What is Forming Fabric? Application, Type, Structure

Forming Fabric is an indispensable and important part of the papermaking industry and is known as the "invisible craftsman" in the papermaking process. It plays a core role in supporting and shaping the pulp fiber network in the forming section of the papermaking machine, directly affecting the quality, uniformity and performance of the paper. From functional principles to material classification, to technological development and application, the knowledge system of Forming Fabric covers a wealth of content.

This guide will start with the basic concepts and comprehensively analyze the structure, function, selection and key role of Forming Fabric in the papermaking process.

What is a Forming Fabric

Forming Fabric is a key component used in papermaking machines. It is the core material of the wet end of the papermaking process. It is located in the forming area of ​​the papermaking machine and quickly removes moisture from the pulp by providing support and filtering functions, while forming fibers into uniform paper sheets.

The Importance of Forming Fabric

• The performance of the forming fabric determines the uniform deposition and moisture distribution of the paper sheet fibers, which ultimately affects the strength, surface finish and uniformity of the paper.

• Through efficient dewatering performance, the forming fabric helps paper machines reduce energy consumption and production costs.

• Different forming fabric designs can meet a variety of needs from ordinary writing paper to high-performance packaging paper.

Types of Forming Fabric

Monowire vs. Twin‑Wire Fabrics

The decision between monowire fabrics and twin‑wire fabrics hinges on factors like drainage rates, sheet uniformity, and machine speed. Monowire fabrics consist of a single woven layer, providing excellent drainage, easy cleaning, and predictable tension profiles even under high machine speeds, reducing fiber retention in fines sections. Twin‑wire fabrics, on the other hand, feature two woven layers that improve sheet support and form stability, making them ideal for delicate fine paper grades that demand uniform fiber distribution across the cross direction.

Key Benefits:

1. Higher drainage and faster dewatering for monowire.

2. Enhanced sheet formation and fibril retention with twin‑wire.

3. Reduced vibration and machine noise, prolonging wire life and reducing edge wear during start-ups and shutdowns.

Polyester vs. Composite Yarns

Choosing between 100% polyester yarns and composite yarns affects both mechanical strength and elongation characteristics, impacting fabric longevity and sheet quality. Polyester yarns deliver consistent tension, low stretch, and minimal elongation over long runs, which is crucial for coated paper where dimensional stability is paramount. Composite yarns, such as PET/PA blends, offer enhanced wear resistance and higher tear strength, significantly extending the fabric life in high-speed, abrasive environments.

List of Considerations:

• Elongation at break values for durability assessment.

• Abrasion resistance ratings per ISO 5470-1 standards.

• Cost per running meter balanced against predicted life-cycle performance and downtime savings.

Specialty Fabrics (e.g., Press‑Supported, Triple‑Layer)

Specialty fabrics address niche requirements like press position support and integrated dewatering layers. Press‑supported fabrics integrate a denser sub-layer to withstand intense nip loads, ensuring optimal sheet dryness and minimizing moisture rewetting in the press section. Triple‑layer fabrics combine forming, press, and breast layers into a single unit, reducing fabric changeover times, lowering operational complexity, and decreasing the total number of fabrics needed in inventory.

Why They Matter:

• Optimized dewatering with multi-layer flow channels.

• Stable sheet transfer across forming and pressing zones, eliminating sheet breaks.

• Lower maintenance through fewer fabric inventory changes and simplified storage logistics.

Applications of Forming Fabric

Newsprint and Linerboard

In high-speed newsprint and linerboard operations, fabrics with wide mesh openings (20–26 mesh) enable lightning-fast dewatering, pushing machine speeds to 1,500 m/min or more. These open structures tolerate dirt and fiber contaminants, minimizing headbox clogs and forming section stoppages. 

1. Rapid Dewatering keeps your runnability steady even at top speeds.

2. Abrasion-Resistant Mesh withstands continuous use, lowering replacement frequency.

3. Low Fiber Retention simplifies cleaning and prolongs headbox life.

By tailoring mesh count and material, you can maintain throughput without sacrificing paper quality.

Fine Paper and Coated Grades

For fine papers and coated boards, a tight mesh (40–60) paired with low-profile yarns ensures smooth surfaces and uniform formation. Composite yarn blends fortify the fabric against heavy nip pressures and chemical exposure from coating processes. 

• Surface Contact: Low-profile yarns reduce voids, preventing pinholes.

• Controlled Open Area balances drainage with sheet formation for flawless coatings.

• Enhanced Durability: Composite yarns extend run lengths under demanding conditions.

This combination keeps premium paper grades meeting exacting standards run after run.

Tissue and Specialty Papers

Producing tissue and specialty papers calls for soft fabrics with up to 35% porosity, allowing gentle fiber support and superior bulk. Advanced weave patterns minimize sheet marking while promoting even fiber distribution, essential for luxury hygiene products.

• Exceptional Absorbency and bulk thanks to high open area.

• Minimal Marking delivers a premium feel in consumer tissues.

• Stable Machine Runs reduce breaks and maintenance needs.

Optimizing porosity and weave ensures your tissue grades stand out in both performance and hand feel.

