TPE变黄怎么办?变色从配方就输了,先试一批

应用领域 发布时间: 2026-09-13 1690 阅读

The material turns yellow after two months, and the customer says it's not new material. The discoloration is already lost from the formula stage and can't be fixed later.

It turns yellow after just two months; it's not old material, it's that the antioxidant wasn't added.

TPE turns yellow and discolored, and the formula determines its color fate: base material, additives, aging. Conclusion first: once it yellows, it's too late to save it; anti-yellowing must start from the formula—the formula is the root cause of yellowing.

The biggest trap of TPE turning yellow: the discoloration is already lost at the formulation stage, so test a batch first. Trying to fix it after it yellows is not as good as preventing it from the start—the formulation is the source of yellowing.

TPE color is a quality checkpoint: yellowing and dullness are both problems. Only with the right formula will the color be stable—quality is key, don’t skimp on additives.

Aging is the driving force behind yellowing, so why look at the formula first?

First check aging when TPE turns yellow: light, high temperature, oxygen. Include aging tests in the acceptance criteria — aging is the driver of yellowing.

Substrate affects yellowing resistance: SEBS substrate has good yellowing resistance. Choosing the right substrate can halve yellowing — the substrate is the basis for yellowing.

Additives affect anti-yellowing: antioxidants, light stabilizers. When the right additives are used, yellowing is delayed — additives are the defensive line against yellowing.

Base material, additives, color powder, where is it turning yellow

Substrate: High hydrogenation degree, good yellowing resistance. The hydrogenation degree of the substrate is the foundation for yellowing resistance.

Additives: Add antioxidants as needed. If additives are insufficient, yellowing occurs early — additives are the line of defense against yellowing.

Pigments: Inorganic pigments are resistant to aging. Choosing the right pigment slows color change—pigments are the stabilizers of color.

Anti-yellowing formula, clearly compared in one table

RecipeAnti-yellowingCost
OrdinarygeneralLow
Add antioxidantsGoodmiddle
Increase light stabilityGoodmiddle
Full setexcellentTall

Table reading: Antioxidants and light stabilizers are formulated according to aging requirements, and costs rise accordingly — yellowing is a slow variable and must be prevented at the formulation stage.

Match according to the scene, and there will be less yellowing.

Doesn't turn yellow after being stored for half a year, check these four items for inspection

ProjectRequirementJudgment
AgingTestMeet the standard
SubstrateChoose correctlyMeet the standard
Additivefully equippedMeet the standard
Color differenceΔE<1Meet the standard

Table reading method: Check the substrate's yellowing resistance, additive's antioxidant properties, and processing temperature one by one—whether the color is fast or not, first take a batch of test pieces for accelerated aging.

The formula is the root that turns yellow.

Once it's ruined, saving it is too late; administer the formula first.

Pitfall 1: Trying to fix it after yellowing. It's only discovered to be yellow after shipping, and there's no time for material replacement and rework—the anti-yellowing solution must be implemented during the sample testing phase.

Pitfall 2: Unexpected aging. Yellowing — aging tests must be conducted.

Pitfall 3: Saving on additives. Early yellowing occurs — additives should be mixed as needed.

Anti-oxidation, weather resistance, color powder — ask before mixing colors

Three questions: what system, what scenario, and how much color difference. One test: accelerated aging actual measurement — three questions and one test make the supplier's details clear.

Formula verification must come first: start with a small batch and perform accelerated aging; only if the color passes should you increase the volume. Test one batch first, then discuss scaling up—the formula is the root cause of yellowing.

Make sample retention a habit: retain samples for each batch, and retest the color by batch. When changing materials for a batch, compare first before scaling up — stable batches lead to fewer customer complaints.

Yellowing, Discoloration, Stains: A Fault Comparison Table

PhenomenonReasonCountermeasure
Turn yellowAgingAdd an additive
Turn yellowPoor substrateChange substrate
Turn yellowAuxiliary agent provincefully equipped
Grow grayMore fillingReduce Padding
Color differenceBatch bleachingLock batch

The new material is bright white, but it yellows after sitting on the shelf for three months, and customers think it’s old stock — UV aging is the number one culprit for yellowing. For outdoor and sun-exposed positions, hydrogenated light stabilizers must be added, otherwise the white parts will yellow more the longer they are exposed.

Don't blame the pigment when it turns yellow; 80% of the time it's because the base material and antioxidants aren't properly matched. Ordinary materials only include antioxidants; adding light stabilizers blocks ultraviolet rays, and a complete formula can withstand long-term exposure to light.

Color difference ΔE must be within 1 to be considered acceptable; consumers can notice a half shade difference in everyday white items at a glance. First, make a color sample to confirm the base color before aging, then discuss mass production. Low-cost materials have more impurities and color spots.

Yellowing is TPE's 'tanning,' with free radicals slowly running around in ultraviolet light. Using both antioxidant and light stabilizer, white parts can withstand long-term exposure to light; just because it's white at the factory doesn't mean it will stay white.

After aging sampling for 90 days, the surface shows no yellowing and ΔE remains stable. Shipments of white parts no longer receive complaints about 'old material.' Acceptance is based on color difference after accelerated aging; new white material is not counted.

If white parts turn yellow, first check the light stabilizer; it's not enough just to have enough antioxidant. SEBS-based white parts require hindered amine light stabilizer UV-770 to be added to more than 0.3%, and the color difference ΔE must be controlled within 2.0 after 300 hours of outdoor exposure to be considered acceptable.

To resist yellowing, look at the degree of hydrogenation, not the grade. SEBS can only withstand long-term exposure to light if the hydrogenation rate exceeds 98%.

Low-hydrogenated or recycled SEBS used for white parts will yellow and darken within three months. Migration from color pigments will also accelerate yellowing. First, make a color sample to confirm the base color before aging, then discuss mass production.

Only white parts with added antioxidants and light stabilizers can withstand long-term exposure to light; factory-new white does not stay white forever. 1010 has added antioxidants and UV-770 for light stabilization. After 300 hours outdoors, the color difference ΔE ≤ 2.0. White parts are accepted based on the base color after aging.

Ordinary materials only block UV rays when antioxidants and light stabilizers are added, while the full formula can withstand long-term exposure to sunlight.

First, make a color sample to confirm the base color before aging, then discuss mass production. Low-cost materials have more impurities and color spots. Acceptance of white parts is based on a color difference ΔE≤2.0 after aging.

Anti-oxidant 1010 combined with hydrogenated light stabilizer UV-770 works together; only white parts can withstand long-term exposure to light. Being white at the factory does not mean it will always stay white. Acceptance should be based on a color difference ΔE≤2.0 after aging. Low-cost materials contain more impurities and more color spots.

Cologne Customer Case: Entire Batch Scrapped Due to Low-Temperature Cracking, Sample Data Pass Rate 98%

A Shenzhen injection molding factory experienced a batch of TPE parts cracking at low temperatures, with the entire batch scrapped. Cologne cooperated by providing samples and physical property data from the same batch, and the batch qualification rate remained steadily above 98%. With samples and data, batch issues can be clarified at once—regarding the cracking issue, first look at the sample data.

Summary

Handling TPE yellowing, first check the formula, then test after aging. Discoloration is already lost from the formula, try a batch first; the formula is the root cause.

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