201 改性尼龙玻纤长度与分布怎么影响性能
做改性这行，最麻烦的询盘是这一句：
"都是 PA66-GF30，你家的怎么比别家贵？"
问的人不刁钻，数据也真实——两家的物性表，玻纤含量一样、密度一样、拉伸差得不多。贵的理由写在表上看不见的地方：玻纤在件里的状态。
有一次我把这个问题变成了一个实验给客户看。同一个客户、同一个连接器件，用我们正常产的 GF30 打了一版；又用他在外面买的便宜 GF30 打了一版。
外观几乎没差别。冲击测试差了三成多。
把两个件的料都烧掉、把玻纤残段摊在显微镜下看：我们的玻纤平均长度还在零点四毫米上下，长度分布窄；那批便宜料的玻纤平均不到零点二毫米，而且长短参差，还有很多碎成粉末的。
玻纤短了，增强的效率就掉了。 这不是配方问题，是加工的问题——那家厂为了省电、赶产量，螺杆转速开得高、剪切强，玻纤在挤出机里就被打碎了。
客户后来那句总结，我常拿出来用：
"原来贵的那几块钱，是花在玻纤没被打碎上。"
这一篇讲的，就是玻纤从进机器到出机器、再到打进件里，这一路上长度和分布都发生了什么。
玻纤在改性尼龙里的长度和分布，决定了这批料是「增强」还是「掺了玻璃的塑料」：同样的玻纤含量，临界长度以上和以下的性能差出一倍不止。
一、先懂原理：玻纤到底在替尼龙干什么
一根玻纤是怎么扛力的
尼龙本身是软韧的基体。玻纤加进去，本质是把外力通过界面传递给这些又硬又强的细棒，让它们像混凝土里的钢筋一样承担主要载荷。
这个传递要有两个前提：
界面结合要好：尼龙和玻纤之间如果没有浸润剂做"桥"，力传不过去，玻纤就是一根根打滑的棍子
玻纤要足够长：太短的玻纤，力还没传进去就从端头拔出来了
这就引出增强领域最重要的一个概念：临界长度。
临界长度：短于它，玻纤等于没加
一根玻纤要把载荷完整地扛起来，它的长度必须超过某个临界值。短于这个值的玻纤，在受力时会直接从基体里被拔出来，增强效率大打折扣。
改性尼龙常用的短切玻纤，进料时是三到五毫米；经过挤出机的剪切之后，成品粒子里的玻纤平均长度通常在零点三到零点五毫米；再经过注塑的二次剪切，留在件里的平均长度往往只剩零点一到零点三毫米。
一路衰减下来，真正能接近临界长度、全力工作的玻纤，只是一部分。
所以同一个 GF30，谁家的玻纤在每一步都少掉一点，最后件里的差距就能拉开两三成。
一张衰减链示意
| 环节 | 平均长度（典型） | 主要损耗原因 |
|---|
| 短切玻纤原丝 | 3-5 毫米 | — |
| 双螺杆挤出后 | 0.3-0.5 毫米 | 螺杆剪切、玻纤间磨损 |
| 注塑后（件内） | 0.1-0.3 毫米 | 螺杆、浇口、流道二次剪切 |
（典型量级，随配方与工艺大幅浮动）
二、长度之外：分布才是稳定性的关键
均值好看不代表料好。玻纤长度是一个分布，不是一个数。
长度分布怎么看
同样平均零点三毫米的两批料，可能完全是两个东西：
A 批：长度集中，多数玻纤在零点二五到零点三五之间——工艺稳定
B 批：从零点零五到零点六都有，还有一堆粉末——平均数一样，但一半玻纤已经废了
B 批这种"两极分化"，通常意味着剪切过强或者混入了回料——回料里的玻纤经历过一次完整的热历程，普遍更短。
分布不匀的另一种表现：玻纤含量不均
除了长度分布，还有空间分布：同一批料，不同粒子里玻纤含量不一样；同一个件，不同位置玻纤含量不一样。
含量波动直接映射到强度波动。 这就是为什么有的料性能数据"看起来还行"，但做成件之后废品率忽高忽低。
三、取向：玻纤在件里不是乱排的
第三个变量是取向。玻纤在熔体流动时会被带着顺着流动方向排。
取向带来的两面性
顺向的力学性能好：拉伸强度、模量在流动方向上更高。
代价是各向异性：垂直方向的性能明显更低，而且收缩率两个方向不一样——顺流方向收缩小、横流方向收缩大。翘曲就是这么来的。
熔接线：玻纤增强件最脆弱的地方
两股熔体在模具里汇合时，两边的玻纤各自顺着各自的流向排，汇合处玻纤垂直于熔接面，几乎不承担跨缝载荷。
所以玻纤增强件的熔接线强度，通常只有本体的一半甚至更低。这是设计上必须考虑的：关键受力位置避开熔接线，或者用改变浇口位置、提高熔体温度来改善。
很多"玻纤件强度不够"的争议，最后发现出事位置恰好在熔接线上。
四、加工端：长度是被谁打碎的
改性厂这一端，玻纤长度的控制点有这么几个。
挤出端的四个控制点
螺杆组合：剪切元件用得越多、越靠前，玻纤碎得越狠。讲究的厂家会在玻纤加入之后用弱剪切组合，给分散留够时间但不留碎掉的机会
