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、纖維蠕變1. Fiber creep

纖維和紗線在恒定拉伸力的作用下，它的變形量與拉伸力成某種比例。但實際上，在此恒定拉伸力的作用下，變形量不是一個恒量，而是一個隨時間不斷變化的量，它將一直不斷增加。在種在一定拉伸力作用下，變形隨時間而變化的現(xiàn)象，叫作“蠕變”。這是所謂輸送帶“跑長”的根本原因，理論上，輸送帶廠家認為它與材料的斷裂伸長的大小基本無關。

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、纖維松弛2. Fiber relaxation

在恒定的拉伸變形下，纖維或紗線內(nèi)部應力(張力)將隨時間的延續(xù)繼續(xù)不斷下降，這種現(xiàn)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".

纖維蠕變和松弛的基本原因在纖維內(nèi)部結(jié)構(gòu)。在恒定張力作用下，纖維內(nèi)大分子皺曲狀態(tài)的延伸，特別是大分子鏈鏈長度的增加和鍵角的張合，只需要極端時間就可以完成，這就是急彈性變形。隨著時間的延續(xù)，大分子主鏈局部旋轉(zhuǎn)，使大分子延伸，微原纖間的位置調(diào)整，特別是大分子在非結(jié)晶區(qū)中被抽拔滑動(粘彈性變形或流變)從而使纖維長度伸長，呈現(xiàn)蠕變現(xiàn)象，逐步使張力降低。

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.

帆布蠕變和松弛除了上述纖維因素外，對于短纖維帆布，它與紗線纖維之間的滑移相關。

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、影響纖維蠕變和松弛的原因3. Reasons affecting fiber creep and relaxation

纖維蠕變和松弛的主要原因在于是大分子之間的滑移，所以影響大分子之間作用力的因素(如溫服、濕度)將影響蠕變和松弛。

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.

許多纖維在高溫高濕環(huán)境下容易蠕變和松弛，所以常用高溫高濕來內(nèi)應力。特別是棉綸。公定吸濕率為4.5%，吸濕會造成直徑變粗，長度變長，同時水分類似于一種增塑劑，使纖維更加容易發(fā)生蠕變，而聚酯公定吸濕率為0.3%，因此不會發(fā)生類似現(xiàn)象。聚酯拉伸變形時松弛極少，所以聚酯的回彈性和抗皺性好，這一點我們從聚酯服裝面料和其他材質(zhì)的面料相比就可以分析出來。因此運輸骨架材料應該選擇聚酯。

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.

當拉伸速率不同，拉伸時間也不同，出現(xiàn)的緩彈性變形量也不同，拉伸曲線也會不同，因此在對骨架材料進行測試時，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.

以上是理論分析，由于棉綸容易出現(xiàn)蠕變，棉帆布由于纖維之間的滑移，也會出現(xiàn)長時間性變長，我們不用擔心輸送帶會出現(xiàn)“跑長”。相信大家對輸送帶跑長的原因也有了一定的了解了，希望能對大家有所幫助。如果還想要了解更多關于輸送帶的相關知識，可以關注我們的網(wǎng)站http://www.ujkdbkh.cn下回給你分享更多的行業(yè)知識。

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 http://www.ujkdbkh.cn Share more knowledge with you next time.