Izod test


Impact tests are, however, used to try to compare the impact strength of different materials. Of these tests four require specific mention. These are the Izod test, the Charpy test, the falling weight tests and the tensile impact test.  [c.192]

Of these the most well known is the Izod test. This consists of a bar, one end of which is held in a vice, the sample being held vertically. The bar is then struck by a striking device under controlled conditions at a specified point above the vice. The energy required to break the sample is noted. It is common to have a notch in the bar which is located during the test at the top of the vice and on the  [c.192]

An alternative to the Izod test is the Charpy test in which a sample supported, but not gripped, at each end is subject to an impact in the centre. According to the test a notch may be present in the centre of the sample on the face opposite to that subjected to impact. In spite of the differences between the tests there is a surprisingly good correlation between Izod and Charpy test results as shown by Figure 9.5 based on tests on several thermoplastics.  [c.194]

Due to the polyether blocks, these polymers retain their flexibility down to about -40°C and only Grade 6333 breaks in an Izod test at this temperature (using specimens of thickness 3.2 mm). The materials generally show excellent resistance to crack growth from a notch during flexure some grades are reported  [c.527]

Exceptionally high Izod impact strength of unreinforced grades, with one ICI grade having a quoted notched Izod figure as high as 931 J/m (approx. 18 ft Ib/in notch). Fibre reinforcement reduces this figure. It should be stressed that these figures apply to Izod test pieces, where a high level of  [c.735]

A critical review (6) of techniques for the evaluation of iasect repellents describes many test methods, including the foUowiag.  [c.113]

Hazardous Air Pollutants. Tide III of the Amendments extends the air toxics component of the Clean Air Act. It attacks the issue of air toxics by estabUshing a long Hst of toxic pollutants to be regulated. The EPA is commanded to impose tight controls ia two stages. The first stage is based oa technology standards which require companies to iastaH maximum achievable control technology (MACT). The second stage may subject some facihties to further regulation once MACT standards have been met, setting tighter emissions requirements based on an assessment of residual risk.  [c.263]

Jptt 70 06,533 (Mar. 5, 1970), M. Ikeda and co-workers (to Takeda Chemical).  [c.73]

What is important to realise is that a polymer may be tough when exposed to tensile load but brittle when assessed by an Izod-type test where a notched sample is subjected to a bending load. Table 9.3 attempts to summarise the behaviour of typical polymers to different stresses.  [c.191]

Because of the diversity of the sources for this book the Izod data frequently referred to are expressed in a variety of units according to the test method used and no attempt has been made to convert the data to the use of a common unit.  [c.193]

Great care must be taken, as always, in the interpretation of impact test results. It is important to be informed on the influence of temperature, speed of testing and shape factor on the tough-brittle transitions and not to rely on results of a single test. A number of examples of the misleading tendency of quoting single results may be given. In the first instance, while 5 in X in bars consistently give Izod values of about 16, the values for in X in bars are of the order of 2.5 ftlbf per inch notch. There appears to be a critical thickness for a given polycarbonate below which high values ( 16 ftlbf per in notch) are obtained but above which much lower figures are to be noted. The impact strengths of bis-phenol A polycarbonates are also temperature sensitive. A sharp discontinuity occurs at about -10°C to -15°C, for above this temperature 5 in X in bars give numerical values of about 16 whilst below it values of 2 to 2 are to be obtained. Heat aging will cause similar drops in strength.  [c.569]

Trade literature can provide a wealth of information. Users should, however, bear in mind that suppliers will naturally wish to emphasise data in the best possible light. For example, if the Izod impact strength increases sharply with decrease in sample thickness, then results may be quoted for thinner section test pieces. Whilst the facts may be stated, the underlying significance may not be fully appreciated by the casual reader.  [c.892]

The required notification must be provided at ieast annually In writing. Acceptable forms of notice are, for example, a letter, product labeling, and product literature distributed to customers. If you are required to prepare and distribute a Material Safety Data Sheet (MSDS) for the mixture under the Occupational Safety and Health Act (OSHA) Hazard Communication Standard, your section 313 notification may be attached to the MSDS or the MSDS may be modified to include the required information. (A sample letter and recommended text for inclusion in an MSDS appear on pages E-4 and E-5 of this appendix.)  [c.94]

In order to provide information on the impact behaviour of materials, metallurgists developed tests methods which involved striking a notched bar with a pendulum. This conveniently subjected the material to triaxiality of stress (at the notch tip) and a high strain rate so as to encourage brittle failures. The standard test methods are the Izod and Charpy tests which use the test procedures illustrated in Fig. 2.81(a) and (b). The specimens have a standard notch machined in them and the impact energy absorbed in breaking the specimen is recorded. With the ever-increasing use of plastics in engineering applications it seemed appropriate that these well established test methods should be adopted. However, even the metallurgists recognised that the tests do have certain shortcomings. The main problem is that the test conditions are arbitrary. The speed of impact, method of stressing and specimen geometry are fixed and experience has shown that it was too much to expect the results to be representative of material behaviour under different conditions.  [c.152]

