1. Debarker
Utilizes mechanical roller or hydraulic cutterhead designs. As the log rotates and feeds through, high-strength alloy tools or hydraulic pressure precisely remove bark, mud, and other impurities. This is not just for aesthetics but crucial to prevent contaminants, molds, and chemicals on the bark from polluting the veneer, wearing out peeling blades, and affecting bond strength in subsequent processes.
Key Features:
High-Efficiency Cleaning: Bark removal rate exceeds 95%, adaptable to different species (e.g., pine, eucalyptus, poplar) and log diameters.
Automated Feeding: Often integrated with log loading systems for continuous automated operation.
Eco-Friendly Design: Equipped with bark and wood chip recovery systems to convey waste to energy plants as fuel.
2. Log Centering Machine
This is key to improving yield. Moving beyond manual experience, modern high-end lines use laser scanning or X-ray imaging to create a 3D model of the log's external shape and internal defects (e.g., heart rot, large knots). A computer calculates the optimal rotational centerline to obtain the maximum volume of high-quality veneer and directly transmits this data to the veneer lathe.
Key Features:
High-Precision Scanning: Laser probes accurately model log geometry.
Intelligent Calculation: Built-in algorithms optimize the centerline for maximum output of quality veneer.
Data Linkage: Seamless integration with the veneer lathe control system for intelligent production.
3. Veneer Lathe
The centered log is gripped between massive spindles and driven at high speed. Simultaneously, a cutting carriage holding a precision-ground blade advances towards the rotating log at a constant linear speed, peeling it like a "pencil sharpener" into a continuous ribbon of veneer at a predetermined thickness. Its core function is to ensure高度一致性 (high consistency) of veneer thickness across the entire log and between different logs.
Key Features:
CNC Servo Drive: Uses servo motors and CNC systems to control carriage feed, achieving precision up to ±0.05mm.
Dual Spindle System: A large-diameter spindle grips the main log; a smaller-diameter spindle extends automatically as the log tapers to continue gripping, reducing the core diameter and improving wood utilization.
Real-Time Parameter Adjustment: Veneer thickness and peeling speed can be set and adjusted via touchscreen.
4. Veneer Clipper
Positioned right after the lathe, the high-speed veneer ribbon passes over it. Using photoelectric sensors or CCD cameras, it detects defects (e.g., knots, splits, discoloration) in real-time. Based on preset dimensions and defect recognition, it drives massive hydraulic shears or rotary knives to perform high-speed, precise cuts, trimming the good sections into rectangular sheets and automatically sorting them.
Key Features:
Machine Vision Recognition: High-resolution cameras ensure accurate defect identification and sorting quality.
High-Speed, High-Precision Cutting: High shearing frequency with clean, splinter-free edges.
Automatic Sorting: Can integrate with conveyors to automatically stack veneer of different grades and sizes into different piles.
5. Veneer Dryer
Green veneer from the lathe has very high moisture content (60%-100%) and must be dried to the process requirement of 8%-12%. Typically multi-tier mesh belt or roller type, it uses hot air (heated by steam, thermal oil, or gas) forced to circulate above and below the veneer to evaporate moisture. Drying temperature and air speed are precisely controlled in multiple zones to prevent veneer warping or becoming too dry and brittle.
Key Features:
Zoned Temperature & Humidity Control: Drying and exhaust zones are independently controlled to optimize the drying curve and ensure quality.
Efficient Air Circulation: Specially designed nozzles ensure even heat distribution and high drying efficiency.
Energy-Saving Design: Often includes heat recovery systems to significantly reduce energy consumption.
6. Veneer Splicer
Joins dried small-format veneer sheets (primarily for core and back layers) into large panels. Main types:
Finger Joint Splicer: Mills finger joints into the veneer edges, applies glue, and joins them longitudinally into long strips.
Cross Feed Splicer: Aligns veneer ends and joins them at the butts using a hot melt glue-coated nylon thread or ultrasonic welding on the back.
