轮罩、挡泥板、内衬板这类件，在整车清单里的地位很特殊：
它们不承力、不涉安规、不影响动力，但要求却一点不少。
而且用量大、单价敏感，成本压力直接。
这类件的选材，考的是"在满足一堆非核心要求的前提下，把成本压到最低"。
轮罩和挡泥板的失效，用户基本看不见，修理工最清楚。
北方一位修理厂老板说，每年开春，挡泥板的活儿最多。
冬季的石击加低温，把整个冬天的损伤攒到化冻时集中暴露。
裂纹从安装孔放射出去，一片一片换。
这个件不贵，但它的选型逻辑在汽车外饰里最接近应试：石击、低温、耐候三科，缺一科就挂。
一、四个要求，缺一不可
第一，韧性。 这是最核心的一条。轮罩要承受石子冲击、路缘剐蹭、装配弯折。脆的件在这个位置活不长。
第二，耐候。 长期暴露在雨水、紫外、泥浆、融雪盐环境里，还要耐高温（靠近轮胎与排气区域）。
第三，抗石击与耐低温冲击。 冬天低温下被石子打到，是这类件最典型的失效场景。所以低温冲击性能是关键指标。
第四，成本。 用量大、技术含量相对低，所以成本几乎和技术指标同等重要。
四条里，韧性和成本是最有张力的两条——增韧要加钱，降本要减配，而这两条都是硬要求。
二、为什么是增韧 PA6，而不是高玻纤
这是一个很典型的选型误区：看到"结构件"就上高玻纤。
但轮罩类件不是靠刚性工作的，靠的是韧性。所以材料方向是：
增韧 PA6（主流）——成本可控、韧性好、加工窗口宽
增韧 PA66——温度和刚性要求更高时
PA6 + 弹性体 + 少量玻纤——需要一定刚性又不牺牲韧性时
为什么不上 GF30/GF50？因为玻纤会让材料变脆，抗石击性能反而下降。石击是冲击载荷，不是静态载荷，这正是玻纤增强料的弱项。
轮罩这类件，玻纤含量越高，冬天越容易被打裂。
所以判断准则可以简化成一句话：这个件的敌人是冲击，不是变形。
三、耐候体系怎么做
耐候有两条路，常常要一起用：
加抗 UV 助剂（光稳定剂）。 这是主要的做法，用于抵抗紫外老化引起的黄变与脆化。
加深色母（如黑色）。 深色本身能遮挡部分紫外，黑色件在这类位置很常见，不是审美选择，是性能选择。
另外要注意的是，耐候和耐水解要一起考虑。轮罩长期接触雨水和泥浆，水解风险和紫外老化是叠加的。
所以完整的表述是：耐候抗 UV + 抗水解 + 低温韧性，三条一起验。
四、副牌料在这类件上的边界
这是一个非常实际的问题。轮罩类件用量大、技术要求相对低，自然会想到用副牌料降本。
能不能用？答案是有条件的能，但要过四个问题：
问题一：偏的是哪一项？ 副牌料的偏差项不同，影响完全不同。如果偏的是黏度或含水率，对韧性影响可能很直接；如果只是色差，对这类件基本无影响。
问题二：用在哪个位置？ 前轮罩比后轮罩更靠近热源，要求更高；挡泥板的力学要求又低于轮罩。
问题三：能不能锁批号？ 副牌料最大的风险不是指标低，是批次之间不一样。锁不住批号的用法，等于把风险交给运气。
问题四：能不能接受换批重验？ 换批号就要重新验证，这条没有例外。
副牌是"尺度偏了"，不是"降质"。 用对位置，它是划算的；用错位置，省下的钱会在售后还回去。
五、三个常见坑
坑 1：为了刚性上高玻纤。
前面说过——石击是冲击载荷，高玻纤反而更脆。这类件的玻纤含量要主动压低。
坑 2：只做常温冲击，不做低温冲击。
冬天被石子打裂是典型失效。低温冲击（如 -30℃）必须单独验。
坑 3：副牌料不做批次验证就直接放量。
小批量试产和批量供货是两件事。先小批验证，再谈放量。
坑 4：忽略再生料与回收料的使用要求。
这条与环保趋势直接相关。部分主机厂已经开始要求提供再生含量与可追溯性数据。轮罩这类非关键件，往往是再生料最先落地的位置之一。
如果要走这条路线，从选型阶段就要把再生料的批次稳定性与性能衰减纳入验证，不要等定完料再补数据。
六、验证清单
1. 低温冲击试验（-30℃ 或更低，按标准）
2. 常温冲击 + 落锤冲击
3. 紫外老化试验（按标准时长，看色差与力学保留）
4. 耐水解浸泡后的冲击保留率
5. 装配弯折试验（模拟装车时的形变）
6. 副牌料批次一致性抽检（用副牌时的必做项）
轮罩挡泥板的料，近几年的主流是增韧体系。
纯 PA66 的低温韧性不够，石击在低温下直接致裂。
增韧改性的 PA6 或 PA66，把脆韧转变点压到零下三十度以下。
