What is the hardness unit ha?

What is the hardness unit of HA?

In materials science and engineering, hardness is an important measure of a material's ability to resist deformation or scratching. Different hardness testing methods correspond to different hardness units, among whichHA(Härte A) is a unit of Shore Hardness, mainly used to measure the hardness of soft materials such as rubber, plastics and elastomers. This article will combine recent hot topics to analyze the definition, application and comparison of HA hardness units with other hardness units.

1. Definition and background of HA hardness unit

Shore hardness is divided into type A and type D. HA stands for Shore A hardness, which is suitable for softer materials (such as rubber, silicone). The test principle is to quantify the hardness value by the depth of the indenter penetrating the material under standard pressure, usually ranging from 0-100 (the higher the value, the harder the material). Recently, with the rapid development of new energy and medical device industries, the popularity of HA hardness testing has increased significantly in fields such as silicone seals and flexible electronic devices.

2. Comparison between HA and other hardness units

The following is a comparison table between HA and common hardness units:

3. Recent popular application scenarios

1.New energy vehicle battery sealing materials: In the past 10 days, many car companies have announced the use of highly elastic silicone (HA 50-70) as battery pack seals. Its high temperature resistance and buffering properties have become a hot topic in technical discussions.

2.Medical gloves material upgrade: Affected by the repeated global epidemic, the demand for latex-free gloves (HA 30-50) has surged due to its hypoallergenicity, and relevant standard revision proposals have triggered heated discussions in industry forums.

3.Flexible wearable devices: The latest smart bracelet strap released by a technology company uses HA 40 antibacterial silicone. Its hardness and comfort balance design has been recommended by many media reviews.

4. Precautions for HA hardness test

1.Ambient temperature effect: Recent research shows that for every 10°C increase in temperature, the HA test results may deviate by ±2 degrees. It is recommended to operate in a standard environment of 23±2°C.

2.Sample thickness requirements: The thickness of the material to be measured must be ≥ 6mm, otherwise the data may be distorted due to substrate effects - this point is emphasized in the latest version of the ASTM D2240 standard.

3.Test timeliness: The material needs to rest for 24 hours after vulcanization or molding before testing to avoid affecting the accuracy of the results due to internal stress not being released.

5. Industry trends and future prospects

According to data disclosed at recent industry conferences, the global HA hardness testing equipment market size is expected to reach US$320 million in 2024, with an annual growth rate of 8.7%. As the demand for biocompatible materials grows, the application of HA hardness testing in artificial organs, food-grade silicone products and other fields will be further expanded. At the same time, the development of intelligent portable HA hardness testers has become the focus of competition among equipment manufacturers. A new Bluetooth connection model launched by a certain brand has set a single-week sales record on the e-commerce platform.

In summary, HA is a key hardness indicator of soft materials, and its technical value is continuing to increase with the explosion of new material applications. Understanding the testing principles and application scenarios of HA is of great practical significance to practitioners in related industries.