密封圈用两年就发粘开裂，客户说不耐候。户外食品件寿命没算清，省的钱不够赔。
发粘开裂不是用旧了，是耐候没选够
食品密封圈是“密封耐候的件”：耐候、密封、迁移。材料要耐候、密封、迁移——结论先给：食品密封圈用 SEBS 基 TPE 是主流；长期户外，TPV 优先。
食品密封圈最大的坑：耐候三年和五年，价格差15%。耐候差两年，价格差一截——耐候年限，是密封圈的价格线。
食品密封圈是食品件：老化、渗漏都是问题。材料选对，食品才稳——食品件，别省料钱。
户外日晒雨淋，为什么选TPV耐候料
食品密封圈用 TPE 的理由：耐候可做、密封可做、迁移可做、效率高——四条合起来，适合密封圈。
耐候是核心：长期使用。耐候测试写进验收——老化，就是问题。
密封不能省：防漏密封。密封测试写进验收——渗漏，就是问题。
密封、耐候、接触，三关各看什么
密封工况：防漏密封。密封数据要验——渗漏，就是问题。
耐候工况：长期使用。耐候数据要验——老化，就是问题。
接触工况：接触食品。迁移数据要验——超标，就是问题。
SEBS基对阵TPV，食品圈选谁
| 维度 | SEBS基TPE | TPV |
|---|
| 耐候 | 可做 | 好 |
| 密封 | 可做 | 好 |
| 迁移 | 可控 | 可控 |
| 成本 | 中 | 中高 |
| 寿命 | 3年 | 5年 |
| 用途 | 常规 | 长期 |
表格读法：TPV 耐候好但贵；SEBS 基性价比高——常规密封圈 SEBS 基，长期 TPV。
按年限选：长期 TPV，常规 SEBS 基。
晒不裂不发粘，验收测这四项
| 年限 | 价格 | 判断 |
|---|
| 3年 | 基准 | 达标 |
| 4年 | +8% | 关注 |
| 5年 | +15% | 达标 |
| 6年 | +22% | 超配 |
表格读法：按货架寿命定耐候年限，多扛两年树脂就升档——三年和五年差一档，单价跟着差一截。
耐候年限，是密封圈的价格线。
只比价格不看年限，两年就报废
坑一：只看价格。选了短年限，货架没到寿命先开裂——密封圈按实际更换周期定档，别超配也别欠配。
坑二：迁移漏测。超标——迁移测试，必测。
坑三：密封漏测。渗漏——密封测试，必测。
耐候年限、密封、批次——定圈前问清
三问：耐候按几年、迁移按什么标准、密封按什么测试。一验：实际使用实测——三问一验，供应商底细清楚。
耐候验证要先行：按产品保质期定加速老化时长，年限对得上再谈价。先定年限，再谈价格——耐候年限，是密封圈的价格线。
留样要成习惯：每批留样，耐候密封按批次复测。批次换料先对比再放量——批次稳，客诉少。
发粘、开裂、渗漏：故障对照一张表
| 现象 | 原因 | 对策 |
|---|
| 老化 | 耐候不足 | 换耐候料 |
| 渗漏 | 密封不足 | 换高密封料 |
| 异味 | 助剂析出 | 换低析出料 |
| 变形 | 耐温不足 | 换耐温料 |
| 无认证 | 证书缺失 | 核认证 |
食品密封圈压变大于30%（70℃×22h），长期密封就靠不住。 反复开合、热汤热水，回弹掉档就漏；迁移测试按油脂、酸、酒分类核。
耐候年限按货架寿命定档，别超配也别欠配。 多扛两年树脂升档、单价跟着涨；密封圈免硫化可回收，比橡胶省一道工序。
验收按全项过：密封打压、迁移、老化、耐温，一项不过不放行。 物性表上的数是典型不是底线，底线写进验收；留样每批复测。
密封圈老化变脆，不是用久了正常，是耐温档没选对。 热菜热汤高温工况选耐高温SEBS/TPV；迁移超标多是充油过量，换低析出配方。
换低析出配方后，迁移放样90天零超标。 食品接触报告按批次核；批次硬度±3A内，客户摸不出两批货差别。
食品密封圈天天泡内容物，TPE 要食品级、压变小、耐油耐酸，压久了回弹不回就漏味。 选食品级 SEBS 基，过 GB4806 和 LFGB；压缩量留 15%-25%，70℃×22h 压变低于 30%，和槽位贴合。
食品件验收看迁移和批次，不是看新料手感。
色母、助剂都要食品级，迁移物超标比基材更要命；每批留样测浸泡液和硬度，换料先小批灌装机试漏。
食品密封圈收尾验收：压变、迁移、试漏三项随批走。 每批留样测 70℃×22h 压变和浸泡液迁移，不超；批次换料先小批灌装机试漏，不渗再放行。
食品密封圈选型说到底，是把压变、迁移、试漏三件事一次问清。 食品级 SEBS 基过 GB4806，压变低于 30%，浸泡迁移不超；先小批灌装机试漏，不渗再放行。
科隆客户案例：阻燃不过检出口卡关，重调配方过检
惠州一家汽车零部件厂，食品密封圈阻燃不过检，出口卡关。科隆配合重调配方（油/助剂/填充比例），阻燃等级过检，顺利出口。配方重调，阻燃关从配方过——阻燃问题，先看助剂体系。
小结
食品密封圈的选型，耐候先定，密封再测，耐候三年和五年价格差15%，耐候年限是价格线。
The sealing ring becomes sticky and cracks after two years, and the customer says it is not weather-resistant. The lifespan of outdoor food parts was not calculated clearly, and the money saved is not enough to cover the losses.
Sticky and cracking is not because it's old, but because the weather resistance was not chosen enough.
Food sealing rings are 'sealing and weather-resistant components': weather resistance, sealing, migration. The material must have weather resistance, sealing, and migration—conclusion first: SEBS-based TPE is mainstream for food sealing rings; for long-term outdoor use, TPV is preferred.
