Glass fiber reinforced PC resin is a modified polycarbonate material for structural parts. It keeps many advantages of PC resin and adds higher stiffness, better strength, lower shrinkage, and improved dimensional stability.
Standard PC resin is known for high impact strength and good heat resistance. But for brackets, frames, supports, and precision structural parts, standard PC may not provide enough rigidity. Glass fiber reinforced PC solves this problem by adding glass fibers into the PC base resin.
This material is often used in automotive parts, electrical housings, industrial components, appliance parts, and other injection molded products that need strong and stable performance.
For buyers, the key is not only to ask for “glass filled PC.” You also need to check the glass fiber content, tensile strength, flexural modulus, impact strength, heat deflection temperature, melt flow rate, mold shrinkage, flame rating, and surface requirements.
What Is Glass Fiber Reinforced PC Resin?
Glass fiber reinforced PC resin is a polycarbonate compound filled with glass fibers. It is also called:
- Glass filled polycarbonate
- Glass fiber reinforced polycarbonate
- Glass reinforced PC
- GF PC resin
- PC-GF resin
- PC GF material
The glass fiber improves the mechanical strength and rigidity of PC. It also helps reduce shrinkage and improves dimensional stability after molding.
Unlike transparent PC resin, glass fiber reinforced PC is usually opaque. It is mainly used for structural performance, not optical clarity.
This makes it suitable for parts that need to resist bending, deformation, heat, and long-term load.
Why Glass Fiber Is Added to PC Resin
Glass fiber is added to PC resin to improve structural performance. It changes standard PC from a tough engineering plastic into a stronger and stiffer material for load-bearing parts.
The main purpose is to improve:
- Tensile strength
- Flexural strength
- Flexural modulus
- Dimensional stability
- Heat resistance under load
- Creep resistance
- Mold shrinkage control
For many injection molded parts, stiffness is more important than transparency or surface gloss. In these cases, glass fiber reinforced PC can be a better option than standard PC.
Higher Strength for Load-Bearing Parts
Glass fiber reinforced PC resin is often selected when the final part must carry load, hold shape, or support another component.
Typical examples include:
- Mounting brackets
- Support frames
- Mechanical fixing parts
- Connector housings
- Motor support parts
- Electrical module structures
Glass fiber can improve tensile and flexural strength. This helps the part resist cracking, bending, or deformation under mechanical stress.
However, buyers should not only ask whether the material is “strong.” Strength has different meanings in plastic selection.
You should check:
- Tensile strength
- Flexural strength
- Notched Izod impact strength
- Elongation at break
- Heat deflection temperature
- Long-term load performance
A PC-GF grade may have higher stiffness and strength than standard PC, but its impact toughness may be lower. This is why datasheet comparison is important before grade selection.
Better Stiffness and Dimensional Stability
Stiffness is one of the most important reasons to choose glass fiber reinforced PC resin.
Standard PC has excellent toughness, but it may bend under load. For structural components, this can cause assembly problems, vibration, noise, or poor dimensional control.
Glass fiber increases the flexural modulus of PC. This means the molded part becomes more rigid and less likely to bend under force.
This is important for:
- Long and thin parts
- Flat parts
- Assembly parts
- Screw-fixed parts
- Precision housings
- Load-bearing brackets
- Parts with tight tolerances
Glass fiber also helps reduce mold shrinkage. Lower shrinkage can improve dimensional accuracy and part stability.
But glass fiber orientation can also create different shrinkage in different directions. If the mold design, gate position, or cooling system is not optimized, warpage may still occur.
So, glass fiber reinforced PC offers better dimensional stability, but it still needs proper mold design and processing control.
How Glass Fiber Content Affects Performance
Glass fiber content is one of the most important selection points for GF-PC resin.
Common glass fiber levels include 10%, 15%, 20%, 30%, and sometimes 40%. Higher glass fiber content usually improves stiffness and lowers shrinkage. But it can also reduce flowability, surface quality, and impact toughness.
Higher glass fiber content is not always better. The right choice depends on the part design, wall thickness, load, surface requirement, and molding process.
PC-GF10: Light Reinforcement
PC-GF10 contains about 10% glass fiber.
It offers light reinforcement while keeping better processability than higher glass fiber grades. It is suitable for small parts that need better dimensional stability than standard PC.
