结论:把套要同时满足皮肤相容和耐摩擦两组要求
手动轮椅的手推圈、推手把套、拐杖和助行器的握把,都是长时间与皮肤直接接触的部件,而且接触方式是持续的摩擦和握持。
这带来两类要求: 一是与皮肤接触的安全性,二是在反复摩擦下的耐久性。两者的材料倾向常常不一致——柔软舒适防滑的材料往往不耐磨,耐磨的材料往往偏硬。
生物相容性方面的考虑
按接触性质,这类部件属于与皮肤接触、且接触时间较长的类别。通常需要考虑的项目包括:
细胞毒性。 基础项目。
皮肤刺激。 直接相关,长期接触尤其重要。
致敏性。 某些橡胶和弹性体材料有致敏风险。
评价时要注意两点:
试样要是最终状态。 经过全部加工和表面处理的成品,不是原材料。加工助剂、脱模剂、表面涂层都可能是刺激源。
要考虑汗液环境。 实际使用中手部出汗,接触界面是潮湿的,某些物质在潮湿条件下更容易迁移。
天然橡胶材料要特别注意致敏问题,这是一个已知的风险点。如果使用这类材料,应当明确标注,便于有相关病史的使用者避开。
耐久性能的测试
| 项目 | 考察什么 | 失效表现 |
|---|---|---|
| 耐磨 | 摩擦下的材料损耗 | 变薄、露底、掉屑 |
| 抗撕裂 | 局部破损后是否扩展 | 小裂口扩大 |
| 粘接强度 | 把套与基体是否脱开 | 转动、脱落 |
| 耐汗液 | 长期接触汗液后的变化 | 发粘、变色、变硬 |
| 耐清洁 | 清洁消毒后的变化 | 变硬、开裂 |
| 压缩永久变形 | 长期握持后能否回弹 | 永久凹陷 |
第三行值得展开。 把套相对基体转动或脱落是常见的实际问题,尤其在手部出汗、施力较大的情况下。这个失效直接影响操作安全——推手把套脱落可能导致照护人员失去控制。
测试时应当模拟实际的受力方式:轴向拉拔、周向扭转,并在潮湿条件下重复。
防滑与舒适的平衡
防滑性能对手动轮椅使用者很重要,因为驱动靠的是手与手推圈之间的摩擦。但:
摩擦系数高有利于驱动,但也增加手部的剪切负荷,长期使用可能导致手部损伤。
表面纹理增加抓握力,但纹理过深会造成局部压力集中,也更难清洁。
柔软的材料握持舒适,但支撑不足时手部更容易疲劳。
处理方式是在测试中同时记录摩擦性能和接触压力分布,找到兼顾的区间。对于长期使用的产品,这个平衡值得花时间优化。
潮湿条件下的性能
这一点单独说,因为它是实际使用中的常态而测试中常被忽略。
手部出汗、户外遇雨、清洁后未完全干燥,都会使接触界面潮湿。很多材料在干燥时防滑良好,潮湿时摩擦系数明显下降。
建议防滑相关的测试在干燥和潮湿两种条件下都做,并在说明书中给出潮湿条件下的使用提示。只给干燥条件的数据,实际使用中会出现落差。
选材建议
把主要考虑列一下:
优先选择已有良好使用记录的材料类别;避免使用已知致敏风险高的材料,或者明确标注;表面处理要考虑清洁的便利性;颜色和外观的稳定性会影响使用者的更换意愿;以及把套应当可以单独更换,作为消耗件供应。
最后一条对产品的长期价值有实际影响。 把套磨损后如果无法单独更换,使用者要么继续用磨损的部件,要么更换整个组件,两种都不理想。
与使用方式的关系
不同使用方式对把套的要求不同,测试方案应当有所侧重:
自主驱动的手动轮椅使用者。 手与手推圈之间是反复的抓握和释放,摩擦量大。这类产品的耐磨和防滑是重点,同时要考虑长期驱动对手部的负荷。
照护人员推行的场景。 推手把套承受推力和转向时的扭矩,粘接强度是重点。
助行器与拐杖。 握把承受较大的垂直载荷,压缩永久变形和粘接强度是重点,同时握把脱落的后果严重。
电动轮椅的操纵杆握把。 接触时间长但受力小,皮肤相容性和舒适性是重点。
按实际使用方式确定测试重点,比套用一份通用清单更有效。
更换与消耗件管理
把套是消耗件,这个定位应当体现在产品设计和售后安排上:
结构上便于更换。 不需要专用工具、不破坏其他部件。
规格标注清楚。 使用者或经销商能准确订购。
供应有保障。 产品停产后一段时间内仍能供应更换件。
更换周期有建议。 基于耐久数据给出,而不是含糊说「磨损后更换」。
最后一条需要数据支撑。 如果做过耐磨测试并换算成使用时长,就可以给出具体的建议,比如「按日常使用约多久检查一次、约多久更换」。这类具体建议对使用者有实际帮助,也体现产品的完善程度。
试验条件的说明
这类材料的测试结果对条件敏感,报告里应当记录清楚:
试样的状态(成品还是材料、是否经过全部表面处理);预处理条件(温度、湿度、时间);测试时的环境条件;对偶材料(做摩擦测试时与什么表面接触);载荷与速度;以及干燥还是潮湿条件。
「对偶材料」这一项容易遗漏但影响很大。 同一个把套材料,与钢质表面、与人造皮肤、与织物摩擦,测出的系数差别明显。做产品比较时,对偶材料必须统一。
与清洁要求的冲突
机构使用的产品需要频繁消毒,而消毒剂对弹性体材料不友好——可能使材料变硬、开裂、褪色。
这与舒适性的要求是冲突的:柔软舒适的材料通常耐化学性较差。
处理方式有两种:选择耐化学性较好的材料,接受一定的舒适度损失;或者把握把设计成易更换的消耗件,接受较短的使用寿命。
哪种更合适取决于使用场景。 建议在产品定位时就明确,并在说明书中给出与之匹配的清洁指引和更换建议。
我们的做法
做这类测试时,我们建议试样用成品状态,并且在干燥和潮湿两种条件下分别测试防滑相关的项目。只在干燥条件下测,数据与实际使用有落差。
对于宣称防滑或者舒适的产品,建议把摩擦性能和接触压力一起测,得到的数据能支撑更具体的表述,也便于与同类产品比较。
有需要可以把材料信息和产品结构发过来一起确定测试项目,或者直接联系:132 4819 8029。检测能力见服务介绍,产品分类见手动轮椅检测与电动轮椅检测,标准信息见标准查询。
English version
Conclusion. Handrims on manual wheelchairs, push handle grips, and the grips on crutches and walking frames are in prolonged direct contact with skin, and the contact takes the form of sustained friction and gripping. That creates two sets of requirements: safety in skin contact, and durability under repeated friction. The material preferences often conflict, since soft, comfortable, grippy materials tend to wear quickly while hard-wearing materials tend to be harder.
Biological considerations. By nature of contact, these components fall into the category of skin contact of prolonged duration. The items usually considered are cytotoxicity as a basic item, skin irritation as directly relevant and particularly important for prolonged contact, and sensitisation, since certain rubbers and elastomers carry sensitisation risk. Two points matter in evaluation. Specimens must be in final condition, meaning finished parts that have been through all processing and surface treatment rather than raw material, since processing aids, release agents and surface coatings can all be irritants. And the perspiration environment must be considered, since hands sweat in use, the interface is moist, and some substances migrate more readily in moist conditions. Natural rubber materials warrant particular attention to sensitisation, which is a known risk; where such materials are used, this should be clearly stated so that users with a relevant history can avoid them.
