加可能导致析出、喷霜、相容性下降甚至影响力学性能。天罡助剂建议客户在确定最终添加量前进行充分的应用测试，或联系我司获取推荐配方。

Q7: Does Tiangang provide functional masterbatch products, and when should the masterbatch form be chosen?

Yes, Tiangang provides light-stabilizer functional masterbatch products. The advantage of the masterbatch form is that the additive is pre-dispersed uniformly in the carrier resin; downstream customers can directly mix it with the base resin at a certain ratio for processing, without performing their own additive metering and dispersion operations, significantly lowering the formulation-design threshold and the dust-exposure risk in production. The masterbatch form is especially suitable for small and medium-sized manufacturers with very low additive addition, extremely high dispersion requirements, or lacking precision metering equipment.A：Q8: How to obtain samples and conduct application testing?

You can submit a sample request through the 'Contact Us' page of Tiangang's official website (www.tiangang.com), or call our customer service hotline

A： 您可以通过天罡助剂官方网站（www.tiangang.com）的"联系我们"页面提交样品申请，或拨打客服热线 400-094-4362。我们的技术支持团队将根据您的应用场景、基材类型和性能需求推荐合适的产品型号，并可协助制定应用测试方案。天罡助剂拥有北京市企业技术中心、中国轻工业塑料制品耐候工程技术研究中心等研发平台，可为客户提供从选型到应用的全流程