Is there a relationship between the strength of plastic and its surface hardness?

The concept and representation of hardness: Hardness refers to a material’s ability to resist being pressed into its surface by other harder objects. The value of hardness is a conditional quantitative indication of the softness or hardness of a material; it is not a simple and definite physical quantity. The hardness value depends not only on the material itself but also on the testing conditions and measurement methods; that is, different hardness measurement techniques yield varying hardness values for the same material. Therefore, to compare the hardness of different materials, it is necessary to use the same measurement method to obtain hardness values in order to ensure comparability. The following are some common methods used to indicate hardness. a. Shore hardness b. Rockwell hardness c. Mohs hardness. Increasing the hardness of modified plastics: This refers to a modification method that involves adding hard additives to plastics. Common hardness additives are rigid inorganic fillers and fibers. Surface treatment improves the hardness of plastics. The method for improving the surface hardness of plastics involves enhancing only the hardness of the outer surface of the plastic product, while leaving the hardness of its interior unchanged. This is a low-cost method for improving hardness. This modification method is mainly used for casings, decorative materials, optical materials, and daily necessities. These modification methods mainly include coating, plating, and surface treatment. Blending and compounding to improve plastic hardness (1) Blending to improve plastic hardness: The method of improving plastics through blending involves mixing a low-hardness resin with a high-hardness resin in order to increase the overall hardness of the material. Common blended resins include PS, PMMA, ABS, and MF, while the resins that require modification are mainly PE, PA, PTFE, and PP. (2) Improving the hardness of composite plastics: The method for improving the hardness of plastics involves coating the surface of low-hardness plastic products with a layer of high-hardness resin. This method is mainly suitable for extruded products such as sheets, plates, films, and pipes. Commonly used composite resins include PS, PMMA, ABS, and MF, etc. The flexibility of modified plastics: Intuitively, the flexibility of plastics refers to the softness of plastic products; the softer a plastic product is, the better its flexibility. In polymer physics, flexibility is defined as the ability of a polymer chain to change its isotropic properties. The flexibility of a plastic depends on the molecular chain structure of its polymer. The main function of plasticizers is to improve the processability of resins, that is, to lower the processing temperature and enhance processing fluidity. However, when added to the relevant resin, it can also impart flexibility to the product. Resins suitable for improving flexibility with plasticizers include PVC, PVDC, CPE, SBS, PA, ABS, PVA, and chlorinated polyethers. The original poster’s question wasn’t fully explained; I just hope this helps you

Plastics have tensile strength and impact strength; I’m not sure which one you’re referring to Tensile strength: The raw material is injection-molded into a dumbbell shape and then pulled using a tensile tester to determine the tensile strength. Impact strength: Plastic raw materials are injection-molded into standard impact specimens, which are then tested using specialized impact testing equipment. Based on the type of testing equipment, these tests can be divided into cantilever and simply supported beam types; whereas based on the shape of the specimen, they can be classified as notched or unnotched.

Generally, the higher the tensile strength, the greater the hardness. But hardness can also be achieved through surface treatment.

Thank you, Brother Dooby, for explaining some aspects of hardness. What I want to know is the relationship between strength and hardness.

I want to know about strength: including the interrelationships among tensile strength, bending strength, impact strength, and surface strength.

There should be no definite relationship between strength and hardness; it might be easier to say something specific about a particular material.

There should be a relationship, but it might differ for specific materials. . .

The higher the crystallinity of a material, the greater its hardness and yield strength will be