Capabilities of Yonghui | Corrugating Rolls Machinery

About
Capabilities

Capabilities

50CrMoA Forged Alloy Steel

Raw Material Quality Assurance

We use 50CrMoA forged alloy steel, sourced from Zhongyuan Special Steel Company, one of China’s top steel manufacturers. This ensures the strength, wear resistance, and thermal stability of our rolls, providing a reliable foundation for high-performance corrugating rolls. The high-quality raw material ensures optimal product durability and performance in high-speed, heavy-duty environments.

Roll body thickness ≥75mm

R&D and Design Advantages

We have spent over 10 years developing its proprietary peripheral heating technology, now successfully implemented in equipment for several renowned global corrugated board manufacturers. This technology accounts for 40% of our orders, demonstrating its market reliability and effectiveness in enhancing production efficiency.

With 20 years of professional expertise and computer-aided optimization, our flute profile designs provide a significant reduction in paper consumption (even with the same flute count and height) while enhancing board physical properties. This advanced technology not only sets us apart but creates a significant technical barrier, offering our clients a competitive edge by helping them reduce raw paper costs.

Core Process Technology

High-precision welding process

Our welding process involves the interference fit welding of the shaft heads and roll bodies, followed by stress-relieving tempering. It ensures that the final product features simple structure, superior alignment for consistent performance, strong load-bearing & impact resistance, and minimal deformation under high operational stresses. This advanced welding technique guarantees the durability and stability of our corrugating rolls, enhancing their long-term performance.

Combined heat treatment
Nitriding
Medium frequency quenching
Cryogenic Treatment

Hardness > HRC 60

Our combined heat treatment technology incorporates nitriding, quenching, tempering, and cryogenic treatment (-190°C), resulting in superior durability and hardness.

Main outcomes

Achieves surface hardness of HRC ≥60, with a 50% improvement in wear resistance, ensuring long-lasting performance.
Superior ability to withstand deformation, with stable roll performance at speeds up to 350 m/min.
Capable of 3 to 4 refurbishment cycles, with an extended lifespan of over 30% compared to traditional methods.

Praxair JP8000 thermal spray machine

Super-hard coating spraying

Using the Praxair JP8000 supersonic flame spraying system imported from the United States, combined with tungsten carbide powder, we achieve a highly uniform coating on our corrugating rolls.

Coating thickness deviation: < ±0.01mm, ensuring precise consistency across the surface
Hardness: Enhanced to HV1200–1500, offering exceptional wear resistance and durability

Sand blasting
Tungsten carbide coating
Polishing

Surface roughness of Ra≤0.4μm

Our precision surface treatment process ensures that the corrugating rolls achieve a smooth surface, polished to Ra ≤ 0.4μm, significantly reducing paper friction and wear.

High-Precision Processing Equipment

CNC grinding machine center
Suction hole drilling
Cell pattern engraving
Fine turning

We are equipped with a comprehensive range of high-precision facilities, including precision machining centers, thermal spraying tungsten coating workshops, CNC gear grinding centers, finished product storage, and quality inspection centers. With an investment exceeding 80 million RMB, the company utilizes specialized corrugating roll manufacturing equipment across key processes:

Machining
High-precision CNC lathes, grinding machines, laser welding machines, and knurling equipment
Heat treatment
Nitriding furnaces, medium frequency quenching, tempering, and cryogenic treatment equipment
Spraying
Praxair JP8000 thermal spray system (imported from the U.S.)
Quality inspection
Fully digitized process control and inspection instruments to ensure the highest standards of quality throughout production

End-to-End Quality Control System

Yonghui implements a 12-step strict quality inspection process, covering the entire production cycle from raw materials to finished products. The process includes:

Raw material testing → Welding airtightness → Dynamic balance testing → Hardness, flute profile, and dimensional checks → Pressure testing → Coating thickness measurement → Final inspection

This comprehensive quality control system ensures that every roll meets the highest standards of performance and durability.

Raw material testing
Welding airtightness testing
Bearing seat run-out testing
Hardness testing after heat treatment
Flute height testing
Run-out testing
Straightness measurement
Diameter testing
Flute profile testing
Surface roughness testing
Test paper
Dynamic balance testing

Quality Control Parameters

Roughness	Ra≤0.4μm
Hardness of roll base metal after medium frequency quenching	>HRC60
Thickness of tungsten carbide coating	0.06-0.08mm
Microhardness of tungsten carbide coating	HV1250-1400
Bonding strength	>75MPa
Deformation	＜0.1mm
Coating thickness tolerance	±0.02mm
Dynamic balancing quality	G2.5 (international standard)