配方里还要耐候，紫外把表面老化之后，石击的抵抗力逐年下降。
所以这类的技术协议通常同时卡两条：低温冲击和氙灯老化后的冲击保持率。
单看出厂数据没有意义，装车两年之后还剩多少才是真数字。
追问一：增韧 PA6 和增韧 PP 在挡泥板上怎么选？
耐温和刚度高用增韧 PA6，成本敏感、耐温要求不高的车型用增韧 PP。PA 系的耐石击恢复性好，PP 的耐化学和价差有优势。喷漆版和非喷漆版要分开评，喷涂件还要加冷热交变后的附着力一项。
追问二：外露件的老化指标怎么定？
按总成厂常见的写法：氙灯若干小时后色差和冲击保持率双指标。只卡色差不管冲击，老化后的抗石击就是个盲区。两条都要，缺一条都是给售后留口子。
一单开春换件潮的追查
北方某车型开春集中换挡泥板，裂纹全从安装孔放射。追查发现孔位没有加强圈，石击能量在孔边应力集中。整改是孔位加厚加翻边，料顺便换成高韧体系。结构缺陷让材料背锅，是外饰件失效里最常见的剧情。
外饰下护件验证清单
低温石击（零下三十度打点）、氙灯后冲击保持、双轮廓装配孔应力核查、耐洗涤剂与融雪剂接触。四项齐全再定点，开春的换件潮就与自己无关。
轮罩挡泥板的装配设计也值得单独说一段。
这类件用卡扣快装，卡扣的保持力和拆卸力是一对矛盾。
保持力不够行车脱落，拆卸力太大赛车不便。
增韧料的蠕变让卡扣保持力逐年下降，设计时要按老化后的保持力校核。
孔位公差和卡扣配合的公差链，交给公差分析而不是经验。
一家厂把卡扣保持力衰减曲线画出来，按第五年的数据做设计输入。
五年数据定设计，三年数据做验证，出厂数据只做基线。
层次分清楚，售后就安静。
三个延伸问题
挡泥板要不要耐融雪剂？北方车必测，融雪剂对塑料的侵蚀比盐雾直接。
石击试验打多少点？按总成厂规范，常见的是低温下多点次打击，重点打孔位和边缘。
喷漆件的漆面和基材谁先失效？多数是附着力先掉，所以冷热交变后的附着力是喷漆件的关键项。
定点资料清单
低温石击报告、氙灯后冲击保持、卡扣保持力衰减曲线、耐融雪剂数据。
挡泥板虽小，四份资料一份不能少，少一份就是开春工单里的一行。
外饰下护件的颜色和外观也有讲究。
挡泥板多为黑色，颜色稳定不是问题，表面质感才是。
皮纹面的模具保养决定质感，料 flow 差会在皮纹面留瑕疵。
所以外护件的流动等级和皮纹深度要配套评审。
有的项目把皮纹翻新写进模具保养条款，质感十年如新。
外护件的管理颗粒度，体现的是整车厂的成熟度。
最后一组追问
挡泥板要不要考虑可回收？法规趋势是这样，单材质、易拆卸的设计以后是主流，选料时留好回收标识。
石击试验和路试哪个准？台架石击用于筛选，路试用于确认，两条数据合着看。
增韧剂加多了会怎样？刚度和耐热下降，表面硬度也降，洗车机器人的刷子都可能留痕，增韧要够用就好。
下护件的选型说到底是耐久和成本的双线平衡，数据齐了平衡点自然现形。
挡泥板这类件最后补一个生命周期视角。
它的更换高峰在第六到第八年，老化加石击叠加期。
配件供应计划要按这个周期提前铺，别等工单来了再排产。
备件料和量产料的牌号要锁定一致，这点常被遗漏。
售后件用错牌号，前期的验证积累全部作废。
收官三点
开春工单是外护件的期末考试，考的是前五年的管理。
孔位和卡扣这些结构细节，比牌号选择更容易被忽略。
外护件的口碑不在展厅里，在修理厂的报价单上。
外护件还要看整车厂平台化的趋势。
同一平台的车型的挡泥板件往往共用，跨车型验证就变得重要。
平台件要覆盖最苛刻的那个车型的工况。
验证矩阵按平台做，成本摊薄，覆盖率反而上升。
配套厂提前布局平台验证，定点效率明显领先。
平台化是外护件供应链的未来十年主线。
这一篇的完整知识地图
低温石击定韧性下限，氙灯保持定耐候等级，卡扣衰减定设计寿命，融雪剂定化学耐受，平台矩阵定验证覆盖。
五个定字串起来，外护件的选型就不再是单件生意，而是一个平台的功课。
挡泥板的学习曲线，本质是外饰件供应链的进阶曲线。
把它学透，车身上一半的外部件都能触类旁通。
挡泥板还要补一个装配辅料的联动。安装孔位常配金属卡扣或者塑料卡扣，卡扣材料和挡泥板材料的热胀系数不同，冷热循环里配合状态会漂。北方车型这个矛盾更突出，冬季温差把卡扣松紧问题放大。成熟做法是卡扣和板材在同一温度范围内做配合验证，别各自验收了事。一家厂把卡扣供应商和板材供应商约到一起做联合验证，两个小时解决了一年的松脱投诉。供应链上的很多问题，缺的不是技术方案，是把两家供应商请到同一间会议室的动作。
