包胶剥离力忽高忽低,量产像开盲盒。螺杆转速快了,剪切热先把料伤了。
剥离力忽高忽低,是剪切热把料伤了
TPE 粘接强度测试,方法和转速都要控:样条、转速、读数。结论先给:螺杆转太猛,剪切热把料烫坏——转速,是测试的干扰源。
粘接强度测试最大的坑:螺杆转速快,剪切热伤料。转速快一截,剪切热伤料——转速,是粘接的隐形杀手。
TPE 测试是工艺活:数据要准,方法要对。测试对了,粘接才稳——工艺活,别省标准。
剥离力是包胶的答卷,为什么必须测
TPE 包胶好不好,剥离力说了算。剥离测试写进验收——剥离力,是粘接的成绩单。
剥离测试要标准:180° 剥离,速度按标准。速度不对,读数偏——速度,是测试的准星。
测试不是走过场:样条制备要一致。样条不一致,数据白测——样条,是测试的前提。
转速、剪切热、降解,链条怎么断
转速高:剪切热大,料降解。剪切热伤料——转速,是热量的开关。
转速低:塑化不足,粘接差。塑化不够——转速,是塑化的天平。
转速按机台调:注塑机、挤出机不一样。机台不同,转速不同——转速,是机台的参数。
转速与剪切热,一张表对照清楚
| 转速 | 剪切热 | 影响 |
|---|
| 低 | 小 | 塑化差 |
| 中 | 中 | 平衡 |
| 高 | 大 | 降解 |
| 过高 | 极大 | 伤料 |
表格读法:转速逐档往上加,料温跟着蹿,粘接强度反而掉——剪切热一大,样条等于被热破坏。
转速按平衡调,粘接才稳。
剥离稳波动小,验收核这四项
| 项目 | 要求 | 判断 |
|---|
| 样条 | 一致 | 达标 |
| 转速 | 平衡 | 达标 |
| 速度 | 标准 | 达标 |
| 剥离力 | 实测 | 达标 |
表格读法:转速、料温、样条状态逐项记,别让一个变量漂——测粘接强度,转速先控住。
转速,是测试的干扰源。
转速乱调方法不对,数据没法比
坑一:转速乱调。为了快把转速拉满,料在料筒里就降解——测试数据失真,全栽在剪切热上。
坑二:样条不一致。数据白测——样条一致。
坑三:速度不对。读数偏——速度按标准。
转速、剥离、方法——测试前问清
三问:什么体系、什么基材、剥离力多少。一验:标准测试实测——三问一验,供应商底细清楚。
转速验证要先行:按推荐转速区间走,料温不超上限再读数。先控转速,再谈粘接——转速,是测试的干扰源。
留样要成习惯:每批留样,剥离力按批次复测。批次换料先对比再放量——批次稳,客诉少。
脱层、力值飘、降解:对照一张表
| 现象 | 原因 | 对策 |
|---|
| 数据漂 | 样条不一 | 统一样条 |
| 读数偏 | 速度错 | 按标准 |
| 粘接差 | 转速高 | 降转速 |
| 粘接差 | 塑化差 | 升转速 |
| 批次漂 | 配方波动 | 锁窗口 |
粘接强度看剥离力,测试在23℃、样条条件一致时测才可比。 包胶粘接做剥离测试,数据写进验收;转速过快剪切热伤料,参数写进工艺卡。
测粘接强度前先处理基材:清洁除油到位。 样条按标准制备,注塑条件一致;测试温度、湿度固定,别换着条件比。
剥离数据忽高忽低,不是胶不行,是样条制备和测试条件没固定。 表面脏油是粘接头号杀手;水分、温度都影响读数。
剥离力是包胶件的“成绩单”——0.5kN/m以下别交卷。 粘接强度测试材料怎么选,先答三问:什么基材、什么软胶、什么工况。
固定条件复测后,数据稳定在工艺窗口内。 测试记录归档,人员操作一致;换料先对比剥离数据再谈价。
包胶粘得牢不牢,不靠手感靠剥离力,剥离力低于 0.5kN/m 别量产。
PP 基材 SEBS 基典型 1.0-2.0kN/m;测试按标准裁样、记剥离角度,弯折五千次后再测,脱胶就不合格,样条制备要统一。
粘接强度验收先选对体系,再谈配方优化。 基材极性不对,胶水再多也脱;ABS 配 SBS、PP 配 SEBS、PC 配 TPU;每批留样剥离数据随批走,换料先小批对比。
粘接强度收尾验收:裁样统一、剥离角度、弯折后复测三项随批走。
剥离力低于 0.5kN/m 不量产,弯折五千次后再测;每批留样剥离数据随批走,换料先小批对比。
科隆客户案例:交期紧现货对不上,重调配方补认证
沧州一家注塑加工厂,交期紧,现货牌号性能对不上。科隆配合重调配方(油/助剂/填充比例),性能对齐,通过第三方检测并补齐认证。配方重调,交期从源头抢回来——性能对不上,先看配方体系。
小结
粘接强度测试的选型,转速先控,方法再对,螺杆转速快剪切热伤料,转速是干扰源。
The adhesive peeling strength is sometimes high and sometimes low, mass production feels like opening a blind box. When the screw speed is too fast, the shear heat damages the material first.
The peeling force fluctuates, which is caused by the material being damaged by shear heat.
TPE bonding strength test, both the method and the rotation speed need to be controlled: specimen, rotation speed, readings. Conclusion first: if the screw rotates too fast, the shear heat will damage the material—the rotation speed is the source of interference in the test.
