ISO 23512:2021

Overview

ISO 23512:2021 - Plastics - Joining of thermoplastic moulded components specifies the minimum essential variables required to produce consistent, high-quality joints for a wide range of thermal joining processes. The standard defines a Thermal Joining Process Specification (TJPS) for each process, ensuring essential variables and their qualified ranges are recorded, controlled and maintained to achieve repeatable component quality.

Key thermal joining processes covered:

• Ultrasonic welding / staking / spot welding
• Infrared welding
• Hot gas convection welding
• Linear and orbital vibration welding
• Spin welding
• Laser welding
• Hot plate welding
• Heat staking (hot air, electrical, infrared)

Key topics and technical requirements

• Thermal Joining Process Specification (TJPS): A qualified document that lists all essential variables and their qualified ranges to ensure process repeatability.
• Essential variables: Conditions that directly influence joint quality and require qualification (examples include frequency, power, amplitude, tool temperature, force, melt/collapse displacement, welding time, cooling time).
• Common requirements: Joint preparation, ambient and sub‑component temperature, dimensional and process reports, visual acceptance criteria.
• Joining Process Qualification Record (JPQR): Record of mechanical test results and qualified ranges used to validate a TJPS.
• Sub-component controls: Material supplier, material designation, moisture content, regrind/masterbatch percentages, dimensional report and process report.
• Organization responsibilities: Identification and documented approval of the joining organization and authorized signatory for TJPS.
• Annexes and templates: Annex A–K provide TJPS templates per process; Annex L–M offer worked examples for hot plate welding and electrical heat staking.

Applications

ISO 23512 is practical for any organization that needs controlled, repeatable thermal joining of thermoplastic moulded parts. Typical uses include:

• Production process documentation and control for manufacturers of consumer products, electronics, automotive components, medical devices and appliances
• Development and qualification of joining procedures to meet quality and regulatory requirements
• Supplier/customer quality agreements specifying production joining criteria

Who should use this standard

• Process engineers and manufacturing engineers developing plastic-joining processes
• Quality managers implementing process control and documentation for welding/staking operations
• Product designers and suppliers establishing joining requirements in component specifications

Related standards

• ISO 472 (Plastics - Vocabulary) is normatively referenced.
• Note: Standards specific to joining plastic pipes, fittings and assessment of resulting joints are developed by ISO/TC 138.

Keywords: ISO 23512:2021, thermal joining process specification, TJPS, thermoplastic welding, ultrasonic welding, laser welding, heat staking, JPQR, quality control.