Custom Plastic Injection Molding Services
Prototype and mass production plastic molding in as fast as 2 weeks.
- Instant, transparent quotes based on your 2D/3D drawings
- Full-service manufacturing from prototype to mass production
- Extensive engineering material selection and surface finishes
- Complimentary DFM engineering review included with every RFQ
- All uploads are secure and confidential.
Plastic Injection Molding Services for Custom Parts
Secrapid has state-of-the-art production facilities, featuring injection molding machines from 90 to 830 tons covering regular to heavy-duty models. We can produce high-quality molded parts even with intricate structural designs.
Standard Molding
Standard injection molding is Secrapid’s core process. This process involves injecting a single molten thermoplastic material into a high-precision steel mold cavity under extremely high pressure. Once cooled and solidified, the mold opens and ejects the molded part, ensuring the product has exceptional dimensional accuracy.
This standard manufacturing method has been extensively optimized by Secrapid and is ideally suited for high-volume, large-scale production, as we utilize automated robotic systems to achieve maximum production efficiency and the lowest unit costs. It is an excellent engineering choice for producing uniform plastic structural components, electronic enclosures, and industrial parts that require consistent quality and strict adherence to international ISO tolerances.
Overmolding
Overmolding is an advanced multi-material manufacturing process. In this process, Secrapid uses an injection molding machine to precisely mold a second layer of material onto the surface of an existing substrate. This includes both traditional overmolding—where soft-touch resins (such as TPE/TPU) are bonded to rigid plastics—and insert molding, where polymers are injected directly around pre-positioned metal components (such as CNC-machined steel parts or other custom metal parts).
By seamlessly fusing different materials without the need for adhesives, Secrapid effectively eliminates subsequent assembly steps and creates monolithic components. This process is widely used to add ergonomic rubber grips, provide robust waterproof seals, and embed structured metal threads, thereby maximizing mechanical strength in demanding environments.
Top Reasons to Choose Secrapid for Plastic Injection Molding
With years of experience manufacturing molded plastic parts for our customers, Secrapid provides unique advantages over our competitors. We offer a truly one-stop injection molding service — from upfront DFM design optimization to final mass production, always guaranteeing the highest quality.
No matter how complex your part geometry, how large or small the part volume, and whatever the scale of your order, here are four reasons why Secrapid is your best choice for a plastic injection molding partner:
In-house Tooling
From mold design to final manufacturing and assembly, all our processes are seamlessly connected under one roof. This not only gives us total control over dimensions and tolerances, but also enables rapid mold trials, significantly shortening lead times
Flexible Order Volumes
Most plastic injection molding companies focus on mass production. But we are more flexible, offering low-quantity prototyping, mass production of 1m+ parts, and everything in between.
Certified Quality
Our experienced engineers can kickstart your project with expert DFM analysis and mold making, before helping you decide on the best injection molding parameters for your parts.
High-Volume Capacity
In addition to our in-house facilities, we are partnered with an extensive plastic injection molding manufacturer network. Fleets of injection machines are ready for your order today.
Injection Molding Materials
Our plastic injection molding service supports the manufacture of parts in a range of molding materials. These include rigid plastics like ABS, flexible plastics like TPE, and mixed materials like PC-ABS. We can also obtain specialty materials and create custom material and pigment blends to suit your order.
Rigid Plastic Materials
The majority of injection molded parts are made from rigid thermoplastics. These include inexpensive and versatile plastics like ABS and PP, as well as naturally transparent plastics like PC and acrylic and high-strength plastics like POM. Other rigid plastics for injection molding include nylon, PET, and PS.
Flexible Plastics
Flexible plastics can be used to make soft or bendy injection molded parts that behave like thermoset elastomers. The most common materials in this category are TPE, which is available in a wide range of hardnesses, and TPU, which is a firm and durable type of TPE. Another option for flexible moldings is LDPE, which also offers good chemical resistance.
Blends
Because injection molding uses plastic pellets as feedstock, plastic injection molding companies can easily mix blends of different materials (and color pigments). Common blends include PC-ABS, which offers excellent toughness and heat resistance, and PS-PPE, which is exceptionally ductile with good impact resistance.
Composites
Injection molding pellets can also be mixed with non-plastics, leading to composite injection molding materials. Such composites include glass-filled polyamide, which is very hard and strong with good creep resistance, and glass-filled polycarbonate, which offers high strength and stiffness with low thermal expansion.
Injection Mold Surface Finishes
We offer SPI surface finishes for your injection molds. Our injection molding expert is here to help you choose the right finish for your project. Upload your design on our quoting platform today and receive a detailed quote within 24 hours.
