“The DFM feedback was incredibly detailed and helped us reduce cycle time by 15%. The transparency in the injection molding process is unmatched.”
PC Resins: Technical Processing & Material Properties
We engineer high-impact polycarbonate components by meticulously managing melt viscosity and advanced desiccant-based moisture control, ensuring that our IATF 16949-certified production maintains optimal molecular weight and optical clarity. By integrating high-precision mold thermoregulation and vacuum-assisted venting into our workflow, we eliminate internal stress and surface defects, which translates to consistent, flash-less overmolding and structural reliability for demanding automotive housings and optical-grade electronic assemblies.
Impact Strength: Unmatched energy absorption and toughness.
Optical Clarity: Up to 91% light transmission rate.
Precision Control: Tight ±0.01mm tolerance management.
Thermal Stability: Reliable performance at high temperatures.
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Technical Handshake
Material Overview: Polycarbonate (PC)
Polycarbonate (PC) is a high-performance amorphous engineering thermoplastic characterized by its exceptional toughness, thermal stability, and optical transparency. As a leading choice for heavy-duty industrial components, PC offers a unique combination of high impact strength—often referred to as "plastic steel"—and the ability to maintain its physical properties across a wide temperature range.By leveraging its naturally high refractive index and rigid molecular structure, injection-molded PC provides superior structural integrity and heat resistance (up to 135°C - 145°C deflection temperatures). It is the primary substrate for precision components that demand "unbreakable" performance, making it the industry standard for protective housings, medical-grade manifolds, and complex hardware integrations where clarity and safety are non-negotiable.
Engineered Excellence
Superior Impact Strength
Often characterized as the “gold standard” for toughness, Polycarbonate exhibits incredible energy absorption. This prevents cracking or shattering under extreme mechanical stress, making it the ideal choice for safety shields, ruggedized electronics, and structural protective gear.
High Thermal Resistance
Unlike standard thermoplastics, PC maintains its mechanical integrity at elevated temperatures. With a high heat deflection point, it is suitable for components exposed to significant heat generation, such as automotive lighting housings and industrial machinery covers.
Optical Clarity & Light Transmission
PC offers glass-like transparency with superior light transmission properties (up to 90%). It allows for high-precision replication of mold optical surfaces, supporting applications ranging from LED lenses to clear medical fluid manifolds.
High Dimensional Stability
With a uniform and predictable shrinkage rate, Polycarbonate allows for the production of high-precision parts with tight tolerances. This stability is critical for complex multi-part assemblies and high-performance insert molding where plastic-to-metal fit is paramount.
Material Grade Variation
General Purpose
Standard high-clarity and high-impact grades suitable for structural housings, protective covers, and transparent consumer goods.Optical Grade
Specifically refined for maximum light transmission and low birefringence, ideal for LED lenses, light pipes, and optical sensors.Flame Retardant
Formulated with specialized additives to achieve UL94 V-0 or 5VA ratings for electrical enclosures and aerospace interiors.Glass-Filled
Reinforced with 10% to 30% glass fibers to significantly increase flexural modulus, reduce creep, and improve dimensional stability in load-bearing parts.Medical Grade
Biocompatible resins designed to withstand various sterilization methods (Autoclave, Gamma, EtO) for surgical instruments and fluid delivery systems.
Technical Specifications
Technical Data Section: Polycarbonate (PC) Material Properties
To assist engineers in evaluating the baseline performance of standard Polycarbonate (PC) resin, the following table details the core physical and mechanical metrics. These PC injection molding material properties are representative of unfilled, general-purpose engineering grades commonly utilized in high-impact structural and optical-grade components.
| PROPERTY | TEST METHOD (ASTM/ISO) | VALUE (METRIC) | VALUE (IMPERIAL) |
|---|---|---|---|
| Density / Specific Gravity | ASTM D792 | 1.20 g/cm³ | 0.043 lb/in³ |
| Melt Flow Rate (MFR) | ASTM D1238 | 15 g/10min | 15 g/10min |
| Mold Shrinkage (Flow) | ASTM D955 | 0.5% - 0.7% | 0.005 - 0.007 in/in |
| Tensile Strength at Yield | ASTM D638 | 65 MPa | 9400 psi |
| Elongation at Break | ASTM D638 | 100% | 100% |
| Flexural Modulus | ASTM D790 | 2350 MPa | 341000 psi |
| Izod Notched Impact Strength | ASTM D256 | 700 J/m | 13.1 ft-lb/in |
| Heat Deflection Temp (1.8MPa) | ASTM D648 | 132°C | 270°F |
| Light Transmission | ASTM D1003 | 89% - 91% | 89% - 91% |
| Flammability Rating | UL94 | V-2 to V-0 | V-2 to V-0 |
Comparison Context: Standard Polycarbonate (PC) vs. PC/ABS Alloy
When evaluating materials for impact-heavy or high-heat environments, engineers frequently compare pure Polycarbonate (PC) against PC/ABS injection molding blends. While pure PC offers unmatched clarity and the highest heat deflection temperatures, upgrading to or selecting a PC/ABS alloy is often a strategic move to improve processability and reduce notch sensitivity, making the alloy superior for complex thin-walled electronic housings.