The biggest pitfall of food sealing rings: they claim to be weather-resistant for three years or five years, with a 15% price difference. A difference of two years in weather resistance results in a significant price gap—weather resistance years are the price line for sealing rings.
Food sealing rings are food parts: aging and leakage are both problems. Choosing the right material ensures food safety—don't skimp on material costs for food parts.
Exposed to sun and rain outdoors, why choose TPV weather-resistant material
Reasons for using TPE for food sealing rings: weather resistance can be achieved, sealing can be achieved, migration can be controlled, efficiency is high—combined, these four points make it suitable for sealing rings.
Weather resistance is key: long-term use. Weather resistance testing is written into acceptance — aging is the problem.
Sealing cannot be overlooked: leak-proof sealing. Include sealing tests in acceptance inspections—any leakage is a problem.
Sealing, weather resistance, contact—what to check in each of the three areas
Sealing conditions: Leak-proof sealing. Sealing data must be verified—leakage indicates a problem.
Weather-resistant conditions: long-term use. Weathering data must be verified — aging is the problem.
Contact condition: in contact with food. Migration data must be tested — if it exceeds the standard, it's a problem.
SEBS vs TPV, which one is chosen in the food industry
| Dimension | SEBS-based TPE | TPV |
|---|
| weather-resistant | Can do | Good |
| Seal | Can do | Good |
| Migration | Controllable | Controllable |
| Cost | middle | Medium-high |
| Lifespan | 3 years | 5 years |
| Purpose | Regular | Long-term |
Table reading: TPV has good weather resistance but is expensive; SEBS is cost-effective - conventional seals are SEBS-based, long-term use is TPV.
Select by duration: long-term TPV, conventional SEBS base.
Does not crack or become sticky when dried; check these four items during inspection
| Years of service | Price | Judgment |
|---|
| 3 years | Benchmark | Meet the standard |
| 4 years | 8% | Follow |
| 5 years | 15% | Meet the standard |
| 6 years | 22% | Over-allocation |
Table reading method: Determine the weather resistance years according to the shelf life; if the resin can last two more years, it moves up a grade—the difference between three years and five years is one grade, and the unit price differs accordingly.
Service life is the price benchmark for gaskets.
Only looking at the price without considering the age, it becomes unusable in just two years
Pitfall 1: Only looking at the price. Choosing a short-term option, the shelf cracks before its lifespan ends — set the seal replacement schedule according to the actual replacement cycle, neither over-supplying nor under-supplying.