Standard Finish
Moldmaker’s choice of finish. Typically SPI B-2, depending on geometry and drafts. Interior, non-cosmetic faces, are typically as-machined.
SPI Finishes
Range of Society of Plastics Industry (SPI) finishes from Grade 3 diamond / high polish to 320 stone low polish. Finishes include: SPI A-1, SPI A-2, SPI A-3, SPI B-1, SPI B-2, SPI B-3, SPI C-1, SPI C-2, SPI C-3, SPI D-1, SPI D-2, and SPI D-3
MoldTech Finishes (Mold Texturing)
Range of finishes including matte, swirls, lines, and patterns. Our most common texture finishes include: MoldTech MT11010, MoldTech MT11020, and MoldTech MT11030. Other textured finishes can be added by request.
Other Textures - VDI
VDI 3400 Surface Finish (commonly known as VDI surface finish) refers to the mold texture standard set by Verein Deutscher Ingenieure (VDI), the Society of German Engineers. This is mainly processed by EDM machining, producing fine to coarse matte finishes.
Injection Molding Services Capabilities
Our injection molding services cover every stage, from design to delivery. We produce prototypes and large-scale parts with tight tolerances, certified quality, and quick lead times for global customers.
| Capability | Details |
|---|---|
T1 Samples Lead Time | As fast as 5 business days; 3 weeks is typical for most projects |
Production Options | Domestic and international |
Materials | Any commercially available injection moldable plastic material |
Machines & Tooling | Single, multi-cavity, and family molds; 50 to 3,700+ ton presses; automated side actions or hand-loaded cores |
Inspection and Certification Options | ISO 9001, AS9100, ISO 13485, IATF 16949 UL, ITAR, and ISO 7 and 8 Medical Clean Rooms; FAI and PAPP available |
Tool Ownership | Customer-owned with mold maintenance |
General Mold Cavity Tolerances | +/- 0.005″ when machining the mold and an additional +/- 0.002″ per inch when calculating for shrink rate |
Critical Feature Tolerances | Xometry can mill to a steel-safe condition on critical features and groom the tool to dial in tight tolerances |
Part to Part Repeatability | +/- 0.004″ or less |
Mold Classes | Steel and aluminum tooling; Class 105 (prototype) to Class 101 (extremely high production) molds |
This table depicts the general tolerances for Xometry’s plastic injection molding service and accounts for adequate draft, radii, and coring for manufacturability. Learn more about our injection molding manufacturing standards.
How Does RapidDirect Injection Molding Process Work
At RapidDirect, we make custom injection molding services simple and efficient. From online quotes to high-quality plastic injection molding and production-ready injection molded parts, our process ensures precision, speed, and reliability.
Upload Design File
Start by uploading your 3D CAD files and 2D drawings to RapidDirect’s online manufacturing platform, setting the stage for precise custom molding.
Get Quote with DFM
Select materials, surface finishes, and shipping options. Receive an online injection molding quote and manufacturability feedback in one day.
Review T1 Sample
We produce a T1 sample for your approve. Check every detail to match your specifications. This step usually takes two weeks.
Production Begins
After approving the sample, we move to full-scale production, maintaining high standards of quality and precision.
Delivery
We ship your custom injection molded parts from our China injection molding facilities to your location, ready for immediate use.
Injection Molding Quality Control
We value quality from design to production. Cross-team reviews and strict controls help achieve a 90% first-pass yield for all plastic molded parts.
Mold and Pre-produdction Inspection
Proper mold design and pre-production checks are key to injection molding quality. Engineers consider part geometry, material flow, and cooling systems to guarantee smooth production. Trial molds are tested to confirm all functions work correctly, providing stable and consistent results.
In Process Quality Control
Continuous checks during production keep custom molded parts consistent. Injection machine parameters such as speed, pressure, and temperature are monitored within set limits. Regular inspections of part dimensions and appearance help detect and fix issues quickly.
Final Inspection
Completed parts undergo thorough final inspection to meet design and quality standards. Teams check dimensions, appearance, and physical properties. Precision instruments like coordinate measuring machines (CMM) and colorimeters verify that all components meet strict standards.
Applications of Injection Molding
Regular users of plastic injection molding services include automotive, aerospace, industrial, medical, and consumer goods companies. Common plastic injection molded parts include medical devices, automotive panels, food containers, packaging, and toys.
