_STP_138-1953.pdf

SYMPOSIUM ON TESTING ADHESIVES FOR DURABILITY AND PERMANENCE Presented at the FIFTY-FIFTH ANNUAL MEETING(FIFTIETH ANNIVERSARY MEETING)AMERICAN SOCIETY FOR TESTLNTG MATERIALS New York,N.Y.,June 26,1952 Reg.U.S.Pat.Ofl.ASTM Special Technical Publication No.138 FIFTIETH ANNIVERSARY PUBLICATION Published by the AMERICAN SOCIETY FOR TESTING MATERIALS 1916 Race St.,Philadelphia 3,Pa.NOTE.The Society is not responsible,as a body,for the statements and opinions advanced in this publication.COPYRIGHT,1953 BY THE AMERICAN SOCIETY FOR TESTING MATERIALS Printed in Baltimore,Md,-January,1953 CONTENTS PAGE IntroductionG.W.Koehn 1 Effect of Specimen Structure in Permanence Tests on Wood AdhesivesRobert P.Hopkins 3 Discussion 11 Glass AdhesivesFranlt Moser 12 Discussion 20 Current Investigations of the Durability of Woodworking AdhesivesR.F.Blomquist 21 Nondestructive Determination of Mechanical Properties and Deterioration of Adhe-sivesAlbert G.H.Dietz,Herman N.Bockstruck,and George Epstein 40 Discussion 53 Field and Laboratory Tests for Durability and Permanence:Adhesives Belonging to the Rubber-Resins SystemsJ.F.Anderson and L.F.Fiedler.54 SummaryR.C.Platow 59 FOREWORD The papers and discussions in this Symposium on Testing Adhesives for Durability and Permanence were presented at the Twenty-fourth Session of the Fifty-fifth Annual Meeting of the American Society for Testing Ma-terials held in New York,N.Y.,June 26,1952.The Symposium was spon-sored by Coromittee D-14 on Adhesives.Mr.A.G.H.Dietz,Professor of Structural Engineering,Massachusetts Institute of Technology acted as Chairman of the Session,while Mr.G.W.Koehn of the Armstrong Cork Co.acted as Secretary and contributed much to the success of this Symposium.SYMPOSIUM ON TESTING ADHESIVES FOR DURABILITY AND PERMANENCE INTRODUCTION BY G.W.KOEHNI One of the most important questions arising when fabrication with an ad-hesive is being considered is the durabil-ity or permanence of the adhesive,or how long the joint will last and how the joint will stand up in service.Many of the adhesives now being used have been developed within the past ten years,and consequently lack the background of many years of service typical of other materials of construction.Accelerated permanence tests are of such importance that Committee D-14 on Adhesives felt it desirable to review in a Symposium,in the light of field Research and Development Center,Armstrong Cork Co.,Lancaster Pa,experience,some of the tests that have been used.This symposium was organized by a Symposium Committee consisting of the following:G.W.Koehn,Armstrong Cork Co.,Chair-man,Frank J.Hanrahan,National Lumber Man-ufacturers Assn.,Louis J.Jaworski,Borden Co.,Ray C.Platow,U.S.Plywood Corp.,John H.Wills,Philadelphia Quartz Co.,and A.G.H.Dietz,Massachusetts Institute of Technology.It is hoped correlation of field data and laboratory test data will eventually result in improved test methodsfor permanence in Committee D-14 on Ad-hesives.STP138-EB/Jan.1953 EFFECT OF SPECIMEN STRUCTURE IN PERMANENCE TESTS ON WOOD ADHESIVES BY ROBERT P.HOPKINS1 SYNOPSIS An effort has been made to obtain specific data on the relationship between the apparent behavior of wood adhesives in permanence tests and the construc-tion of the test specimens.Outdoor exposure and laboratory water-immersion air-dry cycling procedures,with the aid of phenolic or resorcinol resins were used to study this relationship.Brief attention has also been given to recalling the interdependence of construction of plywood test specimens and maximum tensile shear strength,as established by the Forest Products Laboratory years ago.Quantitative test data obtained show that wood species,nature of the wood construction,and size of the specimen have an important bearing on the ap-parent permanence of an adhesive.Small test specimens have been found to exhibit greater mechanical stressing on gluelines than relatively larger speci-mens.Shortcomings of wood adhesive specifications lacking consideration of the variable of test specimen construction are noted.The information has led to the conclusion that greater emphasis should be attached to the construction of the test specimens in any efforts to interpret and develop test methods for wood adhesives.The tonnage quantities of wood ad-hesives consumed in industry at the present time have come about in spite of a lack of,rather than because of,highly-informative testing procedures.The co-incident rise of high polymer chemistry and that of an expanded wood industry,either as plywood or laminated wood,presents the basic explanation for current prominence of wood adhesives.But granted that great credit is due Baeke-land,for example,for his pioneering role in phenolics,and to John for his work on ureas,there can be little doubt that the guiding influence of intelligent 1 Group Leader,Adhesives Applications Group,Re-search Division,Rohm&Haas Co.,Philadelphia,Pa.test procedures is a must for the maxi-mum utilization of the discoveries