What Are the Main Paper Machine Clothing Types?

The three main types of paper machine clothing are forming fabric, press felt, and dryer fabric. Each operates in a different section of the paper machine and performs a different function. Forming fabric supports fiber formation and removes the first large volume of water, press felt removes additional water through mechanical pressing while supporting the fragile wet sheet, and dryer fabric carries and stabilizes the sheet as heat removes the remaining moisture.

Although all three are commonly grouped under the term paper machine clothing, they cannot be selected using the same criteria. Their structures, permeability, surface properties, mechanical loads, operating temperatures, and contamination problems differ significantly. Sun Hong Group's Paper Machine Clothing range covers forming fabrics, press felts, and dryer fabrics for different paper grades, machine speeds, widths, and production conditions.

Understanding these differences is important because clothing performance influences drainage, sheet formation, press dewatering, drying efficiency, paper surface quality, machine stability, energy consumption, and operating cost.

What Is Paper Machine Clothing?

Paper machine clothing refers to the engineered fabrics and felts that continuously carry, support, dewater, and stabilize the paper sheet as it travels through the paper machine.

A modern paper machine begins with an extremely dilute fiber suspension. The stock reaches the forming section through the headbox, where water must be removed rapidly enough to create a continuous wet sheet. The sheet then enters the press section, where mechanical pressure removes more water. Finally, it passes through the dryer section, where heat and ventilation reduce moisture to the required final level.

The clothing changes with each stage because the physical condition of the paper sheet also changes.

These three types work sequentially rather than independently.

A simplified process is:

Headbox → Forming Fabric → Press Felt → Dryer Fabric → Finished Paper

By the time the sheet leaves the dryer section, most water introduced with the original stock has already been removed. The efficiency of each clothing stage affects the workload of the next one. Poor forming-section drainage can increase press-section demand, while poor press dewatering increases steam consumption in the dryer section.

For this reason, paper machine clothing should be considered part of the mill's water-removal and runnability system rather than a simple consumable belt.

1. Forming Fabric: The First Paper Machine Clothing Type

Forming fabric is installed immediately after the headbox and is the first clothing to contact the stock directly. Its main tasks are to support fibers, allow water to drain through its openings, help create an even fiber network, and carry the developing wet sheet toward the press section.

Sun Hong's Paper Machine Clothing Forming Fabric is manufactured from synthetic yarns such as polyester and is available in single-layer, 1.5-layer, 2.5-layer, and triple-layer structures. Different designs balance drainage, fiber support, stability, wear resistance, and paper-side smoothness.

When stock first reaches the forming section, its water content is extremely high. A large proportion of this water must be removed in a short machine distance through gravity, foils, forming boards, vacuum elements, suction boxes, and other dewatering components. The forming fabric must therefore provide sufficient permeability without allowing excessive fiber and fines loss.

Its surface also influences the initial structure of the sheet. If the fabric provides uneven support, the paper can develop wire marks, poor formation, uneven drainage, or two-sidedness. For this reason, the forming fabric is sometimes regarded as one of the most important contributors to early paper quality development.

Main Functions of Forming Fabric

The main functions include:

• Supporting fibers delivered by the headbox

• Allowing rapid water drainage

• Retaining sufficient fibers and fines

• Promoting uniform sheet formation

• Carrying the wet web through the forming section

• Withstanding vacuum and mechanical wear

• Maintaining dimensional stability at operating speed

• Releasing the sheet cleanly toward the press section

These requirements can conflict with one another. A more open structure can increase drainage but reduce fiber support. A very fine paper-side surface can improve sheet quality but may reduce permeability or cleaning ability.

The correct forming fabric is therefore a compromise between hydraulic performance and sheet-support requirements.

Forming Fabric Structures

Forming fabrics are commonly classified according to layer construction.

Single-Layer Forming Fabric

A single-layer fabric uses one basic woven structure. It is relatively simple, provides good drainage, and can be used in applications where sheet-support and machine-speed requirements are moderate.

