Systematic solutions to common problems of plastic parts (with process parameters and radical soluti
Time：2025-08-16 08:08:53 / Popularity： / Source：
Problem solving matrix and core technologies
| Defect types | Generation mechanism | Key technical solutions | Key parameter control |
| Glue shortage | Insufficient fluidity/poor exhaust | 1. Add high shear flow channel design 2. Vacuum assisted injection molding |
Melt flow rate ≥150mm/s, vacuum degree ≤-0.08MPa |
| Cape | Insufficient clamping force/excessive clearance | 1. Zero clearance sealing technology 2. Intelligent clamping system |
PL surface matching ≤0.005mm, clamping force fluctuation <±1% |
| Bubbles | Volatile gas aggregation/involved air | 1. Pulsating pressure holding 2. Supercritical fluid foaming |
Pressure holding gradient: 100%→80%→60%, pressure pulsation frequency 2Hz |
| Shrinkage | Insufficient shrinkage compensation | 1. Dynamic pressure holding compensation 2. Conformal cooling |
Press holding time = (wall thickness × 1.5) s, cooling water temperature difference < 3 ℃ |
| Welding mark | Low-temperature intersection of melt front | 1. Turbine column design 2. Local high-frequency heating |
Convergence angle > 135°, heating power density 30W/cm² |
Material property correction factor: Glass fiber reinforced materials need to increase press holding pressure by 15%-20%
Technical details of radical solution
1. Solution to glue shortage problem
■ **Revolutionary flow channel design**
- Conical acceleration flow channel: inlet Φ6mm → end Φ3mm (acceleration ratio 2:1)
- Surface nanotexturing: micro-pits Φ0.1mm deep 0.02mm (reduced flow resistance by 35%)
- Material: beryllium copper alloy (thermal conductivity 105W/mK)
■ **Exhaust system upgrade**
```plaintext
Three-stage exhaust structure:
1. Main exhaust slot: 0.02×0.5mm (one group per 50mm²)
2. Micropore exhaust: laser drilling Φ0.05mm (density 200 holes/cm²)
3. Vacuum system: -0.08MPa suction (response time <0.5s)
#### **2. Cloak (flash) eradication technology**
```mermaid
graph LR
A[cloak control] --> B[mold dimension]
A --> C[process dimension]
B --> B1(PL surface nano-seal)
B --> B2(slider hydraulic locking)
C --> C1(melt viscosity control)
C --> C2(precise V/P switching)
Sealing innovation:
► PL surface laser micro-cladding: pre-arch 0.005mm
► Intelligent clamping: piezoelectric film real-time monitoring + servo compensation
Process essence:
■ Viscosity window: PC material melt index 12±1g/10min
■ V/P switching point accuracy: ±0.3% filling volume
3. Dual-path strategy for bubble elimination
● Physical path: supercritical N₂ foaming
├─ Injection pressure: 35MPa
├─ Gas solubility: 0.15wt%
└─ Cell density: 10⁹/cm³
● Chemical path: nano degassing agent
├─ Particle size: 30nm calcium oxide
├─ Addition amount: 0.3%
└─ Reaction formula: CaO + H₂O → Ca(OH)₂
4. Dynamic model for shrinkage compensation
Pressure compensation algorithm:
P(t) = P₀ * exp(-k·t) + ΔP·(1 - t/t₀)
Where: P₀=initial pressure holding pressure (MPa)
k=material attenuation coefficient (POM takes 0.15/s)
ΔP=pressure increment (usually 8-12MPa)
t₀=total holding time (s)
Cooling system configuration:
■ Thin-walled area: turbulent cooling (Reynolds number Re>4000)
■ Thick-walled area: heat pipe conduction (λ≥5000W/mK)
5. Weld mark strengthening system
Structural strengthening solution
Technical details of radical solution
1. Solution to glue shortage problem
■ **Revolutionary flow channel design**
- Conical acceleration flow channel: inlet Φ6mm → end Φ3mm (acceleration ratio 2:1)
- Surface nanotexturing: micro-pits Φ0.1mm deep 0.02mm (reduced flow resistance by 35%)
- Material: beryllium copper alloy (thermal conductivity 105W/mK)
■ **Exhaust system upgrade**
```plaintext
Three-stage exhaust structure:
1. Main exhaust slot: 0.02×0.5mm (one group per 50mm²)
2. Micropore exhaust: laser drilling Φ0.05mm (density 200 holes/cm²)
3. Vacuum system: -0.08MPa suction (response time <0.5s)
