油封泡在油里三个月就溶胀漏油，客户车间地上都是油。耐油TPE选错，这根件迟早是漏点。
翻车现场：耐油 TPE，泡出来的问题
耐油 TPE，用在汽车油路密封、工业油封、耐油管件上——翻车现场几乎都是“泡”：
现场一：密封件泡油一周，体积胀大、尺寸飘移——耐油等级没对标油品，溶胀是必然；现场二：
耐油管件泡油后发硬开裂——油把增塑剂抽走了，材料变脆；现场三：油封用普通牌号硬顶——**硬度、耐温、耐油全不达标，三个月就换。
**
耐油得和压缩永久变形一起看：密封件既要耐油，又要长期压缩不失效——两个指标是绑定的。
只耐油、压变大的密封件，短期不漏，长期必漏。双指标验收，是耐油密封件的专业门槛。
油品混用是隐藏风险：设备里混了不同油品，材料可能面对“混合油”工况——混合油的溶胀性，比单一油更难预测。
所以耐油件选型，把“可能接触的所有油品”都列出来，按最严的算。
耐油件的“更换周期”是采购要算的账：普通牌号 3 个月换一次，耐油牌号 12 个月换一次——材料贵 30%，更换成本省 75%。
所以耐油 TPE 的性价比，要按“每小时的密封成本”算，不是按每吨的价格算。
油温和溶胀是协同的：油温越高，溶胀越狠——80℃ 的油和室温的油，溶胀率能差出一倍。
所以耐油件的工况要写“油品+油温”两个数，供应商按两个数出数据。只写“耐油”两个字，供应商没法给准话。
耐油 TPE 的选型，先问“泡什么油、泡多久、泡多热”——三个问题，定体系、定等级、定寿命。
| 步骤 | 动作 | 输出 |
|---|
| 一 | 定油品、定温度 | 介质清单 |
| 二 | 选体系 | 候选体系 |
| 三 | 对数据 | 溶胀率结论 |
原因拆解：耐油的机理
油对 TPE 的伤害，主要是“抽提”和“溶胀”——油把材料里的油分、助剂抽出来，材料变硬变脆；油渗进材料，体积膨胀、强度下降。
耐油等级，看的就是材料在油里的体积变化和强度保留。
| 介质 | 对 TPE 的考验 | 耐油等级需求 |
|---|
| 机油 | 溶胀、抽提 | 高 |
| 柴油 | 溶胀明显 | 高 |
| 液压油 | 溶胀、老化 | 中高 |
| 汽油 | 溶胀剧烈 | 很高 |
| 润滑油 | 中等溶胀 | 中高 |
技术金句：耐油 TPE 的耐油数据，要按“实际油品 + 实际温度”测——标准油的报告，和真实工况可能差两级。
浸泡周期直接改数据：72h 的短泡和 1000h 的长泡，数据完全两样——短期达标、长期溶胀超标的料，市场上不少。
所以耐油件的验收，要按实际更换周期设定浸泡时长，别只看短期报告。
排查步骤：三步锁耐油料
- 1. 定油品：接触什么油？机油/柴油/液压油？——油品不同，等级不同；
- 2. 定温度：泡油时的温度是多少？——温度每升 10℃，溶胀翻倍是常事；
- 3. 对数据：要体积变化率、硬度变化、强度保留率——三个数，定生死。
这三个数的合格线可以更具体：按实际油品、实际温度浸泡 72h，体积变化率一般控制在 5% 以内，硬度变化不超过 ±10 邵氏 A，
拉伸强度保留率不低于 70%。
三个数同时卡，密封尺寸才稳；72h 合格，也不等于 1000h 合格。
成本要按级分着花：不是所有耐油件都要最高级——接触频率低、温度低的件，普通耐油级够用；高温高压动态的件，才上高级别。
分级选型，成本能省两成。
复验要排进年度节奏：耐油数据不是一劳永逸——供应商换原料、换配方，耐油表现就可能变。
所以耐油件建议每年复验一次溶胀数据，或供应商变更时立刻复验。复验是耐油件供应链的年度动作。
给耐油件采购一个“介质清单”模板：油品名称、牌号、温度、压力、接触方式（浸没/溅射/蒸氣）、更换周期——六项写全。
六项越全，供应商的选型越准，返工越少。
给耐油件采购一个“分级表”动作：把厂里所有耐油件按“油品+温度+动静”分三级——轻（常温、静态）、中（中温、静态）、重（高温、动态），
每级锁定对应体系。
分级表建起来，选型、库存、议价全都顺了。
密封结构要和材料一起评审：材料耐油之外，唇口、压缩量这些结构设计也要对——结构不对，再耐油的料也会漏。
所以耐油密封件是“材料+结构”的合体，选料时把结构设计一起过。
溶胀漏油怎么救：料、工艺、体系三处改
料的方向：同体系内调耐油等级——耐油牌号的油分和助剂体系是专门配的，普通牌号耐油差，是配方决定的。
工艺的方向：耐油件的成型，模温料温直接影响密实度——密实度不够，油更容易渗。工艺窗口控住，耐油表现上一个台阶。
体系的方向：耐油分级：SEBS 基耐油一般，TPV 耐油中上，TPEE 耐油好、耐高温——重油场景，直接上 TPV/TPEE。
动静之分要先写清：静态耐油件（垫片）和动态耐油件（油封）要求不同——动态件除了耐油，还要耐摩擦、耐疲劳，材料等级要高一档。
