Duplex Board With Grey Back is a type of paperboard that is white and smooth on the front side and mostly gray-backed on the back side.It is mainly divided into two types according to its use: printing and stationery.Duplex Board With Grey Back is mainly used for single-sided color printing to produce paper boxes for packaging purposes, and it can also be used for design and handmade products. Stationery whiteboard paper is a type of flipchart paper, suitable for training, seminars,and other scenarios.

Raw materials and processes

1. Composition of raw materials

Duplex Board With Grey Back is made by laminating several types of pulp with different qualities, utilizing a multi-layer structural design.Its raw material ratio exhibits distinct layered characteristics:

Top sheet (front side):Bleached kraft pulp or deinked pulp from waste paper is primarily used to ensure surface whiteness and smoothness. Grade A products employ bleached chemical pulp.

Core layer and bottom layer:Mainly using low-grade waste paper pulp,straw pulp,or deinked waste paper pulp to reduce production costs.

Coating layer:Apply inorganic coatings such as porcelain clay on the surface layer, and then press and polish it to further enhance whiteness and printability.

Overall,the utilization rate of waste gray-based whiteboard paper can reach over 80%, making it a typical eco-friendly packaging material.

2. Production process

Duplex Board With Grey Back is typically produced using a multi-layer papermaking process, which involves papermaking on multi-wire multi-dryer paper machines or long wire hybrid paperboard machines. Its production process mainly includes the following steps:

Pulping:Prepare the surface pulp (bleached wood pulp or deinked pulp from waste paper), lining pulp, core pulp, and bottom pulp separately,with different fiber ratios for each layer of pulp, which vary according to product grades.

Copying and manufacturing:The wet paper pulp of each layer is laminated on the paper machine to form a multi-layer wet paper web, with the layers tightly bonded together through wet pressing.

Coating:Single-sided coating is applied to the front side of the paperboard,using an air knife or a doctor blade coating method. The coating material is inorganic paint such as porcelain clay.

Calendering and drying:After coating, it undergoes multi-roller calendering treatment to make the surface smooth and dense, and the moisture content is controlled through the drying process to prevent warping and deformation.

Duplex Board With Grey Back produced through the aforementioned process features a high whiteness, high smoothness, and good ink absorption on the coated surface, making it suitable for the production of single-sided color printing packaging boxes such as offset printing and gravure printing.

Feature

1. Appearance and structural features

The most notable feature of Duplex Board With Grey Back is its distinct appearance of white on one side and gray on the other.The front side is white and smooth, while the back side is gray and relatively rough, hence it is also known as "gray-backed coated white".Its structure is well-defined, typically consisting of a surface layer,a lining layer,a core layer, and a bottom layer. Some products also have a secondary coating layer. Each layer serves a specific function,ensuring high quality printing on the surface while reducing overall costs through the use of lower-quality pulp layers.

2. Physical performance characteristics

Duplex Board With Grey Back exhibits good physical strength:it is strong and tough, with high folding endurance, compact texture,and uniform thickness. Its stiffness, bursting strength,and smoothness all meet the requirements for packaging box molding and printing.The grammage range is generally 200–500g/m²,and some products can cover a range of 180–1800g/m².

3. Printability characteristics

The coated surface of Duplex Board With Grey Back exhibits relatively uniform ink absorption,with fewer issues of powder detachment and fluffing on the surface.It boasts good ink absorption and color reproduction.Its smoothness and whiteness meet the requirements for single-sided color printing,making it suitable for printing colored boxes such as wine boxes, tea boxes,and cosmetics boxes.

4. Limitations

The Duplex Board With Grey Back has a relatively high moisture content, generally around 10%,and exhibits a certain degree of elasticity.Therefore,it is important to control the environmental humidity during printing.Additionally,the back side (gray side) of the paper is not suitable for printing, and only the front side can be used for color printing.

Purpose

In the packaging industry,Duplex Board With Grey Back can be used alone to make small color boxes,or it can be laminated with high-strength corrugated medium and cardboard to serve as the outer layer of corrugated board.In daily necessities,it can be used to make playing card paper, handbags, and clothing lining boards.In stationery and educational supplies,it can be used as book covers, folders,flip charts,and for designing handicrafts.

Duplex Board With Grey Back is a single-sided color printing and packaging material primarily produced from recycled waste paper using a multi-layer papermaking process, with a coating on the front side. Its core advantages lie in its low cost (with a waste paper utilization rate of over 80%),good printability (smooth surface and uniform ink absorption),and environmental friendliness and recyclability.It is one of the most widely used mid-range packaging boards in industries such as consumer electronics, cosmetics, and food.

In recent years, the Duplex Board With Grey Back market has been affected by factors such as fluctuations in raw material prices and industry capacity adjustments,resulting in a downward shift in the price center of gravity.However,due to its rigid demand in the packaging sector and cost advantages,it still occupies a significant share of the packaging board market. With the release of holiday gift box orders,the market trend continues to rise.