中底踩两次就塌，回弹没了，跑着跑着脚先累。鞋中底的回弹档没选对，缓震就是摆设。
中底踩两次就塌，回弹去哪了
鞋中底是“管缓震回弹的件”：回弹、缓震、轻量。材料要回弹好、缓震好、轻量——结论先给：鞋中底用 PEBA 是高端主流；常规中底，TPU 发泡或 EVA 复合更划算。
鞋中底最大的坑：软硬差一档，用途两回事。硬度差一档，回弹缓震完全两回事——按用途选，别按名字选。
鞋中底是功能件：回弹差、变硬都是问题。材料选对，跑鞋才稳——功能件，别省料钱。
PEBA 凭什么又弹又轻
鞋中底用 PEBA 的理由：回弹好、轻量、耐疲劳、缓震好——四条合起来，适合高端中底。
回弹是核心：跑步回弹。回弹率测试写进验收——回弹差，就是问题。
轻量不能省：中底轻一克，脚感好一分。密度数据写进验收——轻量，是中底的加分项。
跑步缓震疲劳，三道关
跑步工况：反复压缩。回弹数据要验——回弹差，就是问题。
缓震工况：落地冲击。缓震数据要验——震脚，就是问题。
疲劳工况：长期使用。疲劳数据要验——变硬，就是问题。
PEBA 还是 TPU？一张表看清
| 维度 | PEBA | TPU |
|---|
| 回弹 | 极好 | 好 |
| 轻量 | 轻 | 中 |
| 缓震 | 好 | 好 |
| 成本 | 高 | 中高 |
| 耐疲劳 | 好 | 好 |
| 用途 | 高端 | 常规 |
表格读法：PEBA 回弹轻量极好但贵；TPU 性价比高——高端鞋 PEBA，常规鞋 TPU。
按定位选：高端 PEBA，常规 TPU。
中底验收：回弹轻量这两笔账
| 项目 | 方法 | 标准 |
|---|
| 回弹率 | 回弹测试 | 按标准 |
| 密度 | 密度杯 | 按目标 |
| 缓震 | 冲击测试 | 按能量 |
| 疲劳 | 循环压缩 | 按次数 |
表格读法：回弹率、缓震、密度四项验收下来，这双中底是跑鞋还是健走鞋就清楚。
用途，才是中底的裁判。
按名字选料，三个坑埋一堆
坑一：按名字选。PEBA 和 TPU 都叫中底料，软硬差一档用途全变——按用途选。
坑二：回弹虚标。报告写回弹，实际偏硬——回弹按实测验收。
坑三：密度漏测。中底重——密度数据，必验。
下单前先把这三个数问死
三问：回弹率多少、密度多少、按什么定位。一验：实际跑步实测——三问一验，供应商底细清楚。
用途验证要先行：先定要回弹还是要缓震，再谈价格——用途，才是中底的裁判。
留样要成习惯：每批留样，回弹密度按批次复测。批次换料先对比再放量——批次稳，客诉少。
中底回弹是核心——PEBA 发泡回弹率高，TPU 发泡耐磨好。超临界发泡对熔体强度和发泡窗口要求高，批次稳定性要验。
中底选型，回弹和发泡工艺一起算。
中底跑几百公里回弹衰减——疲劳数据没测，回弹衰减率不透明。衰减低的中底才配长跑，衰减高的穿几个月就塌。
回弹衰减率，是中底的寿命证据。
夏天回弹变冬天变硬不是料差——温度环境影响材料表现，按实际温度做测试。温度适应性窗口要覆盖全年。硬软变化，先查温度适应性。
PEBA 贵在原料，TPU 贵在工艺——成本结构不同，按结构比价才公平。PEBA 回弹高，TPU 耐磨好，按用途选。同是中底料，硬度档错一档，鞋就跑错了场。
超临界发泡数据要拿出来——熔体强度、发泡窗口、批次稳定性三样验。厚度设计按目标缓震和稳定推配方。发泡数据齐了，中底才做得稳。
鞋中底常见问题与对策表
| 现象 | 原因 | 对策 |
|---|
| 回弹差 | 档位选错 | 按用途选 |
| 震脚 | 缓震不足 | 升缓震档 |
| 变硬 | 老化 | 换耐疲劳料 |
| 尺寸波动 | 收缩率漂 | 小批试产 |
| 超重 | 密度高 | 换轻量料 |
PEBA 发泡中底密度 0.10-0.15 g/cm³，回弹率 60% 以上。 EVA 发泡回弹 30-40%，PEBA 回弹高一倍但贵三倍——竞速鞋用 PEBA，训练鞋用 EVA。
中底压缩永久变形按 50% 形变 70℃×6h 测，超 30% 三个月就塌。 PEBA 压变 <15%，EVA 压变 25-35%——压变数据决定中底寿命，别只看新鞋回弹。
中底材料成本按每克单价乘以密度算，PEBA 比 EVA 贵三倍但回弹高一倍。 竞速鞋为回弹买单，训练鞋为预算买单——按鞋定位算材料账，别一刀切上 PEBA。
科隆客户案例：收缩率不稳尺寸波动，小批试产续三单
中山一家鞋材厂，鞋中底收缩率不稳，尺寸波动大。科隆配合小批试产验证后再放量，尺寸稳定，客户连续三个批次续单。小批试产，把尺寸锁死在放量前——收缩率问题，试产阶段就该暴露。
小结
鞋中底的选型，用途先定，回弹再测，软硬差一档用途两回事，别按名字选。
十几年，只做一件事：把尼龙改成能用的样子。
PA6、PA66 是基本盘，PA46、PA6T、PA9T 是耐高温的门槛，PA11、PA12 管水路和油路，尼龙合金补单一树脂给不了的平衡。改性热塑性弹性体、改性尼龙、改性 PPO、PPS 并行，还有各大化工巨头的尼龙树脂、副牌料、大包料现货。
同一块料，用错地方就是事故。所以先问件，再问料。
- 批次：第 12 批｜TS2
- 主关键词：鞋中底；次关键词：鞋中底PEBA、中底TPU、中底回弹、中底缓震
- 摘要：鞋中底用PEBA还是TPU？软硬差一档，用途两回事。回弹、缓震、选型三张表一次讲清。
- 更新时间：待定
The midsole collapses after stepping twice, and the rebound is gone. My feet get tired while running. The rebound setting of the shoe's midsole wasn't chosen correctly, so the cushioning is just for show.
The midsole collapses after just two steps, where did the rebound go?