The benefits of using plastic injection molding companies to make molded parts include:
Advantages of Injection Molding
- High-volume, consistent production
- Low cost per unit after setup
- Works with many materials (plastics, LSR)
- High precision for complex designs
Disadvantages of Injection Molding
- High upfront tooling costs
- Longer lead times
- Design limitations
- Not cost-effective for low-volume runs
FAQ
What’s injection molding?
Injection molding is a manufacturing process used to produce parts by injecting molten material into a mold. It is commonly used with plastics but can also accommodate metals, glasses, and elastomers. The process begins with melting the material, which is then injected under pressure into a mold cavity. Once the material cools and solidifies, the mold is opened to eject the finished part. This technique is favored for its ability to produce large volumes of identical parts with high precision, complex shapes, and excellent surface finish. Injection molding is efficient and cost-effective, particularly suitable for mass production.
What are 4 stages of injection molding?
Injection molding is a complex process that involves four key stages to create high-quality plastic parts:
- Clamping: Before the injection of the material, the two halves of the mold must be securely clamped together by the injection molding machine. This is crucial to prevent the mold from opening during injection, ensuring that the molten plastic does not escape.
- Injection: Molten plastic is injected into the clamped mold at high pressure. This stage involves packing the plastic into the mold and maintaining pressure to fill every part of the mold cavity completely.
- Cooling: After the mold is filled, the plastic begins to cool and solidify within the mold’s cavities. The cooling must be controlled to prevent defects and ensure that the part maintains proper dimensions and mechanical properties.
- Ejection: Once the part has cooled and solidified, the mold opens and an ejection mechanism pushes the completed part out of the mold. The machine is then ready to start a new cycle with the clamping of the mold for the next part.
What’s the process for injection mold making?
Our injection mold-making process includes six essential steps:
Step 1: Production Arrangement: We begin by thoroughly understanding all requirements and arranging the production details accordingly.
Step 2: DFM Report Analysis: A detailed Design for Manufacturability (DFM) report is provided free of charge. This report helps in conducting a feasibility analysis to ensure the mold will meet all specifications and quality standards.
Step 3: Production of the Mold: The mold is put into production. We provide clients with a Tooling Schedule form that outlines the entire cycle, allowing them to track the progress at any time.
Step 4: Free Sample Testing: Once the mold is produced, a sample is created and provided to the client for testing to ensure it meets the required specifications.
Step 5: Mass Production: Upon client confirmation that the sample meets all quality and functionality criteria, full-scale production commences.
Step 6: Mold Saving: After production and a thorough quality inspection, the parts are delivered. The mold is then cleaned and properly stored to maintain its condition for future production runs.
What are the typical tolerances for injection molded parts?
In injection molding, maintaining precise tolerances is essential to ensure that parts fit correctly and function as intended, avoiding potential assembly issues. At RapidDirect, we strictly adhere to the ISO 2768-c standard for general tolerances, which is commonly used across the industry for molded parts. This standard provides a range of tolerances for different features and dimensions, ensuring consistency and reliability in production. For projects requiring even stricter tolerances, we have the capability to accommodate tighter specifications, based on the unique requirements of each client’s application. This flexibility allows us to deliver precisely engineered parts that meet or exceed all expectations.
What is the minimum order qty?
At RapidDirect, we understand the diverse needs of our clients, which is why we have no minimum order requirement for our injection molding services. This flexibility allows businesses of all sizes to access high-quality molded parts, regardless of the size of their project. While we are equipped to handle orders from a single prototype to thousands of units, it’s worth noting that larger order quantities typically result in more competitive pricing. This volume discount is due to the economies of scale in production, making larger orders more cost-effective per unit. Whether your project is large or small, we are here to provide the best value and service.
How much does your injection molding service cost?
The cost of our injection molding services varies depending on multiple factors, including the size of the component, mold complexity, number of cavities, material type, and any specific post-processing requirements. Each project is unique, and we provide personalized quotes to ensure that you receive a detailed cost assessment tailored to your specific needs. This transparent pricing approach allows you to understand the financial implications before committing to the process. To get an accurate estimate, simply upload your project details on our platform, and we will analyze these factors to provide you with a comprehensive quote.
Can I get prototype parts before full-scale production?
Absolutely, RapidDirect strongly supports the development process by offering rapid prototyping services. This crucial step allows you to test and verify your designs effectively before moving into large-scale production. Prototyping is essential to identify potential issues and ensure that the design meets all functional and aesthetic requirements. By taking advantage of our prototyping services, you can make necessary adjustments early in the development cycle, saving time and costs in later stages. This approach not only enhances product quality but also ensures that the transition to full-scale production is smooth and efficient.