PC Material for Luggage: Complete Material Guide

The First Question I Ask on Any PC Line

When I walk into a sheet extrusion shop, I don't ask about the extruder. I ask about the dryer.

"Is that a desiccant dryer?"

The answer tells me more about the factory's PC capability than an hour of conversation. PC pellets absorb moisture from the air, and if they aren't dried to below 0.02% moisture content before extrusion, the material hydrolyzes during processing. The damage is permanent — mechanical properties drop by 20-40%, and the sheet is compromised before it ever reaches a forming station.

PC is the premium material of mid-to-premium hard-shell luggage for good reasons: impact strength approaching some metals, transparency approaching glass, and the ability to flex under load without permanent deformation. But it demands premium processing discipline. This guide is about specifying PC correctly, verifying grade authenticity, and making sure the material at the forming station is the material on your purchase order.

The Chemistry, Briefly

PC is a linear polyester of carbonic acid, made by reacting bisphenol A (BPA) with phosgene or through melt transesterification. The polymer chain has a rigid aromatic backbone connected by flexible carbonate linkages.

That structure is the whole story: the aromatic rings give stiffness and heat resistance; the carbonate linkages give molecular mobility that absorbs impact energy. Unlike ABS, where impact resistance comes from discrete rubber particles that can degrade over time, PC's impact resistance is inherent to the molecule — it doesn't age out or wear out with repeated impacts.

Molecular weight drives mechanical properties, and it's measured indirectly through melt flow rate (MFR): lower MFR means higher molecular weight means higher impact strength. For luggage, specify PC with an MFR of 5-15 g/10min (at 300°C/1.2kg). Below 5 is difficult to process. Above 20 means reduced impact strength — a 30+ MFR material processes easily and produces brittle shells. Request the MFR value from the datasheet; it's the single most informative number for predicting shell performance.

The Mechanical Property Profile

Tensile strength of 55-75 MPa gives structural integrity.
Izod notched impact strength of 600-850 J/m — roughly 2-3x higher than high-impact ABS.
Flexural modulus of 2.2-2.4 GPa provides the rigidity consumers associate with quality.
Heat deflection temperature of 125-135°C means no warping in a hot cargo hold.
Ductile-to-brittle transition at approximately -20°C means PC keeps its impact resistance where ABS has already gone brittle.

Request the full datasheet for the grade being used and check these values: Izod notched impact at 23°C (above 700 J/m preferred for luggage), tensile strength at yield (above 60 MPa), flexural modulus (2.2-2.4 GPa), HDT at 1.82 MPa (above 125°C), and Izod impact at -20°C for cold-weather applications. Compare the factory's datasheet against the manufacturer's published values for that grade. A mismatch means either an outdated datasheet or material substitution.

And don't evaluate PC by impact strength alone. The combination — high impact plus high rigidity plus high heat resistance — is what makes it valuable. A material with PC's impact but ABS's rigidity feels flimsy. A material with PC's rigidity but ABS's impact cracks easily. It's the package.

Grades — A Brand Name Without a Grade Number Is Not a Spec

PC comes in hundreds of grades: optical (CDs/DVDs, eyewear), automotive (headlamp lenses), electrical (connectors), medical (sterilizable devices), and sheet/extrusion (glazing, signage, luggage). Only sheet/extrusion-grade PC belongs in luggage.

Specify extrusion-grade PC from a named supplier. The leading luggage-grade options: SABIC Lexan 9034 or the Lexan EXL series (formulated for sheet extrusion), Covestro Makrolon GP (general-purpose extrusion) or Makrolon ET (high-flow extrusion), Teijin Panlite L-1250 (standard extrusion grade).

Here's the trap: "Lexan" alone is not a specification. It's a brand covering hundreds of grades across dozens of applications. A factory can truthfully say they use Lexan while using an injection-molding grade completely unsuitable for luggage. The brand names the supplier. The grade number names the material.

Sheet Extrusion — Where Quality Is Won or Lost

PC is more demanding to extrude than ABS:

Drying: PC must be dried to below 0.02% moisture (ABS allows below 0.1%). PC pellets go into a desiccant dryer at 120°C for 3-4 hours. No desiccant dryer, no proper PC processing — full stop.
Extrusion temperature: 260-300°C vs 200-240°C for ABS.
Residence time: PC degrades if it sits too long at high temperature — yellowing, molecular weight reduction, lost mechanical properties.
Sheet inspection: look for yellowing (thermal degradation), gel particles (cross-linked PC from hot spots), surface defects (moisture-related).
Thickness tolerance: ±0.05mm for premium applications.

A factory that runs the same dryer settings for PC and ABS is not drying the PC. The resulting sheet carries degraded mechanical properties from day one.

