Key Words— Hot gas welding, thermoplastics,

heated tool butt welding, joints, evaluation, testing, hot gas extrusion

AWS G1.10M: 2001

An American National Standard

Approved by American National Standards Institute

February 21, 2001

Guide for the Evaluation of Hot Gas, Hot Gas Extrusion, and Heated Tool Butt Thermoplastic Welds

Prepared by AWS G1 Committee on Joining Plastics and Composites

Under the Direction of AWS Technical Activities Committee

Approved by AWS Board of Directors

Abstract

This standard lists and describes defects in hot gas, hot gas extrusion, and heated tool butt welded joints in thermoplastics. Its intent is to make possible a generally valid evaluation giving consideration to graded quality requirements. This stan- dard encompasses the classification, requirements, testing, evaluation, and acceptance of the welds. Details in recording engineering data are described. Tables illustrating cracks, voids, solid inclusions, lack of fusion, defects of shape, and other defects in thermoplastic welds are included. Defect features with descriptions and illustrations are compiled into tables to aid in the evaluation of welds.

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International Standard Book Number: 0-87171-615-1 American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126

© 2001 by American Welding Society. All rights reserved

Printed in the United States of America

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Finally, AWS does not monitor, police, or enforce compliance with this standard, nor does it have the power to do so.

Official interpretations of any of the technical requirements of this standard may be obtained by sending a request, in writ- ing, to the Managing Director Technical Services, American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126 (see Annex C). With regard to technical inquiries made concerning AWS standards, oral opinions on AWS standards may be rendered. However, such opinions represent only the personal opinions of the particular individuals giving them. These individuals do not speak on behalf of AWS, nor do these oral opinions constitute official or unofficial opinions or interpre- tations of AWS. In addition, oral opinions are informal and should not be used as a substitute for an official interpretation.

This standard is subject to revision at any time by the AWS G1 Committee on Joining of Plastics and Composites. It must be reviewed every five years and if not revised, it must be either reapproved or withdrawn. Comments (recommendations, additions, or deletions) and any pertinent data that may be of use in improving this standard are required and should be ad- dressed to AWS Headquarters. Such comments will receive careful consideration by the AWS G1 Committee on Joining of Plastics and Composites and the author of the comments will be informed of the Committee’s response to the com- ments. Guests are invited to attend all meetings of the AWS G1 Committee on Joining of Plastics and Composites to ex- press their comments verbally. Procedures for appeal of an adverse decision concerning all such comments are provided in the Rules of Operation of the Technical Activities Committee. A copy of these Rules can be obtained from the American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126.

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Personnel

AWS G1 Committee on Joining of Plastics and Composites

J. L. Frantz, Chair Branson Ultrasonics Corp.

1. J. McMaster, Vice Chair Honeywell

   1. L. Gayler, Secretary American Welding Society

      *A. Benatar The Ohio State University

      *F. Dibble Crest Ultrasonics

   2. M. Dolan GE Plastics

      *D. Grewell Branson Ultrasonics Corp.

      *R. A. Grimm Edison Welding Institute

      B. E. Gourley Sonics & Materials, Inc.

      *F. He Eastman Kodak Co.

      *K. A. Holt Dukane Corp.

      *S. Hunt Motorola, Inc.

      L. T. Hutton ATOFINA Chemicals

      V. A. Kagan Honeywell

      *W. E. Kenney Consultant

      P. R. Krieger Fisher-Price, Inc.

      1. L. Mikeworth Dukane Corp.

         H. Moore Eastman Kodak Co.

         T. O’Toole Dukane Corp.

         J. Park Visteon

         1. L. Pochardt 3M Co.

            *K. Stratman Dukane Corp.

         2. S. Stumpek EStumpek & Associates

      *A. M. Summo Dukane Corp.

