Test method impact

In particular, standard specimens contain a sharp notch so that it is propagation energy rather than initiation energy which is the dominant factor. In general the standard tests are useful for quality control and specification purposes but not 

Although the Izod and Charpy tests are widely used for plastics, other types of test are also popular. These include tensile impact tests and flexural plate (falling weight) tests. The latter is particularly useful in situations where the effects of flow anisotropy are being assessed. In addition, arbitrary end-product tests are widely used to provide reassurance that unforseen factors have not emerged to reduce the impact performance of the product. 

The results of impact tests are often scattered even with the most careful test procedures. In these circumstances it is normal practice to quote the median strength rather than the average. This is because the median will be more representative of the bulk of the results if there are odd very high or very low results. A non-broken sample can also be allowed for in median analysis but not when the average is used. 

Occasionally the less satisfactory term of energy to break per unit width may be quoted in units of J/m. 

Rigid polyvinyl chloride Cellulose acetate butyrote Nylon (dry) 

Rigid polyvinyl chloride CellulOM ocetote butyrate Nylon (dry) 

---

Refer to the referenced code paragraph for impact testing methods and acceptance. 

IZOD impact test—method for determining the behavior of materials subjected to shock loading. Specimen supported as a cantilever beam is strack by a weight at the end of a pendulum. Impact strength is determined from the amount of energy required to fracture the specimen. The specimen may be notched or unnotched. 

Impact Test. Impact testing is of importance because adhesives, like most polymeric materials, are sensitive to high rates of application of force. The resistance of an adhesive to impact can be determined by ASTM D 950. This test is analogous to the Izod impact test method used for impact studies on materials. 

For explosives of high critical diameter, Eld, D. and Johansson, C. H. described an impact testing method ) by shooting the explosive sample (unconfined filled in bakelite tubes 30 mm 0 30 mm length and covered with paper or plastic foil) with brass cylinders (15mm0 ... 

The indirect impact method should be used when the data generated from the direct impact test method is widely spread. The test procedure for this method only differs from the direct impact method in part (2) as described in the following 2 0 . ... 

Implementing GHS does not change most aspects of the pesticide management. It does not affect supplemental information required on labels such as directions for use or additional hazard information that does not contradict or detract from GHS label requirements. It also does not impact testing methods for health and environmental hazards, data requirements, the scope of hazards covered, policies governing the protection of Confidential Business Information, or risk management measures. 

Some impact testing methods take the minimum drop height at which at least one of ten consecutive trials results in initiation of the sample as a measure of the impact sensitivity. 

The deterioration of mechanical properties is normally assessed by measurements of fracture resistance by pendulum impact test methods or slow speed flexural strength measurements and by ensuring that the surface of the specimens subjected to tensile stresses corresponds to the face exposed to the UV (or weathering) source. These tests are generally more meaningful than nondestructive tests, such as modulus measurements, since the chemical changes and the creation of fine cracks (often invisible to the naked eye) may involve only a very fine layer on the surface of the exposed samples. 

Where applicable perhaps use D-0950, the basic impact test method (see metal, strength, impact). 

One of the biggest drawbacks of the conventional impact test methods is that it... 

This effectively limits the application of noninstrumented impact test methods to quality control and material ranking. Instrumented impact testers are generally suited for research and development as well as advance quality control. 

---