Its open structure can also make cleaning relatively straightforward. However, it generally provides less separation between the paper side and machine side than modern multilayer designs.

1.5-Layer Forming Fabric

A 1.5-layer design modifies the basic weave to improve stability and paper-side support while maintaining relatively good drainage.

It can provide a useful balance between simpler single-layer structures and more sophisticated multilayer fabrics.

2.5-Layer Forming Fabric

A 2.5-layer structure provides greater design flexibility between the paper side and machine side. It can offer improved fiber support and wear resistance while maintaining appropriate water-removal capacity.

This structure is commonly considered where higher machine speeds, improved formation, and longer operating life are required.

Triple-Layer Forming Fabric

Triple-layer structures separate the paper-side function more clearly from the machine-side function. The fine paper-side weave supports fibers and helps improve sheet formation, while the machine-side structure is designed for stability, wear resistance, and drainage.

These fabrics are often selected for higher-speed or quality-sensitive applications because the two surfaces can be engineered for different duties.

However, multilayer construction also makes internal cleanliness important because fines and fillers can enter deeper areas of the fabric.

What Determines the Right Forming Fabric?

A forming fabric should be selected according to the entire forming process rather than only mesh count or layer type.

Important factors include:

A packaging machine using recycled OCC has different requirements from a fine-paper machine using highly refined virgin fiber. The former may emphasize wear resistance, contamination resistance, and drainage capacity, while the latter may place more emphasis on sheet formation and surface quality.

2. Press Felt: Clothing for Mechanical Dewatering

After the sheet leaves the forming section, it enters the press section while still containing substantial water. The sheet is stronger than it was at the headbox, but it is still wet and mechanically fragile.

The press felt supports this wet web as it passes through press nips. Its porous structure receives water squeezed from the sheet under mechanical pressure and carries that water away from the nip region.

Sun Hong's Paper Machine Clothing Press Felt includes different felt constructions for packaging paper, cultural paper, pulp board, tissue, specialty paper, conventional presses, and shoe-press applications.

A press felt must perform several functions simultaneously. It needs enough void volume to accept water rapidly, sufficient permeability to discharge that water after the nip, a smooth enough surface to avoid marking the paper, and enough mechanical stability to withstand repeated compression.

Unlike a forming fabric, which is primarily woven from monofilament yarns, a modern press felt typically combines a woven or laminated base structure with needled batt fibers.

How Is a Press Felt Constructed?

A press felt normally consists of two functional elements:

Base Structure

The base acts as the mechanical skeleton of the felt. It provides dimensional stability, tensile strength, and part of the void structure needed for water handling.

Batt Layer

Fine fibers are needled into the base structure. The batt creates the felt surface, influences water absorption and release, and helps protect the wet paper sheet from impressions created by the base weave.

The relationship between these layers determines how the felt behaves inside the press nip.

A felt with insufficient void volume can become saturated and lose dewatering capacity. A felt that is too open can mark the sheet. Excessive compaction during service can also reduce permeability even if the felt remains mechanically intact.

Main Press Felt Structures

Press felts can be classified according to base-layer construction.

Single-Layer Press Felt

Single-layer felt uses a relatively simple base structure. It can provide good water filtration, manageable weight, and relatively easy cleaning.

It may be appropriate for less demanding press positions or machines where moderate loading is used.

Double-Layer Press Felt

Double-layer felts provide greater structural stability and void volume. They can handle higher nip pressures and maintain more consistent water-handling properties.

The additional structure can also help reduce groove and vacuum marks in suitable press configurations.

Triple-Layer or Laminated Press Felt

Triple-layer and laminated designs are used where high mechanical loading, large void volume, stability, and controlled surface properties are important.

Shoe presses are an important example because the extended nip subjects the felt to substantial compression while removing large amounts of water.

The felt must recover its structure after each compression cycle. If it remains compacted, its ability to accept and transport water falls rapidly.

What Does Press Felt Do Besides Remove Water?

