Laser Demetalization V/s Laser Engraving
Laser demetalization and laser engraving are both precise marking techniques that use focused laser beams, but they serve very different purposes, especially in the context of hologram labels and security printing. Laser demetalization is the process of selectively removing the ultra‑thin aluminium (or other metal) layer from a holographic film. This creates clear, transparent areas (e.g., text, QR codes, barcodes) against the shiny metalized background. It is used exclusively on metalized substrates (holograms, foils) and does not damage the underlying plastic. Laser engraving is the process of etching, vaporising, or discolouring the surface of a solid material – such as plastic (polycarbonate, PVC), metal, wood, or glass – to create a permanent, visible mark. It removes material, creating a cavity or colour change. Engraving is used for serial numbers on ID cards, metal parts, and industrial components. Holoseal offers laser demetalization for hologram labels (to add unique codes) and can advise on laser engraving for complementary applications.
🔬 Detailed Comparison: Laser Demetalization vs. Laser Engraving
| Aspect | Laser Demetalization | Laser Engraving |
|---|---|---|
| Target Material | Thin metal layer (30–50 nm aluminium) on top of a plastic film (PET, polycarbonate). | Solid substrate – plastic (PVC, polycarbonate, ABS), metal (steel, aluminium), wood, glass, etc. |
| Mechanism | Ablation (vaporisation) of the metal coating. Does not damage the underlying plastic. | Material removal (evaporation/melting) or surface discoloration. Creates a cavity or permanent colour change. |
| Resulting Mark | Transparent (clear) area on a shiny metalized background. When backlit, the mark appears bright. | Visible engraved cavity (can be felt), darkened/lightened area, or raised (depending on process). |
| Depth of Mark | Nanometers (only the metal layer, <0.1 micron depth). | Typically 10–500 microns (can be deeper for industrial engraving). |
| Typical Applications | Creating serial numbers, QR codes, Data Matrix, microtext, logos on hologram labels. | Serial numbers on ID cards (polycarbonate), automotive parts, metal tags, electronic housings, tools. |
| Durability | Very high – mark is permanent and cannot be scratched off (the metal is physically removed). | Very high – engraved marks are wear‑resistant and cannot be removed without grinding. |
| Visibility | Visible in reflected light (dark) and transmitted light (clear/bright). | Visible as a contrast (lighter/darker) or physical indentation. |
| Speed (for labels) | Fast – can process hundreds of labels per minute on roll‑to‑roll systems. | Moderate – depends on depth and area; slower for deep engraving. |
| Cost per Unit (volume) | ₹1–10 per label (depends on size and complexity). | ₹5–50+ per part (depends on material and depth). |
🔍 What is Laser Demetalization?
Laser demetalization uses a focused laser beam (typically pulsed fiber laser) to evaporate the thin aluminium coating from a holographic film. The laser energy is precisely tuned to remove only the metal without damaging the PET substrate. The result is a transparent, glass‑like mark that is highly visible when the label is tilted or backlit. Common uses on hologram labels:
- Unique serial numbers (human‑readable and barcode)
- QR codes for smartphone verification
- Data Matrix for pharmaceutical serialisation
- Microtext and hidden logos
🔍 What is Laser Engraving?
Laser engraving removes material from the surface of a solid substrate. It can be performed on plastics (polycarbonate, PVC, ABS), metals (anodised aluminium, stainless steel), wood, glass, and ceramics. The laser vaporises the material, leaving a permanent cavity or a colour change (e.g., darkening on polycarbonate). Engraving is used for:
- Serial numbers on ID cards (polycarbonate e‑passports)
- Metal nameplates and asset tags
- Tool and equipment identification
- Deep marking on industrial parts
🔐 Which One Should You Choose?
- Choose Laser Demetalization – When you need to add variable data (serial numbers, QR codes) to a hologram label without introducing ink. Ideal for high‑security, long‑lasting marks that cannot be scratched off.
- Choose Laser Engraving – When you need to directly mark a solid product (plastic card, metal part, tool). Also for deep, tactile marks that survive harsh environments.
- Combine Both – Some applications use laser demetalization on a hologram label (security), and then laser engrave the serial number on the product itself for dual verification.
🌍 Real‑World Examples
- Laser demetalization on a pharmaceutical hologram label – A unique Data Matrix code is demetalized into the hologram for track‑and‑trace.
- Laser engraving on a polycarbonate ID card – The cardholder’s name and photo are engraved into the card body.
- Laser demetalization on an electronics warranty seal – A QR code is demetalized onto a hologram VOID label.
❓ Frequently Asked Questions
- Can laser demetalization be used on non‑metalized film? – No – it requires a reflective metal layer (aluminium, gold, etc.). On clear film, use printing instead.
- Does laser engraving work on hologram labels? – Engraving would cut through the plastic, destroying the hologram. Use demetalization instead.
- Which is more durable? – Both are very durable. Demetalization removes metal; engraving removes substrate. Neither can be easily removed.
- Which is faster for high volumes? – Laser demetalization can be done roll‑to‑roll at high speed. Laser engraving of individual parts is slower.
- How to order laser demetalized hologram labels from Holoseal? – Provide your artwork, serial number range, and hologram design. We will demetalize the codes onto your labels. Contact us for a quote.