Typical features:
- Better stiffness than standard PC
- Good molding flow
- Lower shrinkage
- Better surface than high-GF grades
- Suitable for small structural parts
Typical applications:
- Small brackets
- Electrical parts
- Small housings
- Fixing parts
- Dimensionally stable components
PC-GF10 is useful when the part needs moderate reinforcement but does not need very high rigidity.
PC-GF15: Balanced Strength and Processing
PC-GF15 is a balanced glass fiber reinforced PC grade.
It offers improved strength and stiffness while keeping reasonable processing performance. It is often used for general structural parts in electrical, industrial, and appliance applications.
Typical features:
- Balanced rigidity and toughness
- Better dimensional stability
- Moderate flow reduction
- Suitable for medium-size parts
- Good option for general reinforced PC use
Typical applications:
- Electrical housings
- Control device parts
- Industrial covers
- Support brackets
- Appliance internal parts
PC-GF15 is often a practical choice when buyers need a balance between performance, molding stability, and cost.
PC-GF20: Medium-High Rigidity
PC-GF20 provides higher stiffness than PC-GF10 and PC-GF15.
It is suitable for structural components that need better load resistance and tighter dimensional control. It is often used in automotive, electrical, and industrial parts.
Typical features:
- Higher rigidity
- Improved load-bearing performance
- Better heat resistance under load
- Lower shrinkage
- Good dimensional stability
Typical applications:
- Automotive interior structural parts
- Connector housings
- Mechanical supports
- Electrical module parts
- Industrial fixing components
PC-GF20 is a good direction when standard PC or low-GF PC cannot meet stiffness requirements.
PC-GF30: High Stiffness Grade
PC-GF30 is one of the most common high-stiffness reinforced PC grades.
It provides high flexural modulus, high strength, low shrinkage, and strong dimensional stability. It is suitable for structural parts that need to resist deformation under mechanical or thermal stress.
Typical features:
- High stiffness
- High flexural modulus
- Strong structural support
- Low shrinkage
- Better dimensional stability
- Higher mold wear than low-GF grades
Typical applications:
- High-strength brackets
- Load-bearing supports
- Industrial structural parts
- Automotive functional parts
- Mechanical housings
- Metal replacement parts in selected designs
PC-GF30 is a strong option for structural applications. But it needs careful processing. Flowability is lower than standard PC, and surface appearance may show fiber marks.
PC-GF40: Very High Rigidity for Special Parts
PC-GF40 contains higher glass fiber content and is used for more demanding structural applications.
It offers very high stiffness and low shrinkage. However, it can be more difficult to mold. It may also increase warpage risk, floating fiber, mold wear, and processing sensitivity.
Typical features:
- Very high rigidity
- Very low shrinkage
- Strong dimensional stability
- Lower flowability
- Higher risk of surface fiber marks
- More tool wear
Typical applications:
- Special load-bearing parts
- Industrial equipment parts
- Metal replacement components
- High-rigidity structural parts
PC-GF40 should be selected carefully. It is not necessary for every structural application. In many cases, PC-GF20 or PC-GF30 may offer a better balance.
Key Properties Buyers Should Check
For procurement, it is not enough to compare only material names. Two glass fiber reinforced PC grades may perform very differently.
Buyers should check the datasheet and confirm the following properties.
| Property | Why It Matters |
| Glass fiber content | Affects stiffness, shrinkage, strength, flow, and surface quality |
| Tensile strength | Shows resistance to pulling force |
| Flexural strength | Shows resistance to bending stress |
| Flexural modulus | Shows stiffness and rigidity |
| Notched Izod impact | Shows impact toughness |
| Heat deflection temperature | Shows heat resistance under load |
| MFR or MVR | Affects flow length and molding conditions |
| Mold shrinkage | Affects final part size and tolerance |
| UL 94 rating | Important for electrical and electronic parts |
| Surface quality | Important for visible parts |
| Color availability | Important for brand or product design |
| Compliance | RoHS, REACH, or other requirements may be needed |
If the part is used in electrical equipment, flame retardancy may be required. In this case, buyers should confirm both the UL 94 rating and the tested thickness.
