The whole core conveyor belt uses flame retardant PVC wrapped fiber to achieve the purpose of flame retardant. Because of the poor adhesion of PVC and the difficulty of adhesion between layers, it is necessary to weave the fibers into one. In order to make the whole braided core filled with PVC paste, the belt core should not be woven very tightly. Therefore, the tension uniformity of the conveyor belt is realized by dipping PVC paste and stretching after initial plasticization, so that the whole core conveyor belt has the following congenital weaknesses.

(a)PVC漿料與化學纖維的粘接性差，兩者不能成為力學整體，應力分散差，是整芯輸送帶的結(jié)構(gòu)損傷和壽命短的根本原因。但是，如果PVC膏能夠通過塑化形成完全的連續(xù)均勻相，則骨架和塑料的應力應變的協(xié)同性變好，輸送帶的強度和疲勞壽命也變好。例如，英國的芬納公司制造的阻燃整芯輸送機，兩三年后骨架基本完整，而國內(nèi)的一部分中小廠商制造的整芯輸送機，在一年左右骨架就被松動破壞了。修訂上的先天不足使整芯輸送機的生產(chǎn)技術(shù)和技術(shù)掌握微妙，采用相同的原料、相同的技術(shù)和設(shè)備，不一定能生產(chǎn)出相同質(zhì)量的產(chǎn)品。

(a) The poor adhesion between PVC slurry and chemical fiber, the two can not become a mechanical whole, and the stress dispersion is poor, which is the fundamental reason for the structural damage and short service life of the whole core conveyor belt. However, if the PVC paste can be plasticized to form a complete continuous homogeneous phase, the stress-strain coordination between the skeleton and the plastic will be better, and the strength and fatigue life of the conveyor belt will also be improved. For example, the frame of flame retardant whole core conveyor made by Fenner company in England is basically complete after two or three years, while the framework of some small and medium-sized manufacturers in China is loose and damaged in about a year. The inherent deficiencies in the revision make the production technology and technology of the whole core conveyor subtle. Using the same raw materials, the same technology and equipment, the same quality products may not be produced.

(b)PVC硬度大，柔軟性差，幾乎沒有緩沖作用，整芯輸送帶耐沖擊性差，容易發(fā)生外傷性損傷。

(b) PVC has high hardness, poor flexibility, almost no buffering effect, poor impact resistance of the whole core conveyor belt, and easy to cause traumatic damage.

(c)由于帶芯的織造結(jié)構(gòu)比較松弛、捻度低、變形能力強的棉紗占有一定的空間，所以即使經(jīng)過成形拉伸，帶芯整體的張力也難以一致，塑化后的帶芯松弛是不可避免的。這是在一段時間使用了很多整芯傳送帶之后產(chǎn)生荷葉邊狀松弛的主要原因，也是傳送帶容易彎曲的原因。當然，在傳送帶上出現(xiàn)荷葉邊緣的根本原因是化學纖維自身具有的高增長率。

(c) Because the weaving structure of the core is relatively loose, the cotton yarn with low twist and strong deformation capacity occupies a certain space, so even after forming and stretching, the overall tension of the core is difficult to be consistent, and the relaxation of the core after plasticization is inevitable. This is the main reason for the lotus leaf edge relaxation after using many whole core conveyor belts for a period of time, and it is also the reason that the conveyor belt is easy to bend. Of course, the root cause of lotus leaf edge on conveyor belt is the high growth rate of chemical fiber itself.

(d)PVC的伸長率與橡膠大不相同，用橡膠保護輸送帶時(PVG輸送帶)，如果目標橡膠過厚(超過3mm)，則在粘接界面上形成明顯的90剝離性應力集中，容易導致目標橡膠的脫落。

(d) The elongation of PVC is quite different from that of rubber. If the target rubber is too thick (more than 3 mm) when the rubber is used to protect the conveyor belt (PVG conveyor belt), the obvious 90 peel stress concentration will be formed on the bonding interface, which is easy to cause the target rubber to fall off.

總之，PVC阻燃整芯輸送機雖然技術(shù)指標能滿足煤礦井下使用的要求，但疲勞壽命和磨損壽命都很短，不僅提高了使用成本，而且給生產(chǎn)帶來了不穩(wěn)定的因素。層疊帆布輸送帶在結(jié)構(gòu)和材料上能夠避免正好整芯輸送帶的上述不足，例如帆布織造時能夠?qū)崿F(xiàn)張緊度的均勻和低的應力伸長和變形，粘貼后能夠柔軟地抵抗沖擊，目標與芯的粘接良好，目標的厚度也能夠自由調(diào)整，輸送帶整體這些本質(zhì)優(yōu)點使層疊帆布輸送帶具有長壽命、穩(wěn)定、可靠性。如能很好地解決帆布阻燃問題，疊層帆布輸送帶將代替整芯輸送帶在煤礦井下普遍應用。

In a word, although the technical indicators of PVC flame retardant core conveyor can meet the requirements of underground coal mine, its fatigue life and wear life are very short, which not only improves the use cost, but also brings unstable factors to the production. The structure and material of laminated canvas conveyor belt can avoid the above shortcomings of the whole core conveyor belt, such as uniform tension and low stress elongation and deformation during weaving, soft resistance to impact after pasting, good adhesion between target and core, and free adjustment of target thickness. These essential advantages of the whole conveyor belt make the laminated canvas conveyor belt have the advantages of uniform tension, low stress elongation and deformation, soft resistance to impact after pasting, good adhesion between target and core, and free adjustment of target thickness Long life, stability and reliability. If the flame retardant problem of canvas can be well solved, laminated canvas conveyor belt will be widely used in coal mine instead of whole core conveyor belt.