假肢衬套材料怎么选?硬度上不去,换体系才治本

应用领域 发布时间: 2026-09-14 3970 阅读

A liner that sticks to residual limbs is too hard, causing skin abrasion, or too loose, causing wobbling. The hardness chart for prosthetic liners is just an approximation; changing the system is the fundamental solution.

Conclusion first: prosthetic liner, skin-contact cushioning tied together

Prosthetic liners are the 'part that adheres to the residual limb': they stick to the skin, cushion, and support. The material needs to adhere well to the skin, cushion well, and support steadily — conclusion first: using gel TPE for prosthetic liners is mainstream; for high sensitivity requirements, medical silicone is used.

The biggest pitfall of prosthetic liners: they can't achieve the desired hardness, and only changing the system can fundamentally solve it. Pushing hardness on the chart is not as good as changing the system—the system is the ceiling of hardness.

Prosthetic liners are trial pieces: pressure sores and abrasions are issues. Choosing the right material ensures comfort while wearing them—since they are trial pieces, don’t skimp on material costs.

Why TPE Protects Disabled Limbs: Can Be Skin-Attached, Cushioning Can Be Added

Reasons for using TPE for prosthetic liners: can be skin-friendly, can provide cushioning, hardness can be adjusted, high efficiency — together, these four points make it suitable for liners.

Skin contact is key: keep the residual limb attached all day. Write the sensitivity test into the acceptance criteria — if there's an allergy, it's a problem.

Cushioning cannot be skipped: shock absorption cushioning. If cushioning data is written into acceptance—bedsores, then it’s a problem.

Wear it all day: skin, weight-bearing, support

Skin contact condition: Wear all day. Sensitization data must be tested—if allergic, it's a problem.

Buffer condition: walking buffer. Buffer data must be checked — pressure sores, that’s the problem.

Support working condition: load-bearing support. Compressed data must be checked—collapse, that's the problem.

Gel TPE or silicone: check if the sleeve rubs the skin

DimensionGel TPESilicone
Skin-fittingCan be doneGood
BufferGoodGood
HardnessAdjustableSomewhat soft
CostmiddleMedium-high
EfficiencyInjection moldingVulcanization
BatchStableStable

Table reading: Silicone is skin-friendly but expensive and slow to vulcanize; gel TPE is cost-effective — conventional liner gel TPE, highly sensitizing silicone.

Select according to sensitization requirements: high-sensitization silicone, conventional gel TPE.

System Matching Table: Don't force it on the hardness table

Hardness requirementsRecommendation systemReason
Very softGel TPEBuffer
Somewhat softSEBS baseBalance
ChinaSoftTPU compositeSupport
hardNo need for TPEChange materials

Table reading: At the same Shore value, the feel of SEBS, TPU, and TPV is vastly different; switching systems is more effective than forcibly adjusting the hardness scale.

System is the ceiling of hardness.

Two pitfalls: force-fitting hardness charts, fake skin-friendly claims

Pitfall 1: Forcing hardness on the hardness scale. Adding fillers to increase hardness in the current system makes the lining both hard and stuffy—choose the system first.

Pitfall #2: Mislabeling as skin-friendly. The report claims it is skin-friendly, but in reality, it causes allergies—sensitization testing is a must.

Pitfall 3: Missed cushioning test. Pressure ulcers — cushioning test is a must.

Three acceptance questions: skin-friendly, breathable, batch

Three questions: Is there a skin patch test, what are the standards for cushioning, and what does the system recommend. One test: actual wearing test—three questions and one test, the supplier's details are clear.

System verification must come first: first determine whether the skin-contact material should be SEBS or TPU, then discuss the price — the system is the ceiling for hardness.

Making sample retention a habit: retain samples from each batch, and re-test the skin buffer by batch. When changing materials for a batch, compare first before scaling up — stable batches lead to fewer customer complaints.

Prosthetic liner Shore 00 30-50 gel feel — soft yet supportive, disperses residual limb pressure. Cushioning performance and pressure distribution data need to be tested, and how much cushioning remains after aging should also be measured. When selecting a liner, consider cushioning and breathability together.

The bushing hardens after a few months of use and loses cushioning—sweat, ultraviolet rays, and repeated washing accelerate aging. After aging, cushioning performance deteriorates, causing local pressure on residual limbs. Hardening is not due to being old; aging has consumed the cushioning.

If the hardness can't be increased, changing the system is the fundamental solution—SEBS-based, TPV, and gel TPE each have lower limits for hardness. When the hardness requirement exceeds the system's capability, forcing it results in performance without bringing comfort. If the hardness is insufficient, changing the system is more effective than adjusting the formulation.

Recommend materials according to the target replacement cycle — materials with a long replacement cycle have high demands, frequent replacements are costly. Provide the supplier with the residual limb's load distribution and breathability requirements.

The replacement cycle is determined first, and then the material grade is decided.

A liner is the 'cushion between a residual limb and a prosthesis'—it needs to be soft, breathable, and able to distribute pressure. If it's too dense it gets hot, if it's too loose it doesn't provide enough support; the balance depends on the combination of material and structure.

The account for cushions is calculated based on load-bearing and breathability.

Table of Common Problems and Countermeasures for Prosthesis Receiving Socket Liners

PhenomenonReasonCountermeasure
Pressure ulcerInsufficient bufferChange the gel material
AllergyAllergenSwitch to hypoallergenic material
collapseLarge compression deformationChange to high-voltage resistant material
worn outSurface frictionAdd processing
The hardness doesn't add upThe system is wrongChange system

Prosthetic liner: TPE with a Shore A hardness of 20-30 is selected to fit the residual limb without causing abrasion. The inner wall of the liner should have a velvety, non-slip texture, and the outer wall should be breathable and sweat-wicking — a double-layer co-extruded structure, soft inner layer and tough outer layer.

Prosthetic liners are considered acceptable if the breathability, tested by water vapor transmission, is greater than 500 g/m²·24h. If the residual limb skin sweats and stays damp for a long time, it can ulcerate. Breathability affects the wearing experience more than the tactile feel—consider both the design of the ventilation holes and the material's breathability.

Cologne Customer Case: Hardness batch drift feels sometimes soft, sometimes hard, switch system for bending

A medical device factory in Hefei experienced batch drift in the hardness of prosthetic liners, with the touch feeling sometimes soft and sometimes hard. Cologne coordinated a system change and switched grades (from SEBS-based to TPV-based), passing the -40°C low-temperature bend test in one go. With the system changed, batch problems are cut off from the source—when there is batch drift, first look at system stability.

Summary

When selecting a prosthetic liner, first determine the system, then measure it against the skin. If the hardness is insufficient, changing the system is the fundamental solution; don’t force it.

First make things clear, then talk about the price.

For some orders, we would rather say 'this component is not suitable with our material' than take them on forcibly. Choosing the wrong type means that even if it's cheap, it turns out expensive. Sub-brand materials are not the official brand; there is a line between usable and unusable, and we are not vague about that line.

Ningbo Cologne New Materials Co., Ltd. produces modified thermoplastic elastomers, modified nylons (PA6 / PA66 / PA46 / PA11 / PA12 / PA6T / PA9T and nylon alloys), modified PPO / PPS, as well as stock of nylon resins, secondary materials, and bulk materials from major chemical giants.

这台机器上的件,说下工况我帮你看看

报个件、说清温度和要过的认证,当天回你两三个能打的方案。电话微信同号,找到人就能聊。

打电话 18969817163发邮件询价
WA