For example, a grade with UL 94 V-0 at 1.5 mm is not the same as a grade with V-0 at 3.0 mm. Wall thickness matters.
Glass Fiber Reinforced PC vs Standard PC
Glass fiber reinforced PC is not simply a better version of standard PC. It is a different material direction for different applications.
Standard PC is better when high impact strength, transparency, and surface appearance are the main requirements.
Glass fiber reinforced PC is better when stiffness, strength, low shrinkage, and dimensional stability are more important.
| Item | Standard PC | Glass Fiber Reinforced PC |
| Transparency | Usually transparent | Usually opaque |
| Impact strength | Very high | May be lower |
| Stiffness | Medium | High |
| Tensile strength | Good | Higher |
| Flexural modulus | Medium | Much higher |
| Dimensional stability | Good | Better |
| Mold shrinkage | Higher | Lower |
| Flowability | Better | Lower with higher GF content |
| Surface appearance | Better | May show fiber marks |
| Mold wear | Lower | Higher |
| Main use | Covers, housings, transparent parts | Brackets, supports, structural parts |
If your part needs optical clarity, standard PC is usually the right direction.
If your part needs rigidity and low deformation, glass fiber reinforced PC may be a better choice.
Glass Fiber Reinforced PC vs Other Engineering Plastics
Buyers often compare GF-PC with other engineering plastics. The best choice depends on the application.
GF-PC vs PC/ABS
PC/ABS usually has better processing performance and surface appearance than glass fiber reinforced PC. It is widely used for housings, covers, and appearance parts.
GF-PC offers higher stiffness and better structural performance. It is more suitable for brackets, frames, and load-bearing parts.
Choose PC/ABS when:
- Better surface appearance is needed
- Good flowability is important
- The part is a general housing or cover
Choose GF-PC when:
- Higher stiffness is needed
- Lower deformation is required
- The part carries load or needs strong dimensional stability
GF-PC vs Glass Fiber Reinforced Nylon
Glass fiber reinforced nylon is strong and widely used in mechanical parts. It can offer good wear resistance and chemical resistance.
However, nylon absorbs moisture. Moisture absorption may affect part dimensions and mechanical properties.
GF-PC usually has better dimensional stability in humid environments than nylon. This can be important for precision parts, electrical housings, and assemblies with tight tolerances.
Choose GF nylon when:
- Wear resistance is important
- Chemical resistance is needed
- The application is suitable for nylon moisture behavior
Choose GF-PC when:
- Dimensional stability is more important
- Lower moisture sensitivity is needed
- Better impact balance is required
GF-PC vs Glass Fiber Reinforced PBT
Glass fiber reinforced PBT offers good dimensional stability, electrical performance, and chemical resistance. It is common in electrical and automotive components.
GF-PC can provide good toughness, stiffness, and heat resistance. It may be selected when impact performance and structural strength are both required.
Choose GF-PBT when:
- Chemical resistance is important
- Electrical performance is a priority
- Fast molding cycle is needed
Choose GF-PC when:
- Toughness and rigidity balance is needed
- Higher impact resistance than some polyester grades is required
- PC-based material compatibility is preferred
GF-PC vs PPS
PPS has excellent heat resistance and chemical resistance. It is used in high-performance parts.
But PPS usually has a higher material cost than GF-PC. For many medium-high performance structural parts, GF-PC may provide enough strength and heat resistance at a more practical cost level.
Choose PPS when:
- Very high heat resistance is required
- Strong chemical resistance is needed
- The application is highly demanding
Choose GF-PC when:
- High stiffness is needed
- Cost control is important
- The heat requirement does not need PPS-level performance
Processing Notes for Glass Fiber Reinforced PC Resin
Processing is a key topic for glass fiber reinforced PC. A good grade can still fail if drying, mold design, or processing conditions are not controlled.
The following points should be checked before molding.
Drying Before Molding
PC resin is moisture sensitive. Glass fiber reinforced PC also needs proper drying before injection molding.
If the material is not dried well, the part may show:
- Silver streaks
- Bubbles
- Poor surface
- Lower impact strength
- Hydrolysis problems
- Weak mechanical performance
Drying conditions should follow the supplier’s datasheet. Do not use general settings for all PC-GF grades without confirmation.
