Views: 0 Author: Site Editor Publish Time: 2026-02-25 Origin: Site
In the injection molding industry, the question of whether to use a cleanroom—and what standard it needs to meet—comes up frequently. The answer is never one-size-fits-all: it completely depends on your product's application and precision requirements.
The difference between an ISO 8 Class (100,000 level) cleanroom for general industrial parts and an ISO 5 Class (Class 100) cleanroom for medical implants is massive—in both technical requirements and investment cost.
Today, we'll break down the cleanroom standards for injection molding, helping you understand what level your product actually needs.
Cleanrooms for injection molding primarily follow two main standard systems:
| Standard System | Standard Number | Scope |
|---|---|---|
| International Standard | ISO 14644-1 | Global cleanroom classification standard, classifying cleanliness levels based on airborne particle concentration |
| Chinese National Standard | GB 50073-2001 | "Code for Design of Clean Rooms" – basis for domestic cleanroom design |
| GB 50591-2010 | "Code for Construction and Acceptance of Clean Rooms" |
This is the core reference table for determining cleanroom requirements. Different classes correspond to different limits for airborne particle concentrations:
| ISO Class | Maximum Concentration Limit for ≥0.5μm Particles (particles/m³) | Equivalent US 209E Standard | Typical Applications |
|---|---|---|---|
| ISO Class 5 | 3,520 | Class 100 | Medical implants, surgical instruments, microchip manufacturing |
| ISO Class 6 | 35,200 | Class 1,000 | Precision electronics, medical core zone local areas |
| ISO Class 7 | 352,000 | Class 10,000 | Medical consumables, electronic connectors, precision automotive parts |
| ISO Class 8 | 3,520,000 | Class 100,000 | Food packaging, precision automotive parts, general medical parts |
| ISO Class 9 | 35,200,000 | Class 300,000 | General industrial parts, everyday products |
Based on industry standards, different injection molded products require different cleanliness levels:
| Product Type | Recommended Cleanroom Class | ≥0.5μm Particle Control Target | Air Changes per Hour |
|---|---|---|---|
| Medical Implants (surgical instruments, infusion port connectors) | ISO Class 5 (Class 100) | ≤3,520 particles/m³ | ≥150 times/hour |
| Medical Consumables Core Zone (e.g., infusion set interface molding stations) | ISO Class 6 (Class 1,000) local | — | Local laminar flow: 0.35-0.5 m/s |
| Medical Consumables Background Zone, Electronic Connectors | ISO Class 7 (Class 10,000) | ≤352,000 particles/m³ | ≥25-30 times/hour |
| Food Packaging, Precision Automotive Parts | ISO Class 8 (Class 100,000) | ≤3,520,000 particles/m³ | ≥15-20 times/hour |
| General Industrial Parts | ISO Class 9 | ≤35,200,000 particles/m³ | ≥12 times/hour |
Special Note: For medical products, in addition to particle control, microbiological monitoring is required—airborne bacteria ≤100 CFU/m³, settling bacteria ≤3 CFU/plate, meeting GMP requirements for sterile medical device production.