      M. W. Wichmann E. I. du Pont de Nemours and Co.

      
      

      AWS G1A Subcommittee on Hot Gas Welding and Extrusion Welding

   3. T. Hutton, Chair ATOFINA Chemicals

G. Hopkins, Vice Chair Plastek Werks, Inc.

1. L. Gayler, Secretary American Welding Society

   *M. D. Beamish Baker College of Owosso

   1. R. Blazejewski Symalit AG

S. A. Burrows ReynoldsTech Fabricators, Inc.

D. Chandler Engiplast, Inc.

T. S. Dean Pro Poly of America, Inc.

*W. H. Drake, Jr. SW Missouri State University

*R. P. Gaspar BFGoodrich

*J. J. Gates AN-COR Industrial Plastics Inc.

G. Glein CERA Consulting

*R. A. Grimm Edison Welding Institute

*P. Habib CPF Dualam, Inc.

N. Hall E. I. du Pont de Nemours and Co.

D. K. Heffner Electrochemical Engineering and Manufacturing Co.

*Advisor

iii

AWS G1A Subcommittee on Hot Gas Welding and Extrusion Welding (Continued)

M. G. Jolley KCH Services, Inc.

D. L. Keeler Viatec, Inc.

*W. E. Kenney Consultant

1. R. Khaladkar DuPont Engineering

   1. K. Lewis DuPont Teflon® Films

      *S. Linnemann RL Industries, Inc.

      1. Lopez Dow Chemical

         1. W. McCuaig Prolite Plastics Limited

            *R. Moubarac CPF Dualam, Inc.

            P. Mullen BFGoodrich

            *J. E. Niesse Consultant

            *J. J. Ploskonka HPG International

            1. W. Renner Renner Associates, Inc.

               *R. C. Reynard SCP Global Technologies

            2. R. Robbins Philip Services Corp.

         *A. Savitski Edison Welding Institute

         B. L. Smith Met-Pro Corp.—Duall Division

         *T. J. Thorpe Boeing

      2. G. Waddingham Isothermal Community College

T. R. Way ReynoldsTech Fabricators, Inc.

L. Y. Woo Fabricated Plastics Limited

1. K. Worthington Tri-Mer Corp.

   1. E. Zarnitz Atlas Minerals and Chemicals, Inc.

   2. Ziegler Wegener NA, Inc.

*Advisor

The subcommittee would like to thank Dr. Detlef Van Hofe of DVS for his contributions to this standard.

iv

Foreword

(This Foreword is not part of AWS G1.10M:2001, Guide for the Evaluation of Hot Gas, Hot Gas Extrusion, and Heated Tool Butt Thermoplastic Welds, but is included for information purposes only.)

The purpose of plastics welding inspection is to determine if a plastics weldment meets the acceptance criteria of a specific code, other standard, or other document. The plastics welding inspector must be thoroughly familiar with plas- tics welding processes, plastics welding procedures, plastics welder qualifications, materials, the limitation of plastics weld testing, be able to read drawings, prepare and keep records, prepare and make reports and make responsible judg- ments. For plastics welding inspectors to be effective, the activities performed should be consistent with the require- ments, and technical and ethical principles.

The AWS G1 Committee on Joining Plastics and Composites was formed in 1989 by industry and academic experts interested in providing process information and test standards for rating the weldability of plastic and composite materi- als. The G1A Subcommittee on Hot Gas Welding and Extrusion Welding was formed in 1993 to create standards for the qualification of hot gas and heated tool plastic welding personnel. DVS 2202-1, Imperfections in thermoplastic welding joints; features, descriptions, evaluation, was used extensively in the creation of this standard.

Comments and suggestions for the improvement of this standard are welcome. They should be sent to the Secretary, AWS G1 Committee on Joining of Plastics and Composites, American Welding Society, 550 N.W. LeJeune Road, Miami, FL 33126.

Official interpretations of any of the technical requirements of this standard may be obtained by sending a request, in writing, to the Managing Director, Technical Services Division, American Welding Society (see Annex C). A formal reply will be issued after it has been reviewed by the appropriate personnel following established procedures.

v

Table of Contents

Page No.