Vacuum Forming — Temperature, Time, and Stress

PC forms at significantly higher temperatures than ABS: 180-220°C vs 140-180°C. Underheating gives incomplete forming and high internal stress. Overheating gives thermal degradation — yellowing, bubbles. Rapid cooling locks in internal stresses that cause delayed cracking later.

Professional PC forming requires: multi-zone infrared or contact heating with ±5°C precision; sheet surface temperature verified with an infrared thermometer (not estimated by heating time); controlled mold temperature of 80-120°C (ABS runs at ambient); controlled cooling in a cooling station rather than air-cooling on racks; and for premium products, post-forming annealing — heating formed shells to 120-130°C for 30-60 minutes and cooling slowly to relieve internal stress.

Annealing adds cost and cycle time. Skipping it adds warranty claims for cracked shells. For premium PC luggage, annealing isn't optional — it's the quality differentiator most buyers never think to ask for.

Virgin vs Recycled vs PC+ABS Blend

"PC luggage" in the market can mean three different materials. Know which you're buying:

Property	Virgin PC	Recycled PC	PC+ABS (70/30)
Composition	100% virgin PC	70-100% recycled PC	~70% PC + ~30% ABS
Izod impact (J/m)	700-850	500-650	400-550
Cold performance	Good to -20°C	Moderate to -15°C	Moderate to -10°C
Flex test response	Smooth flex, silent rebound	Variable, may feel stiffer	Creaking during flex
Burn test	Yellow-orange flame, no black smoke	Similar to virgin, slight variations	Black smoke, styrene odor
Cost (relative)	1.0 (baseline)	0.75-0.85x	0.65-0.80x
Batch consistency	Excellent	Moderate to poor	Moderate
Best application	Premium luggage	Mid-tier with testing	Budget-mid luggage

Recycled PC needs batch-level mechanical property testing. Blends need an honest blend ratio stated — "70% PC / 30% ABS" — and expectations set accordingly: a 70/30 blend lands at 400-550 J/m Izod, better than ABS but well below virgin PC.

And check the material economics. Virgin PC sheet for a 20-inch suitcase costs about $6-9 in material alone, before forming, components, assembly, and margin. If the FOB price of a "PC suitcase" is $12-14, it cannot be virgin PC. The math doesn't work. It's a blend or recycled material, whatever the factory calls it.

Verification — Three Tiers

Visually, virgin PC, recycled PC, and blends look nearly identical. The performance difference is enormous. So verify systematically:

Field tests: flex a shell corner — virgin PC flexes smoothly and rebounds silently; PC+ABS creaks; recycled PC may feel stiffer or more brittle. Burn test: PC burns yellow-orange with minimal smoke and a faint sweet odor; PC+ABS adds black smoke and styrene odor.
Documentation: material certificates from the PC supplier with grade number, batch number, and date; incoming QC records for each batch of sheet.
Laboratory: FTIR for material identification, DSC for thermal properties, Izod impact testing per ASTM D256. For orders above $20,000, lab verification is recommended for at least the first production batch.

Don't rely on a single method. Perfect documentation that fails a field test means a process problem. Passing field tests with no documentation means a supply chain transparency problem. Overlapping methods give overlapping confidence.

The PC Material Specification Checklist

Specification item	Confirmed	Supplier's answer
PC supplier and grade (e.g., SABIC Lexan 9034)	☐
Grade type: extrusion-grade PC (not injection-molding grade)	☐
Melt flow rate: 5-15 g/10min (300°C/1.2kg)	☐
Izod notched impact above 700 J/m at 23°C (virgin PC)	☐
PC pellets dried at 120°C for 3-4hr, moisture below 0.02%	☐
Sheet thickness tolerance ±0.05mm (premium) or ±0.10mm (standard)	☐
Forming temperature: 180-220°C, IR thermometer verified	☐
Mold temperature: 80-120°C	☐
Post-forming cooling: controlled station, above 45 seconds	☐
Post-forming annealing: 120-130°C, 30-60 min (premium products)	☐
Material certificate from PC supplier per production batch	☐
FTIR or DSC verification for first production batch	☐

Three Things We Check on Every PC Order

1. The tap test takes two seconds.

Tap the shell with a fingernail. Virgin PC gives a clear, higher-pitched "tink" — like tapping glass. PC+ABS gives a duller, lower-pitched "thock." Pure ABS gives the dullest sound of all. A factory tour guide who confidently tells you a product is PC while it sounds like ABS has just told you something useful about their honesty.

2. Yellowing usually isn't the sun. It's the extruder.

The most common cause of PC luggage yellowing is thermal degradation during sheet extrusion — PC sitting too long at high temperature yellows from heat alone, before it ever sees sunlight. Inspect the raw sheet before forming. Any yellow tint means the extrusion temperature was too high or residence time too long, and the yellowing is irreversible. Mechanical properties are already compromised.