Key Features:
Automated Feeding: Automatic alignment, gluing, pressing, and length cutting.
High-Strength Joint: The spliced veneer has high strength, minimally affecting subsequent use.
7. Glue Spreader
Applies adhesive (e.g., UF, PF resin) evenly onto the veneer surface via a glue bath and precision metering rolls. Types include four-roll and two-roll spreaders, allowing precise control of spread volume (g/m²). Modern spreaders feature automatic glue monitoring and compensation systems, ensuring consistent application on every sheet, which is critical for controlling panel quality and formaldehyde emissions.
Key Features:
Precision Metering Rolls: Hard chrome-plated steel rolls for high accuracy and wear resistance.
Automatic Gap Adjustment: Adjusts the roll gap based on veneer thickness for uniform spread.
Glue Recirculation System: Continuously stirs the adhesive to prevent settling and maintain consistent viscosity.
8. Layup Station / Automatic Layup Line
Assembles glued core veneers and unglued face/back veneers into a mat (panel) with alternating grain directions.
Manual Layup Station: Operators work with positioning guides. Lower efficiency but high flexibility.
Automatic Layup Line: A hallmark of high-end lines. Uses robots, suction cups, and conveyors to automatically pick and place veneers from different stacks with high precision,completely replacing manual labor, offering high efficiency and consistent, error-free mat formation.
Key Features (Automatic Line):
Machine Vision Positioning: Identifies veneer grain and orientation.
Multi-Axis Robots: High-speed, high-precision picking and placing.
Seamless Integration: Perfectly synchronized with upstream and downstream conveyors.
9. Pre-press
Before entering the hot press, the mat is cold-pressed (or slightly warmed) to initiate bonding between layers and expel air, forming a coherent mat with initial strength. This prevents the mat from collapsing during transfer and loading into the hot press and reduces the hot press's daylight opening, improving efficiency.
Key Features:
High Tonnage Pressure: Provides sufficient pressure for initial mat formation.
Belt Conveyor: Automated conveyor for mat infeed and outfeed.
Short Cycle: Pressing time is typically tens of seconds to a few minutes.
10. Loading & Unloading Machine
They are the "right and left arms" of the multi-opening hot press. The loader lifts the assembled mats layer by layer and accurately feeds them into each press opening. The unloader removes the pressed panels from each opening after the cycle and lowers them layer by layer onto the output conveyor. These are essential for achieving fully automated continuous hot pressing.
Key Features:
Layer Matching: The number of grabbing frames matches the number of press openings.
Synchronized Movement: Precisely synchronized with the press's opening/closing cycle.
High-Strength Structure: Built to withstand the weight of the entire press load, robust and durable.
11. Intelligent Thermal Oil Hot Press - The System Core
This is the value core of the entire line. Here, the mat is subjected to high temperature and high pressure, curing the adhesive and permanently bonding it into a strong plywood panel.
Thermal Oil System: Comprises a thermal oil heater (heat source), high-temperature pump (circulation power), expansion tank (compensates for volume changes), oil-gas separator, and precision piping/valves. Thermal oil is heated to 200-300°C in the heater and pumped through a sealed network of channels within the massive steel press plates, transferring heat to them.
Intelligent Temperature Control: Thermocouples embedded in each press plate monitor temperature in real-time, feeding data to the central PLC. The PLC performs independent, precise closed-loop control of each plate's temperature by adjusting oil flow, heater power, or three-way valve position, maintaining temperature uniformity within ±1-2°C.
Hydraulic System: Provides the high pressure required for pressing (often 20-30 MPa), driven by servo motors for high control accuracy and energy efficiency.
Key Features:
Extreme Temperature Uniformity: Fundamentally solves the worldwide challenge of temperature gradients in steam-heated presses, resulting in panels with consistent physical properties and minimal deformation.
Significant Energy Savings: Closed-loop system with minimal heat loss, overall thermal efficiency is >30% higher than steam systems.
