Hardness testers are essential instruments for evaluating the hardness of rubber and soft plastics, which is a critical property that affects the material's performance and suitability for specific applications.
The term durometer refers to the measurement of a material's hardness. It is named after the instrument used to measure this property, also called a durometer. This device assesses the resistance of a material to indentation. The higher the durometer rating, the harder the material.
Types of Durometers
There are various scales used in durometer measurements, each tailored for different types of materials. The two most common scales are:
Shore A: Used for softer plastics and rubbers.
Shore D: Used for harder plastics and rubbers.
These scales allow for a standardized assessment, making it easier to compare materials and choose the appropriate one for your needs.
Measuring Durometer
The measurement process involves pressing a standardized indenter into the material and recording the depth of the indentation. The result is a numerical value that represents the material's hardness. This value helps manufacturers and engineers determine the suitability of a material for various applications.
Shore A Scale
The Shore A scale is commonly used for materials that are softer and more flexible, such as rubber, elastomers, and some soft plastics. Shore A durometers have a blunt indenter that presses into the material. The readings typically range from 0 to 100, where higher values indicate harder materials. For example:
Shore A 30: Very soft, used in products like rubber bands.
Shore A 60: Moderately hard, used in shoe soles.
Shore A 90: Very hard, used in tires.
Shore D Scale
The Shore D scale is used for harder materials such as hard rubbers, semi-rigid plastics, and thermoplastics. Shore D durometers have a sharper indenter, which allows for the measurement of harder materials. The readings also range from 0 to 100. For example:
Shore D 30: Relatively soft, used in flexible plastics.
Shore D 70: Moderately hard, used in plastic tubing.
Shore D 90: Very hard, used in plastic sheets and panels.
