Izod impact


Izod impact tests  [c.535]

Notched Izod impact  [c.688]

Fig. 3. Dependence of Izod impact strength on temperature for (— Fig. 3. Dependence of Izod impact strength on temperature for (—
Izod impact (notched), J/m 64-96  [c.327]

Izod impact strength, J /m  [c.405]

Izod impact strength at —SO "C, J/m, >640 250 120  [c.271]

The particle size and size distribution are largely controlled by the appHed shear rate during and after phase inversion, the viscosity of the continuous phase, the viscosity ratio of the two phases, and the interfacial tension between the phases (51,202). The viscosity parameters depend on phase compositions, polymer molecular weights, and temperatures the interfacial tension is largely controlled by the amount and stmcture of the graft copolymer available at the particle surface. Phase-contrast micrographs of this phase-inversion sequence, wherein the PS phase is dark, are shown in Figure 27. If shearing agitation is insufficient, then phase inversion does not occur and the product obtained is a network of cross-linked mbber with PS and its properties are much inferior. The morphology of the dispersed mbber phase remains much as formed after phase inversion, unless there is a step change in phase concentration, eg, by blending streams. Rubber-phase volume, including the occlusions, largely controls performance. Izod impact strength depends on mbber particle size and varies from 48 J/m (0.9 ftlbf/in.) at an average particle diameter of 0.6 lm to - 100 J/m (1.9 ftlbf/in.) at 3.5 lm diameter (204).  [c.520]

Izod impact strength. no no 21-213 21-64 varies 18-24 74-640 16-32 750 16-24 64-123  [c.326]

Izod impact strength, J/m 16-80 214-427 240-1500  [c.326]

A variety of ABS grades are available with Izod impact strengths ranging from 106.7 J/m (2 ft-lb/in.) to 640.5 J/m 12 ft-lb/in., heat distortion temperatures from 80 to 115°C, and tensile strengths from 27.6 MPa (4000 psi) to 55.2 MPa (8000 psi). Special ABS resins with high flow characteristics for the injection molding of intricate parts with controlled gloss, or deep-draw vacuum formabiUty can also be made. In addition, certain ABS plastics are available in pellet or powder form for use in blending with other polymers such as PVC. ABS plastics can be processed by all the techniques common to thermoplastics. The consumption of ABS in 1990 was 557,000 t (89). The principal markets for ABS are automotive (25% of total consumption), business machines (24%), and pipes and fittings (13%) (91).  [c.186]

Crystalline nylons are processed by injection molding and extmsion. The extmsion products are mostly films. Coated or laminated with moisture-barrier resin, eg, PVDC or PE polymers, they are used for meat wrappings and shaped food containers. For injection mol dings, extmded pellets are used, available in neat, mineral-filled, glass-reinforced, pigmented, and impact-modified grades. Notched Izod impact resistance can be increased from the usual 100—150-J/m (1.9—2.8-fflbf/in.) (under ambient moisture conditions) to the 1000-J/m (19-fflbf/in.) range (62). Injection-molded parts are used for small mechanical, electrical, and building constmction appHcations. In the automotive area, nylon resins are used for interior, exterior, and under-the-hood appHcations. Parts include filter bowls (amorphous nylon resins), window cranks, electrical coimectors, fuse boxes, and speedometer gears. The electrical and electronic industries use various nylon resins for coimectors, switches, and clamps. Mechanical appHcations include metal replacement in parts such as gears, sprockets, and wedges. The constmction industry uses injection molded parts for fasteners, hardware, and power tools. For many appHcations, nylons compete with polyester and PC resins. Small volumes (about 5% of total nylon engineering appHcations) of nylon-11 [25035-04-5] and nylon-12 [24937-16 ] are used for solvent resistant parts such as automotive fuel line components.  [c.267]

Izod impact (ftlbf/in notch) 4 0.8 5 1.5  [c.276]

Typical products have a specific gravity of 1.3-1.4, a tensile strength of 50 MPa and a flexural modulus of 2500 MPa. ASTM Izod impact strengths range from 1 to 25 ft Ibf/in of notch according to formulation whilst melt flow may also be varied 100-fold in a similar manner.  [c.360]

