件一出模就翘,装不进客户壳体。缩水先看浇口和保压,别一上来就怪料。
出模就翘,不是料差是收缩没控好
TPE 缩水翘曲,浇口和保压是两张牌:浇口、保压、批次。结论先给:尺寸缩了别急着怪料,先把批次对上——批次,是缩水的头一疑点。
TPE缩水最大的坑:缩水查浇口和保压,先看批次。先怀疑料,后查工艺,顺序反了——批次,是缩水的排查起点。
TPE 尺寸是品质关:缩水、翘曲都是问题。尺寸对了,品质才稳——品质关,别省调试。
收缩率是配方的镜子,为什么先看数据
TPE 收缩率随体系变:SEBS 基 1-2%。收缩率,是缩水的尺子。
填充影响收缩:填充多收缩小。填充比例,是收缩的开关。
批次影响收缩:批次漂移收缩漂。先看批次,再谈工艺——批次,是缩水的头一疑点。
浇口位置、尺寸、平衡,哪里在偏
浇口位置:靠近厚壁,缩水改善。位置不对,缩水明显——浇口,是缩水的开关。
浇口尺寸:大浇口补缩快,小浇口补缩慢。尺寸按件定——浇口,是补缩的通道。
浇口平衡:多腔件要平衡。不平衡,尺寸不一——平衡,是浇口的质量。
缩水原因,一张表对照清楚
| 现象 | 原因 | 对策 |
|---|
| 缩水 | 保压低 | 加保压 |
| 缩水 | 浇口小 | 放大浇口 |
| 缩水 | 批次漂 | 锁批次 |
| 翘曲 | 冷却不均 | 调冷却 |
表格读法:缩水现象对着浇口、保压、排泡逐项排——尺寸飘了,先换批次对比再动工艺。
先查批次,再调工艺。
出模不翘不缩,验收核这四项
| 项目 | 要求 | 判断 |
|---|
| 批次 | 锁定 | 达标 |
| 保压 | 按件 | 达标 |
| 浇口 | 合适 | 达标 |
| 尺寸 | 实测 | 达标 |
表格读法:浇口位置、保压曲线、冷却时间逐项核——缩水调不动,多半要回头看批次。
批次,是缩水的排查起点。
先查料后查批次,方向就反了
坑一:先怀疑料。一缩就退料,浇口和保压还没排完——缩水排查从批次和工艺两头进。
坑二:保压乱调。缩水——保压按件调。
坑三:浇口不查。补缩慢——浇口按件定。
浇口、保压、收缩——调机前问清
三问:什么体系、件多厚、什么收缩率。一验:试模尺寸实测——三问一验,供应商底细清楚。
批次验证要先行:留样对比当前批次的熔指和硬度,再动浇口保压。先核批次,再谈工艺——批次,是缩水的头一疑点。
留样要成习惯:每批留样,尺寸按批次复测。批次换料先对比再放量——批次稳,客诉少。
翘曲、缩水、尺寸飘:对照一张表
| 现象 | 原因 | 对策 |
|---|
| 缩水 | 保压低 | 加保压 |
| 缩水 | 浇口小 | 放大浇口 |
| 缩水 | 批次漂 | 锁批次 |
| 翘曲 | 冷却不均 | 调冷却 |
| 尺寸漂 | 填充变 | 锁配方 |
TPE尺寸稳定靠浇口、保压、冷却三兄弟,一项不到位尺寸就飘。 浇口位置按件定;冷却要均匀,不均就尺寸不均;试模先小批,尺寸确认再放量。
缩水排查顺序:先看批次,再看浇口和保压,顺序反了白忙。 尺寸按标准测,数据写进验收;换料先对比尺寸稳定再谈价。
尺寸忽大忽小,不是模具有问题,是批次窗口和冷却没锁死。 保压影响成型密实,不足就收缩;脱模斜度够不够影响脱模,软胶粘模变形。
TPE软、弹性大,冷却慢——她“记住”型腔要时间,冷不透就变形。 浇口位置、冷却水路按件设计;尺寸记录归档,换批先对比。
锁死浇口加保压加冷却后,连续20模尺寸全在公差内。 成型问题记台账;尺寸记录追溯有据,客户验收一次过。
TPE 缩水先看批次再看工艺,别一上来就调机——同体系配方一变,尺寸收缩就跟着漂。
SEBS 基收缩随硬度和填充变;锁模力、保压、浇口三件套配合,小浇口补缩慢就缩,大浇口补得实,冷却水路要走匀。
缩水验收看试模尺寸,不是看出模那一件。
每批留样测尺寸,换料先小批试模量到尺寸再放量;保压不足就缩,冷却不均就变形,记录归档换批先对比。
缩水收尾验收:试模尺寸、保压冷却、换批对比三项随批走。
每批留样测尺寸,小批试模量到尺寸再放量;保压不足就缩、冷却不均就变形,记录归档换批先对比。
科隆客户案例:耐油不足泡油胀,跟产过1000h老化
宁波一家注塑加工厂,TPE 件耐油性不足,泡油后溶胀变形。科隆配合现场跟产调试到良率稳定,溶胀消除,一次性通过 1000h 老化测试。跟产调试,把溶胀锁死在量产前——耐油问题,先看配方再看参数。
小结
TPE缩水的调试,批次先核,保压再调,缩水查浇口和保压先看批次,批次是排查起点。
The part warps as soon as it comes out of the mold and can't fit into the customer's housing. When checking for shrinkage, first look at the gate and holding pressure, don't immediately blame the material.
It warps as soon as it's demolded; it's not poor material, it's poor shrinkage control.
TPE shrinkage and warpage, the gate and holding pressure are two separate factors: gate, holding pressure, batch. Conclusion first: if the size has shrunk, don’t rush to blame the material; first check the batch—the batch is the first suspect in shrinkage.
The biggest pitfall of TPE shrinkage: checking the gate and pressure holding for shrinkage, start with the batch. First suspect the material, then check the process—the order is reversed. The batch is the starting point for investigating shrinkage.
TPE size is a quality checkpoint: shrinkage and warping are both issues. Only when the dimensions are correct can the quality be stable—at the quality checkpoint, don't skimp on adjustments.
Shrinkage rate is the mirror of the formula, why look at the data first
TPE shrinkage changes with the system: SEBS-based 1-2%. Shrinkage is the ruler of shrinkage.
Filling affects shrinkage: more filling results in less shrinkage. The filling ratio is the switch for shrinkage.
Batch affects shrinkage: batch drift causes shrinkage variation. First, look at the batch, then discuss the process — the batch is the first suspect in shrinkage.
Gate position, size, balance, where it is off
Gate location: near thick walls, shrinkage improves. If the location is wrong, shrinkage is obvious — the gate is the switch for shrinkage.
Gate size: A large gate compensates shrinkage quickly, while a small gate compensates shrinkage slowly. The size is determined by the part—the gate is the channel for shrinkage compensation.
Gate balance: Multi-cavity parts need to be balanced. If unbalanced, the dimensions will differ—balance is the quality of the gate.
Causes of shrinkage, clearly compared in one table
| Phenomenon | Reason | Countermeasure |
|---|
| shrink | Low hold pressure | Increase pressure |
| shrink | Small gate | Enlarge the gate |
| shrink | Batch bleaching | Lock batch |
| Warp | Uneven cooling | Adjust Cooling |
How to read the table: Address shrinkage item by item against the gate, holding pressure, and venting—if dimensions fluctuate, compare with another batch before adjusting the process.
First check the batch, then adjust the process.
No warping or shrinking after demolding, check these four items for inspection
| Project | Requirement | Judgment |
|---|
| Batch | Lock | Meet the standard |
| Pressure holding | By piece | Meet the standard |
| Gate | Suitable | Meet the standard |
| Size | Actual measurement | Meet the standard |
Form reading: Check the gate position, hold pressure curve, and cooling time item by item — if shrinkage can't be adjusted, most likely you need to go back and review the batch.
A batch is the starting point for downsized investigation.
Checking the material first and then the batch is the wrong order.
Pitfall 1: Suspect the material first. When it shrinks, the material retreats before the gate and holding pressure are finished — shrinkage troubleshooting should start from both the batch and the process.