The shoe midsole is the 'component for guided cushioning and rebound': rebound, cushioning, lightness. The material should have good rebound, good cushioning, and be lightweight — conclusion first: using PEBA for the shoe midsole is the high-end mainstream; for regular midsoles, foamed TPU or EVA composites are more cost-effective.
The biggest trap of shoe midsoles: a slight difference in firmness means a completely different purpose. A slight difference in hardness results in completely different rebound and cushioning — choose based on purpose, not on the name.
The midsole of a shoe is a functional component: poor rebound or hardening are both problems. Choosing the right material makes running shoes stable—functional components, don't skimp on materials.
Why is PEBA both bouncy and light?
Reasons for using PEBA in shoe midsoles: good rebound, lightweight, fatigue resistance, and good shock absorption—combined, these four qualities make it suitable for high-end midsoles.
Rebound is key: running rebound. Incorporate rebound rate testing into the acceptance—if the rebound is poor, it's a problem.
Lightweight should not be compromised: for every gram the midsole is lighter, the foot feel improves by a fraction. Record the density data in the inspection — being lightweight is a bonus for the midsole.
Running cushioning fatigue, three barriers
Running condition: repeated compression. Rebound data needs to be checked — if the rebound is poor, there is a problem.
Cushioning condition: landing impact. Cushioning data needs to be checked—vibration in the feet is the problem.
Fatigue condition: long-term use. Fatigue data must be tested — hardening indicates a problem.
PEBA or TPU? See clearly in one table
| Dimension | PEBA | TPU |
|---|
| rebound | Excellent | Good |
| Lightweight | Light | middle |
| Cushioning | Good | Good |
| Cost | Tall | Medium-high |
| Fatigue-resistant | Good | Good |
| Purpose | High-end | Regular |
Table reading: PEBA has excellent rebound and is very lightweight but expensive; TPU has high cost performance — high-end shoes use PEBA, regular shoes use TPU.
Choose by positioning: high-end PEBA, regular TPU.
Midsole Acceptance: Lightweight Rebound Accounts
| Project | Method | Standard |
|---|
| Rebound Rate | Rebound Test | According to Standard |
| Density | Density Cup | According to Target |
| Cushioning | Impact Test | By Energy |
| Fatigue | Cycle Compression | By Frequency |
Table Reading: After checking rebound, cushioning, and density, it's clear whether this midsole is a running shoe or a walking shoe.
Purpose is the true judge of midsole.
Select materials by name, three pitfalls are buried in a bunch
Pit 1: Choose by name. PEBA and TPU are both called midsoles, with a difference in softness and hardness changing the use — choose by purpose.
