Polyurethane_Equipment_Dual-Density_Solution
Industry Pain Points
01
Accuracy of Equipment Measurement and Mixing
Insufficient accuracy:
Significant shortcomings in durability
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
Stable bonding at the two-phase interface
Narrow process window：
If any parameter—such as the injection interval, mold temperature, or amount of release agent sprayed—is out of control, the two layers of material will fail to bond, causing delamination and resulting in the part being scrapped.
Material Formulation Challenge:
Materials with two different densities require separate designs while ensuring they are compatible with each other, which complicates the formulation process.
03
Production Stability and Flexibility
Poor stability:
Frequent equipment malfunctions or parameter drift (such as fluctuations in material temperature)This results in inconsistent product quality within the same batch, making it impossible to meet mass production requirements.
Lack of flexibility:
Market demand is constantly changing, and products require different colors, hardness levels, and densities. If equipment is difficult to clean and change over, and formula switching is inflexible, companies will struggle to handle small-batch, high-variety production orders and miss out on market opportunities.
Core of the Solution
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.
Core Solution Modules
R&D of Scenario-Specific Specialized Materials
Ingredients and formulation：
PU polyurethane raw material (A material is generally polyester polyol/B material is generally isocyanate)
The raw material ratio is about 100:40-70
Raw material preheating temperature: 60-70℃ (Note: a drying oven is required)
Other ingredients: demolding agent (function: prevent adhesion), pigment (function: spray color on the sole), (MC) dichloromethane (function: clean the machine head), (DOP) dioctyl phthalate (function: clean the material tank)
Pouring capacity：
Maximum instantaneous flow: 70g/s
Double density shoes (total usage is about 400g–700g)
Measurement accuracy: ±0.5%
Specific Process
| Area | detailed introduction | Corresponding step diagram |
|---|---|---|
| 1 | Complete steps 1,2 and 3 in Figure 1. Place the fixed shoe upper into the specified mold |    |
| 2 | Complete step 4 in Figure 1 to spray the mold release agent |  |
| 3 | Complete step 5 in Figure 1. The caster pours the first material |  |
| 4 | Complete step 6 in Figure 1 to close the mold |  |
| 5 | The mold is sent into the oven for shaping for the first time |  |
| 6 | Complete step 7 in Figure 1 to open the mold |  |
| 2 | Complete step 8 in Figure 1 and continue through region 2 for a second demolding agent spray | |
| 3 | Then complete step 9 as shown in the figure and pour the second material through the pouring machine in area 3 | |
| 4 | Continue to complete step 10 as shown in the figure and then close the mold after region 4 | |
| 5 | The mold is sent into the oven for molding for the second time | |
| 6 | Then follow step 11 in Figure 1 to open the mold | |
| 7 | Complete step 12 in Figure 1 to pick up the shoes and send them to the next process. Complete step 13,14 and 15 in Figure 1 to trim the shoes, check and accept the quality, and then package |    |
Equipment List and Unit Price
| order number | name | quantity | size | Unit price (United States dollars) |
|---|---|---|---|---|
| 1 | drying tunnel | 1 set | Single unit (unit mm)2000×1150×1000 | |
| 2 | Casing machine | 2 sets | Approximate (unit mm) 1300×1000×1000 | |
| 3 | Automatic spray demolding agent manipulator (can be replaced by other equipment) | 1 set | Approximate (unit mm) 750×750×1500 | |
| 4 | air compressor | 1 set | Approximate (unit mm) 1800×1000×2000 | |
| 5 | 60 automatic conveyor lines | 1 set | Approximate (unit mm) 9000×2000×2200 | |
| 6 | Raw material oven | 1 set | Approximate (unit mm)1700×1360×2050 | |
| 7 | casting machine | 1 set | Approximate (unit mm)2200×1400×2200 | |
| 8 | Demolisher storage tank | 1 copy | Approximate (unit mm)300×300×1000 | |