3. Annealing is the cheapest quality upgrade you can buy.

Post-forming annealing relieves the internal stresses built up during vacuum forming, cutting the risk of delayed cracking by 60-80%. It costs about $0.50-1.00 per unit in energy, labor, and cycle time. It eliminates the most frustrating PC warranty claim there is — a shell cracking weeks after production with no apparent cause. If you specify one processing parameter beyond the basics, make it annealing.

Common Mistakes When Specifying PC Material

Specifying "polycarbonate" or a brand name without a grade number. "Lexan" covers hundreds of grades. "Lexan 9034" specifies a sheet-extrusion grade suitable for luggage.
Accepting PC pricing below the virgin material cost floor. If the FOB price can't cover virgin PC sheet, the material is recycled PC, a blend, or pure ABS wearing a PC label. Material economics don't lie.
Not requiring desiccant drying. Hot-air dryers can't reach below 0.02% moisture. Undried PC loses 20-40% of its impact strength permanently.
Processing PC with ABS forming parameters. PC needs higher temperatures, heated molds, controlled cooling. The same settings produce stressed, brittle shells regardless of grade.
Not doing lab verification on premium products. A $150 FTIR test on the first production batch is definitive. That's less than the margin on a single returned unit.

Frequently Asked Questions

How do I verify that PC luggage is 100% polycarbonate?

Three methods, in increasing order of certainty: (1) Burn test — pure PC burns with a yellow-orange flame, minimal smoke, and a faint sweet odor; ABS contamination adds black smoke and styrene odor. (2) Density test — pure PC density is 1.20 g/cm³; PC+ABS blend density is 1.12-1.18 g/cm³. (3) FTIR spectroscopy — definitive material identification that can detect ABS content as low as 5%. For premium products, FTIR verification of the first production batch is recommended.

What is the difference between SABIC Lexan and generic PC?

Lexan is a branded PC from SABIC, produced under tight quality control with consistent molecular weight, additive packages, and batch-to-batch properties. Generic PC comes from smaller manufacturers with less consistent control. The performance difference: Lexan-grade PC consistently achieves Izod impact above 750 J/m; generic PC may range from 550-750 J/m depending on source and batch. For premium luggage, branded PC is preferred. For mid-market products, generic PC is acceptable with appropriate testing.

Why does PC luggage sometimes crack months after purchase?

Delayed cracking comes from residual internal stresses caused by improper forming — inadequate heating, rapid cooling, or insufficient cooling time. The stress relaxes slowly over weeks or months, eventually exceeding the material's strength at a stress concentration point like a corner, attachment hole, or surface defect. Post-forming annealing eliminates this failure mode by relieving the stress before the product leaves the factory.

Is PC luggage safe? Does it contain BPA?

PC is made from BPA, but the BPA is chemically reacted into the polymer chain during production — it isn't present as free BPA in the finished product. Residual BPA levels in PC products are well below regulatory limits. BPA in PC luggage is not a meaningful consumer safety concern. The accurate answer: BPA is fully reacted into the polymer structure and is not bioavailable.

How does PC compare to PP in terms of environmental impact?

PP has a lower production carbon footprint (1.7 vs 5.0+ kg CO2/kg), is more widely recyclable, and incorporates post-consumer recycled content more easily. PC has superior mechanical properties and durability, which can extend product life and reduce replacement frequency. The comparison depends on timeframe: PP wins on production impact; PC can win on lifecycle impact if the product lasts significantly longer.

What temperature range can PC luggage withstand?

PC retains mechanical properties from roughly -20°C to 125°C. Below -20°C, impact resistance begins to degrade (though less severely than ABS). Above 125°C, the material softens and can warp under load. These limits are rarely hit in normal travel — a car trunk in summer can reach 70-80°C, comfortably inside PC's range.

Can PC luggage be produced in transparent or translucent versions?

Yes — and that's one of PC's unique advantages. ABS is naturally opaque; PP is naturally translucent but hazy. PC can be water-clear transparent, various translucent colors, or fully opaque. Transparent PC luggage is a distinctive category, though it shows scratches more visibly than textured opaque finishes.

How do I specify the right PC grade for my product line?

Premium: branded virgin PC (SABIC Lexan 9034, Covestro Makrolon GP) with post-forming annealing. Mid-tier: generic virgin PC with documented mechanical properties (Izod above 650 J/m). Value: PC+ABS blend with a stated minimum PC content (e.g., 70% minimum) and batch-level testing. The grade specification must match your market positioning and price point.

About the Author

Written by the CLK Manufacturing Team — 16+ years of custom luggage OEM/ODM experience from our factory in Ji'an, Jiangxi, China. Updated: 2026-08-15.