What Is Throw Distance in Inkjet Printing?
Throw distance, also known as standoff distance or printhead gap, refers to the space between the printer’s nozzle and the surface being printed on. It’s a key factor in inkjet performance that directly impacts print clarity, droplet placement, and overall code quality. Different printer types and substrates require different optimal distances. If the throw distance is too short or too long, it can cause smudging, distortion, or misfired codes.
Typical Throw Distances by Printer Type
| Printer Type | Recommended Throw Distance | Notes |
|---|---|---|
| CIJ (Continuous Inkjet) | 2–10 mm | Capable of longer throw; ideal for high-speed lines and uneven surfaces |
| TIJ (Thermal Inkjet) | 0.5–2 mm | Requires precise close contact; best for flat, consistent packaging |
| DOD (Drop-on-Demand) | 1–5 mm | Varies by nozzle size and ink viscosity; larger nozzles tolerate more distance |
| TTO (Thermal Transfer Overprinting) | Direct contact | No throw distance; ribbon must press directly onto substrate |
Why Throw Distance Matters
1. Print Quality and Legibility
Greater distances increase the chance of dot scatter or distortion, especially on small fonts or barcodes. Shorter distances improve precision but risk smudging if the surface is curved or unstable.
2. Ink Drying and Overspray
Too long a throw can cause overspray, misting, or uneven drying—particularly with fast-drying solvent inks.
3. Surface Irregularity
Uneven products (e.g., cable, bottle, pouch) may require longer throws to avoid physical contact, but this must be balanced with legibility.
4. High-Speed Printing
At high speeds, consistent throw distance ensures stable droplet trajectory. Any vibration or bouncing can create ghosting or blurred marks.
How to Set the Optimal Throw Distance
- Start with manufacturer-recommended range (see table above)
- Use printhead mounting brackets that allow fine-tuning for height and angle
- For curved surfaces, consider CIJ with a nozzle-to-product gap of 4–8 mm to allow for clearance
- For flat cartons, TIJ works best at 1 mm or closer
Best Practices
- Use consistent conveyor speed and product spacing
- Avoid direct air flow onto the print path—it can affect droplet direction
- Use vision systems or laser guides to help align throw distance accurately
- In dusty environments, slightly increasing throw distance can help prevent nozzle fouling
FAQs
- What happens if my throw distance is too long? You may see faint, blurry, or scattered marks—especially on small characters or thin lines.
- Can I adjust throw distance in real-time? In most systems, no—it must be mechanically adjusted via printhead mounts. Some smart CIJ systems can auto-compensate slightly.
Conclusion
Throw distance is a subtle but vital factor in achieving high-quality, reliable codes in industrial inkjet printing. By understanding the recommended settings for your printer and application, you can avoid smudges, misfires, and rework. Need help configuring your printhead or optimizing throw distance for a new product? Contact Cheef Inkjet at sales@cheef.cn.