Dewatering is its main process function, but it is not the only one.

Press felt also supports the wet web as it moves between machine sections. Without adequate support, the sheet can stretch, wrinkle, break, or become damaged while still weak.

It also distributes pressure in the nip. A uniform felt structure helps prevent concentrated pressure points that could mark or crush the paper.

Press felt can also influence the surface characteristics of the sheet. Surface uniformity, batt fineness, felt cleanliness, and nip conditions all influence the interaction between felt and paper.

For this reason, press felt selection should consider paper quality and mechanical runnability together.

What Determines the Right Press Felt?

Important variables include:

• Paper grade

• Basis weight

• Machine speed

• Press type

• Nip pressure

• Shoe press or conventional roll press

• Vacuum arrangement

• Felt position

• Required permeability

• Required void volume

• Water load

• Sheet surface requirements

• Cleaning conditions

A felt selected for a tissue machine is not automatically suitable for board production. Tissue applications may require a fine and uniform surface, while board machines can demand higher water-handling capacity and greater resistance to heavy mechanical loading.

Press conditions also change throughout felt life. A new felt needs to reach stable operating conditions, while an older felt gradually experiences contamination and compaction. Good felt design aims to maintain useful permeability over as much of the operating life as possible.

3. Dryer Fabric: Clothing for the Drying Section

After pressing, the sheet contains much less water but is still too wet for converting or finishing. The dryer section removes the remaining moisture primarily through evaporation.

A dryer fabric carries and supports the paper as it travels around steam-heated dryer cylinders. Its job is to maintain stable sheet contact with the cylinder surface while allowing evaporated moisture and ventilation air to move through the drying system.

Sun Hong's Paper Machine Clothing Spiral Dryer Fabric is one type of dryer clothing used for paper transport and drying. Sun Hong's broader dryer-fabric range also includes spiral, round-yarn, and flat-yarn designs for different machine speeds and ventilation requirements.

Dryer clothing works in a much hotter environment than forming fabric or press felt. It must therefore maintain strength, dimension, seam integrity, and permeability during prolonged exposure to heat, tension, steam, moisture, and repeated bending over rolls and cylinders.

What Does a Dryer Fabric Actually Do?

The dryer fabric does not absorb water in the same way as a press felt.

Instead, it holds the sheet against heated dryer cylinders and provides controlled support as water evaporates from the paper. Its permeability allows moist air to escape rather than remaining trapped between fabric and sheet.

Its major functions include:

• Supporting the sheet through the dryer section

• Maintaining cylinder contact

• Stabilizing the sheet at high speed

• Supporting moisture evaporation

• Allowing ventilation through the fabric structure

• Reducing flutter and sheet instability

• Withstanding elevated temperature

• Resisting hydrolysis and mechanical wear

• Providing reliable seam performance

Air permeability is therefore one of the most important dryer-fabric parameters.

If permeability is too low, ventilation can be restricted and moisture removal may suffer. If it is too high for the application, sheet stability or drying uniformity may be affected.

Main Dryer Fabric Types

Several structures are commonly used.

Spiral Dryer Fabric

Spiral dryer fabric is formed from interconnected polyester spiral loops rather than a conventional woven warp-and-weft structure.

Its open construction provides high air permeability and good resistance to contamination. The smooth surface and lack of conventional woven intersections can also simplify cleaning.

Different spiral-loop sizes provide different permeability levels. Larger loops generally create a more open structure, while smaller loops provide greater sheet support.

Spiral fabrics can be useful where high ventilation or contamination resistance is important.

Round-Yarn Woven Dryer Fabric

Traditional woven dryer fabrics can use round polyester monofilaments.

These fabrics provide controlled permeability and a defined woven structure. Different weave designs can be selected according to machine speed, paper grade, stability, and drying requirements.

Flat-Yarn Dryer Fabric

Flat-yarn dryer fabrics use yarns with a rectangular rather than circular cross-section in parts of the weave.