玻纤加入方式：侧喂加入优于主喂预混，减少玻纤在螺杆里的滞留时间
螺杆转速与喂料量：转速高、喂料少，单根玻纤经历的剪切次数就多。这是"省电赶产量"最容易牺牲品质的地方
真空与温控：影响的是浸润质量，间接影响界面结合
注塑端，客户也有三个旋钮
改性厂把玻纤状态做好的料，到了注塑端还能被打坏：
背压：背压越大，塑化剪切越强，玻纤越短。在保住塑化质量的前提下，背压能低就低
螺杆转速：同理
回料比例：回料里的玻纤经历过完整热历程，普遍更短更脆，掺入比例越大，件的整体玻纤长度分布越差
这条对我们做采购的读者最实用：如果你发现同一个牌号、同一台机器，掺了三成回料之后冲击性能明显下滑，先别急着怪料——看看是不是玻纤长度被回料拉低了。
五、怎么检测：两个成本不高的办法
办法一：灼烧加显微镜
这是行业标准的土办法，成本低、信息量大：
1. 取几克料，放坩埚里烧掉树脂（马弗炉或酒精灯都行）
2. 把残留的玻纤轻轻摊到载玻片上
3. 显微镜下拍一张，数一数、量一量
看三个东西：平均长度、长度分布、有没有大量粉末。 有条件的用图像软件自动统计，没条件的人工量三十根也有足够的代表性。
办法二：灼烧称重测含量
同一个动作顺手把玻纤含量也测了：烧完剩下的重量除以原样重量，就是玻纤含量。
含量和长度两个数据一起看：含量够但长度短，是剪切问题；含量不够，那就是配方或掺假问题——这两种情况的应对完全不同。
判读速查
| 观察结果 | 大概率原因 | 方向 |
|---|
| 含量达标、长度分布窄 | 工艺受控 | 正常 |
| 含量达标、粉末多 | 剪切过强或掺回料 | 查螺杆组合与回料比例 |
| 含量偏低 | 配方或计量问题 | 复测并追查 |
| 玻纤发黄、脆断 | 浸润剂或热氧化问题 | 查玻纤来源与工艺温度 |
补充一个现象：浮纤和玻纤状态的关系
很多人把浮纤当成纯粹的注塑问题。其实它和玻纤状态也有关联。
浮纤的本质，是玻纤露出在件表面、被树脂包覆得不好。除了模温偏低、干燥不足这些常规原因之外，还有两种情况值得排查：
其一，玻纤与树脂的界面结合差。 浸润剂体系不匹配或者含量不足，玻纤和尼龙"亲和"得不够，加工出来就容易浮在表面。这种情况换一家浸润剂匹配的玻纤，往往立竿见影。
其二，玻纤长度分布异常。 粉末状的碎玻纤特别容易在表面富集，看起来就是严重的白霜感。这一条正好和前文的灼烧检测对上——摊开看一下粉末比例就清楚了。
所以遇到浮纤，别只调注塑参数：先烧一点料看看玻纤状态，把材料这一侧的原因排掉，再动工艺。
六、两条路线：短玻纤与长玻纤
讲到这里，顺带把"长玻纤"这个经常被问到的方向说清楚。
两条路线的差别
| 对比项 | 短玻纤（主流） | 长玻纤 |
|---|
| 粒子里玻纤长度 | 零点几毫米到几毫米 | 一到两厘米，呈浸渍条状 |
| 件内保留长度 | 零点一到零点三毫米 | 一到三毫米 |
| 强度与刚性 | 常规增强水平 | 高出三到五成 |
| 冲击韧性 | 中等 | 明显更高 |
| 表面质量 | 较好，可做外观件 | 较差，多用于内部结构件 |
| 加工窗口 | 宽，普通设备可打 | 窄，对设备与工艺要求高 |
| 成本 | 低 | 明显更高 |
怎么选
一句话：短玻纤够用就不上长玻纤。
长玻纤真正的用武之地，是以塑代钢的承力结构件——比如前端框架、座椅骨架、电池包承力件这一类，用它的目的不是省料钱，是替代金属之后还能扛住同样的载荷。
反过来，常规的结构件、外观件，短玻纤体系加上合理的玻纤含量，多数情况下性价比高得多。
长玻纤的两个使用提醒
如果确实要用长玻纤，有两件事要提前对齐：
其一，浇口要大。 浇口太小会把长玻纤剪短，等于花了长玻纤的钱打出短玻纤的效果。这一条要跟模具设计和注塑工艺同时交底。
其二，流长比要控制。 长玻纤的流动能力弱，薄壁长流程的件要慎重，必要时增加浇口数量。
含量那一轴：GF15、GF30、GF50 怎么挑
玻纤这个话题，除了长度，绕不开含量。简单的选法是三档：
GF15 左右：尺寸稳定性优先。玻纤少、各向异性小、翘曲风险低，适合薄壁精密件和外观要求高的结构件。
GF30 左右：综合性价比的黄金档。强度、刚性、韧性、成本都在一个舒服的位置，所以市面上大部分增强尼龙都停在这一档。
GF45 以上：高刚性路线。模量上得快，但韧性下降、流动性变差、表面浮纤加重、磨损设备，多数用于替代金属的承力件。