The biggest pitfall in bonding strength testing: high screw speed causes shear thermal damage to the material. Increase the speed even a bit, and it causes shear thermal damage—the speed is the invisible killer of bonding.
TPE testing is a craft: the data must be accurate, and the method must be correct. Only if the testing is right will the bonding be stable—it's a craft, don't skimp on the standards.
Peeling force is the answer sheet for encapsulation; why must it be measured?
Is the TPE coating good or not is determined by the peel strength. Write the peel test into the acceptance criteria—the peel strength is the report card of the bonding.
Peel tests must follow the standard: 180° peel, speed according to the standard. If the speed is incorrect, the reading will be off — speed is the benchmark of the test.
Testing is not a formality: the preparation of splines must be consistent. If the splines are inconsistent, the data measurement is meaningless—splines are the prerequisite for testing.
Rotation speed, shear heat, degradation, how the chain breaks
High speed: high shear heat, material degradation. Shear heat damages the material — speed is the switch for heat.
Low rotation speed: insufficient plasticization, poor adhesion. Insufficient plasticization—the rotation speed is the balance of plasticization.
The rotation speed depends on the machine: injection molding machines and extruders are different. Different machines have different rotation speeds — rotation speed is a parameter of the machine.
Rotational speed and shear heat, a table makes it clear at a glance
| Rotational speed | Cutting Heat | Influence |
|---|
| Low | small | Poor plasticization |
| middle | middle | Balance |
| Tall | big | Degradation |
| Too high | extremely large | Damaged material |
Table reading: As the speed increases step by step, the material temperature jumps, yet the bonding strength actually drops — when shear heat is high, the sample is essentially damaged by heat.
Adjust the speed according to balance, so the bonding is stable.
Peeling is stable with small fluctuations, accept and check these four items
| Project | Requirement | Judgment |
|---|
| spline | consistent | Meet the standard |
| Rotational speed | Balance | Meet the standard |
| Speed | standard | Meet the standard |
| Peel strength | Actual measurement | Meet the standard |
Reading the table: record each item of rotation speed, material temperature, and spline condition, don't let any variable drift—when measuring bonding strength, control the rotation speed first.
Rotational speed is the source of interference in the test.