The flatter yarn geometry can create a smoother fabric surface and increase contact area while allowing fabric designers to control permeability and dimensional stability.

These designs can be used on medium- and high-speed paper machines where sheet support and seam performance are important.

Forming Fabric vs Press Felt vs Dryer Fabric

Although the three products are all paper machine clothing, their process functions differ substantially.

This is why purchasing paper machine clothing simply by width and length is inadequate. Each clothing type has a different engineering role.

How Do the Three Clothing Types Work Together?

Paper production is fundamentally a progressive water-removal process.

The forming section removes water while fibers are being organized into a continuous sheet. Because the stock begins extremely dilute, forming fabric handles a very large amount of water relative to the amount of fiber.

The press section then removes water mechanically. Removing an additional unit of water in the press section is generally more energy-efficient than evaporating that same water later with steam. Good press felt performance can therefore reduce the thermal load placed on the dryer section.

The dryer section removes the remaining water through heat transfer and evaporation. Dryer fabric helps maintain sheet contact and ventilation during this process.

The three clothing stages can therefore be viewed as:

Forming Fabric → Initial Dewatering and Sheet Formation

Press Felt → Mechanical Dewatering and Web Support

Dryer Fabric → Thermal Drying and Sheet Stabilization

Performance losses in an early stage can increase cost later.

If forming drainage is poor, more water reaches the press section. If press felt dewatering is poor, the sheet enters the dryer section wetter and requires additional steam. A paper mill seeking to reduce drying energy should therefore investigate forming and pressing performance as well as the steam system.

What Performance Properties Matter for Paper Machine Clothing?

Different clothing types emphasize different specifications, but several properties recur across all three.

Permeability

Permeability determines how readily water or air can move through the clothing.

For forming fabric, it influences drainage. For press felt, it affects water movement and conditioning. For dryer fabric, air permeability influences ventilation and drying.

Higher permeability is not automatically better. The correct value depends on the machine position and paper grade.

Dimensional Stability

The clothing must remain stable across the full machine width while operating under tension.

Excessive elongation, narrowing, distortion, or uneven tension can cause wrinkles, poor tracking, and sheet-quality problems.

Surface Uniformity

The clothing surface contacts or supports the paper sheet.

Irregularities can produce marks, uneven formation, or surface defects. Fine paper grades generally require tighter control of clothing surface characteristics.

Wear Resistance

All paper machine clothing is consumable.

Forming fabrics experience abrasion against dewatering elements. Press felts experience millions of compression cycles. Dryer fabrics repeatedly flex around rolls while exposed to heat.

The clothing must maintain useful properties throughout a reasonable service interval rather than only when new.

Cleanability

Contamination progressively changes permeability and surface behavior.

A fabric or felt that is difficult to clean may lose performance long before it reaches its mechanical wear limit.

Why Does Paper Grade Change Clothing Selection?

Different paper grades have different fiber furnishes, basis weights, surface-quality targets, machine speeds, fillers, additives, and drying requirements.

Packaging paper made from recovered fiber can expose forming fabrics and press felts to high levels of stickies and contamination. The clothing therefore needs good cleanability and stability under relatively demanding stock conditions.

Fine printing and writing grades may place greater emphasis on formation, sheet smoothness, and low clothing marking.

Tissue machines use lightweight sheets and high operating speeds. Clothing must support delicate sheets while maintaining rapid water removal.

Pulp board and heavy board create different water loads and mechanical forces.

No one forming fabric, press felt, or dryer fabric is optimal for all these applications.

A supplier therefore needs process data rather than only machine dimensions.

How Does Machine Speed Affect Clothing Design?

Increasing machine speed reduces the amount of time available for each water-removal operation.

In the forming section, water must drain within a shorter residence time. The forming fabric must remain stable while interacting with foils, suction boxes, and other dewatering elements at higher speed.

In the press section, the felt repeatedly enters press nips at higher frequency. Dynamic stability, water handling, and resistance to compaction become increasingly important.