| PROPERTY / SPECIFICATION | STANDARD POLYCARBONATE (PC) | REINFORCED PC (20% GLASS FIBER) |
|---|---|---|
| Material Composition | Amorphous Engineering Thermoplastic | Glass-Fiber Reinforced Polycarbonate |
| Heat Deflection Temp (HDT @ 1.82 MPa) | 130°C – 140°C (High Heat Baseline) | 145°C – 150°C (+10°C to 15°C Improvement) |
| Tensile Strength (Yield) | 60 – 70 MPa (High Structural Strength) | 100 – 120 MPa (Superior Rigid Performance) |
| Impact Resistance (Notched Izod) | 600 – 850 J/m (Exceptional Toughness) | 100 – 150 J/m (High Rigidity / Reduced Impact) |
| Flexural Modulus | 2,300 – 2,500 MPa | 5,500 – 6,500 MPa (Extreme Structural Stiffness) |
| Processing Temperature | 280°C – 320°C | 300°C – 330°C (Requires Precise Thermal Control) |
| Molded Shrinkage Rate | 0.5% – 0.7% | 0.1% – 0.3% (Ultra-Low Dimensional Drift) |
| Optical Clarity | 89% – 91% Light Transmission | Opaque (Fiber Interference) |
| Primary Applications | Optical lenses, housings, medical valves | Structural frames, automotive load-bearers |
| Flammability Rating (UL94) | V-2 / V-0 (Grade Dependent) | V-0 / 5VA (High-Performance FR Grades) |
| Regulatory Compliance | RoHS & REACH Compliant | RoHS & REACH Compliant |
| Dimensional Stability | Excellent (Low moisture absorption) | Extreme (Fiber-stabilized matrix) |
Technical Analysis
Advantages & Limitations: Polycarbonate (PC) Injection Molding
An objective, engineering-first analysis detailing the industrial strengths and inherent drawbacks of Polycarbonate for high-precision injection molding and heavy-duty structural applications.
Key Advantages
Exceptional Impact Strength: Known as the “Plastic Steel,” Polycarbonate provides unmatched toughness and energy absorption. It is the premier choice for protective housings, safety lenses, and structural components that must withstand extreme mechanical shock without fracturing.
High Thermal Stability: PC maintains its mechanical properties and dimensional integrity at significantly higher temperatures than standard engineering plastics. It is ideal for automotive lighting, industrial power tools, and components exposed to heat-generating electronics.
Superior Optical Clarity: Offering up to 90% light transmission, PC provides glass-like transparency with much higher durability. It excellently replicates high-polish mold surfaces, making it indispensable for optical lenses, light pipes, and clear medical manifolds.
Excellent Dimensional Stability: With a very low and predictable shrinkage rate, PC allows for the production of high-precision parts with extremely tight tolerances. This stability ensures reliable performance in complex multi-part assemblies and precision insert molding.
Flame Retardancy: Polycarbonate possesses inherent flame-retardant properties. When coupled with specialized additives, it easily achieves UL94 V-0 or 5VA ratings, meeting the stringent safety requirements of the aerospace and electrical industries.
Critical Limitations
Internal Stress Sensitivity: PC is prone to developing internal residual stresses during cooling, which can lead to stress cracking over time. To mitigate this, it is essential to optimize mold temperatures and utilize annealing processes, especially for thick-walled or high-complexity components, to relieve latent tension.
Poor Chemical Resistance: The material is vulnerable to aromatic hydrocarbons, ketones, and certain esters, which can cause surface crazing or structural failure. During the DFM (Design for Manufacturing) phase, it is critical to strictly evaluate the chemical environment, including potential exposure to cleaning agents and oils.
