DIN 53579-2015 Testing of flexible cellular materials - Indentation test on finished parts《软泡沫材料的试验 成品件的压印硬度试验》.pdf

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1、April 2015 English price group 11No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 83.100!%cL(“2644105www.din.deDIN 5

2、3579Testing of flexible cellular materials Indentation test on finished parts,English translation of DIN 53579:2015-04Prfung weich-elastischer Schaumstoffe Eindrckversuch an Fertigteilen,Englische bersetzung von DIN 53579:2015-04Essais des produits alvolaires souples Essai dindentation sur produits

3、finis,Traduction anglaise de DIN 53579:2015-04SupersedesDIN 53579:2009-01www.beuth.deDocument comprises 19 pagesDTranslation by DIN-Sprachendienst.In case of doubt, the German-language original shall be considered authoritative.05.17 DIN 53579:2015-04 2 A comma is used as the decimal marker. Content

4、s Page Foreword . 3 Introduction 4 1 Scope 5 2 Normative references 5 3 Terms and definitions 6 4 Test pieces 8 4.1 Shape 8 4.2 Number 8 4.3 Preparation 8 5 Apparatus . 8 5.1 Testing machine . 8 5.2 Test substructure 8 5.3 Indentor 9 6 Procedure . 10 6.1 Preparation 10 6.2 Test sequence parameters .

5、 10 6.3 Test sequence 11 7 Repeat test 12 8 Expression of results 12 9 Precision . 13 10 Test report . 13 Annex A (normative) Additional information on the testing machine and its control 14 A.1 Compensating for the deformation of the load-bearing elements on the testing machine 14 A.2 Exceeding the

6、 specified indentation displacement or indentation force . 14 Annex B (informative) Precision . 15 B.1 General 15 B.2 Details 15 B.3 Results regarding the precision of the method 15 B.4 Repeatability . 15 B.5 Reproducibility . 15 Annex C (informative) Sample parameters for the test sequence . 17 Bib

7、liography . 19 DIN 53579:2015-04 3 Foreword This document has been prepared by Working Committee NA 062-04-37 AA Prfung von Weich- und Hartschumen of DIN-Normenausschuss Materialprfung (DIN Standards Committee Materials Testing). Attention is drawn to the possibility that some of the elements of thi

8、s document may be the subject of patent rights. DIN shall not be held responsible for identifying any or all such patent rights. Amendments This standard differs from DIN 53579:2009-01 as follows: a) normative references have been revised; b) the Scope has been changed due to the withdrawal without

9、replacement of DIN ISO 11752; c) subclause 4.3 “Preparation” has been rendered more precise; d) the standard has been editorially revised. Previous editions DIN 53579-1: 1980-03, 1987-03 DIN 53579: 2009-01 DIN 53579:2015-04 4 Introduction This standard is intended to permit force-deformation diagram

10、s to be recorded for either specified displacements or specified forces. The zero point for the force-displacement has been selected in such a way that it can be applied to finished parts of any design (with convex and concave interfaces, partial ribbing, or recesses) and can be read off the diagram

11、 that is established in each case. DIN 53579:2015-04 5 1 Scope This standard specifies a non-destructive method to be used to determine the indentation hardness of flexible moulded foams with a minimum thickness of 10 mm. Applying this method, it is possible to express the indentation force in Newto

12、n, for a defined indentation displacement; the indentation displacement in millimetres, for a defined indentation force. This method is suitable for conducting tests directly on the moulded parts. The test specified in this standard is not suitable for determining the hardness of extruded profiles t

13、hat are customarily called sponge rubber or expanded rubber. This standard specifies only the test method to be employed. The individual test parameters shall be recorded by the parties involved. Measurement results obtained according to the methods specified in this standard are only valid for the

14、specific moulded parts involved and shall not be compared with results obtained under different testing conditions (e.g. measuring point, indentor, indentation) or with results for other moulded parts. Correlations with characteristics from tests according to different standards (e.g. DIN EN ISO 243

15、9, DIN EN ISO 3386-1 or DIN EN ISO 3386-2) shall be avoided. It is not permitted to convert the determined forces into compressive stresses by reference to the surface of the used indentors. This standard is used exclusively for the testing of pre-fabricated parts and differs from the standards DIN

16、EN ISO 2439, DIN EN ISO 3386-1 and DIN EN ISO 3386-2. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for the application of this document. For dated references, only the edition cited applies. For undated referen

