Since 1954, we at UGP Plastics have remained at the forefront of custom plastic injection molding, delivering high-performance solutions to a wide range of industries across Canada and North America. Among the specialized services we offer, EMI shielding—or electromagnetic shielding—has become increasingly vital for protecting sensitive electronic components in today’s high-frequency, high-density environments.
In this blog, we share our industry-leading insights into EMI shielding solutions for plastic injection molded parts, helping engineers, product designers, and manufacturers understand their options and how to integrate effective shielding early in the design process.
What Is EMI Shielding?
EMI shielding refers to the process of blocking or reducing electromagnetic interference (EMI) from affecting or emanating from an electronic device. This is crucial for maintaining product performance, preventing signal degradation, and meeting regulatory compliance standards. In plastic injection molded components, electromagnetic shielding is particularly important for applications such as:
• Medical devices
• Automotive control systems
• Industrial equipment
• Consumer electronics
• Aerospace & defense electronics
Metal enclosures served as traditional EMI protection solutions until modern applications required lightweight cost-effective customizable alternatives, which led to plastic parts with EMI shielding coatings or additives becoming an ideal solution.
EMI Shielding in Plastic Injection Molding
As experienced injection molders, we have mastered the integration of electromagnetic shielding solutions directly into the plastic manufacturing process. There are three primary approaches to adding EMI shielding to molded plastic parts:
• Conductive Coatings: A thin layer of conductive material such as silver, copper, nickel, or a proprietary alloy is sprayed or vacuum-deposited onto the molded part. This creates a shielded barrier without compromising the aesthetics or geometry of the component.
• Conductive Plastics (EMI Shielding Materials): Specialized resins or polymer blends with conductive fillers like carbon fiber, stainless steel fiber or metal powders can provide inherent EMI shielding properties. These are especially suitable for applications requiring full integration without secondary processes.
• Insert Molding with Metal Components: In scenarios that require enhanced structural integrity and shielding, metal inserts can be integrated directly into the part during the injection molding process, offering hybrid benefits of plastic and metal.
EMI Shielding Effectiveness Standards & Testing
At UGP Plastics, we understand that electromagnetic shielding is only as effective as its ability to meet rigorous industry standards. The performance of EMI shielding is measured in decibels (dB), which quantify the reduction or attenuation of electromagnetic energy that passes through or around a shielded enclosure.
Typically, a higher decibel rating indicates greater shielding effectiveness. In most electronic applications, a shielding effectiveness of 60–90 dB is considered optimal across the critical frequency range of 30 MHz to 1 GHz—a common spectrum for radiated and conducted emissions in commercial and industrial environments.
To ensure compliance and reliability, EMI-shielded plastic components undergo standardized testing based on globally accepted protocols, including:
• MIL-STD-285: A U.S. military standard that outlines testing procedures for measuring electromagnetic attenuation across enclosures.
• IEEE-299: A comprehensive IEEE standard that evaluates the shielding effectiveness of materials and assemblies using full enclosures or partial shielding designs.
• ASTM D4935: A widely used ASTM standard that measures the effectiveness of materials against radiated electromagnetic interference using a coaxial transmission line method.
Our team at UGP Plastics collaborates closely with customers to ensure that molded components not only meet these specifications but exceed them when required by mission-critical applications.
Benefits of Using Plastic Injection Molded EMI Shielding Solutions
Choosing plastic-based electromagnetic shielding solutions offers several advantages:
• Lightweight Design: Reduces overall weight compared to traditional metal enclosures.
• Cost Efficiency: Lower material and assembly costs, especially in high-volume production.
• Design Flexibility: Freedom to create complex geometries and integrate shielding directly into the mold design.
• Corrosion Resistance: Unlike metal, shielded plastic parts resist oxidation and harsh environments.
By incorporating EMI shielding materials and techniques early in the product development cycle, manufacturers can optimize both performance and production efficiency.
At UGP Plastics, our deep-rooted experience since 1954 and cutting-edge capabilities make us the trusted partner for EMI shielding and electromagnetic shielding solutions in injection molded plastics. Whether you’re designing for electronics, automotive, medical, or industrial applications, our team is here to guide you from concept through production.
Ready to engineer precision-shielded plastic parts? Contact UGP Plastics today and leverage over 70 years of trusted expertise.
Frequently Asked Questions (FAQ):
What is the tolerance for plastic molding?
Tolerances in plastic injection molding typically range from ±0.005 in to ±0.020 in depending on the material, part size, and design complexity. High-precision components may require tighter tolerances, which should be discussed during the design phase.
What is EMI shielding?
EMI shielding refers to protective techniques that block electromagnetic interference from affecting electronic components. In plastic parts, this is achieved using conductive coatings, fillers, or metal inserts.
What is the DIN standard for plastic tolerance?
DIN 16742 is commonly referenced for dimensional tolerances in plastic molded parts, offering standardized guidance for part design and manufacturing consistency.
What is the pressure for plastic molding?
Injection molding pressure typically ranges from 200 MPa to 2,000 MPa (or 29,000 to 290,000 psi), depending on the material and mold complexity.
What plastic is used for radiation shielding?
Plastics like high-density polyethylene (HDPE) loaded with barium sulfate or tungsten are commonly used for radiation shielding in medical and industrial applications.