In the dryer section, sheet flutter and ventilation become more challenging. Dryer fabric needs sufficient dimensional stability and suitable permeability to maintain sheet control.

High speed also magnifies small mechanical problems.

Minor roll misalignment that is manageable at low speed can produce severe clothing tracking problems at high speed. Small fabric defects can develop rapidly, and unstable tension can become more damaging.

Clothing design, guiding, tensioning, and machine alignment therefore become more closely linked as speed increases.

Why Is Paper Machine Clothing Cleaning Important?

All three clothing types gradually collect contaminants.

Forming fabrics can collect fibers, fines, fillers, pitch, stickies, chemical deposits, and biological material. Press felts can accumulate fines and fillers inside their batt and base structure. Dryer fabrics can collect fibers, dust, pitch, and other deposits that affect ventilation and sheet contact.

A forming fabric cleaner or other clothing-cleaning system uses showers and nozzles to remove deposits before they significantly reduce performance.

Sun Hong also notes that regular cleaning of forming fabrics, press felts, and dryer fabrics helps prevent pore blockage and loss of dewatering performance.

The cleaning system should match the clothing type. A high-pressure needle shower that is appropriate for one forming fabric position may not be ideal for every felt or dryer-fabric location.

Cleaning should also be preventative.

Waiting until clothing is severely plugged often requires more aggressive cleaning and may not completely restore original permeability.

How Does Upstream Stock Preparation Affect Clothing?

Paper machine clothing begins interacting with stock at the forming section, but many contamination problems originate further upstream.

A pressure screen removes shives, plastics, fiber bundles, and other contaminants from pulp before it reaches the paper machine. Cleaners can remove heavy or light contaminants, while other stock-preparation equipment controls furnish quality and fiber condition.

If upstream separation is inadequate, additional contaminants reach the headbox and forming fabric.

This creates a sequence:

Stock Preparation → Pressure Screening → Headbox → Forming Fabric

Better upstream cleanliness can reduce contamination load on the clothing, but pressure screening cannot remove every dissolved adhesive, colloidal substance, filler particle, or chemical deposit. Clothing cleaning remains necessary even when stock preparation is performing correctly.

This is why recurring forming fabric contamination should not automatically be treated as a shower problem. Mills should also investigate furnish quality, chemical balance, screening efficiency, white-water conditions, and microbial control.

How Do Guiding and Tensioning Affect Paper Machine Clothing?

Even correctly designed clothing will fail prematurely if it does not run in the correct position.

Forming fabrics, press felts, and dryer fabrics travel continuously around multiple rolls. Small alignment differences can cause the clothing to drift sideways.

Pneumatic guiders can use an air bellow to move a guide roll and correct this lateral deviation. Tensioning equipment maintains appropriate clothing tension as the fabric or felt changes dimension during operation.

Too little tension can result in slipping, wrinkles, unstable running, and poor sheet support. Too much tension increases mechanical stress on clothing, bearings, rolls, seams, and machine frames.

The target is therefore controlled tension rather than maximum tension.

Guiding, tensioning, and cleaning work together:

Cleaning maintains permeability.

Guiding maintains lateral position.

Tensioning maintains mechanical stability.

These systems can have as much influence on clothing service life as the original fabric specification.

How Should Mills Select Paper Machine Clothing?

The first step is identifying the exact machine position.

A mill should not request simply “forming fabric” or “press felt.” Two positions on the same machine may require different designs.

For each position, provide:

Existing operating data can be especially useful.

If a mill's current forming fabric has good sheet formation but poor service life, the next design should not sacrifice formation simply to increase wear resistance. If a press felt provides good dewatering when new but compacts rapidly, void-volume retention and conditioning should be investigated.

The purpose of clothing selection is to solve the actual operating limitation.

Common Paper Machine Clothing Problems

Different clothing types develop different symptoms, but several recurring problems can be traced to incorrect selection or operating conditions.

These symptoms should be diagnosed systematically.

Replacing clothing with the same specification without identifying the cause can reproduce the same failure.

