MH-CHP
MINGHUNG
1. Continuous Flat Press vs. Multi-Daylight Press
Feature | Continuous Flat Press | Multi-Daylight Press |
Working Principle | Steel belts continuously compress mat through heated zones | Batch pressing with intermittent loading/unloading |
Production Speed | 60-120 m/min | Cycle time: 8-12 min/layer |
Thickness Uniformity | Deviation ≤±0.1mm; consistent density | Deviation ±0.3mm; lower edge density |
Energy Consumption | 30% energy savings (heat recovery + continuous operation) | High start-stop energy loss |
Suitable Scale | ≥200,000 m³/year | 50,000-150,000 m³/year |
2. Core Components of Continuous Press
2.1 Steel Belt System
Dual Belts: 1.2-1.8mm alloy steel belts (300°C resistant), laser-textured surface for fiber grip.
Tensioning: Hydraulic auto-tension (15-25 kN/m) to prevent misalignment.
Tracking System: Infrared sensors trigger hydraulic correction if deviation >2mm.
2.2 Heating Platen Modules
Zoned Control: 30-60 independent zones with individual pressure/temperature.
Pressure Profile:
High-Pressure Zone (entry): 3.5-5.0 MPa (rapid compression).
Medium-Pressure Zone: 1.5-2.5 MPa (adhesive curing).
Low-Pressure Zone (exit): 0.5-1.0 MPa (stress relief).
Temperature Gradient: 140-160°C (entry) → 100-120°C (exit).
2.3 Heat Recovery System
Thermal Medium: Thermal oil (280°C max) or steam (1.6-2.5 MPa).
Energy Efficiency:
Exhaust heat recovery (pre-dries fibers).
Spiral flow channels (30% higher heat exchange).
3. Key Process Parameters
Main machinery
mat-froming machine
pre-pressing machine
continuoius hot pressing for MDF
edge trimming and cutting machine
Critical Controls:
1. Forming Uniformity: Air forming deviation <±5%.
2. Temperature:
UF adhesive: 140-150°C | MDI: 110-130°C (prevents pre-cure).
3. Press Time:
4-6 seconds/mm thickness (e.g., 18mm board requires ≈90m press length).
4. Technical advantages
Quality improvement:
Eliminate the "edge effect" (the edge density of traditional presses is 20% lower);
More uniform formaldehyde release (CARB P2 compliance rate is 100%).
Cost optimization:
Reduce the amount of sanding (sanding allowance is only 0.1-0.2mm vs. 0.5mm for multi-layer machines);
Save 60% of labor (fully automated control).
Formaldehyde-Free Adhesive Types
Adhesive Type | Primary Composition | Characteristics |
MDI Adhesive | Polymeric isocyanate | Zero formaldehyde, superior water resistance, high bonding strength; higher cost, requires specialized equipment. |
Soy Protein Adhesive | Modified plant protein | Bio-based renewable material; demands precise process control, requires mildew resistance enhancement. |
Lignin Adhesive | Extracted from pulping waste | Eco-friendly waste utilization; requires performance modification. |
Modified PVA Adhesive | Polyvinyl alcohol + crosslinker | Low toxicity; must use formaldehyde-free crosslinkers (e.g., citric acid). |
1. CARB Certification Stages
Standard Tier | Formaldehyde Limit | Applicable Products |
CARB P1 | ≤0.08 ppm | General indoor panels (implemented 2009). |
CARB P2 | ≤0.05 ppm | Strictly regulated products (2010 upgrade). |
ULEF | ≤0.01 ppm | Ultra-low emissions (near natural wood levels). |
NAF | Non-detectable | No Added Formaldehyde (highest certification). |
2. Certification Requirements
Supply Chain Traceability: Full oversight from adhesive suppliers to board manufacturers.
Quarterly Testing: Third-party lab verification (ASTM E1333 or D6007 large chamber method).
Production Records: Adhesive ratios, pressing parameters, storage logs.
1. Fiber Preparation
Moisture content: 8-10% (excess causes blistering; deficiency reduces bond strength).
Fiber morphology: Aspect ratio >20 (avoid excessive fines).
2. Adhesive Application
MDI usage: 4-6% (vs. 8-12% for urea-formaldehyde adhesives).
Bio-adhesive enhancers: e.g., nanocellulose (improves water resistance).
3. Post-Processing
Conditioning: 24-48 hrs at 25°C/60% RH to release internal stress.
Edge Sealing: Immediate sealing after cutting to prevent moisture deformation.
