ASTM D6110 Charpy Impact Resistance of Notched Specimens of Plastics

Get Certified ASTM D6110 Testing for Plastic Impact Resistance

ASTM D6110 testing assesses the toughness and impact performance of plastic materials under controlled conditions to help manufacturers. Notched specimens are prepared to the appropriate size, conditioned to the proper conditions, and placed on the supports of a Charpy impact tester. The instrument drops a pendulum onto the specimen and quantifies the energy absorbed when it breaks. Correct notch preparation, specimen dimensions, specimen conditioning, and equipment verification are important to ensure reliable results.

• Material form: Standard notched test specimens of plastic materials. This test aims to determine and compare the impact resistance of plastics. The procedure measures the energy absorbed during impact fracture and calculates the impact-resistance value. 
• Method: Support a notched specimen horizontally and strike it with a pendulum; measure the energy absorbed. 
• Result: Report impact energy and, if applicable, impact resistance per specimen dimension or per “ligament area” as defined in the standard. 
• Test limitations: Results are applicable to the test geometry and test conditions specified. They are not a guarantee of the performance of an existing plastic component in all service applications.

What Are the Uses of ASTM D6110?

Manufacturers and materials engineers can use ASTM D6110 to assess plastic materials’ resistance to sudden impact. The results can be used to compare materials, control production quality, and investigate changes resulting from processing and conditioning. Notch shape and size affect the specimen’s impact properties, so the same conditions are maintained for similar comparisons. 

• Material selection: Determine differences in impact resistance among plastic grades for products subject to sudden forces. 
• Quality control: Detect variations between production lots/batches or between material lots. 
• Product Development: Assess changes in polymers, additives, or processing conditions. Processing evaluation: Study the influence of molding, thermal treatment, and preparation of specimens. 
• Assessment of notch sensitivity: Compare material behavior under notch stress concentration. 
• Failure investigation: Support investigation of failure differences for given impact conditions.

Which Materials Can Be Tested?

ASTM D6110 covers plastic materials suitable for preparing appropriate notched Charpy specimens. It can test various plastic formulations and processing conditions, provided the samples meet the test requirements and the applicable material specification. Notch and test conditions could yield varying crack responses since plastics vary in their elastic and viscoelastic properties. Materials that may be evaluated include:

• Standard specimens made of thermoplastic materials. 
• Compositions/formulations of plastics. 
• Plastic specimens produced using different molding or fabrication processes. 
• Materials conditioned differently by heat or environment. 
• Comparisons of plastic grades being tested at the same specified conditions for impact resistance.

Why Is ASTM D6110 Testing Important?

Impact resistance matters when plastic parts are likely to experience sudden impacts during handling, transportation, assembly, or service. ASTM D6110 provides a controlled procedure for comparing the energy absorbed by notched plastic parts during fracture. It can also be used to detect variations between products that can occur during manufacture or conditioning. But impact values are useful only when considered alongside fracture behavior, test conditions, notch quality, and specimen geometry. 

Testing Process and Data Collection

The ASTM D6110 testing procedure begins with sample fabrication and notch preparation. Technicians measure and check the dimensions and notch quality of the specimens, condition the specimens to meet standards/specifications, and document the time elapsed between notching and testing. They then rest each specimen on the Charpy tester supports and release the pendulum so that it hits the specimen once. The instrument measures energy loss during impact, and the reported impact value is based on the standard. Technicians also make note of whether a specimen shatters all the way and note the fracture characteristics.

Common Challenges and Troubleshooting

Several factors can affect repeatability and interpretation in ASTM D6110. Reliable comparisons are the result of the control of environment, equipment condition, notch quality, and specimen preparation by technicians. Changes in notched depth, shape, or surface finish can alter stress concentration. Check the notch and ensure that the cutting is correct. The thickness or width under the notch may vary, which will alter the fracture response. Measure a specimen before testing. Molding conditions, processing technology, and thermal treatment can influence impact resistance. Record the production history of documents. If the energy of the hammer is too low, it may not completely crush the specimen. Choose an appropriate capacity of the pendulum for the material. 

• Technicians record the energy absorbed during fracture in the units shown on the testing instrument and in the reporting requirements. Report the results of the absorption of energy per unit specimen width as specified by ASTM D6110. If necessary, check the units and calculation basis in the current edition. 
• Technicians record the specimen identification, grain, fabrication process, size, and thickness below the notch. Make a note of how this notch was prepared and any observations made about the quality of the notch. Include the conditioning and test temperature as specified, and the time between notching and testing. 
• Analysts record whether the specimen broke completely and the fracture characteristics. Concentrate on comparing specimens tested with consistent dimensions, notch geometry, conditioning, and machine conditions. Be able to outline the test equipment (ASTM D6110), specimen information, individual results, units reported, and any deviations from the procedure. 
• The measured impact value is directly proportional to the energy the material absorbs under the given testing conditions. However, this is not a direct measure of energy absorption. In other words, it may not be that way for all applications. The interpretation of results depends on the material’s character, specimen width, fracture type, and intended use conditions.

Link to ASTM D6110