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Plastic Injection Molding

Injection molding is a highly efficient and versatile manufacturing process, and our services stand out due to our advanced capabilities in dual-color injection molding, overmolding, and insert molding. These techniques enable us to produce complex, high-quality plastic parts with enhanced functionality, durability, and aesthetic appeal. Below, we elaborate on the key advantages of our injection molding services.

1. Dual-Color Injection Molding: Enhanced Aesthetics and Functionality

Dual-color injection molding allows the production of parts with two different materials or colors in a single molding cycle. This process offers several benefits:
Improved Product Design: By combining two materials, manufacturers can create parts with varying textures, colors, or hardness levels, enhancing both functionality and visual appeal.
Cost Efficiency: Since the process eliminates secondary assembly steps, it reduces labor costs and production time.
Better Ergonomics: Dual-material components, such as soft-grip handles or seals, improve user comfort and product durability.
Stronger Bonding: The two materials are fused during molding, ensuring a secure bond without the need for adhesives.
Our dual-color molding capabilities ensure precision and consistency, making it ideal for consumer electronics, automotive components, and medical devices.

2. Overmolding & Insert Molding: Durability and Multi-Material Integration

Overmolding and insert molding are specialized techniques that enhance part performance by combining different materials or embedding metal/plastic inserts.
Overmolding Benefits:
Enhanced Grip and Comfort: Soft thermoplastic elastomers (TPE) can be overmolded onto rigid plastics to create non-slip surfaces (e.g., tool handles, medical devices).
Vibration and Noise Damping: Overmolded layers absorb shocks, making them ideal for automotive and industrial applications.
Waterproofing and Sealing: Overmolding can create airtight seals for electronic enclosures or connectors.
Insert Molding Benefits:
Metal-Plastic Hybrid Parts: Inserts like brass threads or metal reinforcements are embedded into plastic parts, improving strength and reducing assembly steps.
Electrical Conductivity: Metal inserts enable conductive pathways in electronic housings.
Weight Reduction: Compared to all-metal components, insert-molded parts are lighter while maintaining structural integrity.
Our expertise in these processes ensures high precision, reduced waste, and superior product performance.

3. Flexible Production Volume: From Prototyping to Mass Production

We support production volumes ranging from 50 to 100,000 pieces, catering to both low-volume prototyping and high-volume manufacturing. This flexibility allows businesses to:
Test Market Viability: Small-batch production helps validate designs before full-scale manufacturing.
Reduce Inventory Costs: Just-in-time production minimizes excess stock.
Scale Efficiently: Our streamlined processes ensure consistent quality, whether producing hundreds or tens of thousands of parts.

4. High-Quality Mold Materials for Longevity and Precision

We use premium mold steels, including:
P20 Steel: Ideal for medium-volume production, offering excellent polishability and wear resistance.
NK80 Stainless Steel: Provides superior corrosion resistance, perfect for medical and food-grade applications.
H13 Mold Steel: Withstands high temperatures and prolonged use, ensuring durability for over 100,000 cycles.

These materials ensure:
Extended Mold Life: Reduces long-term tooling costs.
High Precision: Maintains tight tolerances (±0.01mm) for intricate designs.
Smooth Surface Finishes: Essential for aesthetic parts like consumer electronics.

5. Proactive Mold Maintenance for Uninterrupted Production

To guarantee consistent quality, we provide:
Regular Mold Inspections: Detects wear and tear early to prevent defects.
Timely Repairs: Minimizes downtime and maintains production efficiency.
Process Optimization: Adjusts parameters (temperature, pressure) to extend mold life.

6. High Durability for Cost-Effective Mass Production

Our molds have been meticulously designed to withstand more than million usage cycles, thereby ensuring:
Lower Per-Unit Costs: High-volume runs distribute mold costs effectively.
Consistent Quality: Even after thousands of cycles, parts maintain dimensional accuracy.
Sustainable Manufacturing: Durable molds reduce material waste and replacement frequency.

Our injection molding services—featuring dual-color molding, overmolding, and insert molding—deliver unmatched versatility, durability, and efficiency. With high-quality mold materials, flexible production scales, and proactive maintenance, we ensure high-performance plastic parts tailored to industries like automotive, medical, electronics, and consumer goods. Partner with Zhongyi Precision for precision, reliability, and cost-effective manufacturing solutions.

Display of Machined Finished Product Cases

Zhongyi Precision specializes in the production of high-performance injection molded transparent components and automotive-grade plastic parts. Below we will focus on three key transparent optical products and our automotive plastic solutions that drive innovation in various industries.