外护件再说说颜色件的趋势。部分车型开始推车身同色挡泥板，颜色件把耐候要求提高了一个等级。色差验收标准从目视改成分光光度计打点，材料的色粉耐候性成了选型关键。高耐候色粉成本不低，颜色件和非颜色件要分开报价。趋势摆在那里，提前准备颜色件方案的配套厂，在新车型定点时会多一张牌。
外护件再补一个真实项目的整改故事。某 SUV 的后轮罩在冬季集中开裂，最初的判断是增韧不够，加增韧剂后依旧裂。把开裂件切面看，裂纹起点全在注塑熔接线上，熔接线恰好在轮罩最大应力区。整改把浇口改位，熔接线挪出高应力区，开裂立刻消失。材料只负责它该负责的部分，结构和工艺的债，材料还不起。外护件的排查顺序，永远是先结构后材料，这个顺序颠倒的项目都多花了冤枉钱。
说一说挡泥板与周边件的装配间隙管理。挡泥板和轮眉、内衬板之间的间隙，设计阶段就有公差链，注塑漂移会把公差链推到边界。边界状态下装配应力常年存在，老化后的耐应力开裂能力就是最后一道闸。选料时把耐应力开裂一项列进考核，装到车上才不会在某个冬天突然开裂。间隙链上的每个零件都在替挡泥板分担风险，这个认识到位了，选型才算完整。
结语
轮罩与挡泥板的选材判断链：
先定韧性优先（不用高玻纤）→ 再定耐候体系（抗 UV + 抗水解）→ 最后按位置和批量决定是否用副牌。
如果你手上有个轮罩或挡泥板件在定料，把三样东西发过来：安装位置（是否靠近热源）、低温冲击要求、月用量。
总有人问：副牌料到底能不能用。
我们的回答一直没变——能用的地方很多，不能用的地方一处都不能碰。它和回料是两回事：一个是指标偏了，一个是分子链断了。
Wheel arches, mudguards, and liners hold a special place in the vehicle list:
They don't bear load, don't violate safety regulations, and don't affect power, but their requirements are not lacking.
Moreover, they are used in large quantities and are price-sensitive, so the cost pressure is direct.
The material selection for these parts is based on "minimizing costs while meeting a bunch of non-core requirements."
Users basically don't notice the failures of wheel covers and mudguards; mechanics know best.
A northern repair shop owner said that every spring, mudguards handle the most work.
The winter stone strikes combined with low temperatures accumulate all the damage accumulated during thawing and are exposed.
Cracks radiate out from the mounting holes, replacing them piece by piece.
This part isn't expensive, but its selection logic is closest to the test in automotive exterior trim: stone hits, low temperature, and weather resistance—missing any one means failure.
First, four requirements, none can be omitted .
