Two years after the successful start-up of a complete new ANDRITZ OCC stock preparation line in 2023, HKB-Hoa Lu Paper Joint Stock Company in Ninh Binh Province, Vietnam has recently completed a highly effective upgrade that has essentially enhanced capacity, raw material flexibility, and final paper quality.
When HKB-Hoa Lu Paper (HKB) decided to enter the OCC-based packaging market in the early 2020s, it chose ANDRITZ as its technology partner. The company ordered a complete stock preparation line, including an OCC system, reject handling, and paper machine approach flow and save-all system, which started up successfully in 2023 and quickly reached all performance targets. Production was stable and quality objectives were consistently met.
However, rapidly rising demand for premium packaging grades and a strategic shift toward higher proportions of American Old Corrugated Containers (AOCC) created new challenges for the original system. AOCC, while offering excellent fiber properties, contains significantly more strength with higher kraft pulp content and also more contaminants so therefore requires more robust processing technology than local OCC.
Raw material: AOCC and Local OCC
Raw material: AOCC and Local OCC
Rather than building a completely new line, HKB chose a smarter path- a comprehensive upgrade of the existing ANDRITZ OCC system. The objective was clear: achieve stable processing of 50-60% AOCC, increase line capacity by 30%, and deliver noticeably cleaner pulp and higher final paper quality - all while keeping fiber losses to an absolute minimum.
OCC workshop in HKB-Hoa Lu Paper
Ngo Huu Phuong
Vice Chairman of the Board HKB
Ngo Huu Phuong, Vice Chairman of the Board at HKB, says, “Our company vision is to be a leading cardboard producer. For our new production line, we invested in a complete OCC line from ANDRITZ which was successfully started up in 2023.
As the packaging market quickly evolves, there is an increased demand for top quality paper with high burst strength. In 2024, the decision was made to upgrade the OCC stock preparation system to be able to process more AOCC.
We again chose ANDRITZ due to successful former projects and we fully trust the company’s capability of handling OCC and AOCC.”
The rebuild was executed with surgical precision, focusing on critical process stages where the biggest gains could be realized.
The heart of the upgrade was the installation of a new highly efficient pulper rotor. This innovative design excels at handling high AOCC content, while efficiently managing large contaminants through optimized rag operation and junk removal. The result is stable, trouble-free pulping even with difficult raw material mixes.
LC pulper
The coarse screening section was significantly strengthened. A new deflaking stage with an additional third-stage coarse screen (ModuScreen D) was added. This flexible, multi-stage configuration now delivers superior deflaking efficiency and ensures excellent system runnability paired with minimum fiber losses even at high AOCC content.
ANDRITZ ModuScreen D
To meet the stricter cleanliness requirements of premium packaging grades, HKB installed a new PrimeCleaner LW light-reject treatment system. This advanced technology efficiently removes stickies and micro-plastics, resulting in markedly cleaner pulp and more stable operation in downstream processes.
ANDRITZ PrimeCleaner LW
The long-fiber fine screening stage was upgraded with a PrimeScreen X equipped with a dilution rotor. This high-capacity screen not only supports the increased production volume but also significantly reduces fiber loss while improving overall final paper quality.
ANDRITZ PrimeScreen X
Every component was carefully integrated into the existing line, thus minimizing downtime and making full use of the original ANDRITZ equipment that was still performing well.
The upgraded OCC line has exceeded expectations across all key performance indicators:
Handsheet
Alexander Gscheider
Director, Technology & R&D, Paper & Textile APAC, ANDRITZ
“We mainly focused on the LC pulping system where we implemented a new highly efficient rotor, and also on the deflaking efficiency in the coarse screening system that was enhanced by adding an additional deflaking screen stage.”
Furthermore, ANDRITZ experts rebuilt and upgraded the fine screening system in order to maintain high stock quality at minimum fiber losses.
“In a nutshell, we provided a rebuilt setup with minimum investment to reach the target of increased capacity with high AOCC content at very high final stock quality,” continues Gscheider.
The mill can now produce higher-value packaging papers with confidence, even as raw material composition continues to shift. What once represented a technical challenge has now become a competitive advantage.
High-quality base paper
Both HKB and ANDRITZ emphasize that the project’s success was built on close, trust-based cooperation. From the initial concept discussions through detailed engineering and seamless implementation, the two teams worked hand-in-hand. ANDRITZ’s deep expertise in OCC and AOCC processing technology, combined with HKB’s clear vision and operational know-how, proved to be the winning formula.
HKB and ANDRITZ teams working together
For HKB, the upgraded line represents more than just technical improvements; it is a strategic investment in future competitiveness. With enhanced capacity, superior quality, and the flexibility to handle changing raw material conditions, the mill is now well-positioned to meet growing market demand for high-performance packaging papers in Vietnam and beyond.
Paper machine in operation at the mill
The result is a textbook example of how a targeted rebuild can deliver outstanding returns while maximizing the value of existing assets.
Huu Phuong concludes, “After the upgrade we are now processing up to 60% AOCC and the line capacity has increased by 30%. Furthermore, the paper quality has improved to meet market demands.
“With the success of this cooperation we continue to have complete trust in ANDRITZ, and we look forward to working together on our future projects.”
Finished paper
Processing low-grade furnishes into high-quality pulp
The often used saying “what you put in is what you get out” is very true when it comes to the mechanical pulping process (TMP). Good quality chips are essential for efficient and profitable production, as well as high quality paper products.
Processing low-grade furnishes into high-quality pulp
The often used saying “what you put in is what you get out” is very true when it comes to the mechanical pulping process (TMP). Good quality chips are essential for efficient and profitable production, as well as high quality paper products.
