ISO 5623:2022 プラスチック — 熱可塑性成形部品の接合 — 欠陥に対する品質レベルの仕様 | ページ 2

Foreword

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This document was prepared by Technical Committee ISO/TC 61, Plastics.

Introduction

This document is intended to be used as a reference in the drafting of application specifications. It contains a simplified selection of thermal joining process imperfections in thermoplastics based on the designations given in EN 14728.

The purpose of this document is to define dimensions of typical imperfections which might be expected in normal fabrication. It may be used within a quality system for the production of joints. It provides three sets of dimensional values from which a selection can be made for a particular application. The quality level necessary in each case is intended to be defined by the application specification or the responsible designer, in conjunction with the manufacturer, user and/or other parties concerned.

The quality levels are expected to be prescribed before the start of production, preferably at the enquiry or order stage. They provide basic reference data and are not specifically related to any particular application. They refer to types of joint in fabrication and not to the complete product or component itself. It is possible, therefore, for different quality levels to be applied to individual joints in the same product or component.

It is normally expected that, for a particular joint, the dimensional limits for imperfections can all be covered by specifying one quality level. In some cases, it may be necessary to specify different quality levels for different imperfections in the same joint.

The choice of quality level for any application is expected to take account of design considerations, subsequent processing, mode of stressing (e.g. static, dynamic), service conditions (e.g. temperature, environment) and consequences of failure. Economic factors are also important and include not only the cost of joining process but also of inspection and testing.

Imperfections are quoted in terms of their actual dimensions, and their detection and evaluation may require the use of one or more methods of destructive and/or non-destructive testing. The detection and sizing of imperfections are dependent on the inspection methods and the extent of testing specified.

This document is directly applicable to visual testing of thermal joints and does not include details of recommended methods of detection or sizing by non-destructive means. These limits are not necessarily applicable to non-destructive testing methods and might need to be supplemented by requirements for inspection, examination and testing.

The values given for imperfections are for thermal joints produced using normal joining process practice.

1 Scope

This document specifies quality levels for imperfections in joints in thermoplastic moulded components due to the joining process.

This document does not describe imperfections that can be generated either during service or present before joining, such as poor fit up. The correct preparation before joining is described in the relevant thermal joining process specification (TJPS), as defined in ISO 23512.

Three quality levels are specified in order to permit application for a wide range of the following joining processes:

• a) ultrasonic welding;
• b) ultrasonic spot welding;
• c) infrared welding;
• d) hot gas convection welding;
• e) vibration welding;
• f) spin welding;
• g) laser welding;
• h) hot plate welding; and
• i) heat staking: hot air; electrical, infrared and ultrasonic.

They are designated by symbols B, C and D, where B is the most stringent. The quality levels refer to production quality and not to the fitness for purpose of the manufactured product.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

Bibliography