BS EN ISO 14616-1997 Plastics - Heatshrinkable films of polyethylene ethylene copolymers and their mixtures - Determination of the shrinkage stress and contraction stress《塑料 聚乙烯、乙烯.pdf

1、BRITISH STANDARD BS EN ISO 14616:2004 Incorporating Amendment No. 1 to BS ISO 14616:1997 (renumbers the BS ISO as BS EN ISO 14616:2004) Plastics Heatshrinkable films of polyethylene, ethylene copolymers and their mixtures Determination of the shrinkage stress and contraction stress The European Stan

2、dard EN ISO 14616:2004 has the status of a British Standard ICS 83.140.10 BS EN ISO 14616:2004 This British Standard, having been prepared under the direction of the Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 Septemb

3、er 1997 BSI 8 September 2004 ISBN 0 580 28528 6 National foreword This British Standard is the official English language version of EN ISO 14616:2004. It is identical with ISO 14616:1997. The UK participation in its preparation was entrusted to Technical Committee PRI/75, Plastics and rubber films a

4、nd sheets, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue

5、under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct

6、application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informe

7、d; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN ISO title page, the EN ISO foreword page, the ISO title page, page ii, pages 1 to 5 and a back cover. The BSI copyright noti

8、ce displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments 15251 8 September 2004 Implementation of the European StandardEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 14616 July 2004 ICS 83.140.10 English version P

9、lastics Heatshrinkable films of polyethylene, ethylene copolymers and their mixtures Determination of shrinkage stress and contraction stress (ISO 14616:1997) Plastiques Films thermortractables en polythylne, en copolymres dthylne et leurs mlanges Dtermination des contraintes de rtraction et de cont

10、raction (ISO 14616:1997) This European Standard was approved by CEN on 21 June 2004. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists a

11、nd bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsib

12、ility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,

13、Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1

14、050 Brussels 2004 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 14616:2004 EEN ISO 14616:2004 BSI 8 September 2004 Foreword The text of ISO 14616:1997 has been prepared by Technical Committee ISO/TC 61, Plastics, of the Inter

15、national Organization for Standardization (ISO) and has been taken over as EN ISO 14616:2004 by Technical Committee CEN/TC 249, Plastics, the Secretariat of which is held by IBN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by

16、 endorsement, at the latest by January 2005, and conflicting national standards shall be withdrawn at the latest by January 2005. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria,

17、 Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 1

18、4616:1997 has been approved by CEN as EN ISO 14616:2004 without any modifications.EN ISO 14616:2004EN ISO 14616:2004 ii BSI 8 September 2004 Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of prepa

19、ring International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in l

20、iaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publica

21、tion as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 14616 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 11, Products. Descriptors: plastics, thermoplastic resins, ethylene, polyethylene, heat-

22、shrinkable materials, films, tests, determination, shrinkage.EN ISO 14616:2004 BSI 8 September 2004 1 1 Scope The purpose of this standard is to describe a conventional method for measuring the shrinking and contracting forces of heatshrinkable films made from polyethylene, ethylene copolymers and t

23、heir mixtures. The method described in this standard can possibly be applied to other materials under proper operating conditions. NOTE This method also allows a shrinkage ratio to be assessed. However, the reference method for measuring the shrinkage ratio is ISO 11501, Plastics Film and sheeting D

24、etermination of dimensional change on heating. 2 Definitions For the purposes of this standard, the following definitions apply. 2.1 heatshrinkable film film which is extruded and stretched (hot drawn) during manufacture and which remains in this state after cooling down. NOTE When this film is agai

25、n brought up to the temperature at which the stress was induced and then fixed during its manufacture, this stress is liberated and the film shrinks back. depending on the treatment applied, the film can be either heatshrinkable both lengthwise and crosswise: this film is called “biaxially oriented”

26、; or mainly heatshrinkable lengthwise: this film is called “uniaxially oriented”. 2.2 shrinkage ratio decrease in the length of the specimen when it is brought up to the shrinkage temperature, expressed as a percentage of the initial specimen length 2.3 shrinking force, F r force developed by the fi

27、lm when it reaches the temperature corresponding to that at which the stress was induced at the time of manufacture A high film shrinkage is linked to this small force. This small force and this high shrinkage permit the film to gently shrink down on the load. 2.4 contracting force, F c force develo

28、ped by the film during its cooling process This force, much greater than the shrinkage force, ensures the fastening of the load. 2.5 reference temperature, F r air temperature measured by the probe located 5 mm adjacent to the force measurement specimen 45 s after mounting in the heating hood. Under

29、 these conditions, it is considered that sufficient time is allowed for the thermocouple used for the measurement to reach the temperature 3 Principle of the measurement Specimens connected to a force meter or to a displacement transducer are rapidly brought up to the shrinkage temperature, then coo

30、led in the open air to an ambient temperature of 23 C2 C. A device continuously records the reference temperature, the force and possibly the displacement. The recording of these measurements allows one to determine the optimal shrinking conditions.EN ISO 14616:2004 2 BSI 8 September 2004 4 Apparatu

