ISO 180:2000 download free.Plastics-Determination of Izod impact strength.
1 Scope
1.1 ISO 180 specifies a method lot delermming the lied impact strength of plastics under defined conditions. A number of different types of specimen and test conligurations are defined, Different test parameters ate specified according to the type of material, the type of test specimen and the type of notch.
1.2 The method is used to investigate the behaviour of specified types of specimen under the mipact conditions defined and for estimating the brittleness or toughness of specimens within the limitations inherent in the test conditions.
1.3 The method is suitable for use with the following range 0* materials:
— rigid thermoplastic moulding and extrusion materials. including filed and reinforced compounds in addition to unfilled types; rigid thermoplaslics sheets;
rigid ttiermosetting moulding matenals, including fIlled and reinforced compounds; rigid ttiermosetting sheets, inctuding laminates:
— fd,re-reinforoed thermosetting and thermoplastic composites incorporating unidirectional or non-unidirectional reinforcements such as mat, woven fabrics, woven rovings. chopped strands, combination and hybrid reinforcements, rovings and milled fibres and sheei made from pre-impregnated materials (prepregs);
— Ihermotropic liquid-crystal polymers.
1.4 The method is not normally suitable for use with rigid cellular materials and sandwich structures Containing celkilar malarial. Also, notched specimens are not normally used for long-fibre-reinforced composites or thermotropic llquid.crystal polymers.
1.5 The method is suited to the use of specimens which may be either moulded to the chosen dimensions. machined irom the central portion of a standard multipurpose test specimen (see ISO 3167) or machined from finished or semifinished products such as mouldings. laminates and extruded or cast sheet.
1.6 The method specifies preferred dimensions for The test specimen. Tests which are carried out on specimens of different dimensions or with different notches, or specimens which are prepared under different conditions. may produce resuits which are not comparable Other factors, such as the energy capacity of the apparatus. Ifs impact velocity and the conditioning of the specimens can also influence the results. Consequently, when comparative data are required, these factors must be caretully controlled and recorded
1.7 The method should not be used as a source of data for design calculations. Information on the typical behaviour of a material can be obtained, however, by testing at different temperatures, by varying the notch radius andlor the thickness and by testing specimens prepared under different conditions.
2 NormatIve references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard For dated references, subsequent amendments to, or revisions of, any of these pubhcat.ons do not apply. However, parties to agreements based on ISO 180 are encouraged to Investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and lEG maintain registers of currently valid International Standards.
ISO 291:1997, Ptssfr:s — Standard atmospheres tt cicndrttonirig and testing.
ISO 293:1986, Plastics —Compression moulding test specimens at them,oplastic materials.
ISO 294-1:1996, Plastics — injection moulding of test specimens of lhemoplastic matenats — Part 1: iener& principles, and moulding of muftipwpcise and bar test specimens.
ISO 295:1991, Plastics — Compression moulding of test specimens of thermosettlng mateitia
ISO 1268:1974 U, Plastics — Preparation of glass fibre reinforced, resin bonded, tow pressure laminated plates or panels for test purposes.
1S02602:1960, Statistical interpretation of test results — Estimation of the mean — Confidence ,rtten,at.
ISO 2818:1994, Ptastics — Pteparaf ion of test specimens by machining.
ISO 3l67:2t. Plastics — Multipurpose test specimens.
ISO 10724-1:1998. Plastics — k,1iectlon mouk*ng of test specimens of Thermosetting powder rnouldeg compounds (PMCS) — Patti: Gener-alpnncrples and moulding of multipurpose test specimens.
ISO 13802:1999, Plastics Verification of pendulum impact-testing machines Chaipy, Izod and tensile impacttesting.
3 Terms and definitions
For the purposes of ISO 180, the following terms and definitions apply.
3.1
trod unnotched impact strength
aIU
impact energy absorbed in breaking an unnotched specimen. referred to the original cross-sectional area of the specimen
NOTE lIes expressed m Ieard., per are rnr fk.J1m2).
32
Izod notched Impact strength aIN
impact energy absorbed In breaking a notched specimen, referred to the original cross-sectional area of the specimen at the notch, with the pendulum strdung the face containing the notch
NOTE Ills expressed . In10,oues per sre metre {kjim2).
I) Underrevlsionasaserlesotll pelts.
2) To be pubfished (Revision of ISO 3167:1993)
3.3
parallel impact p
lamina,-reirvforced ptashcs impact with the dwoclion of blow parallel to the plane of reinforcement
NOTE The .ecbun of Sw blow in the Izod test is usually ‘edgewise parallel’ Isp) (see Figure I).
3.4
normal Impact
I’
(lamlna,.rein’f orced plastics impact with the direction of blow normal to the plane of reinforcement
NOTE This kind of Impact not usually used with the tzod test, but indicated for the sake of conipletlon (see o Figure 1).