| 9 | cooling-water | 1 set | Approximate (unit mm)900×600×1100 (Note: it will be smaller in reality) | |
| EXW total | ||||
| Transport: 1 x 40ft container | ||||
| Note: Optional spare parts and consumables (e.g. seals, filters) can be provided as required. | ||||
Technical parameters
Moulding
| Function: First choose the mold to make the product Raw materials: aluminum alloy, Cr12MoV alloy tool steel | Beach shoes/ sandals mould The mold length is about 220-280mm Width about 80-95mm Thickness about 15-30mm  | Labour protection shoe moulds The mold length is about 250-350mm Width about 90-110mm Thickness about 40-60mm  |
Raw material oven system
| Function: Raw material oven preheating and drying AB material Model: XHG×3-2.5, volume m³: 2.5 Temperature set range: 90℃ Temperature control mode: automatic Rated voltage V: 380 Overall power KW: 6.55 |  |
Release agent spraying system
| Function: automatically open the mold Material: Stainless steel/iron Electrical cabinet: one PLC, two servo relays and three sensors Motor: AC servo motor Rated torque: 5.39 Rated voltage V: 380 Power KW: 2 |  |
Automatic opening and closing mold system
| Function: automatically spray release agent at the beginning of the mold cycle Model: SD7/900, brand: Xintida, working range: 912MM Electrical cabinet: one PLC, two servo relays and three sensors Load capacity: 7KG, weight: 35KG Power KW: 1 (depending on the mechanical hand required) |  |
Automatic opening and closing mold system
| Function: the pouring machine is poured according to the formula (single density pouring and double density pouring are realized) Maximum instantaneous flow: 70g/s, rated voltage V: 380 Measurement accuracy: ±0.5%, power phase number: 3 Measuring pump speed adjustment range, RPM: 30-150 Hybrid head speed, RPM: 8600±150 Rated power supply frequency, Hz: 50 Servo motor is used with planetary reducer Electrical cabinet: Electrical control system Cylinder material: stainless steel, cylinder capacity: 120-220 (can be customized according to customer demand) Power of a single machine: 20.55KW (continuous power supply is required) |  |
Drying system
| Function: enter the raw material oven at a uniform speed for maturation and shaping Finally: 1. Single density production (open mold sampling) 2. Double density production (open mold, second pouring, close mold, maturation, open mold, sampling) Baking material: the outer layer is iron, the inner layer is stainless steel Three asynchronous motors: YE3-80M1-4 model, power KW: 0.55, rated voltage: 380V Heating system; infrared lamp tube is used No.7 oven diameter (900×650mm) (Note: the quantity and size can be selected according to the mold situation) | |
60 automatic conveyor lines
| Function: carry the mold uniform speed cycle operation External dimensions: The total length is about 19 meters Gear reducer: Model KCW97RC67-F-543-240914K, transmission ratio i: 543 Brand: Hui Xin Total power of pipeline KW: 45-55 |  |
refrigeration system
| Function: used for cooling the pouring head and mixing chamber Brand: KINGFIT, Model: QLB6FC/UU Nominal cooling capacity KW: 6.02 Power KW:1.91KW Rated voltage/V: 220 Number of pairs: 1 Frequency/Hz: 50 Refrigerant: R22 1.2kg Energy efficiency ratio: 3.2 |  |
Air compressor system
| Function: Cleaning and valve control provide power and cooling source for pneumatic system and pouring head cooling (Continuous power supply required) Brand: Deslan, model specification: DSR-30A Motor power: 22KW Rated/maximum exhaust capacity 1.0Mpa Exhaust volume: 3.2 cubic meters per minute |  |
Production and production efficiency
| production pattern | Double density mode (sandals/flip-flops) |
|---|---|
| Average time of circulation | About 12 minutes (two laps) |
| Class output (8 hours) | ≈ 1200 pairs (about 600kg--960kg of raw materials are needed) |
| Daily production (16 hours) | ≈ 2400 pairs (about 1200kg--1920kg of raw materials are needed) |
| Annual yield (300 days) | ≈ 720000 pairs (the raw material needs about 360t--576t) |
| production pattern | Dual-density mode (labor protection shoes) |
| Average time per cycle loop | About 18 minutes |
