DIN 53 735 specifies the test method for measuring notched impact strength of plastics using a pendulum impact tester. It defines precise specimen preparation, standardized testing parameters, and strict equipment requirements to ensure reliable, reproducible, and comparable results across different laboratories and applications.
Overview of DIN 53 735 standard
DIN 53 735 is a German standard that specifies methods for determining the notched impact strength of plastics using a pendulum impact tester. It plays a significant role in evaluating the behavior of plastic materials and products under sudden impact loading. The aim of this standard is to provide reliable and reproducible methods for measuring the resistance of plastics to impact fracture, which is a crucial property for quality control, material selection, and product development across industries using plastic components. DIN 53 735 aligns with internationally recognized procedures, ensuring compatibility in test results between laboratories.
Test specimens and equipment
The standard defines precise geometric requirements for test specimens, such as the depth, width, and type of notch. It also sets the calibration, mass, and design of the pendulum equipment used to strike the sample. By standardizing these parameters, DIN 53 735 ensures that results are consistent and comparable, regardless of where the test is performed or which manufacturer supplies the testing machine. Recorded values—typically given in kilojoules per square meter—indicate the amount of energy absorbed by the specimen at fracture, offering a quantitative measure of impact resistance.
Applications in industry
DIN 53 735 is widely utilized in the plastics industry to evaluate materials for use in applications where impact strength is critical. Manufacturers of pipes, fittings, automotive parts, consumer goods, and safety equipment may refer to this standard during development and quality control processes. The test data can be used to compare compounds, optimize formulations, or verify that raw material batches meet customer or regulatory requirements. Its procedures are sometimes harmonized with or referenced by international standards such as ISO 179.
Takeaway
DIN 53 735 remains an established reference for assessing the impact resistance of plastic materials through standardized specimen preparation, testing, and reporting.
Preparation and specimen selection
Conducting the notched impact strength test according to DIN 53 735 starts with selecting the material and preparing specimens with highly controlled dimensions and notch geometry. Materials should represent the intended production batch or be taken from finished products. The geometry and dimensions must follow the standard’s guidance exactly to produce valid results. Environmental conditions, like temperature and relative humidity, need to comply with DIN 53 735 requirements to eliminate unnecessary variability.
Specimen notching and pre-conditioning
Once specimens are cut to size and notched, they must be conditioned in a controlled environment to ensure that moisture content and temperature reach equilibrium. Notching is a critical step—improperly formed notches can invalidate the test. Equipment such as a notching machine and calibrators are typically used to create the specified V-shaped notch to exact tolerances.
Test setup and execution
The next phase involves mounting each conditioned and notched specimen in the pendulum impact tester. The pendulum arm is calibrated and checked for proper mass and release height. The impactor strikes the specimen on the notched side, and the resulting energy absorbed at fracture is automatically recorded by the device. Multiple specimens are typically tested to account for variability and ensure statistical relevance of the data. Any deviation from the procedure must be documented in the test report.
Results analysis and reporting
The absorbed energy values are divided by the cross-sectional area at the notch to calculate notched impact strength, usually expressed in kJ/m². Results should be averaged and reported alongside relevant test conditions and any anomalies or departures from the standard. Proper data analysis is essential for comparing materials or validating quality.
Common pitfalls and recommendations
Frequent sources of error include inaccurate notching, incorrect conditioning, and using an improperly calibrated pendulum tester. For reliable results, maintain strict adherence to DIN 53 735 regarding specimen dimensions, environmental conditions, and instrument calibration. Regular verification of test equipment and training of operators further reduce risk of inconsistent or invalid data.
Summary
DIN 53 735 establishes a detailed protocol for measuring notched impact strength in plastics. Proper specimen preparation, rigorous conditioning, and precise execution are key to obtaining valid results. Following its guidelines ensures meaningful material comparison, effective quality assurance, and compliance with customer or regulatory expectations.
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