High Processing Temperatures: Due to its high melt viscosity, PC requires significantly higher processing temperatures and injection pressures. To avoid material degradation and ensure part integrity, the use of high-performance molding machines with precise thermal control is mandatory.
Extremely Hygroscopic Nature: PC resin is highly sensitive to moisture; even trace amounts of water during processing will cause hydrolysis, resulting in bubbles, silver streaks, and brittle parts. Mandatory desiccant drying at 120°C for 3 to 4 hours is required to ensure the resin is completely dry before injection.
Notch Sensitivity: While incredibly tough, PC is sensitive to sharp corners and notches, which act as stress concentrators and lead to cracks. Part designs must adhere to generous radius guidelines (typically R>0.5 mm) and avoid sharp internal transitions to maintain structural durability.
Engineering Analysis: Polycarbonate (PC) Injection Molding Performance
A comprehensive breakdown of technical strengths, ideal use cases, and critical environmental constraints to guide your material selection process for precision mechanical components.
Industrial Strengths
Core mechanical and processing benefits that make Polycarbonate a premium choice for high-performance engineering.The Sweet Spot
Specific scenarios where Polycarbonate outperforms alternative resins in durability, clarity, and safety.Technical Constraints
Inherent physical properties that require strategic design-for-manufacturing (DFM) adjustments.Avoidance Criteria
Critical operational environments or functional requirements where this material is likely to fail.
Technical Process Manual
Injection Molding Processing Guide: Polycarbonate (PC)
To ensure consistent part quality, optimal mechanical performance, and repeatable tolerances across high-volume production, strictly adhere to these fundamental parameters for engineering-grade Polycarbonate.
Pre-Processing & Drying
Polycarbonate is extremely hygroscopic and highly sensitive to moisture at processing temperatures. Any residual water will cause permanent hydrolytic degradation, severely compromising the material’s legendary impact strength and optical clarity.
Drying Temp: 120°C (250°F)
Duration: 3 - 4 Hours
Max Moisture: < 0.02%
Drying Equipment: Desiccant dehumidifying dryer mandatory
Engineer's Note
"Surface appearance is a deceptive metric for Polycarbonate. While splay marks clearly indicate moisture, internal hydrolytic degradation can occur without any visible defects. This invisible structural failure results in brittle parts that shatter under low impact. Always validate moisture levels below 0.02% using a moisture analyzer before initiating the injection cycle to guarantee part integrity."
Troubleshooting & Defect Mitigation: Polycarbonate (PC)
Silver Streaks (Splay Marks)
Silver streaks in PC are almost exclusively caused by moisture-induced hydrolysis or material degradation, where even a 0.02% moisture level can trigger defects. To correct this, verify desiccant dryer performance at 120°C and reduce the melt temperature or residence time if thermal degradation is suspected.Vacuum Voids (Bubbles)
Common in thick-walled PC parts, these bubbles occur when the outer layer freezes faster than the core, creating internal tension. This can be corrected by increasing packing pressure and holding time, as well as optimizing gate size to prevent premature freezing and ensure effective melt compensation.Stress Crazing (Fine Cracks)
PC is highly susceptible to residual internal stress, where high injection speeds or low mold temperatures can "lock in" stress that appears as fine surface cracks over time. To mitigate this, increase mold temperature to 80°C–120°C to allow for slower cooling, and implement a post-mold annealing cycle if the part geometry is complex.Black Specks / Carbonization
Due to high processing temperatures (300°C+), stagnant resin in the barrel can quickly carbonize and result in black specks. Correction requires ensuring the barrel is thoroughly purged with a high-heat stable compound and checking for "dead spots" in the manifold or nozzle tip where material may hang up.
Critical Dos & Don'ts
Engineering pro-tips and specific processing protocols to protect material performance, mold longevity and operator safety
Avoid Thermal Stagnation: Do not allow the PC melt to reside in the barrel for more than 4 to 5 minutes at upper temperature limits (above 300°C). Prolonged exposure at these temperatures triggers rapid thermal degradation, resulting in yellowing and a catastrophic loss of impact strength.
Precision Venting Requirements: PC has a high melt viscosity and requires robust venting to prevent air entrapment. Ensure vent depths are maintained between 0.03 mm to 0.05 mm at the end of fill and along parting lines to prevent diesel burns (gas marks) and incomplete filling.
Implement Controlled Cooling: Because PC is prone to high residual stress, ensure the mold temperature is uniformly controlled via high-performance oil or water heaters. Avoid “shock cooling” the part, as rapid temperature drops will lock in internal stresses that lead to delayed stress cracking or dimensional warping.
