Composants · Inlay
La radio à l’intérieur de la carte
Une bobine d’aluminium gravée sur film PET, liée par un adhésif conçu pour un couple de plastiques que la colle ordinaire ne tient pas. On ne la voit jamais — chaque lecture à chaque porte en dépend.
L’inlay est l’endroit où la carte cesse d’être du plastique pour devenir un support d’accès : une antenne gravée chimiquement sur support PET, plastifiée entre des films de collage dont l’adhésif tient > 7 N/cm à l’état neuf et > 3,5 N/cm après vieillissement en chaleur humide. C’est la construction que les réseaux de transport ont éprouvée sur des milliards de titres.
Points forts
Gravée, pas bobinée
Les bobines photogravées se répètent parfaitement — chaque carte lit à la même distance.
Un collage conçu pour PET-PVC
Les films enduits résolvent le couple que les adhésifs standard lâchent, humidité comprise.
Construction éprouvée en transport
Le même montage derrière des milliards de tickets de métro.
Inlay & antenna materials — technical data
- What it is
- The radio heart of every contactless card: an etched aluminium antenna on a PET carrier, bonded by dip-coated adhesive films
- Antenna
- Aluminium coil chemically etched on a PET film sheet — repeatable geometry, tuned to 13.56 MHz chip families
- Bonding film
- Card-grade PVC dip-coated with adhesive both sides: clear 60–200 μm, white 70–200 μm
- Adhesive
- 6–9 g/m² per side — engineered for the PET-to-PVC bond that ordinary laminate adhesives fail
- Bond durability
- Peel strength > 7 N/cm as made; > 3.5 N/cm after damp-heat ageing — the card stays bonded through years of humidity cycles
- Format
- Webs 200–1300 mm — inlays are laminated as large sheets, then punched to card positions
- Pedigree
- The same construction used in transit smart tickets issued by the billions
Inside an RFID inlay
PET and PVC do not naturally bond — their surface chemistries fight each other. The dip-coated film solves it: a PVC sheet carrying adhesive tuned for exactly this pairing. Antenna sheet plus bonding film laminate into a prelam that behaves as one material, which then disappears invisibly inside the finished card. When a key card still reads after two years of pockets and pool bags, this bond is why.
The prelam at the centre of every contactless card we laminate
- Coated bonding film · 60–200 μm Dip-coated PVC, adhesive on both faces
- Etched antenna on PET + chip Aluminium coil, chemically etched — the card’s radio
- Coated bonding film · 60–200 μm Seals the antenna sheet from the other side
Why the inlay spec matters to you
- Read reliability is bond reliability: a delaminating inlay shifts the antenna and kills reads — the > 7 N/cm bond prevents it.
- Humidity is the real enemy: damp-heat-aged peel strength is the number that predicts survival in tropical properties.
- Etched antennas hold tuning: repeatable geometry means every card in the batch reads at the same distance.
Inlay & antenna questions
What is an “etched” antenna and why prefer it?
The coil is chemically etched from aluminium foil laminated to PET film, like a flexible circuit board. Compared to wound copper wire, etched coils have perfectly repeatable geometry — so resonance tuning, and therefore read distance, is identical from the first card to the hundred-thousandth.
Why does bonding PET to PVC need a special film?
The two plastics have incompatible surface chemistries, and ordinary card adhesives let go — especially in humidity. The dip-coated bonding film carries an adhesive developed for exactly this pairing, holding > 7 N/cm when new and > 3.5 N/cm even after damp-heat ageing tests.
Does the guest ever see or feel the inlay?
Never. The inlay laminates dead-centre in the card stack, and the finished 760 μm body shows no witness lines. Its only visible evidence is behaviour: the card reads instantly, flat or at an angle, year after year.
Is this the same technology as metro tickets?
Yes — single-journey transit tickets are paper-faced cards built on exactly this etched-antenna construction, proven across billions of issued tickets. Hotel key cards inherit a supply chain that transit systems already stress-tested at world scale.
Démarrez votre commande
Besoin de cartes-clés qui fonctionnent parfaitement dès l’arrivée de vos clients ?
Indiquez-nous la marque de votre serrure et la quantité souhaitée : vous recevrez un devis en direct d’usine ainsi qu’un pack d’échantillons gratuits à tester sur vos propres serrures avant de vous engager.