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Plastic Injection Molding

Expert plastic injection molding solutions for custom prototypes and production parts. From concept to completion, TOUWEI delivers high-quality molded components with rapid turnaround times.

custom plastic injection molding- Tuowei Precision
What Is Injection Molding?

Injection molding is one of the most efficient and cost-effective methods for manufacturing plastic parts at scale. The process involves injecting molten plastic into a precision-engineered mold, where it cools and solidifies into the desired shape. This cycle repeats rapidly, producing hundreds or thousands of identical components with consistent quality. Because the same mold is used for every run, costs per unit decrease significantly, making it an ideal solution for large-volume production. Compared to CNC machining or 3D printing, injection molding offers unmatched flexibility in materials, colors, finishes, and surface textures—perfect for both functional and aesthetic applications.

How Custom Plastic Injection Molding Works?

The plastic injection molding process requires three key elements: an injection molding machine, raw plastic material, and a high-quality mold tool. The raw material is melted inside the machine and then injected into the mold cavity, typically made from hardened steel or aluminum where it cools and solidifies into the final part. This repeatable process ensures high efficiency, low waste, and consistent output across every cycle.

Our engineers use your CAD data to create precision mold tooling using CNC machining and other advanced techniques. Once the initial parts are molded, we provide sample runs for validation and fine-tuning before moving into full-scale production. From small medical components to large, complex parts for automotive and aerospace applications, our team ensures that every product is manufactured with accuracy, speed, and reliability.

custom plastic injection molding- Tuowei Precision

TUOWEI Plastic Injection Molding Services for Custom Parts

TUOWEI Precision makes it simple to move from rapid prototypes to full-scale production with high-quality, cost-effective plastic parts delivered in just days. Backed by expert engineering support, we offer comprehensive solutions including precision mold tooling, overmolding, and insert molding. Partnering with TUOWEI means faster lead times, consistent quality, and the flexibility to scale production while keeping costs competitive.

Injection Mold Tooling

We deliver aluminum and steel molds, achieving 0.0008 in tolerances with free mold flow analysis provided.

Overmolding

Our overmolding process bonds plastics to substrates, creating durable, integrated products with strength, flexibility, and customizable finishes.

Insert Molding

Insert molding combines plastics with pre-placed inserts, eliminating fasteners while enhancing strength, efficiency, and overall part performance.

TUOWEI PRECISION Injection Molding Tolerances

TUOWEI Precision delivers advanced injection molding solutions with tight tolerances. Our capabilities guarantee consistent, high-quality production with efficiency and reliability for projects across diverse industries.

Plastic Injection Molding Service Tolerance
Standard Plastic Injection Molding ±0.005" (±0.127 mm)
High-Precision Plastic Molding ±0.001" (±0.025 mm)
Plastic Molding for Large Parts ±0.010" (±0.254 mm)
Plastic Molding with Thin Walls ±0.005" (±0.127 mm)
High-Volume Plastic Molding ±0.003" (±0.076 mm)

plastic injection molding guideline

TUOWEI Precision ensures reliable injection molding tolerances, delivering consistent accuracy and quality for every project.

Design Element Guideline
Wall Thickness Uniform thickness of 1.5 mm to 3 mm is recommended. 
Radii and Corners Minimum radius of 0.5 mm for internal corners. 
Draft Angles Draft angle of 1° to 2° is recommended on vertical walls to ensure smooth part ejection.
Undercuts Use side actions or lifters to accommodate undercuts. Proper mold design is necessary for parts with undercuts.
Tolerances Standard tolerance of ±0.1 mm. For tighter tolerances (±0.01 mm).
Text and Logos Minimum engraving depth of 0.1 mm and width of 0.5 mm. 
Holes and Features Minimum hole diameter of 1.5 mm. For holes larger than 5 mm.
Parting Line and Gate Gates should be placed to minimize defects, and parting lines should be positioned in non-visible areas.
Material Selection Choose appropriate materials such as ABS, polycarbonate, or nylon.

