Paper Grade Knowledge

How Different Paper Grades Require Different PMC Configurations

Each paper grade has unique technical requirements for forming fabrics, press felts, and dryer fabrics.

Packaging Paper (Kraft / Liner / Corrugated)

The highest-volume paper grade, including linerboard, corrugating medium, and sack kraft.

Key Characteristics:

• Basis weight: 80-200+ gsm
• High filler content (10-25% in recycled grades)
• Often high recycled fiber content
• Demanding wear environment

Forming Fabric Requirements:

• Triple-layer or SSB construction for high wear resistance
• Mesh: 35-55 threads/cm
• CFM: 400-650
• PA yarns strategically placed in bottom CD wear zones
• FSI >130 for quality grades
• Life target: 60-120 days

Press Felt Requirements:

• BOM or laminated construction for heavy-duty applications
• Weight: 1500-1800 g/m²
• High void volume for water handling with high filler content
• Good compaction resistance
• Life target: 30-60 days (1st press), 45-75 days (2nd/3rd)

Dryer Fabric Requirements:

• Flat yarn construction preferred
• CFM: 500-800
• High contact area (60-75%)
• Temperature: Standard PET (150°C continuous) usually adequate
• Life target: 60-150 days

Culture Paper (Woodfree / Fine Paper)

Includes copy paper, offset printing paper, and coated grades.

Key Characteristics:

• Basis weight: 40-120 gsm
• Lower filler content (15-25%)
• High quality surface requirements
• Often higher speeds

Forming Fabric Requirements:

• Triple-layer or SSB strongly recommended
• Mesh: 50-70 threads/cm
• CFM: 300-450
• FSI >150 for minimal sheet marking
• High fiber support for smooth surface
• Life target: 60-150 days

Press Felt Requirements:

• BOM construction for modern machines
• Weight: 1400-1700 g/m²
• Fine surface batt layer for sheet quality
• Good water handling for moderate filler loads
• Life target: 45-90 days

Dryer Fabric Requirements:

• Flat yarn standard
• CFM: 400-650
• Smooth surface to prevent sheet marking
• Life target: 90-180 days

Tissue Paper

The most demanding forming environment — extremely lightweight sheets at high speed.

Key Characteristics:

• Basis weight: 14-22 gsm (extremely light)
• Very high speeds: up to 2200 m/min
• Requires high-quality surface finish
• Crescent former or twin-wire configuration common

Forming Fabric Requirements:

• SSB construction mandatory for quality grades
• Mesh: 70-95 threads/cm (very fine)
• CFM: 250-400
• FSI >180 recommended
• Maximum fiber support for ultra-lightweight sheet
• Anti-static may be required
• Life target: 45-90 days

Press Felt Requirements:

• Needle punch construction common (Yankee machine)
• Weight: 1100-1400 g/m²
• Fine surface for sheet quality on Yankee dryer
• Good water handling despite lighter weight
• Life target: 30-55 days

Dryer Fabric Requirements:

• Spiral construction common (complex threading in tissue machines)
• CFM: 300-500
• Anti-static strongly recommended
• Through-air drying (TAD) fabrics are specialty products
• Life target: 50-100 days

Kraft Paper (Sack / Specialty Kraft)

Heavy-duty grades for industrial applications.

Key Characteristics:

• Basis weight: 70-200 gsm
• High strength requirements (long fiber)
• Often higher temperatures in dryer section
• May include wet-strength additives

Forming Fabric Requirements:

• Triple-layer construction
• Mesh: 35-55 threads/cm
• CFM: 450-700
• Heavy-duty wear package (PA in CD)
• Life target: 50-100 days

Press Felt Requirements:

• BOM or heavy laminated construction
• Weight: 1500-1800 g/m²
• High void volume for long-fiber water handling
• Life target: 30-60 days

Dryer Fabric Requirements:

• Flat yarn construction
• CFM: 450-700
• May require HR-PET for higher dryer temperatures
• Life target: 45-90 days

Recycled Board / Containerboard

Heavy basis weight, high contaminant load.

Key Characteristics:

• Basis weight: 150-400+ gsm
• Very high filler and contaminant content
• Lower speeds typically
• Heavy wear environment

Forming Fabric Requirements:

• Single or double-layer may be acceptable (cost-sensitive)
• Mesh: 25-40 threads/cm (coarse)
• CFM: 500-800
• PA yarns essential in wear zones
• Life target: 30-60 days

Press Felt Requirements:

• Laminated or heavy needle punch
• Weight: 1500-1800 g/m²
• Open structure to resist plugging
• Frequent chemical cleaning needed
• Life target: 30-60 days

Dryer Fabric Requirements:

• Spiral or flat yarn
• CFM: 600-1000 (high — aids moisture removal)
• Life target: 45-90 days

Grade Selection Quick Reference

Paper Grade	Basis Weight	Forming Fabric	Press Felt	Dryer Fabric
Tissue	14-22 gsm	SSB, 70-95 mesh	NP, 1100-1400 g/m²	Spiral, CFM 300-500
Culture	40-120 gsm	Triple/SSB, 50-70 mesh	BOM, 1400-1700 g/m²	Flat, CFM 400-650
Packaging	80-200 gsm	Triple/SSB, 35-55 mesh	BOM/Lam, 1500-1800 g/m²	Flat, CFM 500-800
Kraft	70-200 gsm	Triple, 35-55 mesh	BOM/Lam, 1500-1800 g/m²	Flat, CFM 450-700
Recycled Board	150-400+ gsm	Single/Double, 25-40 mesh	Lam/NP, 1500-1800 g/m²	Spiral/Flat, CFM 600-1000