In the pulp and paper industry, pulper blades operate under severe wear and impact conditions. Improving their wear resistance and extending service life have become crucial for maintenance and energy efficiency. In recent years, Plasma Transferred Arc (PTA) hardfacing has emerged as an ideal solution for pulper blade repair and reinforcement, thanks to its superior metallurgical bonding and precise deposition control.
Technical Background: Challenges of Pulper Blade Wear
During pulping, blades are constantly exposed to paper scraps, sand, and impurities, leading to severe abrasion and corrosion. Traditional replacement or basic welding methods are costly, short-lived, and prone to delamination or cracking. As equipment becomes more continuous and automated, the industry urgently needs a high-adhesion, wear-resistant, and customizable surface strengthening technology.
Principle of PTA Hardfacing Technology
PTA hardfacing uses a plasma transferred arc as a high-energy heat source to fuse alloy powder onto the substrate. Its main advantages include:
• Strong metallurgical bonding, with melt temperatures up to 10,000°C forming dense layers;
• Low dilution (<10%), preserving alloy composition and hardness;
• Controllable thickness (1–3 mm) tailored to wear patterns;
• Small heat-affected zone, minimizing distortion and cracking.
Typical Applications on Pulper Blades
Depending on the wear characteristics of each blade area, different alloys can be applied:
• Cutting edges: Cobalt-based (e.g., Stellite 6) or Nickel-based (NiCrBSi+WC) alloys with hardness up to HRC 55–65;
• Transition zones: Iron-based alloys balancing strength and toughness;
• Support surfaces: Nickel-based anti-corrosion layers for chemical resistance.
After PTA hardfacing, pulper blade surfaces become dense and smooth, offering excellent impact and wear resistance. Service life can be extended by 3–5 times, energy consumption reduced by 10–15%, and maintenance intervals greatly prolonged.
Advantages of PTA hardfacing
A leading pulp manufacturer implemented NiCrBSi+WC PTA hardfacing to refurbish worn pulper blades:
• Blade lifespan increased from 3 to 12 months;
• Pulping efficiency improved by 12%;
• Annual maintenance costs dropped by 40%;
• Scrap blade waste was significantly reduced, achieving greener, more sustainable operations.
Market Prospects and Industry Significance
Driven by carbon-neutral policies and energy-saving goals, the pulp and paper industry is shifting toward higher efficiency and sustainability. PTA hardfacing applied to pulper blades, deflaker discs, and refiner rotors can greatly extend equipment life and reduce material waste—aligning with the principles of green manufacturing.
In the future, as automated welding and intelligent inspection systems advance, PTA hardfacing will find broader applications across the pulping, mining, and energy sectors.
Conclusion
PTA hardfacing provides a high-performance, sustainable surface strengthening solution for pulper blades. It overcomes the limitations of traditional welding methods and paves the way for energy-efficient, reliable, and environmentally friendly pulping operations.
Under the trend of cost reduction and efficiency improvement, PTA hardfacing will undoubtedly become a key development direction in papermaking equipment manufacturing and maintenance.
Post time: Nov-07-2025