Durability testing. Abrasion resistance examines material loss under friction, showing as thinning, exposure of the substrate and shedding. Tear resistance examines whether local damage propagates. Bond strength examines whether the grip separates from its substrate, showing as rotation or detachment. Perspiration resistance examines change after prolonged contact, showing as tackiness, discolouration or hardening. Cleaning resistance examines change after disinfection, showing as hardening or cracking. And compression set examines whether the material recovers after prolonged gripping.
Bond strength deserves expanding. Grips rotating on or separating from their substrate is a common real-world problem, particularly with sweaty hands and high applied force. That failure bears directly on operational safety: a push handle grip coming off can leave the carer without control. Testing should reproduce the actual loading, with axial pull-off and circumferential torsion, repeated in moist conditions.
Balancing grip and comfort. Grip performance matters to manual wheelchair users, since propulsion relies on friction between hand and handrim. But a high coefficient of friction aids propulsion while also increasing shear loading on the hand, which over years can contribute to hand injury. Surface texture improves purchase, while deep texture concentrates pressure locally and is harder to clean. And soft materials are comfortable to hold, while insufficient support tires the hand more quickly. Record friction performance and contact pressure distribution together during testing to find a workable range. For products in long-term use, that balance is worth the time to optimise.
Performance when wet. This deserves separate mention because it is normal in use and commonly omitted from testing. Sweating hands, rain outdoors and incomplete drying after cleaning all leave the interface wet. Many materials grip well dry and show a markedly lower coefficient of friction when wet. Perform grip-related testing under both dry and wet conditions and give guidance for wet conditions in the instructions. Data for dry conditions alone will not match what users experience.
Material selection. Prefer material categories with a good service record. Avoid materials with known high sensitisation risk, or state their presence clearly. Consider ease of cleaning in surface treatment. Bear in mind that colour and appearance stability affect whether users bother to replace worn parts. And make grips separately replaceable, supplied as consumables. The last point affects long-term product value: where worn grips cannot be replaced alone, users either continue with worn components or replace a whole assembly, and neither is satisfactory.
How we handle it. We suggest testing finished-condition specimens and performing grip-related items under both dry and wet conditions, since dry-only data diverge from real use. For products claiming grip or comfort we suggest measuring friction performance and contact pressure together, which supports more specific wording and makes comparison with similar products easier.
Send us the material information and construction and we will define the test items. Phone or WeChat: +86 132 4819 8029.