For example, repeated edge damage may indicate a guiding or alignment problem rather than poor fabric quality. Rapid forming-fabric plugging may indicate stock contamination or inadequate cleaning. Poor dryer-fabric life can result from temperature, hydrolysis, seam problems, or mechanical abrasion.

How Are Paper Machine Clothing Types Maintained?

Forming fabrics require regular shower cleaning, inspection for wear, seam or edge checks, and monitoring of drainage performance.

Press felts require continuous conditioning because their internal structure can retain water, fibers, and fillers. Vacuum systems and showers help keep void volume available. Felt permeability, moisture profile, compaction, and surface condition should be monitored.

Dryer fabrics require cleaning, tension control, seam inspection, and attention to heat and contamination. Deposits can reduce permeability and interfere with ventilation.

For all clothing types, operators should regularly inspect:

• Running position

• Tension

• Edge condition

• Seam condition

• Surface damage

• Contamination

• Permeability changes

• Shower performance

• Roll alignment

• Guide response

Maintenance should focus on trends rather than waiting for visible failure.

Gradual loss of drainage, increasing vacuum demand, changing moisture profile, or rising steam consumption can indicate clothing deterioration before physical damage becomes obvious.

Which Paper Machine Clothing Type Is Most Important?

There is no single most important type because each performs a process function that the others cannot replace.

The forming fabric determines how the sheet begins. If formation and initial drainage are poor, later sections cannot fully correct the resulting structure.

Press felt has a major influence on mechanical dewatering. Effective pressing reduces the amount of moisture that must later be evaporated, making it important for energy efficiency.

Dryer fabric controls sheet support and ventilation during the final major water-removal stage. Poor dryer-fabric performance can limit machine speed and increase steam demand.

A useful way to view their roles is:

Forming Fabric = Build the Sheet

Press Felt = Remove Water Mechanically

Dryer Fabric = Stabilize and Dry the Sheet

Paper-machine performance depends on the sequence functioning as one system.

What Should Buyers Compare When Purchasing Paper Machine Clothing?

Price per square meter should not be the only comparison.

The lower-priced clothing can become more expensive if it has shorter service life, poorer drainage, more sheet defects, or greater downtime.

Buyers should compare:

• Clothing structure

• Raw materials

• Permeability

• Thickness

• Basis weight

• Yarn specification

• Seam design

• Surface characteristics

• Dimensional stability

• Wear resistance

• Cleaning requirements

• Recommended machine speed

• Application position

• Expected operating conditions

• Technical support

For press felt, base structure and batt design need additional attention.

For forming fabric, paper-side support and drainage properties are critical.

For dryer fabric, permeability, heat resistance, stability, and seam construction should be examined carefully.

The correct clothing is the one that produces the best overall machine performance, not necessarily the lowest initial purchasing cost.

Why Choose Sun Hong Group?

Sun Hong Group was established in 2010 in Xuzhou, Jiangsu Province. Paper machine clothing was one of its original product areas, with early manufacturing focused on forming fabrics, press felts, and dryer fabrics.

The company's product scope later expanded to stock-preparation equipment, screen baskets, dewatering elements, spray nozzles, doctor blades, rolls, rotary joints, cleaning systems, and other pulp and paper machine components.

This broader product range is relevant because paper machine clothing performance depends on surrounding systems. A forming fabric interacts with dewatering elements, showers, guide rolls, and stock quality. A press felt interacts with press rolls, vacuum equipment, cleaners, and tensioning systems. A dryer fabric operates with dryer cylinders, guide rolls, ventilation, and thermal conditions.

Sun Hong can therefore supply clothing while also considering related machine components and process conditions.

For new or replacement clothing, customers should provide the paper grade, machine type, machine width, operating speed, basis weight, furnish, clothing position, current clothing specification, permeability requirement, and current operating problems. Existing fabric or felt samples, drawings, and machine information can further improve selection accuracy.

