As a team of experts in material-handling systems, Norpak Handling Ltd. is full of information for customers about getting the most from its products. For example, businesses need to consider many factors when choosing a conveyor belt, like the transported material, weight, dimensions, and operating temperatures. Hardness is another important criterion.
Norpak offers the following insight into the basics and importance of the hardness level of a conveyor belt.
The Shore Hardness Test
The hardness of a belt denotes its resistance against forming a permanent indentation; it also signifies resistance to penetration by sharp objects. An instrument called a durometer is used to measure this quality, through the Shore Hardness Test. One employs the durometer to measure the hardness of various kinds of polymers, rubbers, and elastomers on a scale from zero to 100. There are about 12 durometer scales considered the standard; the Shore A and Shore D scales are the most popular.
The process of measurement varies depending on the scale. The main idea is to take the durometer and indent or penetrate the side of the belt with it for an accurate reading. It should not pierce the fabric underneath. The reading on a Shore A scale is around 60 for the SBR rubber used in belts, for example. For a PVC belt, a Shore A scale typically reads about 70, and the same device reads about 90 for a polyurethane belt.
The reading signifies two important things in conveyors made of rubber, polyurethane, or other elastomers: belt flexibility and coefficient of friction (CoF). Belt flexibility particularly refers to the end rollers, and materials with lower hardness have higher flexibility. CoF refers to the amount of friction exerted between two surfaces – in this case, between the belt surface and the transported materials. Low material hardness means low CoF too. But lower or higher durometer values do not directly reflect belt quality, since application is the main factor.
Norpak is the source that Canadian businesses can trust for the best conveyors and belts on the market – and the best selection tips.
To learn more, contact Norpak.