Pitfall 2: Randomly adjusting the holding pressure. Shrinkage — adjust holding pressure according to the part.
Pitfall three: Not checking the gate. To slow shrinkage — the gate is determined per piece.
Gate, holding pressure, shrinkage — ask clearly before adjusting the machine
Three questions: what system, how thick the piece, what shrinkage rate. One inspection: actual measurement of the test mold dimensions—three questions and one inspection, the supplier's details are clear.
Batch verification must come first: compare the sample with the current batch for melt index and hardness before adjusting gate holding pressure. Verify the batch first, then discuss the process — the batch is the first suspect in shrinkage.
Make sample retention a habit: retain samples for each batch, and re-measure the dimensions according to the batch. When changing materials between batches, compare first before scaling up—the batch is stable, and customer complaints are few.
Warping, Shrinkage, Size Variation: Refer to a Table
| Phenomenon | Reason | Countermeasure |
|---|
| shrink | Low hold pressure | Increase pressure |
| shrink | Small gate | Enlarge the gate |
| shrink | Batch bleaching | Lock Batch |
| Warp | Uneven cooling | Adjust Cooling |
| size drift | Fill change | Lock recipe |
TPE size stability relies on the trio of gate, holding pressure, and cooling. If any one is not properly set, the size will vary. The gate position is determined according to the part; cooling must be uniform, otherwise the size will be inconsistent; when trial molding, start with a small batch and confirm the dimensions before mass production.
Shrinkage inspection order: first check the batch, then the gate and holding pressure; if the order is reversed, it’s a waste of effort. Measure dimensions according to standards and record the data in the acceptance report; when changing materials, first compare dimensional stability before discussing price.
The size fluctuates; it's not a problem with the mold, but because the batch window and cooling were not locked. Holding pressure affects the density of molding; if insufficient, it shrinks. The draft angle affects demolding, and soft rubber sticks to the mold and deforms.
TPE is soft and highly elastic, and cools slowly — its 'memory' of the mold cavity takes time, and it will deform if it doesn't cool through. Gate positions and cooling channels are designed for each part; dimensions are recorded and archived, and compared before switching batches.
After locking the gate, adding holding pressure, and cooling, the dimensions of 20 consecutive molds were all within tolerance. Molding issues are recorded in the ledger; dimension records are traceable, and customer acceptance passes in one go.
For TPE shrinkage, first look at the batch, then the process; don't just start adjusting the machine—once the formulation in the same system changes, the dimension shrinkage will follow.
SEBS basic shrinkage varies with hardness and filler; clamping force, holding pressure, and gating system should be coordinated. Small gates shrink slowly, while large gates fill more completely. Cooling channels need to be evenly distributed.
Shrinkage acceptance is based on the size of the trial mold, not the piece when it is demolded.
Measure the dimensions of samples from each batch; when changing materials, first test a small batch to adjust the mold until the correct dimensions are achieved before mass production. If hold pressure is insufficient, reduce it; if cooling is uneven, it will cause deformation. Keep records and archive them. When changing batches, compare first.
Shrinkage Finish Inspection: Trial mold dimensions, pressure-holding cooling, and batch-to-batch comparison are carried out with each batch.
Measure the dimensions of samples from each batch, test the modulus of small batches before scaling up; if the holding pressure is insufficient, shrinkage occurs, and if cooling is uneven, deformation occurs. Record and archive the data, and compare before changing batches.
Cologne customer case: insufficient oil resistance causing oil swelling, consistent with over 1000 hours of aging
A injection molding factory in Ningbo had TPE parts with insufficient oil resistance, swelling and deforming after soaking in oil. Kolon worked together on-site to debug the production until the yield stabilized and the swelling was eliminated, passing the 1000-hour aging test in one go. During production debugging, the swelling was locked down before mass production—the oil resistance issue should first look at the formulation, then the parameters.
Summary
TPE shrinkage debugging: check the batch first, adjust the holding pressure later. For shrinkage, first look at the gate and holding pressure, starting with the batch; the batch is the starting point for troubleshooting.