Izod impact strength at 23°C (ftlbf in D.256 2.0 1.2-1.3 — 3.5 2.9 — —  [c.368]

Izod impact strength ftlbf in- (B.S.) 0.40  [c.406]

The brittleness of isotactic polystyrenes has hindered their commercial development. Quoted Izod impact strengths are only 20% that of conventional amorphous polymer. Impact strength double that of the amorphous material has, however, been claimed when isotactic polymer is blended with a synthetic rubber or a polyolefin.  [c.454]

Mechanical properties of freshly injected compositions are similar for the two nylons but, after conditioning, differences arise largely due to the plasticising effect of the moisture present. Thus for tensile and flexural yield stress, tensile strength and modulus of elasticity, nylon 66 gives slightly higher figures. Yield elongation and elongation at break are greater with nylon 6. Izod impact strengths are similar, with nylon 6 giving marginally higher values.  [c.500]

Izod impact strength (23 C) D.758 0.4 ft lb per in notch  [c.551]

The addition of carbon fibre to polycarbonate can lead to composites with flexural strength three times and flexural modulus seven times that of unfilled resin. Notched Izod impact values are amongst the highest for any fibre-filled thermoplastics material. Flexural creep after 2000 hours loading at 10000 psi (68.97 MPa) is also minimal. Carbon-fibre-reinforced grades also exhibit enhanced deflection temperatures (149°C for 30% fibre loading under 1.8 MPa loading), low volume and surface resistivities, facilitating dissipation of static charge, lower coefficient of friction and increased wear resistance.  [c.567]

Izod impact strength ft Ibf per in notch ASTM D.256-56 12-16 15-18 ca 2.5 ca 2.5  [c.568]

Heat aging effects are somewhat complex. Heating at 125°C will cause reduction in elongation at break to 5-15% and in Izod impact strength from 16 down to 1-2 ft Ibf per in notch and a slight increase a tensile strength in less than four days. Further aging has little effect on these properties but will cause progressive darkening. Heat aging in the presence of water will lead to more severe adverse effects.  [c.573]

Because of the irregular structure the copolymers are amorphous and transparent. The higher the polyester component the higher the softening point, typical grades having values in the range 158-182°C compared with 148°C for unmodified polymer. On thermal aging the polyester carbonates also show a lower tendency to embrittlement than polycarbonate. This is, however, at the cost of a reduction in notched Izod impact strength (35-28 kJ/m, compared to 45 kJ/ m for unmodified polymer) and increased melt viscosity. As with the poly(co-carbonates) based on bisphenol A and bisphenol S, the polyester carbonates have a low level of notch sensitivity. The polyester carbonates are easier to process than the polyarylates.  [c.580]

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

Most of the polymer s characteristics stem from its molecular stmcture, which like POE, promotes solubiUty in a variety of solvents in addition to water. It exhibits Newtonian rheology and is mechanically stable relative to other thermoplastics. It also forms miscible blends with a variety of other polymers. The water solubiUty and hot meltable characteristics promote adhesion in a number of appHcations. PEOX has been observed to promote adhesion comparable with PVP and PVA on aluminum foil, cellophane, nylon, poly(methyl methacrylate), and poly(ethylene terephthalate), and in composite systems improved tensile strength and Izod impact properties have been noted.  [c.320]