Fully Automated Control: The PLC stores hundreds of pressing recipes (temperature, pressure, time curves) for one-touch recall; production data is traceable.
12. Cooling & Turning Machine
Panels exiting the hot press are very hot (>100°C) and pliable. Stacking them immediately would cause warping and accelerate adhesive aging. The cooler uses forced air circulation to rapidly reduce panel temperature, setting their shape. The turner rotates panels 180 degrees, ensuring both surfaces cool evenly and counteracting their inherent stress-induced bending tendency.
Key Features:
Forced Air Cooling System: High-capacity fans for uniform cooling.
Automated Turning: Hydraulic or servo-driven for smooth and reliable operation.
13. Calibrating Sander
After pressing, panels have thickness variations and a pre-cured, rough surface layer. The sander uses 2-4 large sanding heads (coarse, fine grit) to precision-grind both panel surfaces, achieving an exact, consistent final thickness and a smooth, flat surface, providing a perfect substrate for subsequent laminating, painting, or direct use.
Key Features:
Calibrating Sanding: CNC-controlled feed system ensures tight thickness tolerance (e.g., ±0.1mm).
Wide Belt Sanding: Processes large-format panels.
Powerful Dust Extraction: Centralized dust collection maintains a clean working environment.
14. Trimming Saw (Cross-Cut & Edge Saw)
After sanding, the irregular edges of the panel must be trimmed. This equipment consists of a set of edge saws and a set of cross-cut saws. The panel first passes the edge saws to trim the two long sides, then through the cross-cut saws to trim the ends, resulting in a finished panel with precise right angles and standardized dimensions.
Key Features:
Simultaneous Edge Trimming: Saws trim both edges simultaneously, ensuring parallel sides.
CNC Sizing: Servo motors position stops for accurate panel length and width.
High-Speed Alloy Blades: Smooth, splinter-free cuts.
This comprehensive set of equipment constitutes a technology-intensive, highly efficient, energy-saving, and automated modern plywood production system, which is the fundamental guarantee for its ability to produce high-end quality products.
Phase One: Raw Material Preparation
1. Log Debarking:
Purchased logs are fed through a Debarker to remove bark. Bark contains impurities that affect bonding quality and tool life; removing it is the first step to ensuring veneer quality.
2. Log Centering:
Debarked logs enter a Centering Machine. Laser or X-ray scanning finds the log's optimal rotational center, ensuring the subsequent peeling of the longest, most continuous, and most consistent thickness veneer ribbon, dramatically improving yield.
3. Log Soaking (Optional):
For some high-density, hardwood species, soaking and heating in water is required to soften them, reducing peeling resistance and obtaining a smoother veneer surface.
Phase Two: Veneer Production
4. Veneer Peeling:
Centered logs are mounted on a Veneer Lathe. The log rotates at high speed while a sharp blade peels it into a continuous ribbon of veneer at a predetermined thickness (e.g., 1.2mm-3.6mm). This is the core process determining veneer thickness consistency.
5. Veneer Clipping:
The continuous veneer ribbon passes through a Clipper. Using photoelectric sensors or CCD cameras, defects (e.g., knots, splits) are detected in real-time. The ribbon is sheared into full-size sheets based on preset dimensions, with defective sections automatically rejected.
6. Veneer Drying:
Green veneer has very high moisture content and must be dried in a Veneer Dryer (roller or mesh belt type). Hot air (potentially heated by the thermal oil system) reduces the moisture content precisely to the required range of 8%-12% for subsequent gluing.
7. Veneer Sorting & Patching:
Dried veneer is graded based on size and quality. Advanced production lines use Veneer Splicers to join smaller sheets into larger ones or fill minor splits with putty, maximizing material utilization.