For Optical-Grade Camera Lenses

Designed for high-definition video and underwater photography, our polycarbonate (PC) and PMMA lenses feature:
>95% light transmission with anti-reflective coating options
Abrasion, UV and chemical resistance for long-term outdoor use
Precision molding (±0.01 mm tolerance) for distortion-free imaging
Durability in temperatures from -40°C to 120°C
Applications: surround view cameras, LiDAR sensors, night vision systems

Led Light Guide Components And Other Transparent Products

We produce ultra-clear light guides that optimize the lighting effect of automotive lighting:
Micro-patterned surface for uniform light diffusion
PMMA or optical-grade silicone materials
Thin-wall design with thickness as low as 0.5 mm
Customizable color adjustment for brand-specific lighting characteristics
Applications: daytime running lights, interior ambient lighting, instrument panels, crafts.

Automotive Structural And Functional Components

In addition to optical components, we also produce high-performance automotive plastic parts:
A. Underhood components
Intake manifold (PA66-GF35)
Charge air cooler housing
Thermal management components with high temperature resistance of 150°C and above
B. Interior and safety components
Dashboard bracket (PP+LGF)
Airbag housing with controlled deformation
Seat belt components in accordance with FMVSS 302 standard
C. Electrification components
Battery housing in accordance with UL94 V-0 standard
Charging port door with integrated seal
High-voltage connector housing

Manufacturing Advantages

Optical components are molded in Class 8 clean room
Scientific molding with cavity pressure monitoring
In-house metrology laboratory equipped with coordinate measuring machine (CMM) and optical profiler
IMD/IME capabilities for integrated decorative elements

Why work with us?

Materials expertise from commodity resins to engineered polymers
Vertical integration from tooling to final assembly
Global OEM/Tier 1 experience
We combine optical precision with automotive-grade durability, making us the ideal partner for your most demanding applications. Contact our engineering team today to discuss your project needs.

Introduction to the Advantages of Processing Services

Injection molding stands as the most efficient and reliable manufacturing process for mass-producing high-precision plastic parts.
At Zhongyi Precision, we have perfected this technology to deliver exceptional results with industry-leading tolerances control (±0.005mm achievable for critical applications). Below we present a detailed analysis of our injection molding advantages with specific focus on precision capabilities.

1. Unmatched Precision Engineering
Our advanced injection molding process delivers:
Ultra-tight tolerances: ±0.005mm for micro-molded components
Standard commercial tolerances: ±0.025mm to ±0.125mm
Medical-grade tolerances: ±0.010mm for implantable devices
Optical component tolerances: ±0.002mm wavefront distortion
Micro-feature resolution down to 0.05mm

2. Material Versatility with Precision Performance
We maintain strict tolerance control across materials:
Commodity resins (PP, ABS): ±0.15mm standard, ±0.05mm tight
Engineering plastics (POM, Nylon): ±0.10mm standard, ±0.03mm tight
High-performance polymers (PEEK, PEI): ±0.08mm standard, ±0.02mm tight
Optical polymers (PMMA, COP): ±0.05mm standard, ±0.01mm tight
Liquid Silicone Rubber (LSR): ±0.20mm standard, ±0.10mm tight

3. Advanced Process Control Systems
To maintain precision, we employ:
Closed-loop servo hydraulic systems (0.01mm repeatability)
Real-time cavity pressure monitoring (±1% variation control)
Melt temperature control within ±1°C
Injection speed accuracy ±0.5mm/sec
Pack pressure control ±0.2 bar

4. Surface Finish Excellence
Our capabilities include:
SPI A1 mirror finish (Ra <0.025μm)
VDI 3400 texture standards (VDI 0-VDI 45)
Optical clarity <0.5% haze
Class A automotive surfaces
Custom surface treatments (anti-fingerprint, anti-glare)

5. High-Volume Production with Consistent Quality
Cycle times optimized to ±0.5% variation
Automated quality inspection (100% dimensional verification)
Multi-cavity molds (up to 128 cavities) with <0.01mm variation
Tool life exceeding 2,000,000 cycles for high-volume production
24/7 production with <0.1% defect rate

6. Cost-Effective Manufacturing Solutions
Per-part cost reductions up to 60% at volume
Material utilization efficiency >98%
Integrated components reduce assembly costs by 30-50%
Fast changeover (<15 minutes for family molds)
Just-in-time manufacturing capability

7. Quality Assurance Systems
We are ISO9001 certified, and our product quality and workmanship meet ISO 13485 for medical applications, IATF 16949 for the automotive industry, and AS9100D for aerospace.
Full batch traceability
First Article Inspection Report (FAIR)
Statistical Process Control (CPK >1.67)
A full layout inspection report is provided before shipment.

