7850-86 4851903 0058159 T H-56-14 (ISo 7850 International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATIONMEKAYHAPOAHAA OPrAH3AMR IO CTAHAAPTM3ALWW+ORGANISATION INTERNATIONALE DE NORMALISATION Cellular plastics, rigid - Determination of compressive creep Plastiques alveolaires rigides - Détermination du fluage en compression First edition -- 1986-08-15 UDC 678-405.8 : 620.173.2 Ref. No. 1SO 7850-1986 (E) $0 7850-1986 (E) Descriptors : plastics, rigid plastics, cellular plastics, tests, creep tests. Price based on 3 pages Not for Resale hitted without license from IHS 4851903 0058160 6 7850-86 Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies (Iso member bodies). The work of preparing 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 mental and non-governmental, in liaison with iso, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISo Council. They are approved in accordance with 1sO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISo 7850 was prepared by Technical Committee ISO/TC 61, Plastics. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other international Standard implies its latest edition,unlessotherwise stated, ?International OrganizationforStandardization,1986 Printed in Switzerland Copyright International Organization for Standardization No reproduction or networking permitted without license from IHS Not for Resale 7850-86 T978500 E06758h ISO 7850-1986 (E) INTERNATIONAL STANDARD Cellular plastics, rigid - Determination of compressive creep Scope and field of application least 25 cm2. The standard specimen thickness shall be 1 50 ± 1 mm. Minimum thickness shall be 20 ±1 mm. For This International Standard specifies a method for the determi- specimens exceeding 50 mm in thickness, the area of the sur- nation of compressive creep under various conditions of stress, face to be stressed shall be at least equal to the square of the temperature and relative humidity. thickness. The distance between the two test surfaces shall not vary by more than 1 % (tolerance on parallelism). Material skins that form an integral part of the product in its end use appli- 2 References cation shall be retained. iso 291, Plastics -- Standard atmospheres for conditioning NOTE -- Test results of materials with and without integral skins and testing. and/or of different thicknesses are not comparable. Iso 1923, Cellular plastics and rubbers - Determination of 5.2 Preparation linear dimensions. Specimens shall be cut from the sample in such a manner that 3 Principle the thickness direction shall correspond to the direction in which the compressive force will be applied in the intended end Deformation due to compressive stress is determined under use of the material. if this direction is unknown, then two sets specified conditions of time, temperature, relative humidity and of specimens shall be tested in the two principal directions of anisotropy. applied stress. Specimens shall be prepared using a mechanical saw, knife or Apparatus other cutting device and in such manner as to assure that the 4 specimens are undamaged. Dial-gauge micrometer, as specified in ISO 1923, or 4.1 equivalent. 5.3 Conditioning 4.2 Test chamber, capable of being maintained within The test specimens shall be conditioned for a minimum of 24 h ± 2 'C of the required temperature and within ± 5 % of the in the standard atmosphere of 23 ± 2 °C and 50 ± 5 % RH, as required relative humidity. specified in ISO 291. 4.3 Loading device, consisting of two flat plates, at least 5.4 Number of test s