The hardness of extruded acrylic sheet is an important performance indicator that is often used to evaluate its scratch and abrasion resistance. The following is a detailed answer to the hardness of extruded acrylic sheet:

1. **Overview of hardness**:

   - Hardness is the ability of a material to resist the intrusion of external forces, and in the case of acrylic sheet, it determines the abrasion and scratch resistance of its surface.

   - Extruded acrylic sheet, as a common plexiglass material, is lightweight, highly transparent, impact resistant, and not easily discolored.

2. **Hardness test method**:

   - In practice, the hardness of acrylic sheet can be evaluated by a variety of test methods, such as Rockwell hardness test, Brinell hardness test and Vickers hardness test.

   - Rockwell hardness test is a commonly used method, the principle is to embed a conical tool into the surface of the material through a certain impact force, and then measure the depth of the tool embedded to assess the hardness of the material.

3. **Range of hardness values**:

   - The hardness of extruded acrylic sheet is usually between 85 and 105, and the specific value will vary according to the material composition, production process, and testing methods.

   - It should be noted that the hardness value of some special materials may be higher or lower than this range.

4. **Relation between hardness and performance**:

   - Although hardness is an important indicator of the quality of acrylic sheet, it is not the only performance indicator.

   - In actual use, it is also necessary to consider the light transmission of acrylic sheet, UV resistance, chemical resistance and other aspects.

In summary, the hardness of extruded acrylic sheet is usually between 85 and 105, and the specific value depends on a variety of factors. When choosing acrylic sheet, in addition to considering the hardness, you also need to combine other performance indicators and specific application requirements for comprehensive consideration.