Forming Fabric Structure Comparison
The structure of a forming fabric directly determines its drainage capacity, fiber retention, sheet quality, and service life. This guide compares all major structures.
Structure Overview
Single Layer
- One set of warp + one set of weft yarns
- Simplest construction, lowest cost
- Best drainage (500-800 CFM) but lowest fiber support (FSI 50-80)
- Best for: Low-speed machines, heavy grades (200+ gsm)
Double Layer
- Two layers of weft yarns sharing one warp system
- Good balance of drainage (400-650 CFM) and support (FSI 80-120)
- The industry workhorse for mid-speed machines
2.5 Layer
- Extra weft on the top side for improved sheet quality
- FSI 100-140, CFM 350-550
- A cost-effective upgrade from double layer
Triple Layer
- Separate top (fine) and bottom (wear-resistant) layers, bound together
- Excellent fiber support (FSI 130-170)
- Best for: High-speed machines, quality-critical grades
SSB (Sheet Support Binder)
- Premium triple layer variant with paired binder wefts
- Highest FSI (150-200+), longest life (60-150 days)
- Reduced sheet marking and improved first-pass retention
- Best for: High-speed tissue, fine paper, demanding applications
Key Metrics Comparison
| Structure | FSI | CFM | Mesh | Life (days) | Relative Cost |
|---|---|---|---|---|---|
| Single Layer | 50-80 | 500-800 | 25-55 | 30-60 | 1.0x |
| Double Layer | 80-120 | 400-650 | 35-65 | 45-90 | 1.3x |
| 2.5 Layer | 100-140 | 350-550 | 45-75 | 45-90 | 1.5x |
| Triple Layer | 130-170 | 250-500 | 50-85 | 60-120 | 1.8x |
| SSB | 150-200+ | 250-450 | 60-95 | 60-150 | 2.2x |
Selection Decision Tree
- Speed < 300 m/min, heavy grades → Single or double layer
- Speed 300-600 m/min, packaging/fine paper → Double or 2.5 layer
- Speed > 600 m/min, quality-critical → Triple or SSB
- Tissue, highest quality → SSB only
Total Cost Comparison
While SSB costs 2.2x more than single layer, it typically lasts 3-5x longer and delivers 5-15% better FPR. For high-speed machines, the cost per ton of SSB is often lower than single layer despite the higher purchase price.
PAPTEX Forming Fabrics
PAPTEX offers the complete range: SF (single), DL (double), DLH (2.5), LW (triple/SSB), and SSB series. Our PET/PA hybrid designs extend life 20-35% on abrasive furnishes.