First, toughness. This is the core one. Wheel covers must withstand stone impacts, curb scrapes, and assembly bending. Brittle parts won't last long in this position.
Second, weather resistance. Long-term exposure to rain, ultraviolet rays, mud, and de-icing salt, plus high temperature resistance (near tires and exhaust areas).
Third, resistance to stone strikes and low-temperature impacts. Being hit by stones in cold winter is the most typical failure scenario for these parts. So low-temperature impact performance is a key indicator.
Fourth, cost. With large usage and relatively low technical content, cost is almost as important as technical indicators.
Among the four, toughness and cost are the two most tense—toughening requires extra cost, cost reduction requires reduced configuration, and both are hard requirements.
2. Why toughened PA6, not high glass fiber ?
This is a typical selection misconception: just go for high glass fiber when you see a "structural part."
But wheel cover parts don't rely on rigidity; they rely on toughness. So the material direction is:
toughening PA6 (mainstream)—cost-controllable, good toughness, wide processing window
toughened PA66—for higher temperature and rigidity requirements
PA6 + elastomer + a small amount of glass fiber—when some rigidity is needed without sacrificing toughness ,
Why not use GF30/GF50? Because glass fiber makes the material brittle, which actually reduces its resistance to stone impact. Stone impact is a shock load, not a static load, which is precisely the weakness of glass fiber reinforcement.
For parts like wheel covers, the higher the glass fiber content, the more likely it is to crack in winter.
So the judgment criterion can be simplified in one sentence: the enemy of this piece is impact, not deformation.
3. How to build a weather-resistant system
There are two ways to weather resistance, often used together:
Add UV resistance additives (light stabilizers). This is the main method to resist yellowing and brittleness caused by UV aging.
Darken the color masterbatch (such as black). Dark colors themselves can block some ultraviolet rays; black parts are common in these areas, not aesthetic choices, but performance choices.
Another important point to note is that weather resistance and hydrolysis resistance should be considered together. Wheel covers that are in long-term contact with rainwater and mud have combined hydrolysis risk and UV aging.
So the full description is: weather resistance UV resistance + hydrolysis resistance + low-temperature toughness—all three tested together.
4. The boundaries of secondary brand materials in this type of part
This is a very practical issue. Wheel cover parts are used in large quantities and have relatively low technical requirements, so naturally people consider using secondary brand materials to reduce costs.
Can it be used? The answer is conditional yes, but it requires four questions:
Question 1: Which item is biased? Different deviation terms for secondary brand materials have completely different effects. If the bias is viscosity or moisture content, it may directly affect toughness; If it's just color difference, it basically has no effect on these parts.
Question 2: Where is it used? The front wheel cover is closer to the heat source than the rear wheel cover and has higher requirements; The mechanical requirements for the fender are lower than those for the wheel cover.
Question 3: Can you lock the batch number? The biggest risk with sub-brand material isn't low specs, but differences between batches. If you can't lock the batch number, you're leaving the risk to luck.
Question 4: Can you accept batch re-inspection? If you change the batch number, you have to re-verify, and this is no exception.
The secondary brand is 'off-limit', not 'quality degradation.' If used in the right position, it's cost-effective; If used in the wrong position, the money saved will be repaid after sale.
Five, Three Common Pitfalls
Pitfall 1: Use high fiberglass for rigidity.
As mentioned before—stone strikes are impact loads, while high fiberglass is actually more brittle. The fiberglass content in these parts should be actively reduced.
Pitfall 2: Only perform room temperature impact, not low-temperature impact.
Cracking by stones in winter is a typical failure. Low-temperature impact (e.g., -30°C) must be tested separately.
Pitfall 3: Secondary brand materials are scaled up without batch verification.
Small-batch trial production and mass supply are two different things. First, small batch validation, then volume scaling up.
Pitfall 4: Ignoring requirements for recycled and recycled materials.
This is directly related to environmental protection trends. Some OEMs have already started requiring data on recycled content and traceability. Non-critical parts like wheel covers are often among the first places where recycled materials are put to market.
If you want to follow this path, you should include batch stability and performance degradation of recycled material in the verification process from the selection stage, rather than waiting until the material is finalized to add data.