Melt Temperature and Mold Temperature
Melt temperature affects flow, surface quality, and degradation risk.
If the melt temperature is too low, the material may not fill the mold well. If it is too high, PC may degrade and lose mechanical performance.
Mold temperature also matters. A proper mold temperature can improve surface quality, reduce internal stress, and support dimensional stability.
For visible parts, mold temperature control is especially important because glass fiber marks may appear on the surface.
Fiber Orientation and Warpage
Glass fiber orientation is one of the main reasons for warpage in GF-PC parts.
During injection molding, fibers align with the flow direction. This creates different shrinkage rates in different directions.
The result may be:
- Warpage
- Twisting
- Poor flatness
- Uneven shrinkage
- Dimensional variation
- Assembly mismatch
This is especially important for long parts, flat parts, thin-wall parts, and precision housings.
To reduce warpage, mold designers should review:
- Gate location
- Flow path
- Wall thickness
- Cooling balance
- Rib design
- Fiber orientation direction
Gate Design and Flow Length
Gate design affects flow balance and fiber orientation.
Poor gate location can cause weak weld lines, uneven fiber distribution, and higher warpage. For glass fiber reinforced PC, the gate should support stable filling and balanced flow.
For large or thin-wall parts, buyers should confirm whether the selected grade has enough flowability.
High glass fiber grades usually flow less easily than standard PC. If the wall is thin or the flow path is long, a higher-flow grade may be needed.
Surface Appearance and Floating Fiber
Glass fiber reinforced PC may show surface defects, especially when the glass fiber content is high.
Common surface issues include:
- Floating fiber
- Fiber marks
- Flow lines
- Weld lines
- Rough surface
- Lower gloss
This does not always mean the material is defective. It may be related to glass fiber content, mold temperature, injection speed, gate design, or surface texture.
If the part is visible to the end user, buyers should confirm appearance requirements before choosing a high-GF grade.
For internal parts, surface fiber marks may be acceptable if mechanical performance is the main requirement.
Mold and Screw Wear
Glass fiber is abrasive. It can increase wear on the screw, barrel, gate, runner, and mold surface.
This is more obvious with high glass fiber content such as PC-GF30 or PC-GF40.
For long-term production, processors should consider:
- Wear-resistant screw and barrel
- Proper mold steel
- Gate and runner maintenance
- Regular inspection
- Stable processing conditions
This is important for cost control and consistent part quality.
Common Molding Problems and Solutions
Glass fiber reinforced PC can offer strong performance, but it also needs proper molding control.
| Problem | Possible Cause | Suggested Check |
| Warpage | Fiber orientation, uneven cooling, poor gate design | Review gate location, cooling layout, and wall thickness |
| Floating fiber | High GF content, low mold temperature, poor flow | Adjust mold temperature, injection speed, and grade selection |
| Short shot | Low flow, thin wall, long flow path | Use higher-flow grade or adjust part design |
| Brittleness | Poor drying, overheating, wrong grade | Check drying, melt temperature, and impact requirement |
| Weak weld line | Fiber orientation, poor venting, low melt temperature | Improve venting, gate design, and processing settings |
| Surface streaks | Moisture, degradation, poor drying | Improve drying and reduce residence time |
| Mold wear | High glass fiber content | Use wear-resistant tooling and maintenance plan |
| Dimensional variation | Shrinkage difference, unstable molding | Control cooling, pressure, and material drying |
For critical parts, trial molding is recommended before mass production.
Applications of Glass Fiber Reinforced PC Resin
Glass fiber reinforced PC is used where standard PC does not provide enough stiffness or dimensional control.
It is common in automotive, electrical, industrial, appliance, and mechanical applications.
Automotive Parts
Automotive parts often need heat resistance, dimensional stability, and mechanical strength.
Glass fiber reinforced PC can be used for:
- Brackets
- Lamp support parts
- Sensor housings
- Interior structural parts
- Electrical module housings
- Mechanical fixing components
- Functional supports
In automotive applications, buyers may need to check heat aging, dimensional tolerance, flame resistance, color, and long-term supply stability.
Electrical and Electronic Parts
Electrical and electronic components often need flame retardancy, dimensional stability, and stable mechanical performance.
