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Overview of Glass Filled Nylon
Glass-filled nylon, glass-reinforced nylon, or nylon composite is a polyamide powder enhanced with glass fibers. This type of thermoplastic exhibits high creep strength and high mechanical dampening properties, with enhanced heat distortion temperature. Adding glass fibers with nylon resin produces a composite material with improved mechanical properties, making it ideal for applications that require high-performance parts.
The precise composition often varies since glass fibers are added in proportions between 10% – 40% weight. Glass-filled nylon provides a combination of desirable physical properties over unfilled nylon. The added glass fibers reinforce the nylon material. As such, it ensures uniform stress distribution throughout the material and reduces the risk of deformation or failure when exposed to loads.
However, unlike other materials used in engineering, glass reinforced nylon exhibits poor heat resistance in high temperature environments.
Types of Glass Filled Nylons
Glass-filled nylon is available in various grades, each with a distinct percentage of glass fiber content and type of nylon compound. The commonly used types of glass-filled nylon include:
PA12 Reinforced Glass Fiber (PA12-GF)
Polyamide 12, a form of glass-filled Nylon, is the basic compound for PA12-reinforced glass fiber. Polycaprolactone or Nylon 12 are other names for PA12. This glass-filled nylon type exhibits high dimensional stability, excellent chemical resistance, and minimal moisture absorption. Furthermore, PA12-GF may contain different amounts of glass fiber ranging from 10% to 20% or 30%. However, understand that high glass fiber content increases the material’s strength and rigidity while impact resistance and flexibility levels decline.
PA6 Reinforced Glass Fiber (PA6-GF)
Polycaprolactam (PA6/polyamide 6/Nylon 6) is the basic compound for glass-filled nylon or PA6-GF. This glass-filled nylon grade exhibits good impact resistance and strong toughness and performs well when subjected to low temperatures. It also exhibits high dimensional stability and moisture absorption.
PA6 reinforced glass fiber contains 15% to 45% glass fiber content. Rigidity and strength increase in PA6-GF when there is higher glass fiber content, but this decreases toughness and impact resistance.
PA66 Reinforced Glass Fiber (PA66-GF)
Polyamide 66 (PA66) poly hexamethylene adipamide or nylon 66 is the basic compound of PA66 reinforced glass fiber. Unlike PA6-GF, this form of glass-filled nylon offers higher stiffness, strength, heat resistance, and creep resistance.
Manufacturers often prefer this type of glass-filled nylon due to its higher dimensional stability and reduced moisture absorption rate. Glass fiber content in this grade ranges from 13% to 50%. Moreover, increasing glass fiber percentage results in enhanced strength and rigidity but reduces material toughness and impact resistance.
Is Glass-Filled Nylon Strong?
The specific nylon composition and glass fiber percentage determine the glass-filled nylon’s strength. Also, the overall fiber-to-resin ratio, length and type of the glass fibers, and distribution of fibers within the nylon matrix determine how strong a glass-filled nylon material is. Generally, glass-reinforced nylon exhibits greater impact resistance, flexural strength, and tensile strength due to higher glass fiber percentage.
However, glass-reinforced nylon can exhibit approximately 50 to 200 MPa of tensile strength depending on the specific material composition. While the flexural strengths of reinforced nylon can vary from 50 to 300 MPa or higher, you would need to consult the technical data sheet of the material and perform testing with sample parts to calculate the exact strength of a particular glass-filled nylon type or grade.
Benefits of Glass-Filled Nylon
Product designers and engineers widely use Glass-filled nylon due to its numerous advantages. Here are some of the expected glass-filled nylon benefits:
- Excellent Moldability: Nylon reinforced with glass fibers is easily molded into complex shapes and intricate designs. Glass-filled nylons allow the production of cost-effective parts since they can be easily injection-molded to form the desired final product.
- Good Electrical Insulation Properties: Glass-filled nylon exhibits exceptional electrical insulation properties, making it an ideal choice for products with electronic components.
- Improved Strength and Stiffness: The higher tensile strength and modulus of elasticity of reinforced nylon make it suited for applications requiring structural integrity and load-bearing capability.
- High Impact Resistance: Incorporating glass fibers with nylon allows the material to exhibit improved fracturing and cracking resistance and can handle greater impact. Hence, it is well-suited for dynamic loading applications.
- Excellent Dimensional Stability: The added glass fibers lower the coefficient of thermal expansion for enhanced dimensional stability. Thus, glass-reinforced nylon is less susceptible to shrinking, expansion, or warping with temperature variation.
- Good Chemical and Heat Resistance: Nylon reinforced with glass fiber exhibits increased heat distortion temperature (HDT), allowing glass-filled nylon parts to withstand exposure to elevated temperatures without considerable loss of mechanical properties or degradation. Also, the glass-filled nylon versions can handle exposure to various chemicals, strong acids, solvents, and oil..
Limitations of Glass-Filled Nylon
Even though it offers many benefits, there are certain limitations to using glass-filled nylon. Here are some of the constraints of glass-filled nylon:
- Added Weight: Glass-filled nylon generally weighs approximately 15% more than unfilled nylon. It is a major limitation for applications that demand low weight.
