In 2026, a carry-on suitcase is not just a travel accessory – it is the most important piece of luggage for most frequent flyers. As airlines tighten their excess baggage policies, the carry-on determines both comfort and the overall cost of a journey. But not every suitcase is the same. The material from which a hard-shell case is made directly determines its weight, durability and how well it protects its contents. The two most common options are polypropylene (PP) and polycarbonate (PC).
Choosing between them is more than a question of price. It is a decision about how your suitcase will handle rain on the tarmac, pressure in the overhead locker and whether it will still look presentable after ten flights. This article is based on technical specifications from manufacturer data sheets, durability test results and user reviews rather than on marketing claims.
How Polypropylene and Polycarbonate Are Made
Polypropylene – Durability at Low Weight
Polypropylene is a thermoplastic from the polyolefin family, produced by polymerisation of propene (C₃H₆). The raw granulate is heated to approximately 220°C and injected into suitcase moulds. Its key properties are high chemical resistance, low density (approximately 0.9 g/cm³) and elasticity. In modified versions it can be reinforced with talc or glass fibres. Suitcase manufacturers typically use PP copolymers with enhanced crack resistance. The material flexes and deforms under stress rather than breaking, which is an advantage in travel conditions.
Polycarbonate – Premium Rigidity from Precision Forming
Polycarbonate (PC) is a stiffer, heavier and more expensive material produced from bisphenol A (BPA) and phosgene in closed chemical systems. Its production – using brands like Makrolon® from Covestro – is more technologically demanding than standard PP injection moulding. The advantages are UV resistance, very high impact resistance especially at low temperatures, and the ability to achieve precise edge geometry. Suitcase forming uses hot pressing or thermoforming. This enables technologies like Samsonite’s Curv™ and Peli’s HPX²™ – which is a patented PC/PP composite offering the rigidity of PC with improved elasticity.
Both materials are subject to material standards: ISO 1133 for PP flow behaviour and ISO 6603-2 for PC mechanical impact resistance.
Physical Properties – The Technical Data
| Parameter | Polypropylene (PP) | Polycarbonate (PC) |
|---|---|---|
| Density | 0.90 g/cm³ | 1.20 g/cm³ |
| Flexural modulus (23°C) | ~930 MPa | ~1940 MPa |
| Impact resistance (Charpy, 23°C) | ~48 J/m | ~15 kJ/m² (−30°C) |
| Heat deflection temperature (0.45 MPa) | ~110°C | ~138°C |
| Chemical resistance | Very good (acids, bases) | Moderate (sensitive to solvents) |
| UV resistance | Poor without stabilisers | Good (natural and with additives) |
How to interpret this: PP wins on lightness and elasticity – ideal for carry-on baggage carried frequently by hand. PC offers greater rigidity and thermal resistance – better for those carrying delicate equipment or travelling across different climate zones. Both perform well in aviation conditions but require protective coatings against scratches.
Peli Air 1535 Carry-On Cases
The Peli Air range uses HPX²™ – a patented PC/PP composite that combines the rigidity of polycarbonate with the flexibility and lighter weight of polypropylene. The result is a case rated at IP67 (completely dust-tight and waterproof to 1 metre depth), resistant to impacts that would crack standard PC, and up to 40% lighter than traditional hard-shell protective cases.
Weight and Capacity – How Material Choice Changes the Numbers
| Model | Material | External dimensions | Weight | Capacity |
|---|---|---|---|---|
| Travelite Air Base S | PP | 55 × 39 × 20 cm | 2.1 kg | 37 l |
| Samsonite Proxis S | PC (Curv™) | 55 × 40 × 20 cm | 2.2 kg | 38 l |
| Peli Air 1535 | HPX²™ (PC/PP composite) | 55.8 × 35.5 × 22.8 cm | 3.9 kg | 27 l |
What this means in practice: PP cases are noticeably lighter and typically more affordable – an excellent choice for low-cost airline travellers where weight limits are critical. PC cases weigh more but offer greater structural rigidity and better content protection – chosen by those carrying photographic equipment, electronics or important documents. Peli Air is a premium category example – heavier, but engineered for the most demanding conditions: customs inspections, field work, protection of high-value items. The 1.8 kg difference between a 2.1 kg PP case and a 3.9 kg HPX²™ case may mean the difference between staying within a carry-on weight limit or incurring a checked baggage fee.
Scratch and Wear Resistance
PP in Practice
PP’s natural elasticity absorbs impacts well but its surface mats quickly. Cases made from PP typically show visible scratches after a few flights, particularly on corners and sides. The upside is that colour is usually pigmented through the material, so there is no paint to chip or flake.
PC in Practice
PC is more resistant to localised damage but stiffer, meaning it can crack under heavy impact (particularly at corners). Its biggest aesthetic weakness is susceptibility to scratches, especially in gloss finishes. Premium manufacturers increasingly apply scratch-resistant coatings (micro-diamond texture, anti-abrasion layers) that significantly slow the ageing process.
What User Reviews Say
Reviews of PP cases consistently praise structural durability but frequently mention “scratched after the first flight” and “stays strong but shows wear quickly”. PC case users appreciate the rigid feel and elegant appearance but report visible scratches, particularly in dark gloss finishes. Cracks are rare but do occur at low temperatures (below −10°C) and when the case is overloaded.
Before buying: if appearance matters and you want the case to look new longer, look for matte finishes and scratch-resistant coatings. If the case will live mostly in a car boot or overhead locker, scratches matter less and elastic PP will be more practical. PC cases look better but require more careful handling to maintain the premium finish.