Structure and Design Parameters

Influence on Porosity and Tensile Strength

A fabric’s porosity controls your dewatering rate, while tensile strength dictates how well it handles tension without stretching. Aim for an open area near 40% and tensile modulus above 200 N/cm to strike the right balance between drainage efficiency and dimensional stability.

Selecting Yarn Sizes for Targeted Sheet Properties

Yarn diameters from 0.15 to 0.35 mm determine fabric performance. Thinner yarns (< 0.20 mm) enable fine sheet formation and a silky finish, whereas thicker yarns (> 0.30 mm) enhance durability for abrasive environments—albeit with a slight trade-off in surface smoothness.

How Weave Geometry Affects Sheet Formation

Choosing the right weave—plain, twill, or herringbone—tailors fiber lay-down and drainage. 

• Plain Weave: Best for coated papers requiring uniform formation.

• Twill Weave: Accelerates drainage for board and containerboard.

• Herringbone Weave: Offers a balance of drainage and sheet support, reducing wire marking.

These design choices have a direct impact on formation quality, machine vibration, and fabric lifespan.

How to Choose a Suitable Forming Fabric

Choosing the right forming fabric is a crucial step in the production process. The right forming fabric can improve production efficiency, product quality and cost-effectiveness. Here are some key factors to consider when choosing a forming fabric:

1. Mesh size

The mesh size will directly affect the forming effect of the product. Choose the appropriate mesh size according to the product size requirements and production process.

2. Durability and service life

The durability of the forming mesh is very important for production efficiency and cost control. When choosing, you need to consider the wear resistance, anti-aging performance of the mesh material, and whether it can maintain performance under long-term high load.

3. Filtration effect and cleanliness

When choosing a forming mesh, you need to consider its filtration effect and whether it is easy to clean. If the forming mesh needs to be frequently cleaned or replaced during the production process, choosing a mesh material that is easy to clean and not easy to accumulate impurities will be an important consideration.

4. Price and economy

The price of the forming mesh varies depending on factors such as material, specifications and brand. Under the premise of ensuring quality, choosing a forming mesh with a suitable price can help companies control costs while maintaining production quality.

5. Suppliers and brands

It is very important to choose a reputable and experienced supplier. Excellent suppliers can provide technical support and after-sales service to ensure that the selected forming mesh meets production needs.

Common Problems and Solutions in Use

1. Forming fabric wear problem

• Regular inspection and cleaning: Clean the surface of the forming mesh regularly to avoid dirt and fiber accumulation that accelerates wear.

• Optimize operating parameters: Adjust the speed and pressure of the production line to reduce excessive wear on the forming mesh.

• Choose wear-resistant materials: Use forming mesh materials with high wear resistance, such as polyester and nylon blends.

2. Forming fabric deformation

• Maintain the correct tension: Ensure that the tension of the forming mesh is appropriate, avoid being too tight or too loose.

• Uniform force: Regularly check the tensioning device and guide wheel to ensure uniform force and prevent deformation of the mesh surface.

• Proper mesh adjustment: Adjust the mesh size according to different product requirements to avoid uneven force on the mesh surface.

3. Forming fabric clogging problem

• Use proper cleaning methods: Clean regularly and use high-pressure water, chemical cleaning agents or ultrasonic cleaning equipment to remove blockages.

• Optimize material formulation: Adjust the pulp formulation to reduce the use of long fibers or sticky materials to reduce blockages.

• Add a filtration system: Add a more effective filtration device before the forming mesh to reduce impurities entering the forming mesh.

4. Uneven mesh surface

• Adjust mesh density: Properly adjust mesh density to ensure that fibers are evenly distributed on the mesh surface.

• Optimize wet end design: Improve the wet end design of the forming part to ensure that the pulp is evenly distributed on the forming mesh.

• Regularly check the state of the forming mesh: Regularly check whether the mesh surface is damaged, loose or uneven, and repair it in time.

Final Thoughts

We hope this article has given you a more complete understanding of what forming fabric is, why it is essential in the industry, and what types of forming fabric there are. In short, choosing the right forming fabric allows companies to produce large quantities of high-quality products in an efficient and precise manner.

As a leading manufacturer and distributor of forming fabrics and paper machine clothing, Keylife strives to provide you with relevant knowledge and answers to your questions about forming fabrics. We even have an in-house service department to help you with all the paper machine clothing products you want to know. Click here to welcome your visit.

FAQ

1. What is a forming fabric?

A forming fabric is a woven mesh used in the papermaking machine to support pulp, remove water, and shape the sheet during its early formation.

2. How long does a forming fabric typically last?

Depending on conditions and treatment, forming fabrics last between 6 to 18 months. Specialty coatings can significantly extend this life.

3. Can forming fabrics be customized?

Yes. Fabrics can be tailored based on machine size, speed, paper grade, and operating environment to optimize performance and durability.

4. Are surface coatings worth the investment?

Absolutely. Coatings such as polyurethane can increase wear resistance and cut downtime, leading to long-term operational savings.

5. How do I choose the right forming fabric for my machine?

Consider your paper grade, machine speed, drainage needs, and desired surface finish. Consulting a specialist like KEYLIFE is highly recommended.