Surface Finishes For Plastic Injection Molding

Following are the surface finishing techniques used to enhance the appearance and functionality of molded parts:

Polishing

Polishing removes imperfections and burrs from the surface, providing a smooth, glossy finish on the molded parts.

Bead Blasting

Bead blasting creates a consistent matte surface finish that helps mask any mold lines or imperfections on quick-turn parts.

Texturing

Texturing adds visual appeal and grip to the surface of the part, commonly used for quick-turn consumer goods with tactile requirements.

Laser Engraving

Laser engraving is used for precise marking or part identification, allowing for high-speed production without compromising quality.

Vibratory Finishing

Vibratory finishing is used to smooth rough edges and surfaces, ensuring quick-turn molded parts meet both aesthetic and functional standards.

Electroplating

Electroplating applies a thin metal coating, enhancing the part’s appearance, wear resistance, and corrosion protection.

Materials for Plastic Injection Molding

Engineers and leading manufacturers trust TUOWEI  for fast iterations and durable, high-performance parts. Whether for prototyping or full-scale production, our extensive material selection ensures precision, strength, and reliability for any CNC machining project.

General-purpose ABS

High-Impact ABS

Flame Retardant ABS

Medical ABS

 

Low-Density Polyethylene (LDPE)

High-Density Polyethylene (HDPE)

Linear Low-Density Polyethylene (LLDPE)

General-purpose PS

High-Impact PS

Crystal PS

Rigid PVC

Flexible PVC, CPVC

High-Impact PVC

Nylon 6

Nylon 6/6

Glass-Filled Nylon

Heat-Resistant Nylon

Homopolymer POM

Copolymer POM

Glass-Filled POM

Styrenic Block Copolymers (SBC)

Thermoplastic Vulcanizates (TPV)

Thermoplastic Polyurethane (TPU)

PET

PET-G (glycol-modified)

 PET-High Crystallinity (HCPET)

Rigid PU

Flexible PU

TPU (Thermoplastic Polyurethane)

Noryl (PPO blended with polystyrene)

High-Temperature PPO

With Tuowei Precision’s CNC milling service, you’re not just investing in advanced machinery. You’re gaining the assurance of flawless precision, commitment to strict timelines, and the expertise of skilled professionals dedicated to meeting your needs.

Choose Us

Why
/01

High Quality Parts

Tuowei Precision’s ISO-certified CNC machining guarantees exceptional accuracy and quality. Every part is crafted for perfect fit and flawless performance, with rigorous quality control at each stage.

/02
Fast Turnaround

Stay on schedule with Tuowei Precision. Our state-of-the-art equipment and local workshops deliver rapid production to meet your tight deadlines.

/03
Expert Engineering Support

Rely on our team for comprehensive CNC machining support. Our experts are available to optimize design efficiency and ensure top-quality results at every step.

TUOWEI Precision Injection Molding Quality Control

At TUOWEI Precision, quality is at the core of every project. From design to production, our cross-functional reviews and rigorous checks ensure superior results, delivering up to a 90% first-pass yield on all plastic molded parts.

Mold and Pre-Production Inspection

We start with precision mold design and thorough pre-production reviews. Our engineers carefully evaluate geometry, material flow, and cooling systems to ensure seamless processing. Trial runs are conducted to confirm mold performance, guaranteeing stability and consistency before full-scale production.

In-Process Quality Control

During manufacturing, strict monitoring ensures reliability at every stage. Key injection parameters—including temperature, pressure, and speed—are maintained within defined limits. Regular dimensional and visual checks help detect deviations early, reducing waste and ensuring consistent product quality.

Final Inspection

Before delivery, all parts undergo comprehensive final inspection. Our team evaluates dimensions, surface quality, and physical performance using advanced tools such as CMMs and colorimeters. This ensures every component meets both customer requirements and TUOWEI’s strict internal standards.