| Class output (8 hours) | ≈ 800 pairs (about 640kg--1120kg of raw materials are needed) |
| Daily production (16 hours) | ≈ 1600 pairs (the raw material needs about 1280kg--2240kg) |
| Annual yield (300 days) | ≈ 480000 pairs (the raw material needs about 384t--672t) |
Working conditions
| project | ask |
|---|---|
| Workshop requirements | Flat ground (area about 25m×5m), power supply, compressed air, cooling water, ventilation |
| Temperature and humidity | ≤40℃, no condensation environment |
| source | 3×380V±5%,50Hz, reliable grounding |
| compressed air | 0.7-0.8 MPa, dry oil free |
| cooling water | Clean, low mineral content, maximum inlet temperature 15℃ |
| operation staff | 4-5 trained operators (including pouring control, sampling, shoe removal, trimming, cleaning and spraying off the mold) |
Energy consumption
| project | numeric value |
|---|---|
| Installed power KW | The power of the pipeline is about 45-55, and other pouring systems (about 25-30) have a total power of about 70-85 |
| compressed air | 0.6-0.8 MPa, about 0.6 m3 / min |
| cooling water | About 6 m3 / h, ≤15℃ |
Full-Process Automated Production System
Integrated production line
Provide customized complete production lines covering all processes from raw material pretreatment to intelligent sorting. Core equipment adopts Haifeng's independently developed imported configuration, ensuring material mixing uniformity ≥98% and stable and reliable operation.
Customized adaptation
Rely on the CAD modeling and 3D printing capabilities of the Mechanical Design Research Institute to quickly produce customized molds and non-standard components, shortening the R&D cycle of new styles to 7-10 days.
Existing equipment transformation
Install Haifeng's intelligent temperature control, precision proportioning, and automated conveying modules to realize the transformation from solvent-based to solvent-free/water-based processes, reducing labor and raw material losses.
Comprehensive Quality Verification and Compliance Assurance
Intelligent quality inspection
Equip Haifeng's independently developed integrated testing equipment, covering thickness, defect, bonding strength, and key performance tests. With an efficiency of ≥50 pairs per minute, defective products are automatically sorted out.
Real-time control
Adopt Haifeng's intelligent production control system to dynamically adjust parameters, controlling the defect rate at 2-3%; integrate environmental monitoring modules to achieve near-zero VOC emissions.
Certification support
Cooperate with authoritative testing institutions to assist in completing multi-standard certifications, providing technical parameters and sample support to help obtain CE and LA certifications and break through high-end market barriers.
Solution Value and Effects
| Dimension | Traditional Process | Haifeng Automation Solution | Improvement Effects |
|---|---|---|---|
| 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 |
| Labor Requirement | 8-10 people/line | 2-3 people/line | Reduce by 75% and lower the risk of operational errors |
| VOC Emissions | Excessive | Near zero | Achieve environmental compliance and obtain international certifications |
| R&D Cycle | 30-45 days | 7-15 days | Shorten by over 60% for rapid market response |
Implementation Process
Demand Research
Technical team conducts on-site investigations to formulate personalized solutions.
Formula and Process Design
Complete customization and feasibility verification relying on the R&D Center.
Equipment Customization/Transformation and Commissioning
Factory completes production, with engineers conducting on-site installation and commissioning.
Small-Batch Trial Production
Technical team tracks and optimizes parameters.
On-Site Installation and Mass Production
Implement the production line and start mass production, providing technical guidance.
Quality Inspection and Certification Support
Assist in completing testing and certification applications.
After-Sales Operation and Maintenance
Provide maintenance and upgrading services relying on the national service network.