4 Principle
The test specimen, supported as a vertical cantilever beam, is broken by a single impact at a striker, with the line of impact a fixed distance from the specimen clamp and, in the case of notched specimens. from the centreline of the notch (see Figure 2).
5 Apparatus
5.1 Test machine
5.1.1 The principles, characteristics and verification of suitable test machines are detailed in ISO 13802.
5.1.2 Some plastics are sensive to clamping pressure. When testing such materials, a means of standarchzing the clamping force shall be used and the clamng force shall be recorded in the test report. The clamping force can be controlled by using a calibrated torque wrench or a pneumatic or hydraulic device on the vice clamping screw.
5.2 Mlcrometefs and gauges
Micrometers and gauges capable of measuring the essential dimensions of test specimens to an accuracy of 0.02mm are required. For measinng the dimension bN of notched specimens, the micrometer shall be fitted with an anvil of width 2 mm 103 mm and of suitable profile to lit the shape of the noich.
6 Test specimens
6.1 PreparatIon
6.1.1 MouldIng and extrusion compounds
Specimens shall be prepared in accordance with the relevant material specification. When none exists, and unless otherwise specifled, specimens shalt be either directly compression moulded or injection moulded from the material in accordance with ISO 293, 150 294-1, ISO 295 or ISO 10724-1 as appropriate, or machined in accordance with ISO 2818 from sheet that has been compression or injection moulded from the compound. Specimens may also be cut tram multipurpose test specimens compIng with ISO 3t67. type A.
6.1.2 Sheets
Specmiens shall be machined from sheets in accordance with ISO 2618. Whenever possle, specimens with notch A shal be used. The machined surface of unnoiched specimens shall not be tested under tension.
6.1.3 Long-fibre-reInforced materials
A panel shal be prepared in accordance with ISO 1268 or another specified or agreed upon preparation procedure.
Specimens shall be machined in accordance with ISO 2818.
6.1.4 CheckIng
The specimens shall be free ci twist and shaM have mutually perpendicular parallel surfaces. The surfaces and edges shall be tree from saatches, pits, str maths arid flash.
The specimens shall be checked for cant cwmity with these requirement by visual observation against straightedges, squares and flat plates, and by measuring with micrometer callipers.
Specimens showing measurable or observable departure from one or more of These requirements shall be rejected or machIned to proper size and shape before testing.
6.1.5 NotchIng
6.1.5.1 MachIned notches shall be prepared in accordance wlIh ISO 2818. The profile of the cutting tooth shall be such as to produce in the specimen a notch of the contour and depth shown in Figure 2. at right angles to its pnnclpal axes. The notch profile shal be checked at regular Intervals,
6.1.5.2 Specimens with mouided-ln notches may be used ii specified for the material being tested. Specimens with moutdedin notches do not give results comparable to those obtained from specimens with machined notches. The notch profile shall be checked at regular intervals.
6.2 Anlsotropy
Certain types of sheet or panel material may show different impact properties depending on the direction in the plane of the sheet or panel. In such cases, It Is customary to cut groups of test specimens with their major axes respecinrely parallel and perpendicular to the direction of some teature ol the sheet or panel which is either visible or inferred from knowledge of the method of manufacture.
6.3.2 MouldIng and extrusion compounds
Test specimens w,lh one of two ditterent types of notch shall be used as specified In Table 1 and shown in Figure 2. The notch shall be located at the centre 01 the specimen,
The prof erred type of notch is type A. It information on the notch sensitivity of the malarial is desired, specimens with notch types A and B shall be tested.
6.3.3 Sheet m.terlals, Including long-f lbre-r.lnforced materials
The recommended thickness h te 4 mm. If the specimen is cut from a sheet or a piece taken from a structure, the thickness of the spec men. up to 102 mm, shall be the same as the thickness of the sheet or the structure.
Specimens taken tram pieces thicker than 102mm shall be machined to 10mm ±0,2mm from one surface, providing that the sheet Is homogeneous in its thickness and contains only one type of reinforcement uniformly distributed- If unnotched specimens are tested, the origmal surface shal be tested under tension, in order to avoid surface effects.
Specimens shall be tested edgewise parallel, with the exception of specimens with 1, – b = 10mm which can be tested parallel normal to the laminate plane (see Figure 1).
6.4 Number of test specimens
6.4.1 Unless otherwise specified In the standard for the mateflal being tested, a set consisting ottO specimens shall be tested. When the coefficient of variation (see ISO 2602) has a value of less than 5%, a mmimum number of five test specimens Is sufficient.