Our injection molding services combine more than Three decades of processing experience and technical advantages to provide precision components for the most demanding industries such as aerospace, medical devices, automotive and microelectronics. We uphold scientific process optimization methods and strict quality standards to ensure that your parts meet precise specifications while maintaining cost-effectiveness.

Our advanced equipment, material expertise and process knowledge combine to enable us to push the limits of plastic injection molding. From prototyping to full-scale production, we maintain precision at every stage while optimizing manufacturability and cost-effectiveness.

Contact the Zhongyi Precision Engineering team today to discuss how these precision injection molding advantages can be applied to your specific application Requirements

Injection Molding & DFM Quick-Start Guide

The workflow integrates Design for Manufacturing (DFM) with material preparation, mold setup, production, and quality control.With over 30 years of injection molding expertise, Zhongyi Precision's senior engineers operate a complete range of equipment (50-6,600 tons) capable of fulfilling all your production requirements.

Design for Manufacturing (DFM) Phase
Material Preparation Phase
Mold Setup & Validation
Injection Molding Cycle
Part Ejection & Handling
Post-Molding Operations
Quality Control Process
Continuous Improvement

Design for Manufacturing (DFM) Phase

1.1 Initial Design Assessment
Conduct feasibility analysis of 3D part models
Evaluate material selection based on functional requirements
Identify potential manufacturing challenges
Establish critical-to-quality (CTQ) dimensions

1.2 Wall Thickness Optimization
Recommend uniform wall thickness (typically 1-4mm)
Identify and address thick sections causing sink marks
Suggest rib designs for structural reinforcement
Analyze flow length to thickness ratios

1.3 Draft Angle Application
Apply 1-3° draft angles to all vertical surfaces
Increase draft for textured surfaces (additional 1° per 0.025mm texture depth)
Identify critical surfaces requiring zero draft

1.4 Undercut Analysis
Identify all undercut features
Evaluate side-action or collapsible core requirements
Suggest design modifications to eliminate unnecessary undercuts
Calculate additional tooling costs for complex undercuts

1.5 Gate and Runner System Design
Select optimal gate type (edge, tunnel, pin, or hot tip)
Determine gate location for optimal filling
Size runners using mold flow analysis
Balance multi-cavity runner systems

1.6 Ejection Strategy
Plan ejector pin locations
Specify ejection plate requirements
Design stripper plates for thin-walled parts
Prevent part distortion during ejection
Learn More
Material Preparation Phase

2.1 Resin Selection
Choose base polymer based on mechanical requirements
Select appropriate additives (UV stabilizers, flame retardants)
Determine colorant percentage (typically 1-4%)
Verify material certification documents

2.2 Drying Process
Preheat drying hoppers to material-specific temperatures
Maintain drying times (2-6 hours depending on hygroscopicity)
Monitor dew point (-40°C for critical applications)
Verify moisture content (<0.02% for engineering resins)
Mold Setup & Validation

3.1 Mold Installation
Mount mold with precision alignment (within 0.02mm)
Connect cooling lines (water or oil thermal systems)
Install hot runner controllers (if applicable)
Set mold opening/closing speeds

3.2 Process Parameter Setup
Establish barrel temperature profile (3-5 zones)
Set screw rotation speed (20-150 RPM)
Program injection velocity profile (3-5 stages)
Configure holding pressure (50-80% injection pressure)
Injection Molding Cycle

4.1 Plasticization
Screw rotates to melt and homogenize material
Maintain consistent melt temperature (±3°C)
Build shot volume in front of screw
De-gas material when required

4.2 Injection Phase
Inject molten plastic at controlled velocity (50-300mm/sec)
Monitor cavity pressure in real-time
Complete fill within 0.5-5 seconds
Maintain consistent fill pattern

4.3 Packing & Holding
Apply secondary pressure (70-95% injection pressure)
Compensate for material shrinkage
Maintain pressure until gate seals
Typically lasts 5-30 seconds

4.4 Cooling Stage
Circulate temperature-controlled fluid through mold
Maintain consistent mold temperature (±2°C)
Cool part below ejection temperature
Typically 50-80% of total cycle time
Part Ejection & Handling

5.1 Mold Opening
Separate mold halves at controlled speed
Activate ejection system
Verify complete part release

5.2 Part Removal
Use robots or automated systems for consistent handling
Separate parts from runners (manual or automatic)
Place parts in protective containers
Monitor ambient conditions for sensitive materials
Post-Molding Operations

6.1 Gate Removal
Trim gates manually for prototypes
Use automated trimming for production
Smooth gate vestige
Inspect gate area for defects