Which Material Protects Contents Better?
PP – Flexibility and Impact Absorption
PP’s natural springiness means that during an impact it bends slightly, absorbing force without fracturing. It is a “forgiving” material that does not crack easily, even when it hits the edge of a step or an airport gate frame. Chambered structures in some models add cushioning effect with minimal weight increase.
PC – Rigid Protection and Greater Stiffness
PC is stiffer, so it flexes less under impact – providing better protection against point pressure (someone sitting on the case, heavy items crushing it in the hold). Under very heavy impact, instead of flexing it may crack or fracture at corners – this is mainly a concern in cheaper models. Premium brands (Peli, Samsonite, Tumi) use reinforcements and rounded geometry to minimise this risk.
User evidence consistently shows: PP performs better in “wild” conditions (bus travel, train baggage racks, car boots, camping). PC is chosen more often by those carrying expensive items – laptops, cameras, photographic accessories – especially in models with internal foam padding or organisers. Peli Air 1535 with HPX²™ combines the rigidity of PC with the elasticity of PP, providing exceptional impact resistance.
Peli Air Checked Cases
Sustainability and Recyclability
Polypropylene – Easier to Recycle
PP is a thermoplastic recyclable through mechanical processes. It is marked with recycling code 5 – PP and frequently enters second-use flows (automotive, furniture, appliances). Its production requires less energy than PC and the material does not contain bisphenol A (BPA).
Polycarbonate – More Durable But Harder to Recycle
PC is also a thermoplastic but has a more complex chemical structure that makes mechanical recycling more difficult. It is typically marked 7 – OTHER, which in many municipal recycling systems means it cannot be processed in standard facilities. PC production requires higher temperatures and more energy. It may contain BPA – harmless in the finished product but relevant environmentally.
In 2026, several brands offer cases from recycled materials or bioplastics: Samsonite’s Eco line uses PET bottle-derived materials; some PC-based cases use certified recycled polycarbonate. Peli Air’s HPX²™ approach takes a different route: the lifetime warranty significantly reduces product replacement frequency, which has its own sustainability argument – one case used for 20 years has a much lower environmental footprint than three cheaper cases replaced over the same period.
For environmentally conscious buyers: look for “recycled”, “BPA-free”, “produced with renewable energy” or relevant certifications on product descriptions.
Aesthetics and Colour Retention
PP – Muted Tones and Matte Finishes
Most PP cases come in classic colours: black, navy, grey, sometimes red or beige. Typically matte or lightly textured surfaces – less prone to fingerprints, less likely to catch scratches, but they do dull over time. After a season of intensive travel the case looks “travelled” but still neat and neutral.
PC – Bold Colours and Gloss
PC enables production in intense colours and metallic finishes (cobalt blue, gold, burgundy, petrol, lime green). Gloss variants look premium but are vulnerable to scratching and discolouration, particularly in car boots and on airport carousels. The newer trend of brushed and micro-diamond textured surfaces effectively masks wear and is much easier to clean.
Price and Warranty
Budget PP cases start from around EUR 35–50 for basic carry-on models. The mid-range (EUR 75–125) adds better wheels, additional dividers and organisers. Premium PP (Rimowa Essential Lite, Samsonite S’Cure) reaches EUR 200–300 but offers superior UV resistance and scratch protection.
Budget PC cases (typically thin PC or ABS blends) start from EUR 45–60 but wear quickly and crack faster. The mid-range (EUR 100–200) offers solid construction and adequate durability. Premium PC (Samsonite Proxis, Tumi, Peli Air) starts from around EUR 250 and extends to EUR 700+, with the highest-quality components, sealing, and warranty coverage.
Warranty differences are significant: most budget brands offer 2 years covering manufacturing defects only. Mid-range typically adds 5 years with access to replacement parts. Premium brands (Peli, Tumi, Samsonite Proxis) offer lifetime warranties – often including full shell replacement, technical support and global service.
From an economic standpoint: PP is the right choice for occasional travellers or those needing a light carry-on for two to three seasons. PC suits regular travellers, especially when the case carries expensive equipment. The lifetime warranty of a premium PC/HPX²™ case changes the cost calculation significantly over a 10–15 year horizon.
Summary – Which Material to Choose?
| Criterion | Polypropylene (PP) | Polycarbonate (PC) | HPX²™ (PC/PP composite) |
|---|---|---|---|
| Weight | Lightest | Medium | Heavier but IP67 rated |
| Rigidity | Flexible | Stiff | Stiff with controlled flex |
| Scratch resistance | Low (mats quickly) | Medium (coating dependent) | High (engineered surface) |
| Content protection | Good (absorbs impact) | Very good (resists pressure) | Exceptional (IP67 + impact) |
| Recyclability | Good (code 5) | Difficult (code 7) | Long service life argument |
| Best for | Occasional flyers, budget travellers, light use | Regular travellers, equipment carriers, style-conscious | Professionals, field use, high-value contents |
PP is the right choice for occasional travellers who value lightness and simplicity. It masks wear and handles drops well, but has limited visual longevity. PC is heavier and more expensive but offers better protection for delicate electronics and a more premium appearance – though it requires more careful handling to avoid scratches and cracking. HPX²™ (Peli Air) combines the strengths of both: engineered for demanding professional use, with IP67 waterproofing and a lifetime warranty that changes the long-term cost calculation entirely.