6.4.2 If laminates are tested in the normal and parallel directions. 10 specimens shall be used for each direction.
6.5 ConditionIng
Unless otherwise specified in the standard for the material under test. the specimens shall be conditioned tot at least 16 h at 23 ‘C and 50% relauve humidity in accordance with ISO 291, unless other conditions are agreed upon by the inleres*ed parties. In the case of notched specimens, the conditioning time is after noiching.
7 Procedure
7.1 Conduct the test m the same atmosphere as thai used lot condrnonsng. unless otherw*se agreed upon by the interested parties. e.g. lot testing at high or low temperatures.
7.2 Measure the thickness h and width b 01 each lest specimen. In the centre, to the nearest 0.02 mm. In the case ci notched specimens. carefully measure the remaining width bN to the nearest 0.02 mm,
In the case of inpection-moulded specimens, it is not necessary to measure the dimensions of each specimen. It is sufficient to measure one specimen from a set to make sure that the dimensions correspond to those In Table 1. W4h multiple-cavity moulde, ensure that the dimensions 0$ the specimens are the same for each cavity.
7.3 Check that the Impact machine Is able to perform the test with the specified velocity of ripact and that It Is to the correct range of absorbed energy W which shalt be between 10% and 80% of the available energy at impact. E. If mate than one 01 the pendulums conform to these requirements, the pendulum having the highest energy shall be used.
7.4 Determine the frictional losses and correct me absorbed energy In accordance with ISO 13802.
7.5 Lift the pendulum to the prescribed height and support it. Place the specimen in the vice and clamp it as shown In Figure I. In accordance with 5.12. When determining the notched Izod impact strength, the notch shall be positioned on the side that is to be struck by the strtidng edge of the pendulum.
7.6 Release the pendulum. Record the Impact energy absorbed by the specimen and apply any necessary corrections for frictional losses, etc. (see 7.4).
7.7 Four tyees of break designated by the following code-letters may oir:
C complete break: a break in which the specimen separates into two or more pieces
H hinge break: an incomplete break such that both parts of the specimen are held together only by a thm peripheral layer to the form of a hinge having low residual stiffness
P partIal break: an incomplele break that does not meet the dellnibon for hinge break
N non-break: there is no break, and the specimen Is only bent and pushed through the support blocks, possibly combined with stress whitening
8 Calculation and expression of results
8.1 Unnotched specImens
Calculate the Izod impact strength of unnotched specimens. a11,1, expressed In kilooules per square metre, using the following equation:
* is the thickness, In milimetres, of the test specimen; b is the width. in millimetres, of the test specimen
8.2 Notched specimens
Calculate the Izod impact strength ci notched specimens, u. expressed In kilojoules per square metre. with notches A or 8. using the tollowing equation:
Ec is the corrected energy, in loules. absorbed by breaking the test specimen;
h is the thickness, in millimetres, of the test specimen; is the remaining width, in mdhimetres. of the test specimen.
8.3 StatistIcal parameters
Calculate the arithmetic mean of test results and the standard deviation of the mean value, it required, using the procedure given in ISO 2602. For different types of faikire within one sample, the relevant numbers of specimens shall be given and mean values shall be calculated.
8.4 SIgnificant figures
Report all calculated mean values to two significant figures.
9 PrecIsion
The precision of this method not known because Intertaboratory data are not available. When anIeroraiory data are obtained, a precision statement will be added at the following revision.
10 Test report
The test report shall include the following information:
a) a reference to this International Standard;
b) the method used, designated in accordance with Table 1. for example:
Izod impact test ISO 180/A
Type of notch (see Figure 2)
c) all information necessary for identification of the matehal tested. wiclucling type, source, manufacturers code, grade and htetory, where these are known;
d) a descrllon of the nature and form of the matenal i.e. whether a product. semifinished product, test plate or specimen, including principal dimensions. stie. method of manufacture. etc., where these are known;
e) the velocity of impact;
f) the nominal pendulum energy:
g) the clamping pressure. ti applicable (see 5.1.2):
Ii) the method of test specimen preparation;
I) if the material in the form ol a product or a semifinished product, the orientation 01 the test specimen in relation to the product or semifinished product from which It was cut;
j) the number of specimens tested;
k) the standard atmosphere used for conditioning and testing, plus any special conditioning treatment it required by the slandafd low the material or product:
I) the type(s) of failure observed;
m) the lncWldual test results, presented as follows (see also Table 2):
1) group the results according to the three basic types of failure:
C complete break, Including hinge break H
P partial break
N non-break
2) select the most frequent type and record the mean value x of the impact strength for this type of lallure, followed by the letter C or P for the type 01 faiure.
3) if the most frequent failure type is N. record the letter N only,
4) add (between brackets) Ihe letter C, P or N for the second most frequent failure type, but only if Is frequency is higher than 1/3 (if not relevant, insert an asterisk);
n) the standard deviations of the mean values, ii reclred:
0) the date(s) of the test.