31、s 4.1 Heating hood, vertically mobile, equipped with heating elements and with a regulating device capable of maintaining the air temperature at the specified temperature. 4.2 T-shaped bracket, allowing the fixing of the specimen. 4.3 Force meter, allowing the measurement of the shrinkage and contra

32、ction forces within a force range of at least 20 N with an accuracy of 2 %. 4.4 Displacement transducer, capable of measuring a displacement with an accuracy of 1 mm. 4.5 Multichannel acquisition device, allowing the continuous recording of the different variables: times, forces, displacement, . 4.6

33、 Thermocouple probe, having a diameter of 1,5 mm (max), capable of measuring the air temperature 5 mm off the force measurement specimen with an accuracy of 2 C. The thermocouple tip shall be oriented towards the middle of the specimen. This thermocouple is used for determining the reference tempera

34、ture F r . Depending on the heating resistors and on the location of the apparatus (influence of the environment), the performance characteristics of each individual testing apparatus may differ slightly. It is therefore necessary to determine the relationship between the temperature F r(45 s after

35、mounting the heating hood, see 2.5) and that displayed by the regulating device. Plot the correlation curve between F rand the settings of the hood temperature regulating device. This operation shall be repeated at regular intervals in order to detect any possible drift. NOTE In general, this correl

36、ation curve is determined for a range of temperatures F rbetween 100 C and 230 C. 4.7 Thickness gauge, capable of measuring to an accuracy of 1 m. Figure 1 Example of apparatusEN ISO 14616:2004 BSI 8 September 2004 3 5 Specimens Prepare at least ten specimens in each direction (lengthwise and crossw

37、ise). Their width shall be 15 mm 0,5 mm. Their length shall be such that it is possible to have an effective length between jaws of 100 mm. Their thickness, measured by the thickness gauge (4.7) to the nearest 1 m, is represented by the mean of three measurements repeated regularly on the specimen l

38、ength. 6 Procedure 6.1 Measurement of the shrinking and contracting forces The procedure is identical irrespective of the direction of the specimens, lengthwise or crosswise. As the curves obtained with the lengthwise specimens are easier to develop, it is advised to begin testing in the lengthwise

39、direction. 6.1.1 Install the specimens perfectly flat and straight on the force meter without applying any tensile force. 6.1.2 In the absence of a reference temperature F r , known or specified by a product standard, set the temperature regulating device so as to obtain a reference temperature F ro

40、f 200 C3 C using the correlation curve defined in 4.6. 6.1.3 Lower the hood in order to bring the specimens to the shrinkage temperature. Start the timer (or the recording of the time on the plotting table) and the recording of the force. The film shrinkage temperature is reached when the maximum sh

41、rinking force is attained. Record this force, F r , in newtons. When this force has decreased by around 15 % to 30 %, lift the hood and stop the timer (or the recording of the time). Record the time. Continue to record the forces. Record the maximum value of force attained by the contraction, F c ,

42、in newtons. 6.1.4 If the maximum of the recorded shrinking force appears after less than 15 s exposure to the heat, repeat the test by lowering the reference temperature F rby successive steps of 10 C until shrinkage is obtained between 15 s and 30 s. If the maximum shrinking force does not appear a

43、fter 30 s exposure to the heat, resume testing by raising the temperature by successive steps of 10 C until shrinkage is obtained between 15 s and 30 s. 6.2 Assessment of the shrinkage ratio The assessment of the shrinkage ratio can be carried out either at the same time as that of the forces or con

44、secutively, depending on the configuration of the apparatus. It enables one to rapidly compare the properties of the shrinkable films in the production control procedure. NOTE This method does not replace the reference method for measuring the shrinkage ratio specified in ISO 11501. 6.2.1 Install th

45、e specimen perfectly flat and straight, between one of the arms of the bracket and the displacement transducer, the effective length of the specimen being 100 mm. 6.2.2 Conduct the measurement under the same conditions as those adopted for the measurement of the shrinking and contracting forces. Whe

46、n they are conducted simultaneously, make additional provision for recording of the displacements. Record the final value of the displacement after the cooling down of the specimen.EN ISO 14616:2004 4 BSI 8 September 2004 7 Expression of results Calculate: the shrinking stress in pascals, Pa the con

47、tracting stress in pascals, Pa the shrinkage ratio, R, in percentage where: Figure 2 Measurement of the forces and of the shrinkage ratio Example of typical kinetics of the phenomena F r is the shrinking force, in newtons; F c is the contracting force in newtons; S is the area of the initial cross s

48、ection of the specimen, in square millimetres; L o is the initial length of the specimen, in millimetres; L is the length of the specimen after heat shrinking, in millimetres. B r F r S - 10 6 = B c F c S - 10 6 = R L o L L o - 100 =EN ISO 14616:2004 BSI 8 September 2004 5 8 Precision Since the prec

49、ision of this test method is not known because inter-laboratory data are not available, this method is only applicable for comparison purposes within a laboratory. 9 Test report The test report shall refer to this standard and shall mention the following information: a) type and origin of the film being tested; b) thickness of the film; c) degree of orientation; d) reference temperature F r ; e) valu