动静写清楚，采购才能定准等级。
耐油和耐温要组合验：汽车发动机舱里的耐油件，是“油+高温”双工况——单项耐油、单项耐温都达标，组合工况可能掉链子。
双工况的件，要做“高温+油”协同老化测试，别用单项数据推断。
科隆客户案例：溶胀变形跟产调，1000 小时老化一次过
烟台一家改性料应用厂，耐油件泡油溶胀变形。科隆配合现场跟产调试到良率稳定，一次性通过 1000h 老化测试。
溶胀变形，先查密度和配方，再谈换料——跟产调参，常常比换体系省。
耐油料到货查这四项，浸泡增重必测
- 1. 查溶胀数据：实际油品、实际温度的体积变化率；
- 2. 查强度保留：泡油后拉伸强度、硬度变化；
- 3. 查批次：耐油件的批次稳定性，硬度尺寸都要盯；
- 4. 留样对比：泡油测试留样，出争议时同条件复测。
四查里，实际油品测试最该做
| 验收项 | 看什么 | 要点 |
|---|
| 溶胀数据 | 实际油品溶胀率 | 按工况测 |
| 强度保留 | 泡油后强度 | 越高越稳 |
| 批次 | 硬度尺寸波动 | 盯批次 |
| 留样 | 泡油测试留样 | 复测对比 |
供应商的标准油报告，不能替代你的真实介质。
小结
这一篇先讲到这里，耐油 TPE 拿不准的工况随时来问，对号入座即可。
耐油 TPE 的选型是“油品×温度×体系”三件事——油品定等级、温度定难度、体系定上限，密封件才泡得住。
让供应商寄同油品浸泡样品：泡在真实油里一周后看溶胀，比报告直观——实测对比，是耐油采购的最后一关。一周见溶胀，比看报告实在。
装配这步也要防打滑：泡过油的密封件，表面有油膜，容易打滑、错位——装配前擦净或按规范操作。装配环节的管控，直接影响耐油件的实际密封效果。
最后补一个“实际介质留样”建议：把实际用的油品留样，和材料一起做浸泡测试，出争议时同条件复测——油品批次变了，结果可能不同。留样+复测，是耐油件验收的完整闭环。
泡油后的表面析出要查：材料表面可能析出助剂、发粘——析出会影响手感，也可能拖累下游装配。所以耐油件验收要加“泡油后表面状态”检查，发粘、析出的材料要谨慎。
油品类型决定溶胀程度：矿物油、合成油、植物油、液压油，对材料的溶胀完全不同——同样的料，泡矿物油和泡植物油，数据能差一倍。所以耐油件的工况要写“具体油品”，别笼统写“耐油”两个字。
Oil seals soaked in oil for three months swelled and leaked; the customer's workshop floor was covered with oil. Choosing the wrong oil-resistant TPE means this part will eventually become a leak point.
Accident site: Oil-resistant TPE, soaking problems
Oil-resistant TPE used in automotive oil circuit seals, industrial oil seals, oil-resistant pipe fittings—almost all crash sites are "soaked":
On-site 1: Seals soaked in oil for a week, bulge and size shift—oil resistance grade not matching oil, swelling is inevitable; Site 2:
Oil-resistant pipe fittings harden and crack after oil soaking—oil removes plasticizer, making material brittle; On-site 3: Use standard grade hardtop oil seals—if hardness, temperature resistance, and oil resistance all fail to meet standards, replace them every three months.
**
Oil resistance must be considered together with compression permanent deformation: seals must be oil-resistant and must not fail during long-term compression—these two indicators are linked.