两个常见误区
其一，不是越高越好。 玻纤超过四成之后，冲击开始明显下滑，而且加工难度上升。
其二，含量和长度要一起看。 一批玻纤短得可怜的 GF35，实际性能未必打得过玻纤状态好的 GF25。
所以别只盯含量这个数字，把它和本篇前面的长度分布放在一起判断。
七、回到选型：这几条可以用在采购上
最后把技术落回采购动作。
对供应商问三个问题
1. "你们成品里玻纤平均长度多少？"——能答出具体数字并给得出检测照片的，是真在管这一项
2. "玻纤是哪个厂的、什么型号？"——玻纤本身的品质（单丝直径、浸润剂体系）影响界面结合
3. "回料回掺比例怎么管？"——回答会直接反映这一家对玻纤状态的重视程度
验货时的一个低成本动作
烧一点、看一看。 取几粒料烧掉，看玻纤残段的长短和均匀度，两分钟。跟同价位其他家的烧完对比一下，差距经常一眼可见。
一个容易忽略的相关项
玻纤件的外观（浮纤）和玻纤长度、含量也相关。表面浮纤严重，除了模温和干燥，也可能是玻纤分散不良——这一项反过来也能当作判读线索。
判定玻纤质量别只看含量，拿改性尼龙制品做断面金相，玻纤长度分布图比任何报告都诚实。
一句收拢
把判断写成表，把表发给改性尼龙供应商对答案，比电话里来回问省一半时间——这一篇就是那张表的底稿。
结语
玻纤增强这件事，说穿了是一笔"长度账"：
三到五毫米进机器，零点三毫米出粒子，零点二毫米留在件里。 每一步多保住一点，件就强一点；每一步偷懒一点，差距就攒起来。
表上看不见的这几根玻纤，就是同牌号之间真实的价格差异所在。
How do the length and distribution of glass fiber in 201 modified nylon affect performance?
In the business of making modifications, the most troublesome inquiry is this sentence:
They're all PA66-GF30. Why is yours more expensive than others?
The person asking isn't tricky, and the data is real — the physical property tables of the two are the same for glass fiber content, the same for density, and not much difference in tensile strength. The reason for the higher price is written in a place you can't see on the table: the state of the glass fiber inside the piece.
Once I turned this issue into an experiment to show the client. The same client, the same connector, we did one batch using our regular GF30; then did another batch using the cheap GF30 he bought outside.
The appearance is almost the same. The impact test is more than 30% worse.
Burn both batches of material and spread the fiberglass residues under the microscope: the average length of our fiberglass is still around 0.4 millimeters, with a narrow length distribution; the fiberglass in that batch of cheap material averages less than 0.2 millimeters, is uneven in length, and there is also a lot broken down into powder.