The study on commercial HDPE samples could not provide a correlation of the izod impact test with the field performance test, i.e., drop impact resistance on moulded products [113]. It was found that the sample of highest density and lowest izod impact strength passed the drop impact test, but other samples of lower density and higher izod impact strength could not withstand shock loading by drop impact and failed in brittle manner. This may be due to the fact that velocities and modes of loading vary widely in different impact tests. It has been reported that even the qualitative agreement between the different impact tests is poor because the test bars and moulded products often have different orientation characteristics, particularly near the surface [115].  [c.288]

The calixarenes are almost totally insoluble in water and only partially soluble in most organic solvents [1]. The first success in demonstrating their complex abilities was achieved by Izatt and coworkers [2,3]. Izatt, who has carried out extensive investigations on the complex behavior of crown ethers and various related types of compounds, perceived a structural resemblance between the crown ethers, cyclodextrins, and calixarenes, and proceeded to test the latter for their ability to transport cations across a liquid membrane. They also used an apparatus in which an aqueous source phase containing the host molecule (the carrier) and the cations were separated by an organic phase (e.g., chloroform) from an aqueous receiving phase. They discovered that although the calixarenes are ineffective cation carriers in neutral solution, they possess significant transport ability for Group I cations in a strongly basic solution. This is in sharp contrast to 18-crown-6 compounds, which are more effective in a neutral rather than in a basic solution. Group II cations, including Ca, Ba, and Sr, are not effectively transported by these calixarenes. Control experiments with p-tert-hu y phenol, which shows little or no transport ability itself, support the idea that the macrocyclic ring plays a critical role, although it is not yet clear what the role is exactly. The diameters of the annuli of the calixarene mono anions are ca. I.O A for the cyclic tetramer, 2.4 A for the cyclic hexamer, and 4.8 A for the cyclic octamer. Thus, for complexes in which the cation and oxygen are coplanar, the cyclic tetramer has too small an opening even for Li, whereas the cyclic octamer has too large an opening to fit snugly.  [c.339]

Thus, to increase the yield pressure, the designer is tempted to use an excessively high strength steel with much lower transverse impact strength. Manning, who was responsible for the design of the vessels used by ICI in their LDPE process, realized that a low transverse impact strength was undesirable in that it could lead to what he referred to as brittie fracture, now known as fast fracture. Consequentiy he decided to adopt a factor of safety of 2.5 against bursting based on room temperature data and a factor of safety of 1.5 against yield, with an additional requirement that the transverse impact strength as determined by an Izod test should exceed 34 J (25ft Ibf). It was required that the vessel be proof tested to the yield pressure.  [c.96]

Another test protocol is that specified by the International Safe Transit Association (ISTA), East Lansing, Michigan. This also simulates transportation and handhng conditions. Transportation companies—truck, rail—accept ISTA test results and will transport packages bearing the ISTA marks.  [c.1952]

A second melt-processable copolymer containing tetrafluoroethylene residues was introduced by Du Pont in 1972 as Tefzel. This material is similar in many properties to the TFE-FIFP copolymers but claimed to have exceptional abrasion resistance for a fluorine-containing plastics material. It also has very high impact strength and does not fracture in a notched Izod test at room temperature when subjected to impact stresses as high as 20ftlbfin (10.9kgfmem ). Unlike PTFE it cross-links during irradiation. It also differs from PTFE in that glass fibre actually reinforces the polymer, giving tensile strengths as high as 120001b/in (85/MPa).  [c.374]

Tyrosine and cystine are insoluble in water therefore place about 0 2 g. in the test-tube A, dissolve in the dil. NaOH solution, add phenolphthalein as before and then add dil. HCl until pink colour is iust not discharged then proceed as above.  [c.381]

Tyrosine and cystine are insoluble in water therefore place about 0-2 g. in the test-tube A, dissolve in the dil. NaOH solution, add phenolphthalein as before and then add dil. HCl until pink colour is iust not discharged then proceed as above.  [c.381]

Charlie CHARMm Charpy Izod impact Charpy method Charpy test CHARTEK59 Charybdotoxin Chaser mill Chatecholates  [c.189]