Strict Purging Protocol: During temporary shutdowns or material changes, always purge the barrel with a high-heat stable purging compound or a high-viscosity HDPE. Never leave PC in the barrel during a cold restart, as the high torque required to melt stagnant PC can damage the screw and nozzle assembly.
Why Choose Us
Why Industry Leaders Choose Kravzik?
Delivering uncompromising precision, accelerated speed-to-market, and fully integrated manufacturing solutions for the most demanding technical applications.
Accelerated NPI & Rapid Turnaround
We compress your development cycles. By integrating agile manufacturing processes with advanced in-house capabilities, we deliver functional, test-ready components in days—helping you hit tight launch deadlines without sacrificing quality.
Production-Grade Precision & QA
Quality is non-negotiable for medical, aviation, and advanced robotics applications. We achieve strict dimensional tolerances backed by comprehensive in-house metrology, including CMM vision systems, complete FAI reporting, and ISO-compliant workflows.
Proactive DFM & Cost Optimization
We don’t just execute prints; we optimize them. Our engineering team provides rigorous Design for Manufacturability (DFM) reviews upfront. By identifying potential defects early, we significantly reduce tooling risks and overall unit costs.
Seamless Scalability & IP Protection
Grow your volume seamlessly without switching suppliers. We transition your projects from low-volume prototypes to high-yield mass production under one roof. All proprietary CAD designs are strictly protected under legally binding NDAs.
TECHNICAL DATA LIBRARY
Evaluate High-Performance Plastics & Resins Specifications
Polystyrene (PS)
Scalable PS molding solutions delivering glass-like optical clarity and high-rigidity structural performance through IATF-certified precision engineering.
PBT
High-performance PBT molding solutions featuring rapid crystallization and superior chemical resistance for high-volume, precision electrical hardware production.
PETG
High-clarity PETG molding with superior impact resistance and chemical stability. We deliver medical-grade precision and high-volume consistency for complex, durable transparent assemblies.
Polypropylene (PP)
High-volume PP molding specializing in durable living hinges and chemically inert enclosures with 0.05mm precision and IATF-grade quality control.
Request DFM EvaluationAccess Full Material Data Sheets
TECHNICAL REFERENCE
Frequently Asked Questions
Answers to common questions regarding precision, tooling, materials, and our integrated molding capabilities.
We utilize high-precision oil heaters to maintain consistent mold temperatures between 80°C and 120°C. This controlled thermal environment allows for uniform cooling, which prevents the buildup of residual internal stress and eliminates the risk of delayed stress cracking or crazing in structural components.
Yes. Our integrated production facility unifies metal stamping and injection molding under one roof. By controlling the thermal expansion variables and using optical-grade resins, we ensure that the plastic-to-metal interface remains seamless and the transparency of the lens or housing is never compromised by silver streaks or voids.
We mandate the use of desiccant dehumidifying dryers at 120°C for 3 to 4 hours prior to production. To ensure absolute material integrity, we use moisture analyzers to verify that levels are below 0.02%, preventing invisible structural failure and ensuring the legendary impact strength of Polycarbonate is maintained.
Absolutely. Since standard PC is sensitive to UV and surface scratches, we provide secondary functional coatings. These treatments enhance surface hardness and provide a protective UV barrier, making your molded components suitable for long-term outdoor use in automotive or industrial infrastructure applications.
We utilize hardened S136 or H13 stainless steel to withstand the high injection pressures required for PC. Our mold designs feature oversized gates and precision venting (0.03 mm to 0.05 mm) to facilitate smooth material flow and prevent gas traps or diesel burns on high-aesthetic surfaces.
Pure Polycarbonate is the superior choice when your application requires glass-like transparency and the highest possible heat deflection temperature (up to 145°C). While alloys are easier to process, pure PC provides the “unbreakable” impact resistance and structural rigidity necessary for safety-critical medical and industrial equipment.
Yes. We process biocompatible, medical-grade PC resins that are designed to survive various sterilization methods including Autoclave, Gamma, and EtO. Our IATF 16949 certified quality system ensures that every part meets the rigorous safety and traceability standards required for surgical instruments and fluid delivery manifolds.
Our engineering team utilizes Scientific Injection Molding (SIM) and real-time cavity pressure monitoring. By optimizing the packing pressure and hold time, we ensure the core of the part is properly compensated as it cools, effectively eliminating vacuum bubbles and internal voids in thick-walled sections.
Still have questions?
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