Impact tester

Fig. 1. Deceleration and penetration curves from dynamic impact tester. Time vs distance penetrated (A) and deceleration (B). Distance between vertical...

The popular Izod impact tester can use different size specimens depending on the type of plastic and their method of fabrication. The specimen is usually 1/8 in. x l/2 in. x 2 in. other sizes are also used. Specimens can be notched or unnotched. A notch is cut in a specified manner on the narrow face of the specimen. The sample is clamped in the base of a pendulum testing machine so that it is cantilevered upward with the notch facing the direction of impact. The pendulum is released, and the force expended in breaking the sample is calculated from the height the pendulum reaches on the follow-through. The speed of the pendulum at impact is controlled. 

Small and long specimens of tensile bar shape specimens have their major change in dimensions in the necked-down section. The specimen is mounted between a pendulum head and crosshead clamp on the pendulum of an impact tester. The pendulum is released and it swings past a fixed anvil that halts the crosshead clamp. The pendulum head continues forward, carrying the forward portion of the ruptured specimen. The energy loss (tensile impact energy) is recorded, as well as whether the failure appeared to be of a brittle or ductile type. 

Izod nothed impact energy Impact resistance of plastics and electrical insulating materials ASTM D-256-91 Pendulum impact tester type 5102, Zwick... 

The impact resistance of the pseudo-IPN coatings was measured on a Gardner-SPI modified Variable Height Impact Tester using both the direct and the indirect techniques. 

ASTM-D 2794, units are in-lb, impact tester limit was 80 in.lb. ASTM-D 3363 < ASTM-D 3359,5B is 100% cross-hatch adhesion double rubs ASTM-D 522 ASTM-D 1400, General Electric thickness gauge type B, units are l/lOOO in. Sonset of transition, determined by DSC. 

The impact sensitivity should be performed on one of the customary impact testers, using again milligram quantities of the material. Bureau of Mines values of 20 or less, or Ball Drop values of the order of 100 cm or less, or PicArsn Impact Test values of 15 cm or less, all indicate that the expl be treated as a primary expl, in the class of Pb Azide or Mercury Fulminate. Such substances should be stored wet in... 

Fig. 3.5 Lagrangian t-x diagram for soft recovery in a plate impact tester.29...

L. R. Deobald and A. S. Kobayashi A Bar Impact Tester for Dynamic Fracture Testing of Ceramics and Ceramic Composites, Experimental Mechanics, 32, 109-116 (1992). 

ASTM E 23-66 was applied for the dimensions of standard specimens except that the mat reinforced specimen (GC 33 wt % ) used ASTM D 256-56. Specimens were taken from a molded plate along the longitudinal fiber direction, and V notches were cut edgewise, perpendicular to both fiber direction and molding surface. Occasionally a specimen notched on the molding surface (flatwise) was used. Tests were performed with an instrumented Charpy impact tester (10) with a 30 kg-m or 150 kg-cm capacity. Test temperatures were varied from — 196°-250°C. 

CA 59, 12585(1963) (Impact tester is described for detg relative sensitivity to mechanical shock by impact of a 10-kg wt falling 25cm on 7--, 10- 50-mg samples. Relative sensitivity in terms of % explns and rebound of wc as a % of its fall are reported)... 

K. R. Becker, C. M. Mason, R. W. Watson, Bureau of Mines Instrumented Impacted Tester-Preliminary Studies, U.S. Bureau of Mines Report 7670, Pittsburgh, Pa., 1972. 

Impact measurement. The impact tests were conducted in the usual manner on single sheets with a Gardner Laboratory Impact Tester (Model IG-1120) with a 0.625" diameter punch hammer. At least ten drops were performed in the center 50% of the sheets and with points of impact at least 1" apart. The failure criterion was a brittle (not ductile or tear) break. The values reported in Table I are 50% probabilities (energy at which 50% of failures are brittle). The standard deviation of the values is about 10%. 

Impact strength vs. time was determined on solidified samples of the formulation that had been allowed to react from 30 min to 70 days at 135 °C. The impact strengths were measured with a Gardner impact tester on 1/2 in. thick samples. Impact strength values for all samples stabilized in the range 7-9 in.-lb. Hardness of the solidified samples was about 75 Shore D after 1 hr and increased to a maximum of about 80... 

Ariga (45) disclosed developments with CTBN-modified epoxy acrylates which when prepared with other lower molecular weight dicarboxylic acids and select carboxyl-terminated oligopolyesters serve as novel oligomers for photocurable coatings. These systems have low uncured viscosity. In the cured state they possess excellent scratch and crosshatch adhesion, good direct and reverse impacts (duPont impact tester) and pass bending diameters of 2 mm. 

Figure 8.12 shows the principal types of test. In the Charpy test a beam of the polymer is held at each end and is struck at its centre by a hammer with one or two knife edges, giving a three- or four-point impulsive bending stress, respectively. Figure 8.13 shows a diagram of a standard Charpy impact tester. In the Izod test the specimen is held at one end and struck at the other. For either test a notch is cut in the sample at the point where it is to break and the sample is placed in the tester with the notch pointing away... 

Experimental apparatus XJJ-5 J Type Simple Supported Girder Impact Tester. 

Impact Strength (Jim) 7.7x103 DuPont pneumatic impact tester... 

J. Steinebrunner, T. Emmerich, S. Heck, I. Munder and R. Steinbuch, A novel impact tester operating at elevated temperatures for characterising hard coatings. Surf. Coat. Technol. 1996, 86-87, 748-752. 

Bouzakis K-D, Michailidis N, Lontos A, Siganos A, Hadjiyiannis S, Giannopoulos G, Maliaris G, Erkens G (2001) Characterization of cohesion, adhesion and creep-properties of dynamically loaded coatings through the impact tester. Z Metallkd Mater Res Adv Tech92(10) 1180-1185... 

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