Only seals that resist oil and have high pressure changes, will not leak in the short term, but will inevitably leak in the long term. Dual-indicator acceptance is the professional threshold for oil-resistant seals.
Mixing oils is a hidden risk: when different oils are mixed in the equipment, the material may face the "mixed oil" operating condition—the swelling of mixed oil is harder to predict than that of a single oil.
Therefore, when selecting oil-resistant parts, list "all oils that may come into contact" and calculate them as strictly.
The "replacement cycle" for oil-resistant parts is a factor to be accounted for in procurement: ordinary grades are replaced every 3 months, oil-resistant grades every 12 months — materials are 30% more expensive, replacement costs save 75%.
Therefore, the cost-performance ratio of oil-resistant TPE should be calculated by "hourly sealing cost," not per ton price.
Oil temperature and swelling work together: the higher the oil temperature, the more severe the swelling—oil at 80°C and oil at room temperature can differ by half in swelling rate.
Therefore, the operating conditions for oil-resistant parts should be listed as "oil quality + oil temperature," and suppliers provide data based on these two numbers. If only the word "oil resistance" is listed, suppliers cannot provide accurate information. When selecting
Oil-resistant TPE, first ask "What kind of oil to soak, how long, and how hot?"—three questions: determine the system, grade, and lifespan.
| Steps | Action | Output |
|---|
| One | Fixed Oil Quality, Fixed Temperature | Medium List |
| Two | Select System | Candidate System |
| Three | Data | Swelling Rate Conclusion |
Cause Breakdown: Mechanism of Oil Resistance
Oil Damage to TPE, mainly 'extraction' and 'swelling'—oil extracts oil and additives from the material, making it hard and brittle; Oil seeps into the material, causing volume expansion and reduced strength.
Oil resistance rating refers to the material's volume change in oil and strength retention.
| Medium | Test of TPE | Oil resistance requirements |
|---|
| Engine oil | Swelling, pumping/pumping | High |
| Diesel | Significant swelling | High |
| Hydraulic oil | Swelling, aging | Medium-high |
| Gasoline | Severe swelling | Very high |
| Lubricating oil | Medium swelling | Medium-high |
Technical wisdom: Oil resistance TPE oil resistance data should be measured as "actual oil quality + actual temperature"—the standard oil report may differ by two levels from actual operating conditions.
Directly change soaking cycle data: 72h short bubbles and 1000h long bubbles have completely different data—there are many materials on the market that meet short-term standards but exceed long-term swelling standards.
Therefore, when inspecting oil-resistant parts, set the soaking time according to the actual replacement cycle, not just short-term reports.
Troubleshooting steps: three-step lock in oil-resistant materials
- 1. Fixed oil type: what oil does it contact? Engine oil/die/hydraulic oil? —— Different oil grades vary;
- 2. Set temperature: What is the temperature during soaking? —— Temperature is 10°C per liter, and swelling doubles frequently;
- 3. For data: volume change rate, hardness change, strength retention rate—these three numbers determine life and death.
The qualification line for these three numbers can be more specific: soak for 72 hours based on actual oil quality and temperature, with volume change generally controlled within 5%, hardness change not exceeding ±10 Shore A,
tensile strength retention rate not less than 70%.
Only when all three numbers are set together is sealing dimensions stable; 72h passing does not mean 1000h passing.
Costs should be spent by grade: not all oil-resistant parts need to be the highest grade—those with low contact frequency and low temperature are sufficient for ordinary oil resistance grades; Only parts with high temperature and high pressure dynamics are considered high-grade.
Graded selection can save 20% in costs.
Re-inspection should be included in the annual rhythm: oil-resistant data is not a one-time solution—if suppliers change raw materials or formulas, oil resistance performance may change.
Therefore, it is recommended to re-check swelling data once a year for oil-resistant parts, or immediately re-inspect when suppliers change. Re-inspection is an annual action in the oil-resistant parts supply chain.
Create a "media list" template for oil-resistant parts procurement: oil name, grade, temperature, pressure, contact method (immersion/sputter/vapor), replacement cycle—write all six items.
The more comprehensive the six items, the more accurate the supplier selection and the less rework there is.
Prepare a "grading table" for oil-resistant parts procurement: divide all oil-resistant parts in the factory into three levels based on "oil quality + temperature + dynamic and still" — light (normal temperature, static), medium (medium temperature, static), heavy (high temperature, dynamic ).
lock the corresponding system for each level.
Build a grading table, and selection, inventory, and price negotiation all go smoothly.