6.2 Secondary Processing
Perform ultrasonic welding if required
Conduct heat staking for inserts
Apply surface treatments (painting, plating)
Execute precision machining when needed
Quality Control Process

7.1 First Article Inspection
Verify all critical dimensions
Check cosmetic appearance
Test functional requirements
Document measurements

7.2 Process Monitoring
Record key parameters every 15-30 minutes
Perform statistical process control
Adjust parameters as needed
Maintain production log
Continuous Improvement

8.1 Cycle Time Optimization
Reduce cooling time through mold modifications
Optimize robot movements
Streamline material handling
Implement automation where beneficial

8.2 Waste Reduction
Regrind and reuse sprues/runners
Minimize start-up scrap
Optimize shot size
Improve process consistency.

Display of Processable Materials

Surface Treatment Exhibits for Fabricated Components

After injection molding, plastic parts often require surface treatment to enhance their functionality, aesthetics, and durability. The following article details the various surface treatment options available, categorized by technology type, application method, and industry-specific benefits.

1. Mechanical Surface Treatment

1.1 Sandblasting
Process: Spraying the propelling medium (glass beads, aluminum oxide) at a pressure of 2-6 bar
Treatment method:
Dry blasting (20-200μm particle size)
Wet blasting (finer surface treatment)
Effect:
Matte texture (in accordance with VDI 3400 standard grade)
Parting line removal (edge uniformity ±0.1mm)
Paint adhesion improved by 300%
Application: Automotive interior, industrial housing

1.2 Precision polishing
Method:
Diamond polishing paste (for SPI A1 mirrors, 0.1-1μm polishing paste)
Chemical mechanical polishing (for optical lenses)
Equipment:
CNC polishing robot (uniformity ±0.01mm)
Manual polishing (for complex geometries)
Performance:
Coating rate of transparent parts with light transmittance >92%
Surface roughness Ra<0.025μm

2. Coating Technology

2.1 PVD (Physical Vapor Deposition)
Process:
Vacuum chamber deposition (10^-5 to 10^-6 mbar)
Target: CrN, TiAlN, DLC
Features:
Coating thickness 0.5-5μm
Hardness up to 3000 HV
Light absorption of optical components <0.5%
Application: wear-resistant gears, decorative parts

2.2 UV-cured coating
Chemical composition:
Acrylate oligomer, containing 2-5% photoinitiator
Curing wavelength: 365-405nm
Equipment:
Roller coater (5-50μm wet film)
UV LED array (3000mJ/cm²) (dose)
Advantages:
Curing time < 30 seconds
Pencil hardness up to 4H
Chemical resistance > 500 MEK rubs

2.3 Plating
Process flow:
Etching (chromic acid for ABS)
Catalysis (Pd/Sn colloid)
Electroless nickel plating (5-15μm)
Copper/nickel/chromium plating (optional)
Key parameters:
Current density: 1-5 A/dm²
Bath temperature: 40-60°C
Applications: automotive logos, EMI shielding

3. Etching

Solutions:

Chromic acid (for ABS/PC)
Potassium permanganate (for PP)
Process control:
Temperature: 60-80°C
Time: 2-10 minutes
Neutralization required

Results:
Surface morphology changes 0.5-2μm
Enhanced adhesion for insert molding

4. Decorative Surface Treatment

4.1 IMD/IML (In-Mold Decoration)
Film type:
PET/PC (thickness 150-300μm)
Digital printing (resolution 600dpi)
Process:
Film insertion accuracy ±0.05mm
3D molding depth ratio increased to 1:1
Applications: Instrument panels, electrical interfaces
4.2 Water transfer
Steps:
Primer spraying (20-30μm)
Thin film activation (25-32°C water)
Varnish protection (2K polyurethane)
Features:
500 available patterns
Wrapping complex geometries (chamfers >60°)

5. Functional Treatments

Technology:
Nanosecond laser (10-100μm features)
Femtosecond laser (sub-micron accuracy)
Parameters:
1064nm wavelength (suitable for most polymers)
0.1-20J/cm² energy density
Benefits:
Mold texture replication fidelity >95%
Design changes without mold costs
Material selection guide
Recommended materials Avoid treatments
ABS Plating, painting Solvent welding
Polycarbonate Hard coating, IMD Alkaline cleaners
PP plasma, flame treatment Unmodified plating
PEEK Laser marking, sandblasting Chromic acid
Quality verification methods
Adhesion testing: ASTM D3359 (requires Class 5B)
Thickness measurement:
X-ray fluorescence (for metallic coatings)
Elcometer (for organic coatings)
Accelerated weathering:
QUV testing (500-1000 hours UV exposure)
Thermal cycling (-40°C to 85°C, 50 cycles)
A comprehensive portfolio of surface treatments enables customized plastic parts:
Aesthetic requirements (Class A automotive, consumer electronics)
Functional requirements (EMI shielding, fluid resistance)
Regulatory compliance (FDA, RoHS, REACH)
Each technology requires careful consideration of:
Part geometry (undercut, wall thickness)
Production volume (batch vs. continuous production)
Cost target ($0.05-5 per part)
Environmental conditions (outdoor vs. sterile environment)

Do You Need Specific Process Recommendations For Your Material/Application Combination?