If the fiberglass is short, the reinforcement efficiency decreases. This is not a formulation problem; it's a processing issue — that factory, in order to save electricity and speed up production, ran the screw at high speeds with strong shearing, which caused the fiberglass to be broken in the extruder.
I often use that summary the client gave later:
So the few expensive bucks were spent on the fiberglass not being broken.
This article talks about what happens to the length and distribution of fiberglass from the moment it enters the machine, through the machine, and then into the part.
The length and distribution of glass fiber in modified nylon determine whether this batch of material is 'reinforced' or 'plastic with glass mixed in': with the same glass fiber content, the performance difference above and below the critical length is more than double.
1. Understand the principle first: What exactly is fiberglass doing to nylon
How does a single fiberglass withstand force?
Nylon itself is a soft and tough matrix. When glass fibers are added, the essence is to transfer external forces through the interface to these stiff and strong rods, allowing them to bear the main load like the steel bars in concrete.
This transmission requires two prerequisites:
The interface needs to be well combined: if there is no wetting agent acting as a 'bridge' between nylon and fiberglass, the force cannot be transmitted, and the fiberglass will just be a bunch of slipping sticks.
The fiberglass needs to be long enough: if the fiberglass is too short, the force is pulled out from the end before it is transmitted.
This brings up the most important concept in the field of enhancement: critical length.
Critical length: shorter than this, glass fiber is equivalent to not being added
For a single glass fiber to fully bear the load, its length must exceed a certain critical value. Glass fibers shorter than this value will be pulled out directly from the matrix when stressed, greatly reducing the strengthening efficiency.
The commonly used chopped glass fibers in modified nylon are three to five millimeters when fed; after being sheared by the extruder, the average length of glass fibers in the finished pellets is usually 0.3 to 0.5 millimeters; after secondary shearing during injection molding, the average length remaining in the part is often only 0.1 to 0.3 millimeters.
After a continuous attenuation, only a portion of the glass fibers can actually approach the critical length and work at full capacity.
So for the same GF30, if the fiberglass from a certain manufacturer loses a little bit at each step, the final difference in the parts can open up by twenty to thirty percent.
A schematic of a decay chain
| link; segment; part | Average Length (Typical) | Main causes of loss |
|---|
| chopped fiberglass roving | 3-5 millimeters | — |
| After twin-screw extrusion | 0.3-0.5 millimeters | Screw shear, inter-fiber wear |
| After injection molding (inside the part) | 0.1-0.3 millimeters | Secondary shear of screw, gate, and runner |
(Typical magnitude, varies greatly with formulation and process)
2. Beyond Length: Distribution is the Key to Stability
A good average does not mean good material. The length of the fiberglass is a distribution, not a single number.
How to view the length distribution
Two batches of material with the same average of 0.3 millimeters may be completely different things:
Batch A: Length is concentrated, most glass fibers are between 0.25 and 0.35 — process is stable
Batch B: ranges from 0.05 to 0.6, and there's also a bunch of powder — the average is the same, but half of the fiberglass is already wasted
Batch B's kind of 'polarization' usually means the cutting is too aggressive or recycled material has been mixed in — the glass fibers in recycled material have gone through a full thermal cycle once and are generally shorter.
Another manifestation of uneven distribution: uneven glass fiber content
In addition to length distribution, there is also spatial distribution: in the same batch of material, the glass fiber content varies among different particles; in the same part, the glass fiber content varies at different locations.
Fluctuations in content directly translate to fluctuations in strength. This is why some material performance data "looks fine," but after being made into parts, the defect rate fluctuates significantly.
3. Orientation: The fiberglass in the part is not arranged randomly
The third variable is orientation. Glass fibers are carried along the flow direction when the melt flows.
The duality brought by orientation
Good mechanical properties in the flow direction: tensile strength and modulus are higher in the flow direction.
The cost is anisotropy: performance in the vertical direction is significantly lower, and the shrinkage rates differ in two directions—the shrinkage is small in the flow direction and large in the transverse direction. This is how warpage occurs.
Weld line: The most fragile part of fiberglass reinforced components
When two melts converge in the mold, the glass fibers on each side follow their respective flow directions, and at the convergence, the glass fibers are perpendicular to the weld line, barely bearing any load across the seam.