Phase Three: Gluing & Layup
8. Veneer Gluing:
Graded veneer (primarily for core and back layers) passes through a Glue Spreader. Metering rolls apply a uniform layer of adhesive (e.g., urea-formaldehyde resin) to its surface. The glue spread volume, precisely controlled by PLC, directly affects bond strength and formaldehyde emissions.
9. Layup:
Glued veneers (cores) and unglued face/back veneers are assembled into a mat (panel) on a Layup Station, with the grain direction of adjacent layers perpendicular to each other. Automated lines use robotic arms for layup, offering high efficiency and minimal error.
Phase Four: Core Pressing & Curing
10. Pre-pressing:
The assembled mat is first fed into a Cold Press or Pre-press. Applying high pressure at room or slightly elevated temperature initiates bonding, removes air, prevents mat collapse, and reduces the hot press opening height, improving efficiency.
11. Intelligent Thermal Oil Hot Pressing:
This is the core of the entire process, where the value of the "Intelligent Temperature Control Thermal Oil System" is fully realized.
Loading: The pre-pressed mat is automatically fed into each opening of the multi-opening Hot Press by an Auto Loader.
Pressing & Curing:
Heat Source: The Thermal Oil Heater heats the thermal oil to the set temperature (e.g., above 200°C), and a high-temperature pump circulates it through internal channels within the massive steel press plates.
Intelligent Temp Control: Thermocouples embedded in the press plates monitor temperature in real-time, feeding data back to the central PLC. The PLC performs precise closed-loop control of each plate's temperature by adjusting oil flow, heater power, etc., ensuring extreme temperature uniformity across the entire plate surface (±1-2°C).
Pressing: While temperature is precisely controlled, the hydraulic system applies high pressure, rapidly curing the adhesive under heat and pressure.
Advantages: Temperature uniformity eliminates localized under or over-curing, resulting in minimal product deformation, high strength, and extremely consistent quality. The system is also energy-efficient and safe.
Unloading: After pressing is complete, an Auto Unloader removes the formed plywood panels.
Phase Five: Post-processing & Finishing
12. Cooling & Aging:
Panels exiting the press are very hot. They pass through a Cooling and Turning Machine for forced air cooling and flipping. This ensures uniform cooling, releases internal stresses, and sets the shape to prevent warping.
13. Trimming & Sanding:
A Trimming Saw cuts the rough edges to standard dimensions.
A Calibrating Sander performs precision sanding on the top and bottom surfaces, removing the pre-cured layer and thickness variations, resulting in a smooth, flat surface and exact thickness.
14. Grading & Packaging:
Finally, the finished plywood is inspected, graded according to appearance and quality standards, and then packaged, labeled, and stored.
The value of the Intelligent Temperature Control Thermal Oil System permeates the entire production process, but its core role is maximized in the hot pressing stage. Through precise temperature control and uniform heat distribution, it fundamentally solves the quality pain points of traditional heating methods. Coupled with highly automated equipment synergy, it ultimately enables high-efficiency, low-energy-consumption, high-quality plywood production.
Intelligent Temperature Control: PLC ensures precise temperature management for stable product quality.
High Efficiency & Energy Saving: The thermal oil system boasts high thermal efficiency, leading to lower operating costs.
Uniform Heating: Eliminates temperature differences in plate corners, enhancing product quality.
Automated Operation: Reduces labor requirements and increases production efficiency.
Safe & Reliable: Low-pressure system ensures stable and safe operation.
We are Shandong MINGHUNG Wood Based Panel Machinery Co.,Ltd China factory .With a strongfocus on producing high-quality machinery, we specialize in manufacturing thecomplete production line of Medium density fiberboard (MDF), High densityfiberboard (HDF),Particle board (PB), Oriented strand board (OSB) , Veneerable super strong particle board (LSB),Laminated board and veneer.
Request a Quote Today! OEM/ODM solutions available – Start your plywood business with competitive edge!
Our contacts:
Whatsapp: +8618769900191 +8615589105786 +8618954906501
Email: osbmdfmachinery@gmail.com
1. Debarker
Utilizes mechanical roller or hydraulic cutterhead designs. As the log rotates and feeds through, high-strength alloy tools or hydraulic pressure precisely remove bark, mud, and other impurities. This is not just for aesthetics but crucial to prevent contaminants, molds, and chemicals on the bark from polluting the veneer, wearing out peeling blades, and affecting bond strength in subsequent processes.
Key Features:
High-Efficiency Cleaning: Bark removal rate exceeds 95%, adaptable to different species (e.g., pine, eucalyptus, poplar) and log diameters.
Automated Feeding: Often integrated with log loading systems for continuous automated operation.
Eco-Friendly Design: Equipped with bark and wood chip recovery systems to convey waste to energy plants as fuel.
2. Log Centering Machine
This is key to improving yield. Moving beyond manual experience, modern high-end lines use laser scanning or X-ray imaging to create a 3D model of the log's external shape and internal defects (e.g., heart rot, large knots). A computer calculates the optimal rotational centerline to obtain the maximum volume of high-quality veneer and directly transmits this data to the veneer lathe.
Key Features:
High-Precision Scanning: Laser probes accurately model log geometry.
Intelligent Calculation: Built-in algorithms optimize the centerline for maximum output of quality veneer.
Data Linkage: Seamless integration with the veneer lathe control system for intelligent production.
3. Veneer Lathe
The centered log is gripped between massive spindles and driven at high speed. Simultaneously, a cutting carriage holding a precision-ground blade advances towards the rotating log at a constant linear speed, peeling it like a "pencil sharpener" into a continuous ribbon of veneer at a predetermined thickness. Its core function is to ensure高度一致性 (high consistency) of veneer thickness across the entire log and between different logs.
Key Features:
CNC Servo Drive: Uses servo motors and CNC systems to control carriage feed, achieving precision up to ±0.05mm.
Dual Spindle System: A large-diameter spindle grips the main log; a smaller-diameter spindle extends automatically as the log tapers to continue gripping, reducing the core diameter and improving wood utilization.
Real-Time Parameter Adjustment: Veneer thickness and peeling speed can be set and adjusted via touchscreen.
4. Veneer Clipper
Positioned right after the lathe, the high-speed veneer ribbon passes over it. Using photoelectric sensors or CCD cameras, it detects defects (e.g., knots, splits, discoloration) in real-time. Based on preset dimensions and defect recognition, it drives massive hydraulic shears or rotary knives to perform high-speed, precise cuts, trimming the good sections into rectangular sheets and automatically sorting them.
Key Features:
Machine Vision Recognition: High-resolution cameras ensure accurate defect identification and sorting quality.
High-Speed, High-Precision Cutting: High shearing frequency with clean, splinter-free edges.
Automatic Sorting: Can integrate with conveyors to automatically stack veneer of different grades and sizes into different piles.
5. Veneer Dryer
Green veneer from the lathe has very high moisture content (60%-100%) and must be dried to the process requirement of 8%-12%. Typically multi-tier mesh belt or roller type, it uses hot air (heated by steam, thermal oil, or gas) forced to circulate above and below the veneer to evaporate moisture. Drying temperature and air speed are precisely controlled in multiple zones to prevent veneer warping or becoming too dry and brittle.
Key Features:
Zoned Temperature & Humidity Control: Drying and exhaust zones are independently controlled to optimize the drying curve and ensure quality.
Efficient Air Circulation: Specially designed nozzles ensure even heat distribution and high drying efficiency.
Energy-Saving Design: Often includes heat recovery systems to significantly reduce energy consumption.
6. Veneer Splicer
Joins dried small-format veneer sheets (primarily for core and back layers) into large panels. Main types:
Finger Joint Splicer: Mills finger joints into the veneer edges, applies glue, and joins them longitudinally into long strips.
Cross Feed Splicer: Aligns veneer ends and joins them at the butts using a hot melt glue-coated nylon thread or ultrasonic welding on the back.
Key Features:
Automated Feeding: Automatic alignment, gluing, pressing, and length cutting.
High-Strength Joint: The spliced veneer has high strength, minimally affecting subsequent use.
7. Glue Spreader
Applies adhesive (e.g., UF, PF resin) evenly onto the veneer surface via a glue bath and precision metering rolls. Types include four-roll and two-roll spreaders, allowing precise control of spread volume (g/m²). Modern spreaders feature automatic glue monitoring and compensation systems, ensuring consistent application on every sheet, which is critical for controlling panel quality and formaldehyde emissions.
Key Features:
Precision Metering Rolls: Hard chrome-plated steel rolls for high accuracy and wear resistance.
Automatic Gap Adjustment: Adjusts the roll gap based on veneer thickness for uniform spread.
Glue Recirculation System: Continuously stirs the adhesive to prevent settling and maintain consistent viscosity.
8. Layup Station / Automatic Layup Line
Assembles glued core veneers and unglued face/back veneers into a mat (panel) with alternating grain directions.
Manual Layup Station: Operators work with positioning guides. Lower efficiency but high flexibility.
Automatic Layup Line: A hallmark of high-end lines. Uses robots, suction cups, and conveyors to automatically pick and place veneers from different stacks with high precision,completely replacing manual labor, offering high efficiency and consistent, error-free mat formation.
Key Features (Automatic Line):
Machine Vision Positioning: Identifies veneer grain and orientation.
Multi-Axis Robots: High-speed, high-precision picking and placing.
Seamless Integration: Perfectly synchronized with upstream and downstream conveyors.
9. Pre-press
Before entering the hot press, the mat is cold-pressed (or slightly warmed) to initiate bonding between layers and expel air, forming a coherent mat with initial strength. This prevents the mat from collapsing during transfer and loading into the hot press and reduces the hot press's daylight opening, improving efficiency.
Key Features:
High Tonnage Pressure: Provides sufficient pressure for initial mat formation.
Belt Conveyor: Automated conveyor for mat infeed and outfeed.
Short Cycle: Pressing time is typically tens of seconds to a few minutes.
10. Loading & Unloading Machine
They are the "right and left arms" of the multi-opening hot press. The loader lifts the assembled mats layer by layer and accurately feeds them into each press opening. The unloader removes the pressed panels from each opening after the cycle and lowers them layer by layer onto the output conveyor. These are essential for achieving fully automated continuous hot pressing.
Key Features:
Layer Matching: The number of grabbing frames matches the number of press openings.
Synchronized Movement: Precisely synchronized with the press's opening/closing cycle.
High-Strength Structure: Built to withstand the weight of the entire press load, robust and durable.
11. Intelligent Thermal Oil Hot Press - The System Core
This is the value core of the entire line. Here, the mat is subjected to high temperature and high pressure, curing the adhesive and permanently bonding it into a strong plywood panel.
Thermal Oil System: Comprises a thermal oil heater (heat source), high-temperature pump (circulation power), expansion tank (compensates for volume changes), oil-gas separator, and precision piping/valves. Thermal oil is heated to 200-300°C in the heater and pumped through a sealed network of channels within the massive steel press plates, transferring heat to them.
Intelligent Temperature Control: Thermocouples embedded in each press plate monitor temperature in real-time, feeding data to the central PLC. The PLC performs independent, precise closed-loop control of each plate's temperature by adjusting oil flow, heater power, or three-way valve position, maintaining temperature uniformity within ±1-2°C.
Hydraulic System: Provides the high pressure required for pressing (often 20-30 MPa), driven by servo motors for high control accuracy and energy efficiency.
Key Features:
Extreme Temperature Uniformity: Fundamentally solves the worldwide challenge of temperature gradients in steam-heated presses, resulting in panels with consistent physical properties and minimal deformation.
Significant Energy Savings: Closed-loop system with minimal heat loss, overall thermal efficiency is >30% higher than steam systems.
Fully Automated Control: The PLC stores hundreds of pressing recipes (temperature, pressure, time curves) for one-touch recall; production data is traceable.
12. Cooling & Turning Machine
Panels exiting the hot press are very hot (>100°C) and pliable. Stacking them immediately would cause warping and accelerate adhesive aging. The cooler uses forced air circulation to rapidly reduce panel temperature, setting their shape. The turner rotates panels 180 degrees, ensuring both surfaces cool evenly and counteracting their inherent stress-induced bending tendency.
Key Features:
Forced Air Cooling System: High-capacity fans for uniform cooling.
Automated Turning: Hydraulic or servo-driven for smooth and reliable operation.
13. Calibrating Sander
After pressing, panels have thickness variations and a pre-cured, rough surface layer. The sander uses 2-4 large sanding heads (coarse, fine grit) to precision-grind both panel surfaces, achieving an exact, consistent final thickness and a smooth, flat surface, providing a perfect substrate for subsequent laminating, painting, or direct use.
Key Features:
Calibrating Sanding: CNC-controlled feed system ensures tight thickness tolerance (e.g., ±0.1mm).
Wide Belt Sanding: Processes large-format panels.
Powerful Dust Extraction: Centralized dust collection maintains a clean working environment.
14. Trimming Saw (Cross-Cut & Edge Saw)
After sanding, the irregular edges of the panel must be trimmed. This equipment consists of a set of edge saws and a set of cross-cut saws. The panel first passes the edge saws to trim the two long sides, then through the cross-cut saws to trim the ends, resulting in a finished panel with precise right angles and standardized dimensions.
Key Features:
Simultaneous Edge Trimming: Saws trim both edges simultaneously, ensuring parallel sides.
CNC Sizing: Servo motors position stops for accurate panel length and width.
High-Speed Alloy Blades: Smooth, splinter-free cuts.
This comprehensive set of equipment constitutes a technology-intensive, highly efficient, energy-saving, and automated modern plywood production system, which is the fundamental guarantee for its ability to produce high-end quality products.
Phase One: Raw Material Preparation
1. Log Debarking:
Purchased logs are fed through a Debarker to remove bark. Bark contains impurities that affect bonding quality and tool life; removing it is the first step to ensuring veneer quality.
2. Log Centering:
Debarked logs enter a Centering Machine. Laser or X-ray scanning finds the log's optimal rotational center, ensuring the subsequent peeling of the longest, most continuous, and most consistent thickness veneer ribbon, dramatically improving yield.
3. Log Soaking (Optional):
For some high-density, hardwood species, soaking and heating in water is required to soften them, reducing peeling resistance and obtaining a smoother veneer surface.
Phase Two: Veneer Production
4. Veneer Peeling:
Centered logs are mounted on a Veneer Lathe. The log rotates at high speed while a sharp blade peels it into a continuous ribbon of veneer at a predetermined thickness (e.g., 1.2mm-3.6mm). This is the core process determining veneer thickness consistency.
5. Veneer Clipping:
The continuous veneer ribbon passes through a Clipper. Using photoelectric sensors or CCD cameras, defects (e.g., knots, splits) are detected in real-time. The ribbon is sheared into full-size sheets based on preset dimensions, with defective sections automatically rejected.
6. Veneer Drying:
Green veneer has very high moisture content and must be dried in a Veneer Dryer (roller or mesh belt type). Hot air (potentially heated by the thermal oil system) reduces the moisture content precisely to the required range of 8%-12% for subsequent gluing.
7. Veneer Sorting & Patching:
Dried veneer is graded based on size and quality. Advanced production lines use Veneer Splicers to join smaller sheets into larger ones or fill minor splits with putty, maximizing material utilization.
Phase Three: Gluing & Layup
8. Veneer Gluing:
Graded veneer (primarily for core and back layers) passes through a Glue Spreader. Metering rolls apply a uniform layer of adhesive (e.g., urea-formaldehyde resin) to its surface. The glue spread volume, precisely controlled by PLC, directly affects bond strength and formaldehyde emissions.
9. Layup:
Glued veneers (cores) and unglued face/back veneers are assembled into a mat (panel) on a Layup Station, with the grain direction of adjacent layers perpendicular to each other. Automated lines use robotic arms for layup, offering high efficiency and minimal error.
Phase Four: Core Pressing & Curing
10. Pre-pressing:
The assembled mat is first fed into a Cold Press or Pre-press. Applying high pressure at room or slightly elevated temperature initiates bonding, removes air, prevents mat collapse, and reduces the hot press opening height, improving efficiency.
11. Intelligent Thermal Oil Hot Pressing:
This is the core of the entire process, where the value of the "Intelligent Temperature Control Thermal Oil System" is fully realized.
Loading: The pre-pressed mat is automatically fed into each opening of the multi-opening Hot Press by an Auto Loader.
Pressing & Curing:
Heat Source: The Thermal Oil Heater heats the thermal oil to the set temperature (e.g., above 200°C), and a high-temperature pump circulates it through internal channels within the massive steel press plates.
Intelligent Temp Control: Thermocouples embedded in the press plates monitor temperature in real-time, feeding data back to the central PLC. The PLC performs precise closed-loop control of each plate's temperature by adjusting oil flow, heater power, etc., ensuring extreme temperature uniformity across the entire plate surface (±1-2°C).
Pressing: While temperature is precisely controlled, the hydraulic system applies high pressure, rapidly curing the adhesive under heat and pressure.
Advantages: Temperature uniformity eliminates localized under or over-curing, resulting in minimal product deformation, high strength, and extremely consistent quality. The system is also energy-efficient and safe.
Unloading: After pressing is complete, an Auto Unloader removes the formed plywood panels.
Phase Five: Post-processing & Finishing
12. Cooling & Aging:
Panels exiting the press are very hot. They pass through a Cooling and Turning Machine for forced air cooling and flipping. This ensures uniform cooling, releases internal stresses, and sets the shape to prevent warping.
13. Trimming & Sanding:
A Trimming Saw cuts the rough edges to standard dimensions.
A Calibrating Sander performs precision sanding on the top and bottom surfaces, removing the pre-cured layer and thickness variations, resulting in a smooth, flat surface and exact thickness.
14. Grading & Packaging:
Finally, the finished plywood is inspected, graded according to appearance and quality standards, and then packaged, labeled, and stored.
The value of the Intelligent Temperature Control Thermal Oil System permeates the entire production process, but its core role is maximized in the hot pressing stage. Through precise temperature control and uniform heat distribution, it fundamentally solves the quality pain points of traditional heating methods. Coupled with highly automated equipment synergy, it ultimately enables high-efficiency, low-energy-consumption, high-quality plywood production.
Intelligent Temperature Control: PLC ensures precise temperature management for stable product quality.
High Efficiency & Energy Saving: The thermal oil system boasts high thermal efficiency, leading to lower operating costs.
Uniform Heating: Eliminates temperature differences in plate corners, enhancing product quality.
Automated Operation: Reduces labor requirements and increases production efficiency.
Safe & Reliable: Low-pressure system ensures stable and safe operation.
We are Shandong MINGHUNG Wood Based Panel Machinery Co.,Ltd China factory .With a strongfocus on producing high-quality machinery, we specialize in manufacturing thecomplete production line of Medium density fiberboard (MDF), High densityfiberboard (HDF),Particle board (PB), Oriented strand board (OSB) , Veneerable super strong particle board (LSB),Laminated board and veneer.
Request a Quote Today! OEM/ODM solutions available – Start your plywood business with competitive edge!
Our contacts:
Whatsapp: +8618769900191 +8615589105786 +8618954906501
Email: osbmdfmachinery@gmail.com