Please click on the contact window to get reliable advice for your project.

Sandblasting

Electroplate

Polish

What Our Customers Say

Andrew

The precision and quality of your machined parts are outstanding! They fit perfectly into our assembly with zero issues. Will definitely order again!

2024.10.3

Peter

Excellent work! The parts were delivered on time and met all our specifications. Your attention to detail is impressive. Highly recommended!

2024.10.3

Gowthaman

We're very satisfied with the machining services provided. The finish and tolerances are exactly as required. Great job and smooth communication throughout!

2024.10.3

Romen

Consistently high-quality machining services. This is our third order, and as always, no complaints. Keep up the great work!

2024.10.3

Let Us Turn Your Ideas Into Reality - Send Your Inquiry Now!

Zhongyi Precision focuses on providing high-quality injection molding solutions, with more than 30 years of professional experience and a full range of equipment (50-6,600 tons). Whether you need precision prototypes or mass production, we are always ready to provide you with high-quality, fast and cost-effective products.
Why choose us?
End-to-end support - from DFM analysis to post-processing
Material diversity - engineering plastics, liquid silicone rubber (LSR), optical grade polymers, etc.
Precision tolerances- critical application tolerances can reach ± 0.005 mm
Dual-color injection molding - reduce the time and labor cost required for post-processing processes, and the color can be applied directly to the mold.
Fast Delivery – Prototyping within 3-7days and mass production capacity of over 100,000 molds
Next Steps:
Simply reply with your 3D files, material specifications and quantity requirements and our engineers will provide you with:
Free DFM review
Competitive quote within 12 hours
Samples available upon requirements

Plastic Injection Molding

1. Dual-Color Injection Molding: Enhanced Aesthetics and Functionality

2. Overmolding & Insert Molding: Durability and Multi-Material Integration

3. Flexible Production Volume: From Prototyping to Mass Production

4. High-Quality Mold Materials for Longevity and Precision

5. Proactive Mold Maintenance for Uninterrupted Production

6. High Durability for Cost-Effective Mass Production

Display of Machined Finished Product Cases

For Optical-Grade Camera Lenses

Led Light Guide Components And Other Transparent Products

Automotive Structural And Functional Components

Manufacturing Advantages

Why work with us?

Introduction to the Advantages of Processing Services

Injection Molding & DFM Quick-Start Guide

Display of Processable Materials

Surface Treatment Exhibits for Fabricated Components

1. Mechanical Surface Treatment

2. Coating Technology

3. Etching

4. Decorative Surface Treatment

5. Functional Treatments

Do You Need Specific Process Recommendations For Your Material/Application Combination?

What Our Customers Say

Andrew

Peter

Gowthaman

Romen

Let Us Turn Your Ideas Into Reality - Send Your Inquiry Now!

Quick Links

Product Category

Contact Us

Plastic Injection Molding

1. Dual-Color Injection Molding: Enhanced Aesthetics and Functionality

2. Overmolding & Insert Molding: Durability and Multi-Material Integration

3. Flexible Production Volume: From Prototyping to Mass Production

4. High-Quality Mold Materials for Longevity and Precision

5. Proactive Mold Maintenance for Uninterrupted Production

6. High Durability for Cost-Effective Mass Production

Display of Machined Finished Product Cases

For Optical-Grade Camera Lenses

Led Light Guide Components And Other Transparent Products

Automotive Structural And Functional Components

Manufacturing Advantages

Why work with us?

Introduction to the Advantages of Processing Services

Injection Molding & DFM Quick-Start Guide

Display of Processable Materials

Surface Treatment Exhibits for Fabricated Components

1. Mechanical Surface Treatment

2. Coating Technology

3. Etching

4. Decorative Surface Treatment

5. Functional Treatments

Do You Need Specific Process Recommendations For Your Material/Application Combination?

What Our Customers Say​​​​​​​

Andrew

Peter

Gowthaman

Romen

Let Us Turn Your Ideas Into Reality - Send Your Inquiry Now!

Quick Links

Product Category

Contact Us

What Our Customers Say