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 |