Conclusion

The three main paper machine clothing types are forming fabric, press felt, and dryer fabric, and each corresponds to one major stage of papermaking.

The forming fabric receives stock from the headbox, supports fibers, establishes the initial sheet, and removes a large amount of water through drainage and vacuum. Its structure must balance fiber support, permeability, surface quality, dimensional stability, wear resistance, and cleanability.

The press felt supports the wet sheet through the press section and removes additional water under mechanical pressure. Its base structure and needled batt must provide sufficient void volume, pressure distribution, permeability, surface uniformity, and resistance to repeated compression.

The dryer fabric supports and stabilizes the sheet as steam-heated cylinders remove the remaining moisture. Air permeability, heat resistance, seam performance, dimensional stability, and sheet contact become particularly important in this section.

These three clothing types should not be selected independently. Efficient forming reduces the load on pressing, efficient pressing reduces the thermal load on drying, and correct cleaning, guiding, tensioning, and upstream pressure screen performance help all three maintain stable operation.

Sun Hong Group supplies forming fabrics, press felts, dryer fabrics, and related paper-machine components. To select suitable clothing, provide the paper grade, machine type, width, speed, basis weight, furnish, clothing position, current specification, permeability requirement, and existing operating problems. This allows the clothing structure to be matched to the actual paper-machine duty rather than selected only by dimensions or price.

FAQ

What are the three main types of paper machine clothing?

The main types are forming fabric, press felt, and dryer fabric. They are used in the forming, press, and dryer sections respectively.

What does a forming fabric do?

A forming fabric supports fibers from the headbox, allows water to drain through the fabric, helps form a uniform wet sheet, and transports the sheet toward the press section.

What does a press felt do?

A press felt supports the wet paper sheet inside the press section and receives water removed by mechanical pressure. It also helps distribute nip pressure and protect the sheet from marking.

What does a dryer fabric do?

A dryer fabric carries and stabilizes the paper through the dryer section, holds the sheet against heated cylinders, and allows ventilation that supports moisture evaporation.

What is the difference between forming fabric and press felt?

Forming fabric is mainly a woven synthetic fabric used for initial drainage and sheet formation. Press felt normally combines a structural base with needled batt fibers and is designed for mechanical press dewatering.

What is the difference between press felt and dryer fabric?

Press felt receives liquid water squeezed from the wet sheet inside press nips. Dryer fabric primarily supports the sheet while heat evaporates the remaining moisture.

What forming fabric structures are available?

Common designs include single-layer, 1.5-layer, 2.5-layer, and triple-layer forming fabrics. The correct design depends on machine speed, paper grade, furnish, drainage, and surface-quality requirements.

What types of press felt are available?

Press felts can use single-, double-, triple-, or laminated base structures and may be designed for conventional presses, shoe presses, tissue machines, packaging paper, cultural paper, pulp board, and specialty grades.

What types of dryer fabric are commonly used?

Common types include spiral dryer fabrics, round-yarn woven fabrics, and flat-yarn woven dryer fabrics. Different structures provide different air permeability, stability, and sheet-support characteristics.

How does paper machine clothing affect energy consumption?

Efficient forming and press dewatering reduce the amount of water that must be evaporated in the dryer section. Good clothing performance can therefore reduce vacuum, steam, and overall energy requirements.

Why does paper machine clothing need regular cleaning?

Fibers, fines, fillers, pitch, stickies, chemicals, and other deposits can block clothing openings. Cleaning maintains permeability, dewatering performance, sheet quality, and service life.

Does pressure screening affect paper machine clothing?

Yes. A pressure screen removes certain contaminants from pulp before the stock reaches the paper machine. Better stock cleanliness can reduce contaminant loading on forming fabric and downstream clothing, although clothing still requires regular cleaning.

What information is needed when ordering paper machine clothing?

Provide paper grade, machine type, machine speed, machine width, basis weight, furnish, clothing position, current clothing specification, permeability, operating conditions, and any problems such as poor drainage, marking, wear, contamination, or tracking.