Therefore, the weld line strength of fiberglass reinforced parts is usually only half or even less than that of the base material. This must be considered in the design: avoid weld lines in critical stress areas, or improve them by changing the gate position or increasing the melt temperature.
Many disputes over 'insufficient strength of fiberglass parts' were ultimately found to occur precisely at the welding lines.
4. Processing end: Who broke the length?
On the side of the modification plant, there are several control points for the length of the fiberglass.
Four control points at the extrusion end
Screw combination: The more shear elements used and the closer they are to the front, the more severely the glass fibers are broken. Thoughtful manufacturers will use a low-shear combination after adding glass fibers, allowing enough time for dispersion without giving the fibers a chance to break.
Method of adding fiberglass: Side feeding is better than main feeding premix, reducing the residence time of fiberglass in the screw.
Screw speed and feed rate: High speed and low feed result in each individual glass fiber undergoing more shear cycles. This is the area where 'saving electricity and pushing output' most easily compromises quality.
Vacuum and temperature control: they affect the infiltration quality and indirectly affect the interfacial bonding
At the injection molding end, the customer also has three knobs.
Even when the modified factory prepares the fiberglass material properly, it can still be damaged at the injection molding stage:
Backpressure: The greater the backpressure, the stronger the plasticizing shear, and the shorter the glass fibers. Under the premise of maintaining plasticizing quality, backpressure should be as low as possible.
Screw speed: likewise
Recycled material ratio: The glass fibers in the recycled material have undergone a complete thermal history, generally becoming shorter and more brittle. The higher the mixing ratio, the worse the overall glass fiber length distribution in the part.
This tip is most practical for our readers in procurement: if you find that the impact performance of the same grade and the same machine drops significantly after adding 30% recycled material, don't rush to blame the material—check whether the glass fiber length has been reduced by the recycled material first.
5. How to test: Two low-cost methods
Method 1: Cauterization plus microscope
This is the industry's standard homemade method, low cost and high in information:
1. Take a few grams of the material, put it in a crucible, and burn off the resin (a muffle furnace or alcohol lamp will work).
2. Gently spread the remaining fiberglass onto the slide
3. Take a photo under the microscope, count and measure
Look at three things: the average length, the length distribution, and whether there is a large amount of powder. If conditions allow, use image software to automatically count; if not, manually measuring thirty pieces is also sufficiently representative.
Method 2: Burn and Weigh to Measure Content
With the same action, I also conveniently measured the glass fiber content: the weight remaining after burning divided by the original sample weight is the glass fiber content.
Look at the content and length data together: if the content is sufficient but the length is short, it's a cutting issue; if the content is insufficient, then it's a formulation or adulteration issue—these two situations require completely different responses.
Quick Reference for Judgment
| Observation Results | most likely reason | Direction |
|---|
| Meets content standards, with a narrow length distribution | Process Controlled | Normal |
| Meets content standards, lots of powder | Excessive cutting or mixing in recycled material | Check screw combination and return material ratio |
| Low content | Formula or measurement issues | Retest and investigate |
| Fiberglass yellowing and brittle fracture | Infiltrant or thermal oxidation problem | Check the source of fiberglass and processing temperature |
Add a phenomenon: the relationship between the state of floating fibers and glass fibers
Many people regard floating fibers as purely an injection molding problem. In fact, it is also related to the state of glass fibers.
The nature of fiber float is that the glass fibers are exposed on the surface of the part and are not well coated with resin. In addition to conventional reasons such as low mold temperature and insufficient drying, there are two other situations worth investigating:
First, the interface bonding between fiberglass and resin is poor. If the sizing system is mismatched or the content is insufficient, the fiberglass and nylon do not have enough 'affinity,' and during processing, it easily floats on the surface. In this case, changing to a fiberglass with a compatible sizing often yields immediate results.
Secondly, the glass fiber length distribution is abnormal. Powdery broken glass fibers are especially prone to surface enrichment, which gives a severe frosted appearance. This point corresponds exactly with the previous burn test — just spread it out and the proportion of powder becomes clear.
So when you encounter floating fibers, don't just adjust the injection molding parameters: first burn a little material to see the state of the glass fibers, eliminate the causes from the material side, and then adjust the process.
6. Two Routes: Short Glass Fiber and Long Glass Fiber
Speaking of this, let's also clarify the direction of 'long glass fiber', which is often asked about.
