Решения

Polyurethane_Equipment_Solution_Single_Density

Болевые точки отрасли

01 Mechanical Challenges in Coating Precision and Uniformity

Difficulty in controlling accuracy:

Precise control of coating application and mechanical precision are two key factors limiting the development of solvent-free laminating machines-3. Even slight deviations in the speed difference or gap accuracy between the coating roller and the metering roller can cause significant fluctuations in the coating amount.

Poor uniformity:

Traditional top-coating methods tend to leave excessive coating residue on the base fabric, which not only wastes material but also causes the base fabric to warp and become damaged due to the excessive coating thickness.

Hydrolytic degradation: Polyester-based PU is prone to hydrolysis in humid or high-temperature environments, causing the sole to become brittle, crack, and flake off—a problem that is particularly pronounced in southern regions and during the rainy season.

02 Process window issues caused by material reaction characteristics

Quick-setting:

After mixing and reacting, solvent-free slurry hardens to some extent within a short period of time; ambient temperature and the low temperature of the roller blade itself accelerate this process.

Blocking Guns and Sticking Knives:

It is difficult to precisely control the reaction time, and issues such as nozzle clogging and material sticking to the blade often arise during use-4. This forces production lines to shut down frequently for cleaning, and these shutdowns cause the unused slurry to harden further, resulting in waste.

03 Thermal Management and Cleaning Design for Equipment

Lack of active temperature control:

If the roller knife and piping are not equipped with a heating and insulation system, the slurry will solidify more quickly in low-temperature environments. The current solution involves installing a heating layer inside the roller knife to maintain the slurry temperature and prevent solidification.

Difficulty in cleaning and changing materials:

Compared to EVA (lightweight and inexpensive), rubber (wear-resistant), and TPU (tough and resilient), single-density PU offers no distinct advantages and lacks value for money.

Основа решения

Haifeng Automation, a veteran in the polyurethane automation equipment industry, focuses on the core demands of “comprehensive protection, long-lasting durability, green environmental protection, and intelligent efficiency”. It integrates independently accumulated solvent-free/water-based PU technology, precision manufacturing processes, and intelligent quality control systems, integrating core equipment and process solutions into the entire industrial chain of safety shoes. Leveraging technical experience in PU foaming equipment, precision metering systems, and other fields, it achieves four core goals, adapts to multi-scenario needs, and provides integrated “technical solution + equipment implementation” services.

Модули основного решения

R&D of Scenario-Specific Specialized Materials

Ingredients and formulation：

A1, A2 (polyester polyol), B1, B2 (isocyanate), C1-C4 (color paste)

Proportion range of raw materials: 100:40-100

Preheating temperature of raw materials: 20-40°C

Other ingredients: Cleaning agent (MC: for cleaning the machine head), nitrogen (function: to prevent material deterioration), compressed air (function: power source)

Pouring capacity：

Maximum instantaneous flow rate: 100 g/s (6 kg/min)

Low-density products (e.g., apparel leather, thin furniture leather): 300g/sm

Heavy-duty products (e.g., shoe leather, heavy furniture leather): 600g/sm

Applicable products: Solvent-free synthetic leather (foamed/mirror finish type)