GF-PC can be used for:
- Connector parts
- Switch housings
- Relay housings
- Control unit parts
- Electrical covers
- Power device parts
- Internal support structures
For these applications, buyers should confirm UL 94 rating, wall thickness, electrical requirements, and compliance documents.
Flame retardant glass fiber reinforced PC is often used when both structural strength and fire safety are needed.
Industrial Components
Industrial parts often need rigidity, strength, and long service life.
GF-PC can be used for:
- Machine covers
- Frames
- Supports
- Fixing components
- Mechanical housings
- Equipment structural parts
- Functional brackets
For industrial use, buyers should check load level, working temperature, chemical exposure, and dimensional tolerance.
Appliances and Consumer Goods
Glass fiber reinforced PC can also be used in home appliances and consumer products.
Typical applications include:
- Internal brackets
- Motor support parts
- Appliance structural components
- Power tool housings
- High-strength covers
- Functional fixing parts
If the part is visible, surface appearance should be reviewed carefully. If the part is internal, strength and dimensional stability may be more important than gloss.
How to Select the Right Glass Fiber Reinforced PC Grade
Selecting the right GF-PC grade requires more than choosing a glass fiber percentage.
Buyers should match the grade with the part design, processing method, and performance target.
Use the following selection direction as a starting point.
| Grade Direction | Typical Features | Suitable Applications |
| PC-GF10 | Light reinforcement, better flow, moderate stiffness | Small brackets, electrical parts, small housings |
| PC-GF15 | Balanced strength, stiffness, and processing | General structural parts, appliance parts, industrial covers |
| PC-GF20 | Medium-high rigidity and better dimensional stability | Automotive parts, supports, connector housings |
| PC-GF30 | High stiffness, low shrinkage, strong structural support | Load-bearing brackets, industrial parts, metal replacement |
| PC-GF40 | Very high rigidity, low shrinkage, higher processing difficulty | Special structural parts, high-load components |
| FR PC-GF | Flame retardant and reinforced | Electrical and electronic housings |
| Heat Stabilized PC-GF | Better heat aging performance | Automotive and high-temperature parts |
| Custom Colored PC-GF | Reinforced PC with color matching | Visible structural parts |
| Equivalent Replacement GF-PC | Matches existing datasheet requirements | Cost reduction and supply replacement projects |
Before final selection, buyers should confirm:
- Required stiffness
- Required impact strength
- Required heat resistance
- Required flame rating
- Wall thickness
- Part size
- Surface requirement
- Mold design
- Processing equipment
- Compliance requirement
- Existing grade to be replaced
Buying Checklist for Glass Fiber Reinforced PC Resin
Before buying glass fiber reinforced PC resin, prepare clear technical information.
This helps the supplier recommend the correct grade and avoid trial failures.
Key Questions to Confirm
- What glass fiber content do you need?
- What is the target flexural modulus?
- What tensile strength is required?
- What impact strength is acceptable?
- What heat deflection temperature is needed?
- Is flame retardancy required?
- What UL 94 rating is needed?
- What is the tested wall thickness for flame rating?
- What is the part wall thickness?
- Is the part visible or internal?
- Is surface gloss important?
- Is floating fiber acceptable?
- What shrinkage range is required?
- Is warpage a concern?
- Is the part long, flat, or thin-wall?
- What color is required?
- Is UV resistance needed?
- Is heat aging resistance needed?
- Are RoHS or REACH documents needed?
- Are you replacing an existing grade?
If you are replacing an existing material, provide the current datasheet or grade name. This allows better comparison and faster recommendation.
Suke Plastics Supply Support
Suke Plastics supplies glass fiber reinforced PC resin for automotive, electrical, industrial, appliance, and custom injection molding applications.
We can help customers select the right PC-GF grade based on real part requirements, datasheet targets, processing conditions, and cost goals.
Our support includes:
- PC-GF10 resin
- PC-GF15 resin
- PC-GF20 resin
- PC-GF30 resin
- Higher glass fiber PC grades
- Flame retardant glass fiber reinforced PC
- Heat stabilized PC-GF resin
- Custom colored reinforced PC
- Equivalent replacement for existing GF-PC grades
- Datasheet comparison
- Material selection support
- Trial order support
- Stable supply for injection molding projects
If you are developing a new structural PC part, please share your application, part drawing, wall thickness, processing method, and target properties.