Pitfall 2: Missed migration testing. Exceeding the limit — migration testing is mandatory.
Pitfall 3: Seal leakage testing. Leakage—seal testing must be performed.
Service life, sealing, batch — ask clearly before setting the ring
Three questions: How many years for weather resistance, what standards for migration, what tests for sealing. One verification: actual measurement in use — three questions and one verification, the supplier's details are clear.
Weather resistance verification comes first: set the accelerated aging duration according to the product's shelf life, and only when the years match can the price be discussed. First determine the years, then discuss the price — the weather resistance period is the price line for sealing rings.
Making sample retention a habit: retain samples for each batch, and reseal them for periodic testing. When changing materials between batches, compare first before scaling up—the batch remains stable, and customer complaints are fewer.
Sticky, Cracked, Leaking: A Fault Comparison Table
| Phenomenon | Reason | Countermeasure |
|---|
| Aging | Insufficient weather resistance | Replace with weather-resistant material |
| Leakage | Insufficient sealing | Replace with high-density sealant |
| Odor | Additive precipitation | Switch to low precipitation material |
| Transformation | Insufficient temperature resistance | Change to heat-resistant material |
| Unverified | Certificate missing | Nuclear Certification |
If the compression of the food sealing ring increases by more than 30% (70°C × 22h), it cannot rely on long-term sealing. Repeated opening and closing, hot soup, and hot water will cause leaks if the rebound fails; migration tests are classified according to oil, acid, and alcohol.
The service life is set according to the shelf life, neither over-specifying nor under-specifying. Holding on for a couple more years allows the resin to upgrade, with the unit price rising accordingly; the sealing ring can be recycled without vulcanization, saving a process compared to rubber.
Acceptance is all-or-nothing: sealing pressure test, migration, aging, and temperature resistance; if any item fails, it is not released. The numbers on the physical property table are typical, not the minimum; the minimum is written into the acceptance criteria. Samples are retested for each batch.
The sealing ring becomes aged and brittle, which is not normal wear from use, but because the temperature resistance grade wasn't selected correctly. For high-temperature conditions with hot dishes and soups, choose high-temperature resistant SEBS/TPV; excessive migration is mostly due to over-filling with oil, so switch to a low-exudation formula.
After switching to a low-extractable formula, migration testing after 90 days showed zero exceedances. Food contact reports are checked by batch; if batch hardness is within ±3A, customers cannot feel any difference between the two batches.
The food sealing ring soaks in the contents every day. The TPE must be food-grade, have low compression set, and be oil and acid resistant. If compressed for a long time and it doesn't rebound, it will leak flavor. Choose food-grade SEBS base, compliant with GB4806 and LFGB; leave a compression of 15%-25%, compression set after 70°C × 22h is less than 30%, and fit with the groove.
Food item acceptance should be based on migration and batch, not on the feel of the new material.
Color masterbatch and additives must all be food-grade; migration exceeding the limit is more dangerous than the base material. Keep samples from each batch to test soaking liquid and hardness, and when changing materials, first test a small batch on the filling machine for leaks.
Food sealing ring final acceptance: Compression set, migration, and leakage test are conducted with each batch. For each batch, samples are kept to measure compression set and migration in soak solution at 70℃ × 22h, not exceeding limits; when changing material for a batch, a small batch is tested on the filling machine for leakage, and only if there is no seepage is it released.
When it comes to selecting food sealing rings, it ultimately comes down to asking about three things at once: compression set, migration, and leak testing. Food-grade SEBS meets GB4806 standards, with a compression set below 30% and migration limits not exceeded; first, conduct leak tests on a small batch filling machine, and only release if there is no leakage.
Cologne Customer Case: Flame Retardant Failed Inspection, Export Blocked, Reformulated to Pass Inspection
A car parts factory in Huizhou faced a problem where food-grade sealing rings failed the flame retardancy test, causing export issues. Cologne assisted in readjusting the formula (oil/additive/filler ratio), allowing the flame retardancy to pass and the products to be exported smoothly. When the formula is readjusted, passing the flame retardancy stage is about the formula — for flame retardancy issues, start by looking at the additive system.
Summary
For selecting food-grade sealing rings, first determine weather resistance, then test sealing performance. The price difference between three-year and five-year weather resistance is 15%, with the weather resistance period determining the price line.