6. Verification Checklist
1. Low-temperature impact test (-30°C or lower, according to standards)
2. Room temperature impact + hammer drop impact
3. Ultraviolet aging test (according to standard duration, retained based on color difference and mechanics)
4. Impact retention rate after hydrolytic soaking
5. Assembly bending test (simulating deformation during loading)
6. Batch consistency sampling inspection of sub-brand material (mandatory item when using sub-plates)
For wheel cover mudguard materials, the mainstream in recent years is toughening systems.
Pure PA66 lacks sufficient low-temperature toughness; stone strikes crack directly at low temperatures.
Toughened PA6 or PA66 pushes the brittleness transition point below minus 30 degrees.
The formula also requires weather resistance; after UV aging the surface, the resistance to stone strikes decreases year by year.
So these technical protocols usually restrict two conditions simultaneously: low-temperature impact and impact retention rate after xenon lamp aging.
Just looking at factory data is meaningless; the real number is how much remains after two years of installation.
Follow-up question 1: How to choose toughened PA6 and toughened PP for mudguards?
For high temperature and stiffness, use toughened PA6; for cost-sensitive and low-temperature models, use toughened PP. PA series has good stone impact resistance and recovery, while PP has advantages in chemical resistance and price difference. Painted and unpainted versions should be evaluated separately, and coated parts must also have adhesion after alternating hot and cold conditions.
Follow-up question two: How to determine the aging indicators for exposed parts?
According to assembly manufacturers' common usage: xenon lamps after several hours have both color difference and impact retention rate. If only color difference is used without impact, aging stone impact resistance becomes a blind spot. Both are needed; missing one leaves a loophole for after-sales service.
Tracking the spring part replacement wave for one order
A certain model in northern China had a concentrated spring mudguard replacement, with cracks radiating from the mounting holes. Investigation found no reinforcement rings at the holes, and the energy from stone strikes concentrated stress at the hole edges. The rectification involved thickening the holes and flanging edges, and replacing the material with a high-toughness system. Structural defects blame the material for the blame is the most common scenario in exterior parts failure.
Exterior Lower Protective Parts Verification Checklist
Low temperature stone strike (minus 30 degrees Celsius strike), xenon lamp rear impact hold, dual-profile assembly hole stress check, and resistance to detergent and de-icing agent contact. Once all four are complete, the spring replacement surge is no longer related to me.
The assembly design of the wheel cover mudguard also deserves a separate comment.
For these types of parts, clip fast-fitting is a contradiction between clip retention and removal force.
If the holding force is insufficient, the clip will fall off during driving; if the disassembly force is too strong, racing is inconvenient.
Creep of toughening material causes clip retention to decrease year by year; design should be based on aging retention strength.
Tolerance chains for hole position and clip fitting are left to tolerance analysis, not experience.
A factory plots the clip retention force attenuation curve and inputs design data based on the fifth year's data.
Five years of data sets the design, three years of data validates, and factory data only serves as the baseline.
Clear hierarchy means quiet after-sales service.
Three extended questions
Do mudguards need de-icing agents? Must-test for northern vehicles: de-icing agents erode plastics more directly than salt spray.
What points should be applied in the stone strike test? According to assembly factory specifications, common methods are multiple strikes at low temperatures, focusing on drilling positions and edges.
Which fails first, the paint surface or the substrate of painted parts? Most cases cause adhesion to lose first, so adhesion after alternating hot and cold is the key item for painted parts.
Fixed point data list
Low temperature stone strike report, xenon lamp post-impact hold, clip holding force attenuation curve, de-icing agent data.
Although the fender is small, one of the four documents must be missing; missing one is the line in the spring work order.
The color and appearance of protective parts under the exterior are also important.
Fenders are mostly black; stable color is not an issue, but the surface texture matters.
Mold maintenance for leather texture determines quality; poor material flow will leave flaws on the textured surface.
Therefore, the flow level and texture depth of outer protective parts must be evaluated together.
Some projects include leather texture refurbishment in mold maintenance terms, making the texture look like new for ten years.
The management granularity of exterior protective parts reflects the maturity of the vehicle manufacturer.
The last group followed up with
Should we consider recyclability for mudguards? The regulatory trend is this: single-material, easy-to-remove designs will become mainstream, and recycling labels should be left when selecting materials.
Which is more accurate, stone strike test or road test? Bench stone strikes are used for screening, road tests are for confirmation—look at both data together.
What happens if too much toughening agent is added? Stiffness and heat resistance decrease, surface hardness also drops, and even car wash robot brushes may leave marks. Toughening should be sufficient for durability.
