Pubdate：04-30-2022 Views：12312
The reinforcement usually found on the inside of a conveyor belt is normally referred to as the "carcass." In a sense, the carcass is the heart of the conveyor belt since it must:
The carcass is normally rated by the manufacturer in terms of "maximum recommended operating tension" permissible (pounds per inch i.e., piw).
Similarly, the manufacturer rates the finished belt in terms of "maximum recommended operating tension" per inch of width (which is the total of the preceding, multiplied by the number of plies in the belt construction) i.e., 4 plies of 110# fabric = a 440 pound per inch of width (PIW) working tension belt. The manufacturer determines the maximum recommended operating tension per inch of width with considerations given to:
There is a relationship between the recommended maximum operating tension per inch of width of the belt and the ultimate tensile strength (breaking strength) of the belt which will be explained later.
The most common carcass design is made up of layers or plies of woven fabrics bonded together (see Illustration below). This "conventional plied" belt construction, generally employs a plain weave or twill weave carcass which is built up into as many layers as is required to provide the necessary belt strength, usually bound together with rubber.
In the plain weave, the warp yarns (lengthwise yarns) and the fill yarns (crosswise yarns) pass over and under each other. This means that both members are crimped (Essentially, each assumes a sine-wave-like configuration). This fact, plus the basic characteristics of the fiber used give the belt its stretch characteristics.
Conventional plied carcass belts have been used for decades. Consequently, they are the most common belt design used today. Most conveyor engineers and millwrights are familiar with conventional plied belting constructions and their characteristics. Virtually, all belting mechanics know how to splice conventional plied belts. This familiarity with the belt's characteristics and the ease of vulcanized splicing gives the conventional plied belting design its broad customer acceptance.
When cotton and similar materials were widely used as carcass components in plied belts, a breaker strip, an additional layer of open weave fabric, was added between the carcass and the top cover for heavy abuse constructions, helping absorb the loading impact. The switch to modern synthetic carcass materials (like polyester and nylon) has essentially eliminated the need for the breaker strip. Today, breaker strips are seldom found in plied belt constructions except in extreme impact applications.
Conventional plied belting constructions, employing all synthetic carcasses and elastomeric covers appropriate to the end use, are particularly recommended for:
