loading
| Availability: | |
|---|---|
MH-CHP
MINGHUNG
Ⅰ.Medium Density Fiberboard (MDF)
1. Definition and Characteristics: Medium Density Fiberboard (MDF) is an engineered wood product manufactured by bonding wood fibers (typically derived from wood processing residues like sawdust, shavings, etc.) with synthetic resin binders (primarily urea-formaldehyde or melamine-modified urea-formaldehyde resin) under high temperature and pressure.
Its defining features include uniform density, typically ranging from 450 kg/m³ to 880 kg/m³ (standard MDF around 600-800 kg/m³), a dense and compact structure, a smooth and flat surface, and a homogeneous internal structure free from knots or grain directionality. This makes MDF exceptionally suitable for various surface finishing treatments (like veneering, painting, laminating) and machining operations (such as engraving, milling, drilling). It possesses good dimensional stability, mechanical strength, and screw-holding capacity, making it a core material in furniture manufacturing, interior decoration, door cores, flooring substrates, audio equipment, crafts, and more.
1. Overview of Production Process:
A typical MDF production process involves several key stages:
2.1 Raw Material Preparation: Wood raw materials (logs, small-diameter timber, branches, recycled wood, etc.) are chipped and screened to obtain qualified wood chips.
2.2 Fiber Separation: Wood chips undergo pre-steaming and are then fed into a defibrator (refiner) where they are separated into individual wood fibers under high-pressure saturated steam.
2.3 Blending and Drying: The separated fibers are mixed thoroughly with precisely metered resin binder, waterproofing agent (wax), and other additives (e.g., hardener) in a blow-line. Subsequently, the wet fibers are conveyed through a drying tube where they are rapidly dried to the appropriate moisture content (usually 8-12%) using hot air.
2.4 Forming: The dried fibers are distributed by a forming station (or "felter") onto a moving steel belt or conveyor mat to create a continuous, uniform "lofty" mat with consistent thickness and density distribution.
2.5 Pre-pressing and Hot Pressing: The lofty mat first passes through a pre-press to achieve initial compaction, removing most of the air and increasing initial strength for easier entry into the hot press. The core process occurs in the hot press (typically a continuous press), where the mat is subjected to defined temperature (180-220°C), pressure (reaching several tens of MPa in the high-pressure zones), and time (determined by thickness and line speed, typically minutes) to cure the resin and bond the fibers into a solid board strip.
MDF pre press machine
continuous hot press
2.6 Finishing: The pressed continuous board strip undergoes cooling (often via star cooler), trimming, cross-cutting to required lengths, sanding (to ensure precise thickness and surface smoothness), inspection, and finally emerges as finished MDF panels.
Dryer rack
Cross-cut saw
sanding machine
3. Energy Consumption Focus: Within the entire MDF production chain, the hot pressing stage is the absolute dominant energy consumer, accounting for over 40% or even significantly more of a plant's total energy usage. This is primarily due to the massive mechanical energy required (to close the press, build and maintain pressure) and thermal energy needed (to heat the platens to achieve curing temperature in the core layer of the mat). Therefore, improving the energy efficiency of the hot press, especially its drive system, is critically important for reducing the overall energy consumption and operating costs of MDF production.
Ⅱ. Continuous Press Line (CPL)
1. Core Equipment and Working Principle: The continuous flat press is the standard core equipment for modern MDF and High-Density Fiberboard (HDF) production, replacing the less efficient and more energy-intensive batch-type multi-opening hot presses.
Its core structure comprises:
Infeed Section: Includes mat transfer, metal detection, continuous weighing, mat acceleration devices to ensure smooth and accurate feeding of the mat into the press.
Hot Press Main Body: The heart of the continuous press. It consists of two massive, high-strength, heat-resistant continuous steel belts. The mat is conveyed while being held between these two belts. Inside (or beneath) the belts are arranged numerous (tens to hundreds) of individually controlled, zoned heating platens (typically oil-heated or steam-heated). Each platen zone is equipped with its own hydraulic cylinder and pressure/position sensors.
Press Frame: A robust frame structure supporting all platens, cylinders, and drive systems, designed to withstand enormous pressing forces.
Drive System: Responsible for driving the two steel belts at precisely synchronized, continuous speeds and controlling belt tension.
Outfeed Section: Includes belt detachment, board transfer, tensioning devices, belt cleaning, and cooling systems.
2.Workflow: The formed lofty mat, after pre-pressing, is accelerated by the infeed section into the entry "wedge zone" of the continuous press. In the wedge zone, the gap between the upper and lower steel belts gradually decreases, compressing the mat initially and expelling air. The mat then enters the main pressing zone, where the zoned platens apply the required heat and pressure according to a preset pressure profile (high pressure at entry, progressively decreasing pressure in the middle sections, low pressure at exit for setting). Held between the belts, the mat moves continuously at constant speed through the entire press length to complete resin curing. Finally, at the exit end, the belts separate, and the formed board strip is discharged for further processing.
3. Advantages:
Continuous Production: Very high production efficiency, suitable for mass production.
Superior Product Quality: The mat is subjected to continuous, uniform pressure and temperature fields throughout the curing process, resulting in uniform density distribution, minimal thickness variation, excellent surface quality, and consistent physical-mechanical properties.
High Automation Level: Facilitates automation and intelligent control of the production process.
Ⅲ. Dual Servo Drive System
1. System Components: This advanced system specifically designed for continuous press steel belt driving consists mainly of:
1.1 Two High-Dynamic Servo Motors: Precisely drive the upper and lower steel belts of the continuous press independently. Servo motors offer superior torque control accuracy, speed control accuracy, and extremely fast dynamic response (millisecond level).
1.2 Two High-Precision Servo Drives: Receive speed/torque commands from the main press control system and provide real-time feedback on motor status (position, speed, torque, temperature). Drives incorporate advanced motion control algorithms.
1.3 Servo Pump Control Units (Key Innovation): This is the core enabling significant energy savings. The traditional centralized hydraulic power unit (HPU) (using asynchronous motors driving fixed or variable displacement pumps to supply oil to all zone cylinders) is completely replaced. Instead:
1.3.1 Each platen zone (or a small group of zones) is equipped with an independent, low-power servo motor.
1.3.2 Each servo motor directly drives a small-displacement, high-precision hydraulic pump (e.g., internal gear pump or piston pump).
1.3.3 This servo pump unit directly provides hydraulic power to its corresponding one (or few) cylinders, forming an independent closed-loop or open-loop hydraulic circuit.
1.4 Intelligent Control System: The main press PLC, servo drives, servo pump units, and all pressure/position sensors form a high-speed communication network. The system continuously collects data (belt speed, tension, zone pressures, cylinder positions), performs complex calculations (like synchronization control, pressure closed-loop control, tension control, energy management), and sends precise commands to the servo drives and pump units.
2. Core Working Principles:
2.1 Steel Belt Drive: Two servo motors independently drive the main drive rolls (or sprockets) of the upper and lower steel belts. The control system implements high-precision speed synchronization control and torque balancing control (i.e., tension control) by comparing the torque and speed of both motors in real-time. This ensures smooth, synchronous belt running, constant tension, and eliminates slip or tracking risks. The inherent efficiency and precise control of servo motors already save energy compared to traditional drives.
2.2 Hydraulic Pressure Control (Revolutionary Change): This is key to the 40% energy reduction.
2.2.1 On-Demand Oil Supply: Each independent servo pump unit activates its servo motor to drive the hydraulic pump only when its corresponding zone cylinder requires action (e.g., pressurizing, depressurizing, position fine-tuning). The pump delivers precisely the flow and pressure needed for the cylinder's required action speed and force. When no action is needed (pressure holding phase), the servo motor stops completely or runs at minimal speed to maintain standby pressure (near-zero energy consumption).
2.2.2 Elimination of Throttling and Overflow Losses: Traditional centralized HPUs using proportional or servo valves to control zone pressure suffer significant throttling losses (heat generation from pressure drop as oil flows through valve orifices). During the holding phase, the pump continuously delivers high-pressure oil, and excess flow must be dumped back to the tank via relief valves, causing massive overflow losses (useless work converted entirely to heat). The servo pump control system, by directly controlling pump output via motor speed and torque, enables a more direct "pump-controlled cylinder" approach, minimizing or even eliminating the need for restrictive valves, thus largely removing throttling and overflow losses.
2.2.3 Energy Recovery: During cylinder depressurization or retraction, the high-pressure oil discharged from the cylinder (or potential energy) can drive the servo pump to act as a hydraulic motor, causing the servo motor to generate electricity. This regenerated energy can be fed back to the grid or used by other equipment. This is impossible with traditional hydraulic systems.
2.3 Intelligent Coordination: The main control system dynamically coordinates the actions of all servo pump units and the belt servo drives based on mat characteristics, target thickness, preset pressure profiles, and real-time press status, achieving optimal and most energy-efficient operation of the entire press system.
Ⅳ. Mechanism for Achieving 40% Energy Reduction
1.Elimination of Central HPU Idle and Overflow Losses: Traditional large asynchronous motor-driven pump sets must run continuously even when the press is idle or only holding pressure in some zones, causing significant no-load losses (motor idling, pump internal friction, oil circulation heating). More critically, during the holding phase, pressure maintenance relies heavily on relief valve overflow. The power consumed (Pressure Overflow Flow Rate) is completely wasted and heats the oil, requiring additional cooling energy. The servo pump control system delivers energy precisely only when needed; pumps stop (or barely move) during holding, virtually eliminating these two major loss sources. Statistics show these losses account for over 50% of energy consumption in traditional hydraulic systems.
2.Drastic Reduction of Throttling Losses: Traditional valve-controlled systems regulate flow and pressure by changing valve orifice openings (throttling), inevitably generating pressure drop (ΔP) losses (Power Loss = ΔP Flow Rate). Servo pump control adjusts flow by directly changing pump displacement or speed; pressure is load-dependent. Flow passing through valves is minimal with very low pressure drop (or even using on/off valves), significantly reducing throttling losses.
3.Efficient Energy Recovery: During depressurization, cylinder retraction, or similar actions, the servo pump system can effectively convert hydraulic energy or potential energy back into electrical energy and feed it to the grid, recovering energy that would otherwise be lost as heat through throttling.
4.High Intrinsic Efficiency of Servo Motors: Servo motors maintain high operating efficiency over a wide range of speeds and loads (especially at partial loads), far superior to standard asynchronous motors.
5.Optimized System Control: The intelligent control system can dynamically adjust zoned pressure profiles and belt speed based on actual production conditions (e.g., different thicknesses, board grades), avoiding unnecessary energy consumption (e.g., over-pressurization, excessive hold times, suboptimal speed settings). The high responsiveness of the servo system also minimizes energy waste during adjustments.
6.Reduced Cooling Demand: The significant reduction in hydraulic system heat generation (primarily from throttling, overflow, and pump inefficiencies) leads to a substantial decrease in hydraulic oil temperature rise. This consequently reduces, or potentially eliminates, the energy required for hydraulic oil cooling (cooling water pumps, fans).
7.Combined Effect: The synergistic effect of all these energy-saving measures results in a significant reduction of up to 40% in the total energy consumption related to driving and hydraulics within the continuous press line (primarily steel belt driving and pressure build-up/maintenance for all zones). This translates directly into lower factory operating costs and reduced carbon emissions. The actual savings depend on specific line configuration, product type, and operating parameters, but 40% is a validated and widely recognized typical value in the industry.
For more information, welcome contact us, we will reply you quickly and offer working videos with you.
Whatsapp: +8618769900191 +8615589105786 +8618954906501
Email: osbmdfmachinery@gmail.com
Ⅰ.Medium Density Fiberboard (MDF)
1. Definition and Characteristics: Medium Density Fiberboard (MDF) is an engineered wood product manufactured by bonding wood fibers (typically derived from wood processing residues like sawdust, shavings, etc.) with synthetic resin binders (primarily urea-formaldehyde or melamine-modified urea-formaldehyde resin) under high temperature and pressure.
Its defining features include uniform density, typically ranging from 450 kg/m³ to 880 kg/m³ (standard MDF around 600-800 kg/m³), a dense and compact structure, a smooth and flat surface, and a homogeneous internal structure free from knots or grain directionality. This makes MDF exceptionally suitable for various surface finishing treatments (like veneering, painting, laminating) and machining operations (such as engraving, milling, drilling). It possesses good dimensional stability, mechanical strength, and screw-holding capacity, making it a core material in furniture manufacturing, interior decoration, door cores, flooring substrates, audio equipment, crafts, and more.
1. Overview of Production Process:
A typical MDF production process involves several key stages:
2.1 Raw Material Preparation: Wood raw materials (logs, small-diameter timber, branches, recycled wood, etc.) are chipped and screened to obtain qualified wood chips.
2.2 Fiber Separation: Wood chips undergo pre-steaming and are then fed into a defibrator (refiner) where they are separated into individual wood fibers under high-pressure saturated steam.
2.3 Blending and Drying: The separated fibers are mixed thoroughly with precisely metered resin binder, waterproofing agent (wax), and other additives (e.g., hardener) in a blow-line. Subsequently, the wet fibers are conveyed through a drying tube where they are rapidly dried to the appropriate moisture content (usually 8-12%) using hot air.
2.4 Forming: The dried fibers are distributed by a forming station (or "felter") onto a moving steel belt or conveyor mat to create a continuous, uniform "lofty" mat with consistent thickness and density distribution.
2.5 Pre-pressing and Hot Pressing: The lofty mat first passes through a pre-press to achieve initial compaction, removing most of the air and increasing initial strength for easier entry into the hot press. The core process occurs in the hot press (typically a continuous press), where the mat is subjected to defined temperature (180-220°C), pressure (reaching several tens of MPa in the high-pressure zones), and time (determined by thickness and line speed, typically minutes) to cure the resin and bond the fibers into a solid board strip.
MDF pre press machine
continuous hot press
2.6 Finishing: The pressed continuous board strip undergoes cooling (often via star cooler), trimming, cross-cutting to required lengths, sanding (to ensure precise thickness and surface smoothness), inspection, and finally emerges as finished MDF panels.
Dryer rack
Cross-cut saw
sanding machine
3. Energy Consumption Focus: Within the entire MDF production chain, the hot pressing stage is the absolute dominant energy consumer, accounting for over 40% or even significantly more of a plant's total energy usage. This is primarily due to the massive mechanical energy required (to close the press, build and maintain pressure) and thermal energy needed (to heat the platens to achieve curing temperature in the core layer of the mat). Therefore, improving the energy efficiency of the hot press, especially its drive system, is critically important for reducing the overall energy consumption and operating costs of MDF production.
Ⅱ. Continuous Press Line (CPL)
1. Core Equipment and Working Principle: The continuous flat press is the standard core equipment for modern MDF and High-Density Fiberboard (HDF) production, replacing the less efficient and more energy-intensive batch-type multi-opening hot presses.
Its core structure comprises:
Infeed Section: Includes mat transfer, metal detection, continuous weighing, mat acceleration devices to ensure smooth and accurate feeding of the mat into the press.
Hot Press Main Body: The heart of the continuous press. It consists of two massive, high-strength, heat-resistant continuous steel belts. The mat is conveyed while being held between these two belts. Inside (or beneath) the belts are arranged numerous (tens to hundreds) of individually controlled, zoned heating platens (typically oil-heated or steam-heated). Each platen zone is equipped with its own hydraulic cylinder and pressure/position sensors.
Press Frame: A robust frame structure supporting all platens, cylinders, and drive systems, designed to withstand enormous pressing forces.
Drive System: Responsible for driving the two steel belts at precisely synchronized, continuous speeds and controlling belt tension.
Outfeed Section: Includes belt detachment, board transfer, tensioning devices, belt cleaning, and cooling systems.
2.Workflow: The formed lofty mat, after pre-pressing, is accelerated by the infeed section into the entry "wedge zone" of the continuous press. In the wedge zone, the gap between the upper and lower steel belts gradually decreases, compressing the mat initially and expelling air. The mat then enters the main pressing zone, where the zoned platens apply the required heat and pressure according to a preset pressure profile (high pressure at entry, progressively decreasing pressure in the middle sections, low pressure at exit for setting). Held between the belts, the mat moves continuously at constant speed through the entire press length to complete resin curing. Finally, at the exit end, the belts separate, and the formed board strip is discharged for further processing.
3. Advantages:
Continuous Production: Very high production efficiency, suitable for mass production.
Superior Product Quality: The mat is subjected to continuous, uniform pressure and temperature fields throughout the curing process, resulting in uniform density distribution, minimal thickness variation, excellent surface quality, and consistent physical-mechanical properties.
High Automation Level: Facilitates automation and intelligent control of the production process.
Ⅲ. Dual Servo Drive System
1. System Components: This advanced system specifically designed for continuous press steel belt driving consists mainly of:
1.1 Two High-Dynamic Servo Motors: Precisely drive the upper and lower steel belts of the continuous press independently. Servo motors offer superior torque control accuracy, speed control accuracy, and extremely fast dynamic response (millisecond level).
1.2 Two High-Precision Servo Drives: Receive speed/torque commands from the main press control system and provide real-time feedback on motor status (position, speed, torque, temperature). Drives incorporate advanced motion control algorithms.
1.3 Servo Pump Control Units (Key Innovation): This is the core enabling significant energy savings. The traditional centralized hydraulic power unit (HPU) (using asynchronous motors driving fixed or variable displacement pumps to supply oil to all zone cylinders) is completely replaced. Instead:
1.3.1 Each platen zone (or a small group of zones) is equipped with an independent, low-power servo motor.
1.3.2 Each servo motor directly drives a small-displacement, high-precision hydraulic pump (e.g., internal gear pump or piston pump).
1.3.3 This servo pump unit directly provides hydraulic power to its corresponding one (or few) cylinders, forming an independent closed-loop or open-loop hydraulic circuit.
1.4 Intelligent Control System: The main press PLC, servo drives, servo pump units, and all pressure/position sensors form a high-speed communication network. The system continuously collects data (belt speed, tension, zone pressures, cylinder positions), performs complex calculations (like synchronization control, pressure closed-loop control, tension control, energy management), and sends precise commands to the servo drives and pump units.
2. Core Working Principles:
2.1 Steel Belt Drive: Two servo motors independently drive the main drive rolls (or sprockets) of the upper and lower steel belts. The control system implements high-precision speed synchronization control and torque balancing control (i.e., tension control) by comparing the torque and speed of both motors in real-time. This ensures smooth, synchronous belt running, constant tension, and eliminates slip or tracking risks. The inherent efficiency and precise control of servo motors already save energy compared to traditional drives.
2.2 Hydraulic Pressure Control (Revolutionary Change): This is key to the 40% energy reduction.
2.2.1 On-Demand Oil Supply: Each independent servo pump unit activates its servo motor to drive the hydraulic pump only when its corresponding zone cylinder requires action (e.g., pressurizing, depressurizing, position fine-tuning). The pump delivers precisely the flow and pressure needed for the cylinder's required action speed and force. When no action is needed (pressure holding phase), the servo motor stops completely or runs at minimal speed to maintain standby pressure (near-zero energy consumption).
2.2.2 Elimination of Throttling and Overflow Losses: Traditional centralized HPUs using proportional or servo valves to control zone pressure suffer significant throttling losses (heat generation from pressure drop as oil flows through valve orifices). During the holding phase, the pump continuously delivers high-pressure oil, and excess flow must be dumped back to the tank via relief valves, causing massive overflow losses (useless work converted entirely to heat). The servo pump control system, by directly controlling pump output via motor speed and torque, enables a more direct "pump-controlled cylinder" approach, minimizing or even eliminating the need for restrictive valves, thus largely removing throttling and overflow losses.
2.2.3 Energy Recovery: During cylinder depressurization or retraction, the high-pressure oil discharged from the cylinder (or potential energy) can drive the servo pump to act as a hydraulic motor, causing the servo motor to generate electricity. This regenerated energy can be fed back to the grid or used by other equipment. This is impossible with traditional hydraulic systems.
2.3 Intelligent Coordination: The main control system dynamically coordinates the actions of all servo pump units and the belt servo drives based on mat characteristics, target thickness, preset pressure profiles, and real-time press status, achieving optimal and most energy-efficient operation of the entire press system.
Ⅳ. Mechanism for Achieving 40% Energy Reduction
1.Elimination of Central HPU Idle and Overflow Losses: Traditional large asynchronous motor-driven pump sets must run continuously even when the press is idle or only holding pressure in some zones, causing significant no-load losses (motor idling, pump internal friction, oil circulation heating). More critically, during the holding phase, pressure maintenance relies heavily on relief valve overflow. The power consumed (Pressure Overflow Flow Rate) is completely wasted and heats the oil, requiring additional cooling energy. The servo pump control system delivers energy precisely only when needed; pumps stop (or barely move) during holding, virtually eliminating these two major loss sources. Statistics show these losses account for over 50% of energy consumption in traditional hydraulic systems.
2.Drastic Reduction of Throttling Losses: Traditional valve-controlled systems regulate flow and pressure by changing valve orifice openings (throttling), inevitably generating pressure drop (ΔP) losses (Power Loss = ΔP Flow Rate). Servo pump control adjusts flow by directly changing pump displacement or speed; pressure is load-dependent. Flow passing through valves is minimal with very low pressure drop (or even using on/off valves), significantly reducing throttling losses.
3.Efficient Energy Recovery: During depressurization, cylinder retraction, or similar actions, the servo pump system can effectively convert hydraulic energy or potential energy back into electrical energy and feed it to the grid, recovering energy that would otherwise be lost as heat through throttling.
4.High Intrinsic Efficiency of Servo Motors: Servo motors maintain high operating efficiency over a wide range of speeds and loads (especially at partial loads), far superior to standard asynchronous motors.
5.Optimized System Control: The intelligent control system can dynamically adjust zoned pressure profiles and belt speed based on actual production conditions (e.g., different thicknesses, board grades), avoiding unnecessary energy consumption (e.g., over-pressurization, excessive hold times, suboptimal speed settings). The high responsiveness of the servo system also minimizes energy waste during adjustments.
6.Reduced Cooling Demand: The significant reduction in hydraulic system heat generation (primarily from throttling, overflow, and pump inefficiencies) leads to a substantial decrease in hydraulic oil temperature rise. This consequently reduces, or potentially eliminates, the energy required for hydraulic oil cooling (cooling water pumps, fans).
7.Combined Effect: The synergistic effect of all these energy-saving measures results in a significant reduction of up to 40% in the total energy consumption related to driving and hydraulics within the continuous press line (primarily steel belt driving and pressure build-up/maintenance for all zones). This translates directly into lower factory operating costs and reduced carbon emissions. The actual savings depend on specific line configuration, product type, and operating parameters, but 40% is a validated and widely recognized typical value in the industry.
For more information, welcome contact us, we will reply you quickly and offer working videos with you.
Whatsapp: +8618769900191 +8615589105786 +8618954906501
Email: osbmdfmachinery@gmail.com