Ultimately, the selection of lower protective parts is a dual balance between durability and cost; when the data is aligned, the balance point naturally emerges.
For mudguards, here's a lifecycle perspective.
Its replacement peak is from the sixth to eighth year, during the period of aging and stone strike stacking.
Parts supply plans should be planned in advance according to this cycle, not waiting for work orders to be scheduled for production.
The grade of spare parts and mass production materials must be locked in the same way, which is often overlooked.
Using the wrong grade for after-sales parts will ruin all the initial verification accumulation.
Final Three Points
The spring work order is the final exam for external protective parts, testing management over the previous five years.
Structural details like hole positions and clips are easier to overlook than grade selection.
The reputation of external protective parts is not in the showroom, but in the repair shop's quotation sheet.
External protective parts also depend on the trend of platform adoption by vehicle manufacturers.
Fenders on the same platform are often shared, making cross-vehicle verification important.
Platform components should cover the most demanding vehicle conditions.
Validation matrices are built according to platforms, diluting costs and increasing coverage.
Suppliers plan platform validation in advance, with clearly superior efficiency at specific locations.
Platformization is the main theme for the exterior protective parts supply chain over the next decade.
The complete knowledge map for this article
Low-temperature stone strikes set the lower toughness limit, xenon lamps maintain a fixed weather resistance rating, clip attenuation sets design life, deicing agents determine chemical resistance, and platform matrix validation coverage.
When these five fixed characters are combined, selecting exterior protective parts is no longer a one-piece business but a platform's homework.
The learning curve of the fender is essentially an advanced curve in the exterior parts supply chain.
Master it thoroughly, and half of the exterior parts on the car body can be traced back and forth.
Fenders also need to be supplemented with the linkage of assembly accessories. Mounting holes are often fitted with metal or plastic clips, but the thermal expansion coefficients of clip materials and mudguard materials differ, causing the fit to drift during hot and cold cycles. This contradiction is even more pronounced in northern models, where winter temperature differences amplify the issue of snap fit and tightness. A mature approach is to verify the compatibility between clips and panels within the same temperature range, rather than just accepting them separately. One factory arranged for joint verification between clip suppliers and panel suppliers, resolving a year-long loosening complaint within two hours. Many supply chain issues are not lacking technical solutions, but the process of bringing both suppliers into the same meeting room.
Outer protective parts Let's talk about the trend of color parts. Some models have started promoting mudguards of the same color on the body, raising weather resistance requirements by a notch. Color difference acceptance standards shift from visual to spectrophotometers, and the weather resistance of the color powder has become the key to selection. High weather-resistant colorants are costly, and colored and non-colored parts must be quoted separately. The trend is clear: suppliers who prepare color parts plans in advance will have an extra card when new models are targeted.
External protective parts adds another real project rectification story. A certain SUV's rear wheel covers cracked in winter; the initial judgment was insufficient toughening, and even after adding toughening agent, cracks persisted. Looking at the cracked parts cross-section, the cracks all started on the injection-molded welding line, which was exactly in the wheel cover's maximum stress zone. Rectification repositioned the gate, moved the welding line out of the high-stress zone, and the cracking disappeared immediately. Materials only handle what they should be responsible for; structural and process debts cannot be repaid by materials. The inspection order for external protective parts always starts with structure before materials; projects with reversed order end up wasting money.
Talk about managing the assembly clearance between mudguards and peripheral parts. The gap between the mudguard, wheel arches, and liner plates is designed with tolerance chains; injection molding drift pushes the tolerance chains to the boundaries. Assembly stress exists year-round in the boundary state, and the stress crack resistance after aging is the final barrier. When selecting materials, include stress crack resistance in the assessment so that the vehicle won't suddenly crack in winter. Every part on the gap chain helps the mudguard share risks; only when this is recognized properly is the selection complete.
Conclusion
Chain of material selection for wheel covers and mudguards:
First, determine toughness (don't use high fiberglass)→ then decide on the weather resistance system (UV resistance + hydrolysis resistance)→ Finally, decide whether to use secondary brands based on location and batch size.
If you have wheel covers or mudguards in the final selection, send us three things: installation location (near heat source), low-temperature impact requirements, and monthly usage.
People always ask: Can secondary brand materials actually be used?
Our answer hasn't changed—there are many usable places, but not a single unusable part. It's different from recycled materials: one is the biased indicator, the other is the molecular chain break
