ISO INTERNATIONAL STANDARD 7808 First edition 1992-12-01 Plastics - Thermosetting moulding materials - Determination of transfer flow la fluidité partransfert Not for Resale ISO 7808:1992(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work technical committees. Each member body interested in a subject for and non-governmental, in liaison 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. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 7808 was prepared by Technical Committee ISO/TC 61, Plastics, Sub-Committee SC 12, Thermosetting materials. 1SO1992 C All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means. electronic or mechanical, including photocopying and microfilm, without per- mission in writing from the publisher. International Organization for Standardization Case Postale 56 · CH-1211 Geneve 20 · Switzerland Printed in Switzerland ii icensefrom IHS Not for Resale ISO 7808:1992(E) INTERNATIONAL STANDARD s Thermosetting moulding materials Plastics Determination of transfer flow Scope 1 4. Test portion This International Standard specifies a method for The test portion shalt be a 50 g ± 0,5 g portion of a sample of the moulding material to be tested. measuring the transfer flow of thermosetting mould- ing materials during a specified moulding process. It is intended only for production control and should not be used as part of a mandatory material specification. Procedure 5.1 Adjust the temperature of the mould (see 3.3) Principle to the value specified in table 1 for the particular ma- terial to be tested. The method determines the percentage mass of moulding material that is transferred through two ap- Table 1 - Moulding temperatures ertures in the punch of a disc mould during a mould- Temperatures in degrees Celsius ing process carried out under defined conditions. Moulding temperature Material Apparatus Phenolic 165 ± 2 3 Granular polyester 165 ± 2 Epoxy 165 ± 2 3.1 Balance, to weigh 50 g to within ± 0,1 g. Diallyl phthalate 165 ± 2 3.2 Hydraulic press, with a capacity of at least 125 kN, fitted with a controlled variable pressure- 5.2 Preset moulding the pressure to reducing valve. The press closing time, between 7 MPa ± 0,2 MPa, 12 MPa ± 0,5 MPa or loading the powder into the mould until pressure first 19 MPa ± 0,5 MPa, chosen so that the measured shows on the gauge, shall not exceed 10 s. transfer flow falls within the range 15 % to 85 %. The final speed of closure shall be adjusted so as to avoid displacement of powder from the mould. 5.3 Place the test portion (see clause 4) inside the mould cavity and immediately close the press (3.2) 3.3 Moulding tool (see figure 1), the moulding cav- ity of which has a diameter of 90 mm and a depth of 5.4 Allow sufficient time for the material to cure, 25 mm ± 5 mm (the depth of the cavity may be in- open the press, remove the mouiding, detach the creased if necessary to accommodate bulky ma- extrudate, allow the moulding to cool to room tem- Thepunchshall havetwo terials). recesses perature and then weigh it to the nearest 0,1 g. 2,45 mm ± 0,0i mm deep and 7,5 mm ± 0,5 mm high diametrically opposite each other; their profile is 5.5 Calculate the transfer flow of the test portion as shown in detail A of figure 1. described in 6.1. Repeat the test until the numerical The clearance between the male and female mould values of two consecutive transfer flows so obtained parts shall not exceed 0,05 mm (moulds wear with do not differ by more than 10 % of the numerical value of their mean. use and the toleran