Processings Conditions. Certain variables should be monitored, measured, and recorded to aid in reproducibiUty of the desired balance of properties and appearance. The individual ABS suppHers provide data sheets and brochures specifying the range of conditions that can be used for each product. Relying on machine settings is not adequate. Identical cylinder heater settings on two machines can result in much different melt temperatures. Therefore, melt temperatures should be measured with a fast response hand pyrometer on an air shot recovered under normal screw rpm and back-pressure. Melt temperatures range from 218 to 268°C depending on the grade. Generally, the allowable melt temperature range within a grade is at least 28°C. Excessive melt temperatures cause color shift, poor gloss control, and loss of properties. Similarly, a fiU rate setting of 1 cm/s ram travel will not yield the same mold filling time on two machines of different barrel size. Fill time should be measured and adjusted to meet the requirements of getting a fliU part, and to take advantage of shear thinning without undue shear heating and gas bums. Injection pressure should be adjusted to get a fliU part free of sinks and good definition of gloss or texture. Hydrauhc pressures of less than 13 MPa (1900 psi) usually suffice for most mol ding. Excessive pressure causes flash and can result ia loss of some properties. Mold temperatures for ABS range from 27 to 66°C (60 to 82°C for high heat grades). The final properties of a molded part can be iafluenced as much by the mol ding as by the grade of ABS selected for the appHcation (121). The factors ia approximate descending order of importance are polymer orientation, heat history, free volume, and molded-ia stress. Izod impact strength can vary severalfold as a function of melt temperature and fiU rate because of orientation effects, and the response curve is ABS grade dependent (122). The effect on tensile strength is qualitatively the same, but the magnitude is ia the range of 5 to 10%. Modulus effects are minimal. Orientation distribution ia the part is very seasitive to the flow rate ia the mold therefore, fiU rate and velocity-to-pressure transfer poiat are important variables to control (123). Dart impact is also sensitive to mol ding variables, and orientation and thermal history can also be key factors (124). Heat deflection temperature can be iafluenced by packing pressure (125) because of free volume considerations (126). The orientation on the very surface of the part results from an extensionaHy stretching melt front and can have deleterious effects on electro-plate adhesion and paintabiUty. A phenomenon called the mold-surface-effect, which iavolves grooving the nonappearance half of the mold, can be employed to reduce unwanted surface orientation on the noncorresponding part surface (127—129). Other information regarding the influence of processiag coaditioas oa part quality are givea ia refereaces 130—134.  [c.206]

PiirtDesign. Eor optimum economics and production cycle time, wall thicknesses for ABS parts should be the minimum necessary to satisfy service strength requirements. The typical design range is 0.08 to 0.32 cm, although parts outside this range have been successfliUy molded. A key principle that guides design is avoiding stress concentrators such as notches and sharp edges. Changes ia wall thickness should be gradual, sharp corners should be avoided, and generous radii (25% of the wall thickness) used at wall iatersections with ribs and bosses. To avoid sinks, rib thickness should be between 50 and 75% of the nominal wall. Part-strength at weld lines can be diminished thus welds should be avoided if possible or at least placed ia aoacritical areas of the part (135). Because of polymer orieatatioa, properties such as impact strength vary from poiat to poiat oa the same part and with respect to the flow direction (121). Locations of highest Izod impact strength can be poiats of lowest dart impact strength because of the degree and direction of orientation. ABS suppHers can provide assistance with design of parts upon iaquiry and through design manuals (136). There are a number of special considerations when designing parts for metal plating to optimize the plating process, plate deposition uniformity, and final part quaHty (137). ABS parts can be also designed for soHd—soHd or soHd—foam co-iajection mol ding (138) and for gas-assisted-iajection mol ding (139).  [c.206]

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]

Izod impact strength, J /m of notch ASTM D256 21.35-53.38  [c.441]

PC resins are glassy, amorphous polymers with Htde color and excellent optical properties. The high molecular weight resins are tough, with notched Izod impact values of 600—800 J /m (11.2—15.0 fdbf/in.). Heat-deflection temperatures of unfilled grades are near 130°C glass reinforcement increases these values by 10°C. Flex modifli above 2400 N/mm (348,000 psi) allow PC resins to be formed into large rigid parts. Below 100°C, creep under load is low, as is predictable from the high glass-transition temperatures. PC resin products have good hydrolytic stabiUty but should not be used for appHcations requiring repeated autoclaving. Like most amorphous resins, they are susceptible to attack by some organic solvents. Although PC resins have good resistance to fmit juices, aUphatic hydrocarbons, aqueous alcohol, and strong battery acids, they dissolve in chlorocarbon solvents and stress-crack in contact with ketonic solvents such as acetone and methyl ethyl ketone. Properties are given in Table 9.  [c.270]


See pages that mention the term Izod impact : [c.57]    [c.191]    [c.202]    [c.373]    [c.360]    [c.410]    [c.428]    [c.266]    [c.267]    [c.303]    [c.320]    [c.405]    [c.449]    [c.465]    [c.83]    [c.86]    [c.209]    [c.532]    [c.218]    [c.499]    [c.526]   
Plastics engineering Изд.3 (2002) -- [ c.152 ]