Other Substances. Driving under the influence of alcohol cases are compHcated because people sometimes consume alcohol with other substances (11—13). The most common iUicit substances taken with alcohol are marijuana and cocaine (see Table 1) (14). In combination with alcohol, some dmgs have an additive effect. When a blood or urine alcohol sample is tested for alcohol and the result is well below the legal concentration threshold yet the test results are not consistent with the arresting officers observation that the subject was stuporous, further toxicological tests for the possible presence of dmgs are indicated.  [c.486]

ASTM E1050-90 also makes use of a tube with a test specimen at one end and a loudspeaker at the other end, but iastead of a single movable microphone there are two microphones at fixed locations ia the tube. The signals from these microphones are processed by a digital frequency analysis system which calculates the standing wave pattern and the normal iacidence sound-absorption coefficients.  [c.312]

Mechanical properties are determined on soHd polymers ia arbitrary forms defined precisely by standard test methods ia ISO, ASTM, or other national standards organizations. Parts are formed by either iajection mol ding, compression mol ding, or milling from extmded sheet or molded plaques. Viscoelasticity of polymers dictates that the technique used to make the part must have a significant effect on the mechanical behavior of the polymer. For vahd comparison of materials, they should be prepared similarly and conditioned under the same environment. Viscoelastic effects are also the reason for the rate of strain effects on the modulus values of materials under tensile, flexural, and compressive testing (195). Several types of impact testing have been developed to measure a plastic s response to a high rate of strain. Notched or Charpy Izod impact are pendulum impact tests essentially uniaxial ia direction. Although both tests have been long estabUshed for quaUty control tests and material property data sheets, they have tittle practical value ia determining the impact response of a plastic. ASTM D256 (196) lists multiple cautions on usiag data from these tests. Notched Izod s primary practical value ia characterizing a plastic material is to establish how notch-sensitive the material is. Drop-weight impacts, either manual (197) or iastmmented (198), give more practical information because these are multiaxial test procedures and closer to normal impact seen ia part applications. Instmmented impact allows the recording of the fliU impact event as a stress—strain curve, showiag similar characteristics to tensile or other modes of stress—strain tests. Instmmented impact is preferred for monitoring ductile—brittle transitions and determining the effects of polymer composition on material toughness (199). Large equipment is available for testing the actual parts with data correlated to performance (200). Newer high speed impact testing equipment (hydrauhcaHy controlled) can be used to test at speeds greater than 1.6 x lO" mm/s (201) and to simulate automotive impact conditions.  [c.153]

A third method is similar to the first oae, ia that additioas of aluminum nitride ia sufficieat amouats (5—10%) are made, iastead of TiN as ia the case of the first method, to the cemeated carbide mix and vacuum siatered containing Type B1 porosity. This enhances the surface toughness of the cemented carbide by promotiag biader enrichment and depletion of aluminum nitride near the peripheral surface, obtained by decomposition of aluminum nitride duriag sintering (94). The Co-eariched zoae is also characterized by the preseace of straight tuagstea carbide and depletion of multicarbides. Thus this zone consists of Co-enriched tungsten carbide, and after appropriate coatiag, the tool would provide the required toughness ia iatermpted or heavy-duty cuttiag.  [c.210]

There are numerous appHcations for trace or ultratrace analyses ia the chemical process iadustry. The foUowiag two examples highlight the need for such analyses. Although much controversy stiU surrounds the nature of its toxicity and possible safe levels, dioxia (2,3,7,8-tetrachlorodibenzo-/)-dioxiQ (TCDD)) is frequentiy described as the worst poison known. It has been found to cause abortion ia monkeys, even at a level of 200 parts per trillion (ppt) (5). Allowing for a hundredfold margin of safety for human exposure, the safe food level for TCDD would have to be less than 2 ppt. Polychlotinated biphenyls (PCBs) at 0.43 parts per biUion (ppb) ia water have been found to weaken the backbones of trout by interfering ia coUagen synthesis (6). The analysis of fish backbones from such water revealed excess calcium levels and a deficiency ia coUagen and phosphoms. The fish were also deficient ia vitamin C, a cofactor ia coUagen synthesis. Thus it was concluded that the trout used vitamin C for detoxification of PCBs iastead of for skeletal development.  [c.241]

The usefulness of a hindered phenol for a specific appHcation depends on its radical-trappiag ability, its solubility ia the substrate, and its volatility under test conditions. Table 2 shows the importance of volatility to stabilizet performance. Equimolar quantities of alkyl esters (6) of 3,5,di-/ f2 -butyi-4-hydroxyhydrocinnamic acid were evaluated ia polypropylene at 140°C usiag two different procedures (15). When tested ia an air stream, only the octadecyl ester, (6) where n = 18, was effective ia stabilizing the polymer. Under these conditions, the lower homologues were lost by volatilization. The oxygen-uptake test, carried out ia a closed system that minimizes evaporative loss, showed that homologues were effective to varyiag degrees. The differences ia effectiveness can probably be attributed to differences ia the solubility of various homologues ia the amorphous phase of the polypropylene. When dodecane, a Hquid ia which all the compounds ate soluble, was used as a substrate iastead of polypropylene, the antioxidant activities were relatively close.  [c.224]