#### **2. Cloak (flash) eradication technology**
```mermaid
graph LR
A[cloak control] --> B[mold dimension]
A --> C[process dimension]
B --> B1(PL surface nano-seal)
B --> B2(slider hydraulic locking)
C --> C1(melt viscosity control)
C --> C2(precise V/P switching)
Sealing innovation:
► PL surface laser micro-cladding: pre-arch 0.005mm
► Intelligent clamping: piezoelectric film real-time monitoring + servo compensation
Process essence:
■ Viscosity window: PC material melt index 12±1g/10min
■ V/P switching point accuracy: ±0.3% filling volume
3. Dual-path strategy for bubble elimination
● Physical path: supercritical N₂ foaming
├─ Injection pressure: 35MPa
├─ Gas solubility: 0.15wt%
└─ Cell density: 10⁹/cm³
● Chemical path: nano degassing agent
├─ Particle size: 30nm calcium oxide
├─ Addition amount: 0.3%
└─ Reaction formula: CaO + H₂O → Ca(OH)₂
4. Dynamic model for shrinkage compensation
Pressure compensation algorithm:
P(t) = P₀ * exp(-k·t) + ΔP·(1 - t/t₀)
Where: P₀=initial pressure holding pressure (MPa)
k=material attenuation coefficient (POM takes 0.15/s)
ΔP=pressure increment (usually 8-12MPa)
t₀=total holding time (s)
Cooling system configuration:
■ Thin-walled area: turbulent cooling (Reynolds number Re>4000)
■ Thick-walled area: heat pipe conduction (λ≥5000W/mK)
5. Weld mark strengthening system
Structural strengthening solution
| **Spoiler column array** | **Micro heating coil** | **Energy controller** |
| Φ1.2mm×45° tilted | Constantan alloy wire Φ0.1mm | 20kHz high-frequency power supply |
| Spacing = 3×wall thickness | Power density 30W/cm² | PID temperature control ±1℃ |
| Accelerate melt convergence | Local temperature rise 30-50℃ | Response time <0.1s |
Process window control standard
| Parameters | Ordinary plastics | Engineering plastics | Ultra-precision requirements |
| Barrel temperature | ±5℃ | ±3℃ | ±1℃ |
| Mold temperature | ±3℃ | ±1.5℃ | ±0.5℃ |
| Injection speed | ±5% | ±2% | ±0.5% |
| V/P switching point | ±2% | ±1% | ±0.3% |
| Packaging pressure | ±0.5MPa | ±0.2MPa | ±0.05MPa |
Frontier technology application
1. Digital twin system:
- Real-time mapping of molding process
- Predict defects 20 seconds in advance
- Automatically generate optimization parameters
2. Self-repairing mold:
- Microcapsule repair agent: repair 0.05mm cracks
- Shape memory alloy: compensate for thermal deformation
- Smart coating: regenerate 2μm coating after wear
Effect verification index:
1. Digital twin system:
- Real-time mapping of molding process
- Predict defects 20 seconds in advance
- Automatically generate optimization parameters
2. Self-repairing mold:
- Microcapsule repair agent: repair 0.05mm cracks
- Shape memory alloy: compensate for thermal deformation
- Smart coating: regenerate 2μm coating after wear
Effect verification index:
| Defect type | Defect rate before improvement | Target after improvement | Detection method |
| Glue shortage | 3.5% | ≤0.1% | CT scanning + weighing method |
| Cloak | 5.2% | ≤0.05% | Laser profile scanning |
| Bubble | 2.8% | ≤0.01% | Microfocus X-ray imaging |
| Shrinkage | 4.1% | ≤0.3% | White light interferometer |
| Weld mark | 6.3% | ≤0.2% | Polarized light stress detection |
Implementation of this solution can achieve:
▪ Reduce the overall defect rate by 95%
▪ Increase material utilization rate by 15%-25%
▪ Extend mold maintenance cycle by 300%
Six-word motto of injection molding factory:
Material must be pure · Mold must be accurate · Temperature must be stable · Pressure must be precise · Speed must be controlled · Air must be smooth
▪ Reduce the overall defect rate by 95%
▪ Increase material utilization rate by 15%-25%
▪ Extend mold maintenance cycle by 300%
Six-word motto of injection molding factory:
Material must be pure · Mold must be accurate · Temperature must be stable · Pressure must be precise · Speed must be controlled · Air must be smooth
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