Sealing structure must be reviewed together with materials: besides oil resistance, the design of lip and compression must also be correct—if the structure is wrong, even the oil-resistant material will leak.
Therefore, oil-resistant seals are a combination of "material + structure," and structural design should be reviewed together during material selection.
How to fix swelling oil leakage: Modifications in materials, processes, and systems
Material direction: Adjust oil resistance levels within the same system — oil and additive systems of oil-resistant grades are specially formulated; poor oil resistance of ordinary grades depends on the formula.
Process direction: molding of oil-resistant parts, mold and material temperature directly affect density—insufficient density, easier oil seepage. Control the process window to elevate oil resistance performance.
System direction: oil resistance classification: SEBS base oil resistance average, TPV oil resistance medium to high, TPEE oil resistance good and high temperature resistance — heavy oil scenario, directly TPV/TPEE.
Distinguish between dynamic and static first: static oil-resistant parts (gaskets) and dynamic oil-resistant parts (oil seals) require different requirements—dynamic parts must not only be oil-resistant, but also resistant to friction and fatigue, and the material grade should be one level higher.
Clearly describe both dynamic and static components, so procurement can accurately determine the grade.
Oil resistance and temperature resistance must be tested together: The oil-resistant parts in the car engine compartment operate under dual "oil + high temperature" conditions—each item meets both oil resistance and temperature resistance, but combined conditions may fail
For parts with dual operating conditions, a 'high temperature and oil' combined aging test should be conducted, rather than inferring from single-item data.
Cologne Customer Case: Swelling deformation addressed with production adjustments, 1000-hour aging passed in one go
A modified material application factory in Yantai experienced oil swelling and deformation of oil-resistant parts. Kolon cooperated on-site with production to adjust and debug until the yield stabilized, passing the 1000-hour aging test in one go.
Swelling deformation: first check the density and formulation, then talk about changing the material—adjusting production parameters often saves more than changing the system.
Check these four items when oil-resistant materials arrive; soaking and weight gain must be tested.
- 1. Check swelling data: the volume change rate of actual oil at actual temperature;
- 2. Check strength retention: changes in tensile strength and hardness after oil soaking;
- 3. Check batches: Monitor the batch stability of oil-resistant parts, and keep an eye on both hardness and dimensions;
- 4. Sample Comparison: Keep samples from the oil soaking test, and retest under the same conditions in case of disputes.
Among the four checks, actual oil product testing is the one that should be done the most
| Acceptance item | What are you looking at? | Key points |
|---|
| Swelling data | Actual oil swelling rate | Measure according to operating conditions |
| Intensity retention | Strength after oil soaking | The higher, the more stable |
| Batch | Hardness size fluctuation | Monitor batch |
| sample retention | Oil immersion test sample retention | Retest comparison |
The supplier's standard oil report cannot replace your actual medium.
Summary
We'll stop here for this part. If you're unsure about the working conditions of oil-resistant TPE, feel free to ask anytime and just match them accordingly.
The selection of oil-resistant TPE involves three factors: 'oil × temperature × system' — the type of oil determines the grade, the temperature determines the difficulty, and the system determines the upper limit, so that the seals can withstand it.
Have suppliers send samples soaked in the same oil: soak them in real oil for a week to observe swelling, which is more intuitive than the report — based on actual measurements, it's the final step in sourcing oil-resistant materials. Seeing the swelling after a week is more concrete than just looking at the report.
This assembly step also needs to prevent slipping: seals that have been oiled have an oily film on the surface, making them easy to slip or misalign—clean them before assembly or follow standard procedures. Controlling the assembly process directly affects the actual sealing performance of oil-resistant parts.
Finally, an additional suggestion for 'actual medium sampling': keep a sample of the oil actually used and perform the soaking test together with the materials. In case of disputes, retest under the same conditions—the results may differ if the oil batch changes. Sampling and retesting constitute a complete closed loop for the acceptance of oil-resistant parts.
After being soaked in oil, the surface should be checked for exudation: the material surface may exude additives or become sticky—exudation can affect the feel and may also hinder downstream assembly. Therefore, the acceptance inspection of oil-resistant parts should include a 'post-oil-soaking surface condition' check, and materials that become sticky or exude substances should be handled with caution.
The type of oil determines the degree of swelling: mineral oil, synthetic oil, vegetable oil, hydraulic oil all cause completely different swelling in materials — with the same material, soaking in mineral oil and soaking in vegetable oil can yield data that differs by a factor of two. Therefore, the operating conditions for oil-resistant parts should specify the 'specific type of oil' rather than vaguely writing 'oil-resistant'.