Measurement accuracy 3

Specific Process

Phase 1: Production Preparation
Raw Material Preparation and Loading	Raw materials A, B, and color slurry (C1-C4) are separately conveyed to the corresponding storage tanks of the equipment. Subsequently, the system performs constant temperature heating and continuous stirring of the raw materials within the tanks.
Equipment Preparation and Parameter Settings	Initiate the full-path temperature control system for preheating, then retrieve the predetermined production formula from the main control panel to set all process parameters with one click. Finally, execute automatic cleaning and trial operation to verify the status of all equipment systems and the mixing effluent quality.
Kibb preparation	Mount the release paper or base fabric (e.g., non-woven fabric, knitted fabric) onto the unwinding device, and pull it through the entire coating line.
Phase II: Coating Production
Precision Measurement and Mixing	The metering pump delivers each component of raw materials precisely according to the formula ratio, which is then collected through insulated pipelines to the pouring head. Within the pouring head, the raw materials achieve uniform mixing.
Coating and Forming	The cast truss drives the head to perform precise reciprocating motion, ensuring uniform coating on the base fabric surface, followed immediately by surface texture formation via the embossing roller.
Reaction curing and molding	The coated wet film enters the drying tunnel. After curing completion, the product proceeds to the cooling section for temperature reduction.
Phase III: Post-processing and Packaging
Rolling and ripening	The cooled synthetic leather (if release paper is used, it is collected together with the release paper) is automatically wound up. The wound-up product requires aging in a constant-temperature warehouse for 24-48 hours to ensure complete reaction and achieve stable performance.
Post-processing and Inspection	If release paper is used, it should be separated from the synthetic leather after maturation using a peeling machine.Surface treatment: Post-processing such as embossing, printing, spraying, or embossing may be required to achieve specific appearance and tactile characteristics. Inspection and packaging: The finished product undergoes inspection for appearance, thickness, and physical properties (e.g., wear resistance, hydrolysis resistance). Upon passing inspection, the product is packaged and stored.

Equipment List and Unit Price

order number	name	quantity	Specification Parameters
1	Solvent-free PU Blending System	1 set	Measurement accuracy: ±0.5%
2	Casing machine	1sets	Maximum coating width: 1800mm
3	Oven system	1 set	Length: 25 meters Temperature range: Room temperature to-150°C
4	coolant passage	1 set	Hydraulic cooling + air cooling combination
5	batch up gear,batching apparatus	1 set	Maximum winding diameter with automatic tension control: 1200mm
6	Release Paper Treatment System	1 set	Including unwinding, alignment correction, and winding devices
7	Central Control System	1 set	PLC + Human-Machine Interface, Recipe Storage Function

Technical parameters

Coating machine system

Tank system: A1 and B1 with a capacity of 500 liters (2 sets),
A2 and B2 with a capacity of 50 liters (1 set each).
Materials: Inner layer made of 304 stainless steel,
middle layer with a heating layer, and outer layer with
polyurethane rigid foam insulation.

Measurement System: A1A2 high-precision
metering pump (25cc, 1 set each),
B1B2 high-precision metering pump (20cc, 1 set each).
Motor: 1.3KW servo motor with planetary reducer.

Color additive system: High-precision metering pump 0.6cc (4 sets),
50-liter storage tank, Drive motor: 0.75KW servo motor

Frame system: Left-right digitalized movement
(1 set): The moving motor is a 0.75KW servo motor;
Up-down digitalized movement
(1 set): The moving motor is a 1.0KW servo motor.

Head system: Needle valve-type head (1 set), driven by servo motor
Material temperature control system: 3
temperature control units (4 units),
with independent temperature control for material tanks,
each heating power of 9KW

Head cooling system: 2 chillers (1 unit)

Nose cleaning system: 20-liter cleaning tank (1 unit)

Vacuum system: 30L vacuum pump (1 unit),
equipped with 2 vacuum buffer tanks

A Feeding System: Diaphragm pumps (2 units),
with independent feeding pipelines for storage tanks

B Feeding System: Manual feeding or vacuum pump feeding,
with the storage tank equipped with independent feeding pipelines.

Rack assembly: Frame structure (1 set), with aluminum alloy doors
and windows installable on all four sides
(to be procured and installed by the purchaser)

Control System: PLC; various models of modules (1 set);
brand: Inovance; 15-inch touchscreen (1 unit);
brand: Kunlun Tongtai; 7-inch touchscreens (2 units);
brand: Kunlun Tongtai; low-voltage electrical equipment (1 set);
brand: Tai'an; various models of sensors (1 set); brand: Taiwan Jiazhun

Oven system

Heating method: Hot air circulation + infrared auxiliary heating Temperature control range: room temperature to-150°C Temperature control accuracy: ±1℃ Number of heating zones: 6 zones with independent temperature control Rated voltage: 380V Power consumption: approximately 120-150 kW

coolant passage

Function of the cooling roller: A large-diameter metal drum
with circulating cooling water inside, through which the fabric
passes in close contact with its surface, and heat from
the fabric is removed via thermal conduction.