17、ces, the latest edition of the referenced document (including any amendments) applies. DIN EN ISO 1302, Geometrical Product Specifications (GPS) Indication of surface finish in technical product documentation DIN EN ISO 2439, Flexible cellular polymeric materials Determination of hardness (indentati

18、on technique) DIN EN ISO 7500-1, Metallic materials Verification of static uniaxial testing machines Part 1: Tension/compression testing machines Verification and calibration of the force-measuring system DIN ISO 23529, Elastomers General procedures for preparing and conditioning test pieces for phy

19、sical test methods DIN 53579:2015-04 6 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 indentation I surface area subject to loading, that is smaller, for the entire duration of the testing process, than the surface of the moulded part being

20、tested that faces the indentor 3.2 indentation force IF force under which a moulded part is deformed in an indentation test Note 1 to entry: The indentation force is used for the determination of the indentation displacement or results from a specified indentation displacement. 3.3 indentation displ

21、acement ID displacement by which a moulded part is deformed in an indentation test Note 1 to entry: The indentation displacement is used for the determination of the indentation force or results if a specified indentation force is applied. 3.4 displacement zero point zero point of the indentation di

22、splacement Note 1 to entry: The displacement zero point is specified as follows: for the first three indentations (pre-stressing cycles), it is the displacement zero point at which the preliminary force is attained during loading in the first cycle; for the fourth indentation (measurement cycle), it

23、 is the displacement zero point at which the preliminary force is attained during loading in the fourth cycle. 3.5 preliminary force F0force at which the instrument for measuring the indentation displacement is set to zero Note 1 to entry: The force is expressed in Newton. 3.6 pre-stressing cycle cy

24、cle during which the flexible foam settles due to mechanical effects Note 1 to entry: No test results are recorded for the indentation during the pre-stressing cycles. This standard sets the number of pre-stressing cycles at 3. 3.7 test speed for pre-stressing cycles vc controlled speed at which the

25、 indentor moves up and down relative to the supporting surface, during the pre-stressing cycles Note 1 to entry: The speed is expressed in millimetres per minute. DIN 53579:2015-04 7 3.8 maximum indentation force during pre-stressing cycles IFc force in the pre-stressing cycles that is applied up to

26、 indentation Note 1 to entry: The force is expressed in Newton. 3.9 maximum indentation displacement for pre-stressing cycles IDc displacement in the pre-stressing cycles that is applied up to indentation Note 1 to entry: The displacement is expressed in millimetres. 3.10 discharge point of the inde

27、ntor LR point of displacement to which the indentor is discharged at controlled test speed, after each pre-stressing cycle Note 1 to entry: This guarantees a comparable recovery of the foam between cycles. This point of displacement is specified in relation to the displacement zero point and is norm

28、ally a negative value. Note 2 to entry: The displacement is expressed in millimetres. 3.11 measurement cycle last indentation of the moulded part Note 1 to entry: For this final indentation, establish the results according to this standard. 3.12 test speed in the measurement cycle vM speed with whic

29、h the indentor moves relative to the supporting surface, in the direction of loading, during the measurement cycle Note 1 to entry: The speed is expressed in millimetres per minute. 3.13 maximum indentation force in the measurement cycle IFM force in the measurement cycle up to indentation Note 1 to

30、 entry: The force is expressed in Newton. 3.14 maximum indentation displacement in the measurement cycle IDM displacement in the measurement cycle up to indentation Note 1 to entry: The displacement is expressed in millimetres. DIN 53579:2015-04 8 4 Test pieces 4.1 Shape The test pieces are the moul

31、ded parts in their particular shape. 4.2 Number The number of test pieces shall be agreed on. 4.3 Preparation Materials shall not be tested less than 72 h after manufacture unless it can be demonstrated that the mean results obtained at either 16 h or 48 h after manufacture do not differ by more tha

32、n 10 % from those obtained after 72 h, in which case testing is permitted at 16 h or 48 h, respectively. Prior to the test, the test pieces shall be conditioned according to DIN ISO 23529, deformed and stress-free, for at least 16 h in one of the following standard atmospheres: (23 2) C, (50 5) % re

33、lative humidity; (27 2) C, (65 5) % relative humidity. The conditioning time may be counted as the final part of the waiting time subsequent to production. 5 Apparatus 5.1 Testing machine The testing machine required shall be capable of indenting test specimens between a supporting surface and an in

