Eversorb for TPU Light Stabilizer — All-in-One Anti-Yellowing Protection

3 Aug, 2026

Author : Specialty Chemical Business Unit

Eversorb® for TPU
Protecting the Beauty of Transparent TPU Film, Starting with Anti-Yellowing

A Light Stabilizer Built for TPU — All-in-One Protection for Transparency, Light, Heat & Phenolic Resistance

TPU (Thermoplastic Polyurethane) combines high transparency, excellent elasticity, abrasion resistance, and easy processability, making it widely used across the footwear, textile, and leather industries. Transparent TPU film and hot-melt adhesive film are often laminated onto fabric, synthetic leather, or other substrates as composite materials — providing bonding, support, and protective functions while directly shaping the final product's appearance. This makes transparency, initial color, and yellowing resistance critical performance requirements.

It's worth noting that even though transparent TPU film is often hidden within a composite product, any hint of color or gradual yellowing in the film will still cause light-colored or white products to shift in tone — much like laying a faintly yellow transparent sheet over a piece of white paper. Even though the sheet itself remains transparent, the whole page loses its original whiteness, directly affecting the perceived quality and value of the final product.

Three Yellowing Challenges: Light, Heat & Phenolic Compounds

Compared with conventionally colored materials, transparent TPU film is far more sensitive to color change — even the slightest yellowing is easily noticeable to the eye. Beyond UV-induced light yellowing, high-temperature processing can trigger heat-induced yellowing, while phenolic antioxidant off-gassing during packaging, shipping, or storage can cause phenolic yellowing in the footwear and textile industries. Achieving low initial color while effectively controlling all three types of yellowing has become a critical challenge for high-performance transparent TPU film.

✳ Light-Induced Yellowing

UV exposure degrades the material, causing yellowing after prolonged outdoor exposure — the most common cause of yellowing.

✺ Heat-Induced Yellowing

Thermal oxidation during high-temperature processing (such as injection molding) or in high-temperature environments causes discoloration.

✤ Phenolic Yellowing

Volatile compounds from phenolic antioxidants react with the material during packaging, shipping, or storage, resulting in yellowing.

The Dilemma of Conventional Formulations: Balancing Trade-offs

Conventional anti-yellowing formulations typically rely on a combination of light stabilizers and antioxidants to improve the light and heat resistance of transparent TPU film. However, selecting stabilizers requires careful attention to overall formulation compatibility. Combining multiple additives not only increases the complexity of formulation design, raw material sourcing, and inventory management, but different additives may also interact with one another, reducing overall protective performance — and in some cases, even worsening phenolic yellowing test results. Balancing light and heat yellowing resistance while avoiding any negative impact on phenolic yellowing performance, all while simplifying formulation complexity, has become a top priority in transparent TPU film development.

The Innovative Solution: Eversorb® for TPU — All-in-One Protection in a Single Additive

To address these industry challenges, Everlight Chemical has introduced Eversorb® for TPU, a light stabilizer purpose-built for transparent TPU film. This white powder additive, used at just 0.6% loading, delivers comprehensive protection for the appearance and durability of transparent TPU film — breaking through the trade-offs of conventional multi-additive formulations.

Additive Appearance Comparison

Market Product (Pale Yellow Powder)

Eversorb® for TPU (White Powder)

Comprehensive Protection, No Trade-offs Significantly improves light and heat yellowing resistance without compromising phenolic yellowing performance

One Additive, Simplified Formulation Replaces complex multi-additive combinations, greatly simplifying formulation design

Reduces Hidden Risks Effectively avoids interaction and compatibility risks between different additives

The Data Speaks: Four Key Test Results

All tests below were conducted on clear, colorless polyester-based TPU (2mm thickness), processed by high-temperature injection molding (190–210°C), with an unadditized control and a commercial additive of the same type (0.6% loading) used as reference points.

Comparison Item	No Additive (Control)	Market Product_0.6%	Eversorb® for TPU_0.6%
Additive Appearance	—	Pale yellow powder	White powder
Initial Color (YI)	1.3	3.8	1.5
Weathering ΔE (QUV 340nm, 24hr)	22.7	2.3	1.5
Weathering Grey Scale	1	3.5	4
Heat Yellowing ΔE (130°C, 2hr)	5.1	1.5	1.5
Heat Grey Scale	2.5	4	4 (Comparable)
Phenolic Yellowing ΔE (ISO 105-X18)	0.5	2.2	0.7
Phenolic Grey Scale	4.5	3.5	4.5

※ Grey Scale: rated 1–5, with 5 indicating the best result (virtually no visible fading or yellowing).