Cooling roller body: The material is typically steel or stainless steel.

Roll surface temperature: 10°C–25°C
(adjusted according to production line speed and requirements)

Cooling water temperature: 7°C-15°C
Roll diameter: 500 mm–1000 mm (typically)
Surface treatment: Electroplated hard chrome or mirror-polished finish

Coiling device system

Function: The synthetic leather product,
after completion of coating, curing,
and cooling, is wound into rolls with constant
tension and neat edges to facilitate storage,
transportation, and subsequent processing.

Maximum coil diameter: Φ1000mm, Φ1500mm

Maximum roll width: 1800mm, 2200mm

Maximum linear speed: 10-30 meters per minute

Tension control range: 50–500 N

Control mode: Automatic/manual, Constant tension/conical tension control

Power supply requirements: 380V/3-phase/50Hz

Drive system: AC servo motor or frequency converter

Release Paper Treatment System

Function: Ensure the release paper is used flatly and stably in the
production process while protecting it from damage, and allow for reuse.

Maximum paper roll width: 1800mm-2500mm

Maximum unwinding/unwind diameter: Φ1000mm, Φ1500mm

Inner diameter of the core: 3 inches or 6 inches

Maximum mechanical speed: 30-50 meters per minute
Working speed: 10-25 meters per minute

Tension control range: 50-500N

Tension control accuracy: ±1%–±5%

Correction accuracy: ±1 mm

Total power: 5-15KW Compressed air specifications:
Pressure (0.6-0.8 MPa), Flow rate (0.2 Nm³/min)

Power supply: 3-phase, 380VAC, 50Hz

Production output and production efficiency

production pattern	Heavy-duty products (such as shoe leather and heavy furniture leather)	Low-density products (e.g., garment leather, thin furniture leather)
Product weight (based on actual measurement)	600(g/sm)	300(g/sm)
Effective working width	1.6m	1.6m
The theoretical maximum linear speed V = extrusion volume / (gross weight × width)	V = 100 g/s / (600 g/sm × 1.6 m) ≈ 0.104 ≈ 6.25	V = 100 g/s / (300 g/sm × 1.6 m) ≈ 0.208 ≈ 12.5
Daily production (16 hours) (16小时)	Area: 9,600 square meters per day	Area: 19,200 square meters/day
Annual output (300 days)	2,880,000 square meters per year	5,760,000 square meters per year

Working Conditions

subject of entry	requirement
Workshop Requirements	Cleanroom, with an area of approximately 30m×10m and a minimum height of 5 meters
humiture	Temperature: 20–30°C; Humidity: 40–70% RH
current source	3×380V±5%,50Hz, total power approximately 250kW
compressed air	0.6-0.8 MPa, dry and oil-free, flow rate approximately 1.5 m³/min
water coolant	Circulating cooling water, pressure 0.3–0.4 MPa, temperature ≤25°C
operation staff	Each shift consists of 3-4 personnel (including the main operator, assistant workers, and quality inspector).

Full-Process Automated Production System

Comprehensive Quality Verification and Compliance Assurance

Значение и последствия решения

Размер	Традиционный процесс	Haifeng Automation Solution	Эффект улучшения
Compliance Rate of Protective Performance	Below 85%	Above 99%	Meet national/international standards and eliminate safety hazards
Defect Rate	10-15%	2-3%	Reduce by over 75% and minimize rework losses
Raw Material Waste Rate	≥15%	≤5%	Reduce by 67%, saving over 300,000 yuan in raw material costs per line annually
Требование к труду	8-10 people/line	2-3 people/line	Reduce by 75% and lower the risk of operational errors
Выбросы летучих органических соединений	Чрезмерное количество	Около нуля	Achieve environmental compliance and obtain international certifications
R&D Cycle	30-45 days	7-15 days	Shorten by over 60% for rapid market response