- Anisotropic Properties: Due to its anisotropic properties, the mechanical properties of glass-reinforced nylon often vary according to the loading direction. The glass fibers’ alignment during manufacturing can result in strength and stiffness variation along different axes of the part.
- Increased Abrasiveness: The glass fiber’s abrasive effects on mating surfaces make the material less suitable for sliding applications. Similarly, glass-filled nylon’s high abrasiveness causes rapid tool wear in CNC cutting tools.
- Moisture Absorption: Glass-filled nylon exhibits dimensional/structural weaknesses in parts used in wet environments since the material tends to absorb moisture.
- Higher Cost: Nylon reinforced with glass is more expensive than unfilled nylon. Also, it may not be cost-effective for certain applications since its added performance and higher strength don’t come cheap.
- More Brittle: Glass-reinforced nylon exhibits higher brittleness than unfilled nylon. Hence, it is more likely to crack or fracture under high-stress conditions.
How Is Glass-Filled Nylon Different from Nylon 12?
Glass-filled nylon and nylon 12 are unique materials with varying composition and mechanical properties. Glass-filled or reinforced nylon is a composite made by reinforcing nylon matrix with glass fibers, making it stronger and more durable than Nylon 12. Manufacturers typically use glass-reinforced nylon in applications that demand high rigidity and strength, including industrial components, automotive parts, consumer products, etc.
In contrast, Nylon 12, or polyamide 12 (PA 12), is an unfilled thermoplastic polymer and a member of the nylon family. It is a semi-crystalline material with a combination of desirable mechanical properties, including high impact resistance, good mechanical strength, and chemical resistance.
Unlike glass-filled nylon, Nylon 12 exhibits low moisture absorption, making it ideal for making parts exposed to wet/humid environments. Due to its low friction properties and good dimensional stability, aerospace, automotive, and electronics manufacturers typically use polyamide
Parts Production Processes Compatible with Glass-Filled Nylon
Manufacturers and product designers use glass-filled nylon to produce different parts using different production techniques, including CNC machining, 3D printing, and injection molding.
CNC Machining
CNC machining is an effective technique for processing glass-filled nylon into desired final products. However, the abrasive properties of glass-filled nylon pose certain challenges, such as increased wear in CNC tools. However, experts recommend using ceramic or carbide CNC machine tools to machine glass-filled polymers for the best machining outcomes. Also, it would be best to reduce the cutting speed to ensure lower tool wear.
3D Printing
3D printing is a robust additive manufacturing technology that uses glass-filled nylon to create desired products one layer after the other. Multi Jet Fusion (MJF), Fused Deposition Modeling (FDM), and Selective Laser Sintering (SLS) are three primary forms of 3D printing that use glass-reinforced materials.
However, engineering experts recommend using hardened steel nozzles for 3D printing of nylon reinforced with glass due to the material’s abrasiveness. Glass-filled nylon grades such as nylon 6 (PA 6) with 30% filler are compatible with FDM 3D printing, while nylon 3200 glass-filled filaments or PA 12 with approximately 40% glass fiber are commonly used with SLS 3D printing.
Injection Molding
Plastic injection molding works well with different grades of glass-filled nylon materials, including glass-filled nylon 66, which has about 10 – 50% fiber reinforcement. Since the material is highly abrasive, making tools with harder steel would be best to ensure extended injection mold life.
Applications of Glass-Reinforced Nylon
The wide array of glass-filled nylon’s desirable properties makes it ideal for producing parts subjected to high static loads over extended periods in high-temperature conditions. Here are the typical applications of glass-reinforced nylon:
- Industrial: Glass-filled nylons are ideal for making structural parts, valves, fittings, pipes, pumps, bushings, pipes, rollers, conveyor belts, and other industrial machinery and components.
- Automotive: Automotive manufacturers use nylon reinforced with glass to make vehicle parts like latches, fuel tank caps, bearings, gears, manifolds, fan blades, and other under-hood components.
- Electrical: Manufacturers use glass-filled nylons for electronic or electrical components like printer cartridges, electronic component pallets, earphones, cameras, printers, etc.
- Household: Glass-filled nylon is suitable for producing consumer goods such as combs, water purifiers, spools, vacuum cleaners, sanitary equipment, rice cookers, and other household appliances.
Conclusion
Glass-filled Nylon resin is a high-performance engineering thermoplastic widely used due to its good fatigue strength, and thermal stability. It is compatible with a wide array of applications requiring rigidity and structural integrity because the added glass fibers act as reinforcement, ensuring uniform stress distribution throughout the material. However, understanding the advantages and trade-offs of glass-filled nylon helps choose according to the specific needs of the intended application.
AT-Machining is the right CNC shop to partner with whenever you need a cost-efficient and time-saving solution for applications with high performance and durability demands. Our experts deliver custom products according to the end-product requirements. Don’t hesitate to contact us with more inquiries about engineering glass-filled nylons. Our engineering experts can help you with material selection for your project!