❶ Initial Color (YI, Yellowness Index)

Test Conditions: Loading 0.6% | Metric: Yellowness Index (YI)

1.3

No Additive

3.8

Market Product

1.5

Eversorb® for TPU

※ Lower values indicate a lighter initial color. Eversorb® for TPU stays close to the unadditized baseline, while the market product shows a noticeably yellow tint.

No Additive

Market Product_0.6%

Eversorb® for TPU_0.6%

❷ Weathering Yellowing (QUV 340nm Accelerated Aging)

Test Conditions: QUV 340nm | Irradiance: 0.78 W/m²/nm | Test Temperature: 45°C | Duration: 24 hours | Metrics: ΔE, Grey Scale

22.7

No Additive

2.3

Market Product

1.5

Eversorb® for TPU

※ Grey Scale: Market Product 3.5 / Eversorb® for TPU 4. Eversorb® for TPU outperforms the market product in both ΔE and Grey Scale under weathering testing.

No Additive

Market Product_0.6%

Eversorb® for TPU_0.6%

❸ Heat Yellowing (130°C Circulating Oven)

Test Conditions: 130°C circulating oven | Duration: 2 hours | Metrics: ΔE, Grey Scale

5.1

No Additive

1.5

Market Product

1.5

Eversorb® for TPU

※ Grey Scale is identical at 4, and ΔE is also identical at 1.5. Eversorb® for TPU performs on par with the market product for heat resistance — both far outperform the unadditized baseline.

No Additive

Market Product_0.6%

Eversorb® for TPU_0.6%

❹ Phenolic Compatibility (ISO 105-X18)

Test Conditions: Per ISO 105-X18 | Metrics: ΔE, Grey Scale

0.5

No Additive

2.2

Market Product

0.7

Eversorb® for TPU

※ Grey Scale: Market Product 3.5 / Eversorb® for TPU 4.5. The market product actually shows greater phenolic yellowing than the unadditized baseline, while Eversorb® for TPU stays close to baseline levels — confirming its core claim of "no negative impact on phenolic yellowing."

No Additive

Market Product_0.6%

Eversorb® for TPU_0.6%

Key Advantages at a Glance

✪ Enhanced Multi-Protection — Overall Aging Resistance Outperforms the Market Product ✪

➤ Outstanding Low Initial Color｜Crystal-Clear Clarity A white powder additive with no impact on the initial appearance of transparent TPU film, easily maintaining high transparency and a clean, pure look.		➤ Excellent Light Yellowing Resistance｜Built for Sun Exposure Efficiently absorbs and blocks UV-induced degradation, maintaining a clear appearance even under prolonged sun exposure.

➤ Reliable Heat Yellowing Resistance｜Enhanced Thermal Stability Effectively suppresses thermal oxidation-induced discoloration during high-temperature processing and in high-temperature environments, improving processing stability.		➤ No Formulation Conflicts｜Won't Interfere with Phenolic Performance Delivers excellent light and heat protection without affecting phenolic yellowing test results — simplifying formulation design and improving overall yield for R&D teams.

Applications

Footwear

Athletic and fashion footwear often use transparent TPU film as a decorative composite material. Eversorb® for TPU helps footwear maintain a clear, clean appearance throughout long-term display and wear.

Textiles

Functional textiles laminated with TPU film or hot-melt adhesive film benefit from Eversorb® for TPU, which helps prevent color shift caused by substrate yellowing — keeping light-colored and white fabrics consistent.

Tents

Outdoor tents and functional fabrics face prolonged exposure to sunlight and high temperatures. Eversorb® for TPU helps slow the yellowing of composite film materials, keeping outdoor gear looking clear and transparent even after extended exposure to wind and sun.

✦ Protecting Your Product's Appearance, Starting with Anti-Yellowing ✦ Eversorb® for TPU by Everlight Chemical — letting the beauty of transparent TPU film withstand the triple test of light, heat & phenolic exposure

As the footwear, textile, and leather markets increasingly demand transparent, high-clarity designs and a premium look, transparent TPU film has become a core material for high-value-added products — and the clearer and purer the product, the less tolerance it has for issues in initial color and yellowing resistance. Everlight Chemical's Eversorb® for TPU combines low initial color, excellent light and heat resistance, and no negative impact on phenolic yellowing performance, delivering overall aging resistance that outperforms the market product. It helps you maintain high transparency while extending appearance stability and product lifespan, improving yield and reducing the risk of customer complaints. Everlight Chemical remains committed to its brand philosophy of "Better Chemistry for a Better Life," continuing to develop forward-looking material solutions and partner with you to create functional products that combine beauty, durability, and quality.

✆ Take the First Step Toward Anti-Yellowing
For product applications, custom formulations, or technical testing needs, please feel free to contact Everlight Chemical's sales and technical service team. We provide comprehensive application testing support to help you evaluate the feasibility of incorporating Eversorb® for TPU into your specific formulation system.