Why does the conveyor belt run long for a long time? This is because the running length of the conveyor belt is only related to the type of skeleton material used, that is, to the creep performance of the skeleton material. Next, the conveyor belt manufacturer will explain the reasons why the conveyor belt runs long, including fiber creep, fiber relaxation, and the reasons affecting fiber creep and relaxation.

1、纤维蠕变1. Fiber creep

纤维和纱线在恒定拉伸力的作用下，它的变形量与拉伸力成某种比例。但实际上，在此恒定拉伸力的作用下，变形量不是一个恒量，而是一个随时间不断变化的量，它将一直不断增加。在种在一定拉伸力作用下，变形随时间而变化的现象，叫作“蠕变”。这是所谓输送带“跑长”的根本原因，理论上，输送带厂家认为它与材料的断裂伸长的大小基本无关。

Under the action of constant tensile force, the deformation of fiber and yarn is in proportion to the tensile force. But in fact, under the action of this constant tensile force, the deformation is not a constant, but a variable with time, which will continue to increase. Under the action of a certain tensile force, the deformation changes with time, which is called "creep". This is the fundamental reason for the so-called "long run" of conveyor belt. In theory, conveyor belt manufacturers believe that it has nothing to do with the breaking elongation of materials.

2、纤维松弛2. Fiber relaxation

在恒定的拉伸变形下，纤维或纱线内部应力(张力)将随时间的延续继续不断下降，这种现象叫作“松弛”。

Under constant tensile deformation, the internal stress (tension) of fiber or yarn will continue to decrease with time. This phenomenon is called "Relaxation".

纤维蠕变和松弛的基本原因在纤维内部结构。在恒定张力作用下，纤维内大分子皱曲状态的延伸，特别是大分子链链长度的增加和键角的张合，只需要极端时间就可以完成，这就是急弹性变形。随着时间的延续，大分子主链局部旋转，使大分子延伸，微原纤间的位置调整，特别是大分子在非结晶区中被抽拔滑动(粘弹性变形或流变)从而使纤维长度伸长，呈现蠕变现象，逐步使张力降低。

The basic cause of fiber creep and relaxation lies in the internal structure of the fiber. Under the action of large molecular stretch angle, the length of the chain can only be increased under the action of large molecular stretch angle. With the extension of time, the macromolecular main chain rotates locally to extend the macromolecules and adjust the position between the micro fibrils. In particular, the macromolecules are pulled out and slid (viscoelastic deformation or rheology) in the amorphous region, so as to lengthen the fiber length, present the creep phenomenon and gradually reduce the tension.

帆布蠕变和松弛除了上述纤维因素外，对于短纤维帆布，它与纱线纤维之间的滑移相关。

Canvas creep and relaxation in addition to the above fiber factors, for short fiber canvas, it is related to the slip between yarn fibers.
3、影响纤维蠕变和松弛的原因3. Reasons affecting fiber creep and relaxation

纤维蠕变和松弛的主要原因在于是大分子之间的滑移，所以影响大分子之间作用力的因素(如温服、湿度)将影响蠕变和松弛。

The main reason for fiber creep and relaxation is the slip between macromolecules, so the factors affecting the force between macromolecules (such as warm clothing and humidity) will affect creep and relaxation.

许多纤维在高温高湿环境下容易蠕变和松弛，所以常用高温高湿来内应力。特别是棉纶。公定吸湿率为4.5%，吸湿会造成直径变粗，长度变长，同时水分类似于一种增塑剂，使纤维更加容易发生蠕变，而聚酯公定吸湿率为0.3%，因此不会发生类似现象。聚酯拉伸变形时松弛极少，所以聚酯的回弹性和抗皱性好，这一点我们从聚酯服装面料和其他材质的面料相比就可以分析出来。因此运输骨架材料应该选择聚酯。

Many fibers are easy to creep and relax in high temperature and high humidity environment, so high temperature and high humidity are often used to eliminate internal stress. Especially cotton fiber. The determined moisture absorption rate is 4.5%. Moisture absorption will make the diameter thicker and the length longer. At the same time, moisture is similar to a plasticizer, which makes the fiber more prone to creep, while the determined moisture absorption rate of polyester is 0.3%, so no similar phenomenon will occur. Polyester has little relaxation during tensile deformation, so polyester has good resilience and wrinkle resistance, which can be analyzed from the comparison between polyester clothing fabric and other fabrics. Therefore, polyester should be the first choice for transporting skeleton materials.

当拉伸速率不同，拉伸时间也不同，出现的缓弹性变形量也不同，拉伸曲线也会不同，因此在对骨架材料进行测试时，要同一拉伸速率。

When the tensile rate is different, the tensile time is also different, the amount of slow elastic deformation is also different, and the tensile curve will be different. Therefore, the same tensile rate should be used when testing the skeleton material.

以上是理论分析，由于棉纶容易出现蠕变，棉帆布由于纤维之间的滑移，也会出现长时间性变长，我们不用担心输送带会出现“跑长”。相信大家对输送带跑长的原因也有了一定的了解了，希望能对大家有所帮助。如果还想要了解更多关于输送带的相关知识，可以关注我们的网站https://www.huafengxiangsu.com下回给你分享更多的行业知识。

The above is the theoretical analysis. Because cotton fiber is prone to creep and cotton canvas will grow for a long time due to the slip between fibers, we don't have to worry about the "running length" of conveyor belt. I believe you have a certain understanding of the reasons for the long running of the conveyor belt. I hope it can be helpful to you. If you want to know more about conveyor belt, you can follow our website https://www.huafengxiangsu.com Share more knowledge with you next time.