A sequence of tests has been devised to evaluate antioxidants for use in automotive crankcase lubricants. The Indiana Stirring Oxidation Test (ISOT) JISK2514 is an example of a laboratory screening test. The oil is stirred at 165.5°C in the presence of air. Copper and iron strips are used as metal catalysts. The development of sludge, viscosity, and acidity are deterrnined periodically. Failure time is determined when the development of acidity requires  [c.234]

Oxidation deposits ia aircraft engines are related to the thermal stresses imposed by heat soakback, which results from the off/oa cycles associated with many landings and takeoffs. In contrast, ground turbiaes tead to operate longer at coastant flow and do not subject fuel to the same degree of thermal stress. Fuel stabiUty testing has not been estabUshed as a quaUty requirement, although a carbon residue test (ASTM D524) provides a rough screening tool to protect against the tendency for carbonization ia a fuel iajectioa system.  [c.414]

The boundary of aeeeptable design for a eomponent or assembly eharaeteristie in the zone S > 6 eorresponds fairly elosely to a failure eost line equivalent to 0.01% of the unit eost. The region of unaeeeptable design is bounded by the inter-seetion of the horizontal line of Cpi = 1 and the 1 % isoeost. A proeess is not eon-sidered eapable unless Cpi > 1 and a failure eost of less than 1 % is thought to be aeeeptable.  [c.71]

The ductile-to-brittle transition temperature for some steels ean be as high as O C, depending on the eomposition of the steel (Ashby and Jones, 1989). However, there is no way of using the data direetly from impaet tests quantitatively in the design proeess. Design speeifieations do usually state a minimum impaet strength, but experienee suggests that this does not neeessarily eliminate brittle failure (Faires, 1965). The Robertson test ean yield more information than either the Charpy or Izod tests beeause the transition temperature is statistieally eorrelated with the temperature at whieh the aetual strueture has been known to fail in a brittle manner (Benham and Warnoek, 1983 Ruiz and Koenigsberger, 1970). The test uses a severely notehed speeimen tested under statie tension, and a plot showing the variation of the nominal stress at fraeture with the test speeimen temperature drawn. The test gives useful results from whieh design ealeulations ean be based however, the test is more expensive and eomplex eompared to other methods. In general, it is dangerous to use a material below its transition temperature beeause most of its eapaeity to absorb energy without rupture has been lost and eareful design and analysis is required.  [c.161]

Provided all conductive components in the tank are grounded the only source of a static spark is charged, isolated slugs of water. These may form during breakup of a jet, drainage from an overhanging tank component, or sloshing of water heels inside a vessel at sea. in the absence of steam, test work and calculations (A-5-6.1) suggest significant hazards only occur in tanks exceeding 1000 ml Precautions for washing large tanks such as marine center tanks are given in ISGOTT [5j. Analyses (A-5-6.1) suggest that the hazard can be neglected for tanks less than 100 ml although more conservative guidelines have been published for industrial tank applications [127] as noted below.  [c.145]

Y. IsHiDA, K. Tsuda, M. Terauchi, M.Tanaka in Proe. Intemat. Cong. El. Mierose.,  [c.308]

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.  [c.153]

Takeda, Y., Isohata, E., Amano, R., Uchiyama, M. J. Assoc. Off. Anal Chem. 1979, 62, 573-578.  [c.116]

Takeda, Y., Isohata, E., Amano, R., Uehiyama, M. J. Assoc, off. Anal. Chem. 1979, 62, 573-578.  [c.150]

Takeda, Y., Isohata, E., Amano, R., Uchiyama, M. J. Assoc. Off. Anal. Chem. 1979, 62, 573-578.  [c.169]

H. S. Kim, and Y. Okamoto, J. Heterocycl. Chem. 30,782 (1993). Y. Kurasawa, Y. Matsumoto, A. Ishikura, K. Ikeda, T. Hosaka, and A. Takada, / Heterocycl. Chem. 30,1463 (1993).  [c.110]


See pages that mention the term Izod test : [c.535]    [c.239]    [c.65]    [c.254]    [c.97]    [c.329]    [c.283]    [c.75]    [c.323]    [c.131]    [c.377]   
Designing capable and reliable products (2000) -- [ c.160 ]

Plastics materials (1999) -- [ c.374 , c.567 ]