Advanced 5-axis CNC machining for rapid prototyping projects- Tuowei Precision

APPLICATIONS

Applications of Injection Molding at TUOWEI Precision

Injection molding is a highly efficient process used to manufacture a wide range of products, from automotive components to medical devices. It delivers consistent, high-quality parts with tight tolerances at a low cost per unit, making it the preferred choice for mass production across industries.

Advantages

Advantages of Injection Molding at TUOWEI Precision

Injection molding is a highly efficient process used to manufacture a wide range of products, from automotive components to medical devices. It delivers consistent, high-quality parts with tight tolerances at a low cost per unit, making it the preferred choice for mass production across industries.

Let’s Build What’s Next Together

Partner with TUOWEI to Shape Your Vision

From detailed prototypes to high-volume production runs, TUOWEI is your trusted partner for precision CNC machining. Reach out today and take the first step toward streamlined, high-quality manufacturing solutions.

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What are the Different Types of Injection Molding?

Injection molding includes a range of specialized methods, each designed to suit different materials, geometries, and production goals, making it possible to manufacture anything from micro-scale components to large, intricate parts with precision and efficiency.

Plastic Injection Molding

This is the most common process, where molten plastic is injected into a metal mold to form high-precision parts. It’s ideal for mass-producing identical items quickly and cost-effectively.
Advantage: Excellent for high-volume production with consistent quality.
Limitation: High upfront tooling costs make it less economical for small runs.

Overmolding

Overmolding combines two or more materials in one part by molding a secondary material over a base component. Often used for ergonomic grips, soft-touch surfaces, or sealing functions.
Advantage: Enhances product functionality and aesthetics without extra assembly.
Limitation: Requires complex mold design and careful material compatibility checks.

Insert Molding

In this process, pre-made inserts (like metal parts) are placed into the mold, and plastic is molded around them. Common in electronics and automotive applications.
Advantage: Strong bonding between components and reduced assembly steps.
Limitation: Manual placement of inserts can slow production if automation is not used.

Gas-Assisted Injection Molding

Gas is injected into the molten plastic inside the mold to create hollow sections, reducing weight and material use. Often used for large, thick-walled parts.
Advantage: Produces lightweight yet strong components with minimal warping.
Limitation: Higher equipment and process complexity compared to standard molding.

Micro-Injection Molding

This method manufactures extremely small and precise components, often under 1 gram in weight. Widely used in medical devices, electronics, and micro-mechanics.
Advantage: Unmatched precision for tiny, intricate designs.
Limitation: Specialized machinery and expertise are required, increasing costs.

What Challenges Exist in Injection Molding and How TUOWEI Solves Them?

Injection molding can present hurdles such as defects, material inconsistencies, and dimensional variances, these challenges are overcome through advanced engineering, precise mold design, and rigorous quality control, ensuring flawless results from the first shot to the millionth.

Warping and Dimensional Inaccuracy

The Challenge: Warping occurs when different sections of a molded part cool at different rates, causing bending or twisting. This can compromise part fit and function, especially in high-precision industries like automotive or medical.
TUOWEI’s Solution: We use advanced mold temperature control systems and uniform cooling channel designs to ensure even cooling, along with material selection strategies to reduce shrinkage rates.

Sink Marks and Surface Imperfections

The Challenge: Sink marks small depressions on the surface happen when thicker sections cool unevenly, leading to cosmetic and structural defects.
TUOWEI’s Solution: Our engineers optimize part geometry in the design phase, adjust packing pressure profiles, and use simulation software to predict and eliminate sink mark risks before production.

Flash Formation on Mold Parting Lines

The Challenge: Flash refers to excess material seeping out at mold parting lines, which requires post-processing and increases production costs.
TUOWEI’s Solution: We maintain precision tooling with tolerances as tight as ±0.005 mm, perform regular mold maintenance, and use clamping force calibration to prevent material leakage.