The difference between the two routes
| Comparison item | Short Glass Fiber (Mainstream) | Long glass fiber |
|---|
| Length of glass fibers in the particles | From a few tenths of a millimeter to a few millimeters | One to two centimeters, appearing as impregnated strips |
| Reserved length in the part | zero point one to zero point three millimeters | One to three millimeters |
| Strength and rigidity | Conventional enhancement level | 30% to 50% higher |
| Impact toughness | Medium | Significantly higher |
| Surface quality | Better, can be used for exterior parts | Poor, mostly used for internal structural components |
| Processing window | Wide, can be used with ordinary equipment | Narrow, with high requirements for equipment and processes |
| Cost | Low | Significantly higher |
How to choose
In one sentence: If short glass fibers are enough, don't use long glass fibers.
The real application of long fiberglass is in load-bearing structural components that replace steel with plastic — for example, front-end frames, seat frames, and battery pack load-bearing parts. The purpose of using it is not to save material costs, but to be able to withstand the same load after replacing metal.
On the other hand, for conventional structural and exterior parts, a short glass fiber system combined with a reasonable glass fiber content is in most cases much more cost-effective.
Two usage reminders for long glass fibers
If you really need to use long glass fibers, there are two things that need to be aligned in advance:
First, the gate should be large. If the gate is too small, it will cut the long glass fibers short, which is equivalent to spending money on long glass fibers to produce the effect of short glass fibers. This point needs to be explained together with mold design and injection molding process.
Second, the flow length ratio needs to be controlled. Long glass fibers have weak flowability, so thin-walled parts with long flow paths should be handled with caution, and the number of gates should be increased if necessary.
Content axis: How to choose GF15, GF30, GF50
When it comes to the topic of fiberglass, aside from length, content is unavoidable. A simple way to choose is three levels:
GF15 or so: Prioritize dimensional stability. Contains less fiberglass, low anisotropy, low risk of warping, suitable for thin-walled precision parts and structural parts with high appearance requirements.
GF30 or so: The golden range of overall cost-performance. Strength, rigidity, toughness, and cost are all at a comfortable level, which is why most reinforced nylons on the market stay in this range.
GF45 and above: High rigidity route. Modulus increases quickly, but toughness decreases, flowability worsens, surface fiber float increases, and equipment wears out. Mostly used to replace metal load-bearing parts.
Two common misconceptions
Firstly, higher is not always better. After the glass fiber content exceeds 40%, impact resistance begins to noticeably decline, and the difficulty of processing increases.
Secondly, both content and length should be considered together. A batch of GF35 with pathetically short glass fibers may not actually perform better than GF25 with well-maintained glass fiber condition.
So don't just focus on this number for the content; consider it together with the length distribution mentioned earlier in this article.
7. Back to selection: these few points can be used for procurement
Finally, bring the technology back to the procurement action.
Ask the supplier three questions
1. 'What is the average length of the fiberglass in your finished products?' — Those who can provide a specific number and supply the inspection photos are genuinely managing this aspect.
2. 'Which factory is the fiberglass from, and what model?' — The quality of the fiberglass itself (single filament diameter, sizing system) affects interface bonding.
3. 'How is the proportion of recycled material mixed managed?' — The answer will directly reflect this company's emphasis on the condition of the glass fiber.
A low-cost action during inspection
Burn a little and take a look. Burn a few grains of material to see the length and uniformity of the glass fiber fragments, about two minutes. Compare it with similar products from other brands in the same price range after burning, and the difference is often immediately obvious.
A related item that is easy to overlook
The appearance of fiberglass parts (floating fibers) is also related to the length and content of the fiberglass. If the surface has severe floating fibers, besides mold temperature and drying, it may also be due to poor dispersion of the fiberglass — this can, in turn, be used as a clue for judgment.
When assessing fiberglass quality, don’t just look at the content. For cross-sectional metallography of modified nylon products, the fiberglass length distribution chart is more honest than any report.
In One Sentence
Turn your assessment into a table and send it to the modified nylon supplier for answers. This saves half the time compared to back-and-forth questions over the phone — this article is the draft of that table.
Conclusion
Fiberglass reinforcement, when you break it down, is essentially a 'length accounting':
Three to five millimeters go into the machine, 0.3 millimeters come out in particles, and 0.2 millimeters remain in the part. Every step that preserves a little more makes the part a little stronger; every step that cuts corners, the difference adds up.
The few fibers you can't see on the table represent the real price difference between the same grade products.