If you are replacing an existing grade, please share the original brand, grade number, datasheet, and final application. Suke Plastics can help compare available PC-GF options and recommend a suitable material direction.
FAQ About Glass Fiber Reinforced PC Resin
1. What is glass fiber reinforced PC resin?
Glass fiber reinforced PC resin is a polycarbonate compound filled with glass fibers. The glass fiber improves stiffness, strength, dimensional stability, and heat resistance under load.
It is used for structural parts instead of transparent or optical PC applications.
2. What is the difference between PC and glass filled PC?
Standard PC has high impact strength and can be transparent. Glass filled PC has higher stiffness, higher strength, lower shrinkage, and better dimensional stability.
However, glass filled PC is usually opaque and may have lower impact toughness than standard PC.
3. Is glass fiber reinforced PC stronger than standard PC?
In tensile strength, flexural strength, and stiffness, glass fiber reinforced PC is usually stronger than standard PC.
But impact strength may be lower. Buyers should check the datasheet before choosing a grade.
4. Is PC-GF30 better than PC-GF10?
Not always.
PC-GF30 has higher stiffness and lower shrinkage than PC-GF10. But it also has lower flowability, higher mold wear, and higher risk of surface fiber marks.
PC-GF10 may be better for small parts, better surface quality, or easier processing.
5. What glass fiber content should I choose?
It depends on the part requirements.
- PC-GF10 is suitable for light reinforcement.
- PC-GF15 offers balanced performance.
- PC-GF20 offers medium-high rigidity.
- PC-GF30 is suitable for high-stiffness structural parts.
- PC-GF40 is used for special high-rigidity applications.
Final selection should be based on datasheet, part design, and molding trial.
6. Can glass fiber reinforced PC be flame retardant?
Yes. Flame retardant glass fiber reinforced PC grades are available.
They are often used in electrical housings, connector parts, control units, and electronic components. Buyers should confirm UL 94 rating and tested wall thickness.
7. Can glass fiber reinforced PC be transparent?
Usually no.
Glass fiber reinforced PC is normally opaque because glass fibers affect optical clarity. If transparency is required, standard transparent PC is usually a better choice.
8. Why does glass fiber reinforced PC warp?
Warpage is often caused by fiber orientation, uneven shrinkage, poor gate design, uneven cooling, or unbalanced wall thickness.
Long, flat, and thin-wall parts need special attention during mold design and material selection.
9. Does glass fiber reinforced PC need drying?
Yes. PC resin is moisture sensitive, and GF-PC also requires proper drying before molding.
Poor drying can cause silver streaks, bubbles, weak impact strength, and surface defects.
10. What are the disadvantages of glass fiber reinforced PC?
Common disadvantages include lower flowability, possible surface fiber marks, higher mold wear, higher warpage sensitivity, and possible reduction in impact toughness.
These issues can often be managed by proper grade selection, mold design, and processing control.
11. Is glass fiber reinforced PC suitable for automotive parts?
Yes. It is suitable for many automotive structural and functional parts, such as brackets, lamp supports, sensor housings, electrical module housings, and interior structural components.
Buyers should confirm heat resistance, dimensional stability, impact strength, and long-term supply requirements.
12. Can Suke Plastics help replace existing GF-PC grades?
Yes. Suke Plastics can help compare and recommend glass fiber reinforced PC alternatives based on your current grade, datasheet, application, processing method, and performance target.
Please provide the original grade number and technical requirements for a more accurate recommendation.
Conclusion
Glass fiber reinforced PC resin is a strong material choice for structural parts that need higher stiffness, better strength, low shrinkage, and improved dimensional stability.
It is widely used in automotive, electrical, industrial, appliance, and mechanical applications. The most common grade directions include PC-GF10, PC-GF15, PC-GF20, PC-GF30, flame retardant PC-GF, heat stabilized PC-GF, and custom reinforced PC grades.
For procurement, the best grade is not always the one with the highest glass fiber content. The right grade should match the part design, load requirement, heat condition, surface standard, flame rating, and molding process.
If you need glass fiber reinforced PC resin for a new project or material replacement, Suke Plastics can help you compare datasheets, select suitable grades, and support stable material supply for injection molding production.