Short Shots and Incomplete Filling

The Challenge: Short shots occur when molten material doesn’t completely fill the mold cavity, resulting in missing sections or weak spots in the final part.
TUOWEI’s Solution: We optimize injection pressure, gate design, and melt temperature, combined with real-time monitoring systems to ensure complete mold filling every cycle.

Material Degradation and Color Inconsistency

The Challenge: Overheating, excessive residence time, or poor mixing can degrade materials, causing brittleness, discoloration, or reduced performance.
TUOWEI’s Solution: Our automated material handling and drying systems control moisture and temperature precisely, while our color masterbatch blending ensures consistent aesthetics across large production runs.

Tuowei Proto's Solutions

Whether you’re creating a small batch of custom parts or scaling up for high-volume production, Tuowei Proto services offer the flexibility you need.

Rapid Prototyping

CNC rapid prototype machining is perfect for creating engineering or production prototypes that closely resemble the final product in both appearance and functionality. At Tuowei, we offer instant quotes and fast delivery, providing you with precise, high-quality CNC machined prototypes for your needs.

Low Volume Manufacturing

Low volume CNC machining often acts as a bridge between prototyping and mass production for new and emerging production. With Tuowei, this process becomes easier, more efficient, and cost-effective, allowing you to scale production quickly while maintaining high-quality standards.

End-use Production

CNC production machining is the best solution for producing a thousand parts or more efficiently. Leveraging a diverse selection of materials and automation and multi-axis capabilities, Tuowei delivers high-volume production with tight tolerances, superior dimensional accuracy, high reliability and fast turnaround times.

Explore Insights & Innovation

Stay ahead with expert tips, industry trends, and precision manufacturing insights from the team at Tuowei. Read our latest blogs to gain valuable knowledge and discover how we’re shaping the future of CNC production.

Frequently Asked Questions

Plastic Injection Molding

  • Can I Get Prototype Parts Before Full-Scale Production?

    Yes. TUOWEI Precision offers rapid prototyping services to validate designs before committing to mass production. Prototyping allows for design testing, early detection of issues, and cost-effective adjustments, ensuring a smoother transition to full-scale manufacturing. This step helps optimize performance, minimize risks, and guarantee production-ready parts.
     

  • How Much Does Injection Molding Cost?

    Pricing depends on part size, mold complexity, number of cavities, chosen material, and finishing requirements. Every project is unique, so TUOWEI Precision provides customized quotes tailored to your specifications. This transparent approach ensures you understand costs upfront. Upload your CAD files and requirements, and our team will provide a detailed estimate.
     

  • What Is the Minimum Order Quantity?

    TUOWEI Precision has no minimum order requirement for injection molding services. Whether you need a single prototype or thousands of units, we deliver the same commitment to quality. Larger orders benefit from cost savings due to economies of scale, making bulk production more affordable per unit.
     

  • What Are the Typical Tolerances for Injection Molded Parts?

    TUOWEI Precision adheres to ISO 2768-c standards for general tolerances, ensuring consistent, reliable part production. For projects requiring stricter specifications, we provide tighter tolerances customized to each client’s needs. This flexibility guarantees parts fit accurately, function correctly, and meet the demanding requirements of industries such as aerospace, automotive, electronics, and medical devices.
     

  • What Are the 4 Stages of Injection Molding?

    Injection molding is a systematic process with four critical stages that ensure high-quality, precise plastic parts:Clamping: The two halves of the mold are securely clamped to prevent leakage during injection Injection: Molten plastic is injected into the mold cavity under high pressure for complete filling.

    Cooling: The plastic cools and solidifies inside the mold, ensuring correct dimensions and durability.Ejection: Once solidified, the part is ejected from the mold, and the cycle begins again. 

Get In Touch With Us!
Prompt response guaranteed within 12 hours
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