Beyond cleanliness, cleanrooms require control of the following parameters:
| Parameter | Control Standard | Notes |
|---|---|---|
| Temperature | General: Winter >16°C±2°C, Summer <26°C±2°C Precision molding: 22±1°C Medical/Electronics: 22±2°C | Stabilizes melt flow, reduces dimensional variation |
| Relative Humidity | General: 45-65% RH Precision molding: 55±3% RH PA material storage: 40-50% (prevents hydrolysis) PC molding: ≤50% (avoids silver streaking) | Reduces electrostatic attraction, prevents material moisture absorption |
| Pressure Differential | Clean zone to non-clean zone: ≥10Pa positive pressure Between different class cleanrooms: ≥5Pa | Prevents backflow of lower-class air |
| Air Changes per Hour | ISO Class 5: ≥150 times/hour ISO Class 7: 25-30 times/hour ISO Class 8: 15-20 times/hour | Ensures air purification effectiveness |
| Illumination | Main areas: ≥300 Lux Inspection/operation areas: ≥500 Lux | Meets production operation requirements |
| Noise | ≤65 dB(A) | Protects operator hearing |
| Fresh Air Makeup | 20%-30% of total supply air | Ensures indoor air quality |
If your product is a medical device, in addition to the particle control requirements of ISO 14644, the following special requirements apply:
Airborne bacteria: ≤100 CFU/m³ (ISO Class 7 background zone)
Settling bacteria: ≤3 CFU/plate (ISO Class 7 background zone)
Regular microbiological and particle沉降 testing required
Mold surface roughness: Control to Ra 0.05μm or below, reducing particles generated by plastic flow friction
Injection molding machine: Use all-electric machines to reduce contamination from hydraulic oil leakage; barrel and screw surface roughness Ra≤0.8μm
Lubrication system: Use food-grade lubricants to avoid contamination
Medical-grade cleanrooms must pass a three-level validation process:
Design Qualification (DQ): Verify meets product precision requirements
Installation Qualification (IQ): Verify equipment positioning, leak-free piping connections
Operational Qualification (OQ): Continuous monitoring, parameter达标
Performance Qualification (PQ): Simulate production, verify product合格率
Medical-grade facilities must pass:
ISO 13485 (Medical devices – Quality management systems)
GMP (Good Manufacturing Practice) audits
To meet the above standards, a cleanroom requires the following systems:
| Filtration Stage | Filtration Efficiency | Function |
|---|---|---|
| Primary Filter (G4) | Captures ≥5μm particles | Protects subsequent filter layers |
| Medium Filter (F8) | Captures 1-5μm particles | Reduces HEPA filter load |
| HEPA Filter (H13/H14) | ≥0.3μm particle efficiency ≥99.97% | Ensures final cleanliness |
ISO Class 5 areas: ULPA filters (U15) required at the end, with ≥99.9995% efficiency for 0.12μm particles
Pressure gradient: Clean zone to non-clean zone ≥10Pa, between different class cleanrooms ≥5Pa
Airflow pattern: ISO Class 5 areas require vertical unidirectional flow (velocity 0.35-0.5 m/s); ISO Class 7-8 use turbulent flow with adequate air changes
Flooring: Anti-static epoxy self-leveling, surface resistance 10⁶-10⁹Ω, ground resistance ≤1Ω
Ionizers: Install at critical workstations
Personnel protection: Anti-static workwear, conductive shoes (resistance 10⁶-10⁸Ω)
| Your Product | Recommended Cleanroom Class | Key Control Points | Estimated Air Changes |
|---|---|---|---|
| Surgical instruments, implants | ISO Class 5 | Particles + microbiology, local laminar flow | ≥150 times/hour |
| Infusion sets, syringes, catheters | ISO Class 7 background + local ISO Class 6 | Microbiological monitoring, GMP compliance | ≥25-30 times/hour |
| Electronic connectors, precision terminals | ISO Class 7 | Particle control, electrostatic protection | ≥25-30 times/hour |
| Food packaging containers | ISO Class 8 | Microbiology + odor control | ≥15-20 times/hour |
| Automotive sensor housings | ISO Class 8 | Particle control, stable temperature/humidity | ≥15-20 times/hour |
| General housings, daily products | ISO Class 9 or workshop | Basic dust prevention | ≥10-12 times/hour |
Once your cleanroom is built, ongoing maintenance and regular validation are essential:
| Item | Maintenance Cycle | Requirements |
|---|---|---|
| Primary filters | Monthly replacement | Replace when resistance exceeds 1.5× initial value |
| Medium filters | Quarterly replacement | Same as above |
| HEPA filters | Leak test every 6-12 months | Leak rate ≤0.01% |
| Environmental monitoring | Daily | Temperature, humidity, pressure differential records |
| Particle concentration | Weekly | Test critical areas |
| Microbiological monitoring | Monthly | Airborne bacteria, settling bacteria |
| Anti-static performance | Monthly | Floor resistance, ground resistance |
The core logic for selecting cleanroom standards is: Let product precision determine cleanliness class, and production process determine system configuration.
Medical implants: ISO Class 5 (Class 100), microbiological control, GMP compliance
Medical consumables/Electronics: ISO Class 7 (Class 10,000), particle + microbiological dual control
Food packaging/Automotive precision parts: ISO Class 8 (Class 100,000), basic cleanliness
General industrial parts: ISO Class 9 or workshop
If you're manufacturing medical products for export, we recommend targeting ISO Class 7 or higher and ensuring ISO 13485 certification. This positions you to meet FDA and CE market access requirements effectively.
