Plastic Fabrication Methods: IR Welding

August 13, 2025

Infrared (IR) welding is a precision, non-contact method for joining thermoplastic pipes. It is especially valued for PVDF (Polyvinylidene Fluoride) systems, where eliminating the possibility of contamination at the weld point is critical. By heating pipe ends with infrared radiation rather than a contact plate, IR welding produces ultra-clean, strong, and repeatable joints — ideal for high-purity and chemically demanding applications. While the method can also be used with PE and PP, it is most commonly selected for PVDF due to its contamination-sensitive uses.

The Basics of IR Welding for PVDF Pipe

IR welding uses a controlled infrared heat source positioned between two prepared pipe ends. The infrared energy penetrates and heats the joint surfaces without physical contact, eliminating the risk of particulates from the heating tool embedding into the weld.

For PVDF pipe, this results in:

Zero contact heating: No risk of foreign material transfer
Minimal surface oxidation: Preserves chemical resistance and purity
Excellent repeatability: Critical in validated systems such as pharmaceuticals or microelectronics

Equipment & Tools

IR Welding Machine: Designed specifically for thermoplastic pipe with programmable settings for temperature, heating time, change-over time, and joining force.
Infrared Emitter: Matched to PVDF’s absorption spectrum for efficient, uniform heating.
Precision Clamping & Alignment System: Holds pipe and fittings square to maintain bore alignment.
PLC Controls & Data Logging: Records weld parameters for traceability and quality assurance.

General Process

Preparation: Cut and face pipe ends square; clean to remove dust or surface contamination.
Alignment Check: Secure and align in clamps to prevent offset.
Heating Phase: Position the IR emitter between pipe ends; surfaces are softened evenly without contact.
Change-Over: Withdraw the IR heater swiftly and bring ends together under a defined pressure.
Fusion & Cooling: Maintain pressure during the cooling cycle to form a stress-free, homogenous joint.
Inspection: Visually check weld quality and record parameters for QA records.

Materials Commonly Used

PVDF: Primary use for IR welding due to high purity requirements in pharmaceutical, semiconductor, and chemical processing industries.
PE (Polyethylene): Suitable for water and chemical service where contactless heating is advantageous.
PP (Polypropylene): Used in high-temperature, chemical-resistant systems where clean internal surfaces are beneficial.

Applications

IR welding of PVDF pipe is widely used in:

High-purity water systems: Semiconductor manufacturing, laboratory, and pharmaceutical production
Aggressive chemical handling: Acids, solvents, and high-temperature fluids
Food & beverage production: Hygienic, crevice-free joints for process lines
Corrosion-resistant process pipework: Offshore, industrial, and chemical plant environments

Fusion's IR Welding Services

Fusion's in-house plastic fabrication team are experts in IR welding. Check out some of our recent work or contact us today for assistance with your next installation project!

In-House Fabrication Facilities and Site Services

Fusion Plastics boasts in-house plastic fabrication facilities located on both the east and west coasts of Australia. These facilities are equipped with advanced tools and machinery to handle complex fabrication projects involving PVDF, HDPE, PP and other thermoplastics.

Custom Fabrication: From pipe spools to tanks and liners, our in-house capabilities ensure precise and high-quality outcomes tailored to specific project requirements.
Quality Assurance: Each fabricated component undergoes rigorous testing to ensure compliance with industry standards, delivering durability and reliability for applications in water treatment plants, chemical processing facilities, and beyond.

In addition to our fabrication facilities, Fusion Plastics offers comprehensive site services staffed by trained professionals skilled in plastic welding techniques, including butt welding.

On-Site Installation: Our site teams have successfully installed and fabricated pipe spools for water treatment plants and chemical processing facilities across Australia. By utilizing advanced techniques like butt welding, they ensure robust, leak-proof connections even in challenging environments.
Support for Complex Projects: From large-scale industrial installations to specialized piping systems, our experienced staff can handle projects of any complexity, ensuring efficient and reliable execution.

Challenges & Tips

Challenges:

Requires dedicated IR welding equipment with emitters matched to PVDF
Environmental control is critical for high-purity welds
Operator training is essential to maintain consistency and minimise change-over time

Tips:

Always protect the weld area from airborne dust or debris during site work
Follow manufacturer-recommended settings for heating time, change-over time, and pressure
Use data logging to provide weld traceability in regulated industries

Tips for Successful Butt Welding

Follow Manufacturer Guidelines: Always adhere to the recommended parameters for temperature, pressure, and cooling time.
Ensure Clean Surfaces: Clean the surfaces thoroughly to remove contaminants.
Use Quality Equipment: Invest in reliable welding machines and tools for consistent performance.
Train Operators: Proper training ensures operators understand the nuances of the process and can troubleshoot effectively.
Inspect Welds: Regular inspection and testing, such as hydrostatic pressure tests for pipes, confirm the integrity of the butt joints.

Maintenance and Quality Control

We maintain our IR welding machines to ensure stable, repeatable performance. Welds are inspected visually and, where required, undergo additional destructive or non-destructive testing. Full QA documentation, including parameter logs, can be supplied for installations in validated systems.

Conclusion

When welding PVDF pipe, IR welding is the gold standard for contamination-free joints. Its non-contact heating preserves material integrity, ensures high-purity performance, and produces reliable, repeatable results. Whether for semiconductor manufacturing, pharmaceutical process lines, or aggressive chemical service, Fusion delivers PVDF IR welding to the highest industry standards in Australia.

Fusion's IR Welding Services

Fusion's in-house plastic fabrication team are experts in IR welding. Check out some of our recent work or contact us today for assistance with your next installation project!