What is ASTM D 695 standard test method for compressive properties of rigid plastics?

ASTM D 695 is a standard test method developed by ASTM International for determining the compressive properties of rigid plastics. This test method provides a means to evaluate materials' behavior under compressive loading conditions and is commonly used in quality control, material selection, and design of plastic components.

The key points of the ASTM D 695 standard test method for compressive properties of rigid plastics are as follows:

1. Sample Preparation: Prepare cylindrical or rectangular test specimens according to specified dimensions. The choice of specimen shape depends on the material and desired testing objectives.

2. Testing Apparatus: Use a compression testing machine with platens or a compression fixture suitable for the specimen shape. The machine should have sufficient capacity to apply the required load.

3. Conditioning: Condition the specimens according to defined temperature and humidity conditions before testing to ensure consistency and reproducibility of results.

4. Test Procedure: Place the specimen between the compression platens or within the compression fixture. Apply a compressive load to the specimen at a specified strain rate until failure occurs or until a predetermined deformation is reached.

5. Data Collection: Record the load and deformation at specified intervals during the test to create a load-deformation curve. Typical parameters include compressive strength, compressive modulus, yield strength, ultimate compressive strain, and deformation behavior.

6. Analysis and Reporting: Calculate the compressive properties based on the recorded data. Report the results along with relevant information such as specimen dimensions, conditioning conditions, and any deviations from standard procedures.

It's important to note that specific details regarding test specimen dimensions, temperature and humidity conditions, test speed, and acceptance criteria may vary depending on the material and application requirements. Therefore, it is crucial to refer to the ASTM D 695 standard itself for precise instructions when conducting compressive testing on rigid plastics.