Whatsapp: +8618769900191 +8615589105786 +8618954906501
Email: osbmdfmachinery@gmail.com
1. Continuous Flat Press vs. Multi-Daylight Press
Feature | Continuous Flat Press | Multi-Daylight Press |
Working Principle | Steel belts continuously compress mat through heated zones | Batch pressing with intermittent loading/unloading |
Production Speed | 60-120 m/min | Cycle time: 8-12 min/layer |
Thickness Uniformity | Deviation ≤±0.1mm; consistent density | Deviation ±0.3mm; lower edge density |
Energy Consumption | 30% energy savings (heat recovery + continuous operation) | High start-stop energy loss |
Suitable Scale | ≥200,000 m³/year | 50,000-150,000 m³/year |
2. Core Components of Continuous Press
2.1 Steel Belt System
Dual Belts: 1.2-1.8mm alloy steel belts (300°C resistant), laser-textured surface for fiber grip.
Tensioning: Hydraulic auto-tension (15-25 kN/m) to prevent misalignment.
Tracking System: Infrared sensors trigger hydraulic correction if deviation >2mm.
2.2 Heating Platen Modules
Zoned Control: 30-60 independent zones with individual pressure/temperature.
Pressure Profile:
High-Pressure Zone (entry): 3.5-5.0 MPa (rapid compression).
Medium-Pressure Zone: 1.5-2.5 MPa (adhesive curing).
Low-Pressure Zone (exit): 0.5-1.0 MPa (stress relief).
Temperature Gradient: 140-160°C (entry) → 100-120°C (exit).
2.3 Heat Recovery System
Thermal Medium: Thermal oil (280°C max) or steam (1.6-2.5 MPa).
Energy Efficiency:
Exhaust heat recovery (pre-dries fibers).
Spiral flow channels (30% higher heat exchange).
3. Key Process Parameters
Main machinery
mat-froming machine
pre-pressing machine
continuoius hot pressing for MDF
edge trimming and cutting machine
Critical Controls:
1. Forming Uniformity: Air forming deviation <±5%.
2. Temperature:
UF adhesive: 140-150°C | MDI: 110-130°C (prevents pre-cure).
3. Press Time:
4-6 seconds/mm thickness (e.g., 18mm board requires ≈90m press length).
4. Technical advantages
Quality improvement:
Eliminate the "edge effect" (the edge density of traditional presses is 20% lower);
More uniform formaldehyde release (CARB P2 compliance rate is 100%).
Cost optimization:
Reduce the amount of sanding (sanding allowance is only 0.1-0.2mm vs. 0.5mm for multi-layer machines);
Save 60% of labor (fully automated control).
Formaldehyde-Free Adhesive Types
Adhesive Type | Primary Composition | Characteristics |
MDI Adhesive | Polymeric isocyanate | Zero formaldehyde, superior water resistance, high bonding strength; higher cost, requires specialized equipment. |
Soy Protein Adhesive | Modified plant protein | Bio-based renewable material; demands precise process control, requires mildew resistance enhancement. |
Lignin Adhesive | Extracted from pulping waste | Eco-friendly waste utilization; requires performance modification. |
Modified PVA Adhesive | Polyvinyl alcohol + crosslinker | Low toxicity; must use formaldehyde-free crosslinkers (e.g., citric acid). |
1. CARB Certification Stages
Standard Tier | Formaldehyde Limit | Applicable Products |
CARB P1 | ≤0.08 ppm | General indoor panels (implemented 2009). |
CARB P2 | ≤0.05 ppm | Strictly regulated products (2010 upgrade). |
ULEF | ≤0.01 ppm | Ultra-low emissions (near natural wood levels). |
NAF | Non-detectable | No Added Formaldehyde (highest certification). |
2. Certification Requirements
Supply Chain Traceability: Full oversight from adhesive suppliers to board manufacturers.
Quarterly Testing: Third-party lab verification (ASTM E1333 or D6007 large chamber method).
Production Records: Adhesive ratios, pressing parameters, storage logs.
1. Fiber Preparation
Moisture content: 8-10% (excess causes blistering; deficiency reduces bond strength).
Fiber morphology: Aspect ratio >20 (avoid excessive fines).
2. Adhesive Application
MDI usage: 4-6% (vs. 8-12% for urea-formaldehyde adhesives).
Bio-adhesive enhancers: e.g., nanocellulose (improves water resistance).
3. Post-Processing
Conditioning: 24-48 hrs at 25°C/60% RH to release internal stress.
Edge Sealing: Immediate sealing after cutting to prevent moisture deformation.
Whatsapp: +8618769900191 +8615589105786 +8618954906501
Email: osbmdfmachinery@gmail.com