34、dentor, at a uniform speed while measuring the indentation force and indentation displacement. The force measurement chain shall comply with the requirements for Class 1 as specified in DIN EN ISO 7500-1. The measuring device for the indentation displacement shall be in a position to determine the i

35、ndentation displacement with a measurement uncertainty of 0,1 mm or better. The deformation of the load-bearing elements of the testing machine shall be taken into account and compensated if applicable (see Annex A). 5.2 Test substructure It shall be possible for the test pieces to be applied to the

36、 supporting surface in the manner employed in practice, by means of an appropriate fixing device. This will generally be achieved using a rigid substructure. If the moulded part incorporates recesses (cavities, holes or similar profiles on the underneath), these will not be filled in if they are not

37、 filled in when in service. Align the test substructure in such a way that the force acts in an axial direction vis-vis the force transducer and the measurement accuracy of the force sensor is not impaired beyond the specified limits by transverse forces. The test substructures shall be agreed on by

38、 all the parties involved, or shall be identical constructions. DIN 53579:2015-04 9 5.3 Indentor The different designs of moulded parts to be tested and the wide range of requirements imposed in practice frequently make it necessary to use indentors adapted to the particular test situation. The test

39、 indentors in Table 1 and Figure 1 have proved successful for a wide range of test cases and practical conditions. Select the appropriate indentor from the indentors listed in Table 1. The surface of the indentor shall be bright polished and shall have a roughness value, Rz, of 25 m according to DIN

40、 EN ISO 1302. Table 1 Indentors I to XXI Circular, flat indentora Indentor IbII III IV V Rated size (load-application area) cm2323,7 100 50 25 5 Diameter, D mm 203 112,8 79,8 56,4 25,2 Edge radius, r mm 1 1 1 1 1 Recommended preliminary force, F0N 20 10 5 5 5 Spherical indentorc Indentor XI XII XIII

41、 Hemisphere diameter, d mm 75 20 165 Recommended preliminary force, F0N 5 2 5 Circular, convex-cambered indentoraIndentor XXI XXII XXIII Diameter, D mm 200 200 150 Radius of curvature, R mm 200 400 400 Edge radius, r mm 5 9 9 Recommended preliminary force, F0N 20 20 20 NOTE Although the preliminary

42、forces recommended in this table are relatively large for flexible cellular materials, they have been selected because they improve the reproducibility of the test results. aCircular flat indentors and circular cambered indentors shall be connected to the force measurement system via a ball and sock

43、et joint. The distance between the ball and socket joint and the lowest point of the indentor surface should be 20 mm to 25 mm. bIndentor according to DIN EN ISO 2439. cSpherical indentors shall be rigidly connected to the force measurement unit.DIN 53579:2015-04 10 Dimensions in millimetres a) Circ

44、ular flat indentor of type I to Vab) Spherical indentor of type XI to XIII c) Circular convex cambered indentor of type XXIaKey 1 ball and socket joint D outer diameter Sd diameter of spherical indentor R radius of curvature r edge radius aCircular flat indentors and circular convex-cambered indento

45、rs shall be connected to the force measurement unit via a ball and socket joint. The distance between the ball and socket joint and the lowest point of the indentor should be between 20 mm and 25 mm. Figure 1 Indentor I to XXI 6 Procedure 6.1 Preparation The area to which the load is to be applied,

46、and the direction of loading, shall be agreed on and specified on a drawing with the relevant dimensions. The test piece shall be supported by a rigid, positive-fit test substructure (see 5.2). 6.2 Test sequence parameters The parameters for controlling the test sequence and also for establishing th

47、e results shall be agreed on. Run the pre-stressing cycles with a considerably greater indentation displacement than the measurement cycle. It is normal for the indentation displacement during the pre-stressing cycles to be about 70 % of the thickness. The indentation displacement or indentation for

48、ces at which the results in the measurement cycle are to be determined should be approximately 40 % of the thickness of the moulded part. NOTE Sample parameters of the test sequence are described in Annex C. DIN 53579:2015-04 11 Table 2 Test speeds Thickness of moulded parts in the test zone Test sp

49、eed (vc) during load application and load removal in the pre-stressing cycles Test speed (vM) during load application and load removal in the measurement cycle mm mm/min mm/min 50 200 100 20 to 50 100 50 20 50 20 Define the test sequence as follows: a) indentor to be used according to this standard; b) specified preliminary force, F0(see Table 1); c) test speed for pre-stressing cycles, vc(see Table 2); d) maximum indentatio