Plot 2: Rebound and false labeling. Report says rebound, but actual hardness is on the side — rebound is tested and accepted.
Pit 3: Density was missed. Midsole weight—density data, must be verified.
Ask these three numbers before ordering
Three questions: What is the rebound rate, density, and how to position. First test: Actual running test—three questions and one verification, supplier details are clear.
Purpose verification comes first: decide whether you want to rebound or cushion, then discuss price—use is the true judge of the midsole.
Make sampling a habit: Retain samples for each batch, retest rebound density by batch. Compare batch material before scaling up—stable batches, few customer complaints.
Midsole rebound is the core—PEBA foaming has high rebound rate, TPU foam has good wear resistance. Supercritical foaming requires high melt strength and foaming window, batch stability must be tested.
Midsole selection, calculating rebound and foaming process together.
Midsole runs hundreds of kilometers for rebound attenuation—fatigue data not measured, rebound attenuation rate is not transparent. Midsoles with low attenuation are only suitable for long-term use; high attenuation will collapse after just a few months of wear.
Rebound attenuation rate is proof of midsole's lifespan.
Rebound in summer and hardened in winter is not material difference—temperature affects material performance, test based on actual temperature. The temperature adaptability window should cover the entire year. For changes in hardness and softness, first check temperature adaptability.
PEBA Value is the raw material, TPU is valuable because of the process—cost structures differ, so price comparison is fair. PEBA has high resilience, TPU is wear-resistant, so choose according to usage. For the same midsole, if the hardness is off, the shoe will end up on the wrong stage
Supercritical foaming data needs to be pulled out—check three things: melt strength, foaming window, and batch stability. Thickness design should formulate according to target cushioning and stability. Only when the foaming data is complete can the midsole be made reliably.
Table of Common Problems and Countermeasures of Shoe Midsoles
| Phenomenon | Reason | Countermeasure |
|---|
| Poor rebound | Wrong gear selected | Select by use |
| Stomp the foot | Insufficient cushioning | Increase cushioning level |
| harden | Aging | Replace with fatigue-resistant material |
| Size fluctuation | Shrinkage rate drifting | Small batch trial production |
| Overweight | High density | Switch to lightweight material |
PEBA foam midsole density is 0.10-0.15 g/cm³, with a rebound rate over 60%. EVA foam rebound is 30-40%, PEBA rebound is twice as high but three times as expensive—PEBA is used for racing shoes, EVA for training shoes.
Midsole compression permanent deformation is measured at 50% deformation, 70°C × 6h; if it exceeds 30%, it will collapse in three months. PEBA compression set is <15%, EVA compression set is 25-35% — compression set data determines midsole lifespan, don’t just look at the rebound of new shoes.
The cost of midsole materials is calculated by multiplying the unit price per gram by the density. PEBA is three times more expensive than EVA but has twice the rebound. Racing shoes pay for rebound, while training shoes pay for the budget—calculate the material costs according to the shoe positioning, and don't just apply PEBA across the board.
Cologne Customer Case: Unstable Shrinkage Rate and Size Fluctuations, Small Batch Trial Production Continues with Three Orders
A shoe material factory in Zhongshan has unstable shrinkage rates in shoe midsoles, with large size fluctuations. Cologne coordinated small batch trial productions for verification before increasing production, and the sizes became stable, with the customer placing consecutive orders for three batches. Small batch trial production locks the sizes before mass production—the shrinkage problem should be exposed during the trial production stage.
Summary
When selecting the midsole of a shoe, determine its purpose first, then test its rebound. A difference of one level in softness or hardness means two different uses, so don't choose based on the name.
For more than ten years, I've been doing only one thing: turning nylon into something usable.
PA6 and PA66 are the basic plates; PA46, PA6T, PA9T are the threshold for high-temperature resistance; PA11 and PA12 are pipes and oil lines, and nylon alloys provide a balance that a single resin cannot provide. Modified thermoplastic elastomers, modified nylon, modified PPO, and PPS are available in parallel, along with nylon resin, sub-brand materials, and large bulk materials from major chemical giants in stock.
Using the same material in the wrong place is an accident. So first ask about the part, then about the material.
- Batch: Batch 12 ｜ TS2
- Main keywords: shoe midsole; secondary keywords: shoe midsole PEBA, midsole TPU, midsole rebound, midsole cushioning
- Summary: Should the shoe midsole use PEBA or TPU? The difference in softness is one level, the application is a different matter. Rebound, cushioning, and selection—explained clearly in three tables at once.
- Update time: To be determined
