PC (Polycarbonate)

Polycarbonate (PC), often known by trade names like Lexan or Makrolon, is a naturally transparent amorphous thermoplastic known for its incredibly high impact resistance and toughness. It is virtually unbreakable, making it the ideal material for safety shields, optical lenses, and robust electronic housings. However, machining PC to optical clarity requires expertise. At Jucheng Precision, we specialize in producing optically clear Polycarbonate parts. We combine precision CNC milling with secondary processes like Vapor Polishing and hand buffing to remove tool marks and restore transparency. Our ISO 13485 certified facility ensures that even complex medical manifolds or automotive lighting prototypes are produced with strict adherence to dimensional tolerances (+/- 0.02mm) and cosmetic standards.

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Available Polycarbonate (PC) Grades

Grade	Common Name	Key Characteristics	Typical Applications
Standard PC	General Purpose (GP)	High impact strength, good heat resistance, and transparency. The most common grade for machining.	Machine guards, transparent manifolds, structural housings, electrical connectors.
Optical Grade PC	Lexan® / Makrolon®	Formulated for low haze and high light transmission. Optimized for polishing.	Lenses, light pipes, windows, display screens, automotive lighting.
Glass-Filled PC	GF10 / GF20 / GF30	Reinforced with glass fibers (10-30%). Significantly increased stiffness and tensile strength, but opaque.	Structural components, rigid housings, industrial brackets.
Machine Grade PC	Stress-Relieved	Processed to reduce internal stress, making it easier to machine without cracking.	Precision prototypes, tight-tolerance insulators.

Polycarbonate Machining Capabilities

Capability	Technical Description	Jucheng Advantage
Vapor Polishing	Exposing machined PC parts to chemical vapor to melt the surface microscopic layer, creating an optically clear finish.	We can turn a translucent machined part into a glass-like clear component for internal verification.
Stress-Free Machining	PC is prone to “crazing” (micro-cracking). We use sharp tools and annealing cycles to manage stress.	Ensures durability and chemical resistance of the final part, preventing failure in service.
Complex 5-Axis Milling	Machining complex automotive light guides and headlight bezels with organic curves.	Our 5-axis machines allow for continuous contouring required for optical surfaces.
High-Speed Drilling	Drilling precise hole patterns without melting or cracking the material.	Optimized peck cycles and coolant prevent heat buildup, crucial for deep holes in PC.

Fabrication Guidelines for PC

Coolant Sensitivity:
Polycarbonate is highly sensitive to chemical attack. Standard cutting fluids can cause immediate stress cracking. We use strictly compatible, non-aromatic water-soluble coolants or air blast.

Polishing Strategy:
To achieve optical clarity, the part must first be machined with a very fine step-over to minimize tool marks, followed by sanding (up to 2000 grit) and final vapor polishing or buffing.

Annealing:
Machining induces stress. For parts with tight tolerances or those requiring heavy solvent bonding/polishing, we anneal the parts in an oven to relieve internal stresses.

Tooling:
We use extremely sharp, uncoated carbide tools with high clearance angles. Coated tools can sometimes be too dull for plastic, causing heat friction that melts the PC.

Primary Application Industries

Automotive
Key Parts: Headlight lenses, interior light pipes, dashboard instrument panels.
Why PC: Combines optical clarity with high impact resistance to withstand road debris.

Medical Devices (ISO 13485)
Key Parts: Blood oxygenators, surgical reservoirs, manifolds.
Why PC: Clear visibility of fluids, biocompatible grades available, and withstands sterilization (Gamma/EtO).

Safety & Security
Key Parts: Blast shields, riot gear visors, machine guards.
Why PC: Its legendary impact toughness (bullet-resistant in thick sections) protects personnel.

Electronics
Key Parts: LED covers, robust handheld device housings, battery cases.
Why PC: Flame retardance (UL94 V-0 grades) and durability against drops.

Material Properties

Density	1.20 - 1.22 g/cm³
Tensile Strength	55 - 75 MPa
Impact Strength	600 - 900 J/m
Heat Deflection Temp	130 - 145 °C
Hardness	70 - 85 Rockwell M
Continuous Service Temp	115 - 130 °C
Water Absorption	0.15 - 0.35 %
Dielectric Strength	15 - 17 kV/mm
Light Transmission	88 - 90%
Max. Part Size	2000 mm (L) x 800 mm (W) x 600 mm (H)