3,800 mm Coated White Paperboard Machine Project in Jiangsu, China – 150,000 Tons/Year

Project Overview

In 2021, our company completed the manufacturing and supply of a 3,800 mm coated white paperboard production line for a paper mill in Jiangsu Province, China.

The project was designed to produce high-quality coated white paperboard for packaging applications. Following installation, commissioning, and process optimization, the production line was successfully put into operation.

The machine has a design speed of 400 m/min and an annual production capacity of 150,000 tons. It has been in stable commercial operation since 2021, demonstrating reliable performance in industrial paperboard production.

Key Project Specifications

Project Objectives and Raw Materials

The primary objective was to establish a reliable production line capable of manufacturing coated white paperboard with consistent surface quality and mechanical strength.

The finished paperboard is suitable for a wide range of packaging applications, including:

• Food packaging cartons

• Pharmaceutical packaging

• Consumer goods packaging

• Gift boxes

• Printed folding cartons

The production process uses locally sourced recycled fiber pulp for the middle and back plies, together with a small proportion of bleached wood pulp for the top ply.

This furnish arrangement combines good surface quality with economical raw material utilization, helping the mill maintain competitive production costs.

Three-Ply Fourdrinier Forming Section

The machine adopts a three-ply Fourdrinier forming configuration.

The forming section is equipped with three independent air-cushion headboxes, allowing the top, middle, and back plies to be formed separately.

A vacuum dewatering system provides controlled water removal during sheet formation.

This configuration offers several advantages:

• Improved surface quality

• High paperboard stiffness

• Stable multi-ply sheet structure

• Efficient utilization of different fiber grades

The three-ply arrangement enables the mill to use higher-quality fibers where surface appearance is most important while incorporating recycled fibers in the inner layers.

Independent Headbox System

Each ply is supplied by an independent headbox:

• Top ply headbox

• Middle ply headbox

• Back ply headbox

Independent stock flow control allows operators to adjust the characteristics of each layer and maintain consistent finished paperboard quality.

Press Section

The press section features a four-roll combined vacuum press arrangement incorporating a shoe press.

The system is designed to provide effective mechanical dewatering before the dryer section.

Its main benefits include:

• Improved water removal

• Higher sheet dryness after pressing

• Reduced drying load

• Lower steam consumption

Rubber-covered and granite press rolls are incorporated into the press arrangement to support stable operation.

Dryer Section

The dryer section is equipped with 42 cast-iron dryer cylinders, each with a diameter of 1,800 mm.

The drying system includes:

• Sectional steam temperature control

• Semi-enclosed dryer hood

• Hot-air circulation system

This configuration supports uniform drying, stable paperboard quality, and moisture profile control across the machine width.

Two-Stage On-Machine Coating System

One of the key features of this project is its integrated two-stage on-machine coating system.

The coating process consists of two stages.

Stage 1: Air-Knife Pre-Coating

Coating Method: Air-Knife Coating

Coat Weight: 14–20 g/m²

The pre-coating stage prepares the paperboard surface for the subsequent top-coating process.

Stage 2: Blade Top-Coating

Coating Method: Blade Coating

Coat Weight: 10–16 g/m²

The top-coating stage provides the surface characteristics required for high-quality printing and packaging applications.

Each coating stage is followed by a dedicated hot-air drying system.

This arrangement helps:

• Prevent coating from sticking to dryer cylinders

• Reduce dust generation

• Improve surface quality

• Enhance the printability of finished paperboard

Soft-Nip Calendering

A two-roll soft-nip calender is installed after the dryer section.

The calender is designed to:

• Improve surface smoothness

• Enhance caliper uniformity

• Improve printing performance

• Provide a more consistent finished appearance

Automation and Quality Control

The production line is equipped with an automated control system incorporating:

• Distributed Control System (DCS)

• Online Quality Control System (QCS)

The system monitors key production parameters, including:

• Basis weight

• Moisture content

• Paperboard profile stability

These control systems help maintain consistent product quality and improve the operational efficiency of the production line.

Auxiliary Equipment and Stock Preparation

In addition to the main paper machine, the project includes a complete range of auxiliary equipment:

• Recycled fiber stock preparation system

• Wastepaper pulping and cleaning equipment

• Stock screening system

• Multi-disc thickeners

• Stock delivery system

A 3,950 mm underfeed rewinder is also installed as part of the finishing equipment.

Project Results

Following successful commissioning, the production line achieved stable industrial operation.

The main project results include:

• Successful production of coated white paperboard

• Reliable commercial operation since 2021

• Annual production capacity of up to 150,000 tons

• Production of paperboard in the 250–450 g/m² basis weight range

• Cost-effective use of locally sourced recycled fibers

The project demonstrates the performance of a three-ply Fourdrinier paperboard machine equipped with an integrated two-stage on-machine coating system.

Our Paperboard Machine Solutions

This project reflects our experience in engineering and supplying complete paperboard production lines for the packaging industry.

Our services include:

• Process engineering and production line design

• Paper machine manufacturing

• Auxiliary equipment supply

• Installation and commissioning

• Operator training

• Technical support

Whether you are planning a new coated white paperboard mill or upgrading an existing production line, we can help develop an equipment solution based on your production capacity, raw materials, and finished product requirements.

Contact us to discuss your coated white paperboard production project.