Personnel iii

Foreword v

1. Scope, Purpose, and Range of Application 1

2. Referenced Documents 1

3. Definitions 2

4. Evaluation Groups 2

   1. Classification 2

   2. Criteria for Establishment 2

5. Requirements for Welded Joints 2

   1. Quality Features for Classification of the Weld (Annexes VII through IX) 2

6. Details In Engineering Data. 2

7. Testing and Evaluation 3

   1. Evaluation 3

   2. Reworking Defective Welded Joints 3

   3. Overlapping Defects 3

8. Acceptance 3

Annexes—Mandatory Information

Annex I—Cracks 5

Annex II—Voids 7

Annex III—Solid Inclusions 9

Annex IV—Lack of Fusion 11

Annex V—Defects of Shape 13

Annex VI—Other Defects 15

Annex VII—Description of Evaluation Groups for Hot Gas Fan and Speed Welds 17

Annex VIII—Description of Evaluation Groups for Hot Gas Extrusion Welds 21

Annex IX—Description of Evaluation Groups for Heated Tool Butt Welds 25

Annexes—Nonmandatory Information

Annex A—Other Documents 29

Annex B—Document Sources 31

Annex C—Guidelines for Preparation of Technical Inquiries for AWS Technical Committees 33

AWS List of Documents on Plastics Welding 35

vii

AWS G1.10M:2001

Guide for the Evaluation of Hot Gas, Hot Gas Extrusion, and Heated Tool Butt Thermoplastic Welds

1. Scope, Purpose, and Range of Application

   1. These guidelines list and describe defects in welded joints in thermoplastic materials. The objective is to make possible a generally valid evaluation giving con- sideration to graded quality requirements.

   2. By classification into one of the evaluation groups in 4.1, specific defects can be excluded or kept within limits when welded joints are produced.

   3. The application of these guidelines and the measures through which they can be met may be included in con- tractual specification or form part of the generally recog- nized specifications.

   4. Welding Processes. Defects produced by the follow- ing welding processes are addressed. This guide applies to the following processes:

      
      

      Hot gas fan (rod) welding	Abbreviation WF	Annex VII
      Hot gas speed welding	WZ	VII
      Hot gas extrusion welding	WE	VIII
      Heated tool butt welding	HS	IX

   5. Materials. These guidelines apply to welded joints on components and systems made from the engineering thermoplastics listed below:

      Abbreviation Material Description

      ECTFE Ethylene chlorotrifluoroethylene ETFE Ethylene tetrafluoroethylene

      FEP Fluorinated ethylene-propylene

      MFA Perfluoromethylvinylether M PTFE PFA modified PTFE

      PE-HD High density polyethylene (rigid PE) PFA Perfluoroalkoxy

      PP-B Polypropylene block copolymer

      Abbreviation Material Description

      PVC-HI High-impact polyvinyl chloride

      PVC-U Unplasticized polyvinyl chloride (rigid PVC)

      PVDF Polyvinylidene fluoride

      PVDF/HFP Polyvinylidene fluoride/hexafluoropropy- lene

   6. The use of these guidelines for welding other thermo- plastic materials must be agreed upon between the cus- tomer and the fabricator.

   7. This standard makes use of the International System of Units (SI).

   8. Safety. The activities described in this document may bring the user of this standard in contact with pro- cesses and materials that may be hazardous to the user’s health. Safety precautions mandated by OSHA and rec- ommendations for material handling in MSDS sheets should be observed. The fabricator’s operating manual and safety instructions should always be carefully stud- ied and complied with when operating equipment.

      Note: This standard may involve hazardous materials, op- erations, and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices. The user should determine the applicability of any regulatory limitations prior to use.

      
      

2. Referenced Documents

Reference should be made to the latest edition of the following documents:

ASTM C 904 Standard Terminology Relating to Chemi- cal-Resistant Nonmetallic Materials1

PP-H Polypropylene homopolymer

PP-R Polypropylene random copolymer PTFE Polytetrafluoroethylene

PVC-C Chlorinated polyvinyl chloride

1. ASTM documents are published by the American Society for Testing and Materials, 100 Barr Harbor Drive, West Consho- hocken, PA 19428-2959.

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