The method of adjusting the rotation speed is incorrect, so the data cannot be compared.
Pitfall 1: Messing with the speed. In an attempt to quickly max out the speed, the material degrades in the hopper—the test data becomes distorted, all caused by shear heat.
Pitfall 2: Inconsistent splines. Data test blank—splines consistent.
Pitfall three: Incorrect speed. Readings are biased — speed according to the standard.
Rotational speed, peeling, methods—ask before testing
Three questions: what system, what substrate, how much peel strength. One test: measured by standard testing — three questions and one test, supplier details clearly understood.
Speed verification should be done first: follow the recommended speed range, and take readings only when the material temperature does not exceed the upper limit. Control the speed first, then discuss bonding—speed is the source of interference in the test.
Making sample retention a habit: retain samples from each batch and retest peeling strength by batch. Before switching materials between batches, compare them first before scaling up—the batch is stable, and customer complaints are few.
Delamination, fluctuating force values, degradation: compared with a table
| Phenomenon | Reason | Countermeasure |
|---|
| Data drift | Inconsistent quality | Unified spline |
| Reading bias | Speed error | According to the standard |
| Poor adhesion | High speed | Reduce speed |
| Poor adhesion | Poor plasticization | Increase speed |
| Batch bleaching | Formula fluctuation | Lock window |
Bonding strength is determined by peel force; the test can only be compared when conducted at 23°C with the samples under the same conditions. For overmolded bonding, perform a peel test and record the data in the acceptance; if the rotational speed is too high, it can shear and thermally damage the material, and the parameters should be noted in the process card.
Before testing bonding strength, pre-treat the substrate: clean and degrease thoroughly. Prepare specimens according to the standard, with consistent injection molding conditions; keep testing temperature and humidity fixed, do not compare under different conditions.
The peeling data fluctuates; it's not that the adhesive is bad, but that the sample preparation and test conditions are not consistent. Dirt and oil on the surface are major killers of bonding strength; moisture and temperature also affect the readings.
Peel strength is the "report card" for coated parts—if it's below 0.5 kN/m, don't submit it. When choosing materials for adhesion strength testing, first answer three questions: what is the substrate, what is the soft adhesive, and what are the working conditions.
After retesting under fixed conditions, the data remained stable within the process window. Test records are archived, and personnel operations are consistent; before changing materials, first compare peeling data before discussing the price.
Whether the coating adheres firmly or not does not rely on touch but on peel strength. If the peel strength is below 0.5 kN/m, do not mass-produce.
PP substrate SEBS-based typical 1.0-2.0 kN/m; the test is performed by cutting samples according to standards and recording the peel angle. After bending 5,000 times, it is tested again. If delamination occurs, it is considered unqualified. Sample preparation must be uniform.
For bonding strength acceptance, first choose the right system, then discuss formulation optimization. If the substrate polarity is wrong, no matter how much glue is used, it will still peel off; ABS with SBS, PP with SEBS, PC with TPU; keep peel test data for each batch, and when changing materials, compare with a small batch first.
Bonding strength final acceptance: sample cutting is uniform, peeling angle, and re-measurement after bending - three items are checked with each batch.
Do not mass-produce if the peel strength is below 0.5 kN/m; re-test after bending 5,000 times. Keep peel data for each batch accordingly, and compare small batches first when changing materials.
Cologne Customer Case: Tight delivery schedule with mismatched stock, reformulating and re-certifying
A plastic injection processing factory in Cangzhou has tight delivery deadlines, and the properties of the in-stock grades do not match. Cologne assisted in adjusting the formulation (oil/additive/filler ratio), aligning the properties, and completed third-party testing and certification. With the formulation readjusted, the delivery schedule is reclaimed from the source—if the properties do not match, first look at the formulation system.
Summary
For the selection of bonding strength tests, control the rotational speed first, and then choose the method correctly. A fast screw speed causes shear heat damage to the material; speed is the source of interference.