Pressure Sensitive Adhesive Coating Machine: Technology, Applications & Equipment Guide
Pressure sensitive adhesive (PSA) coating machines apply adhesives that remain permanently tacky at room temperature — no heat, moisture, or solvent activation required. Hot melt PSA coating is the dominant industrial process for labels, tapes, and medical adhesives.
This guide covers PSA coating technology, machine types, technical parameters, and applications. For broader context, see our Hot Melt Coating Machine Ultimate Guide.
What Is PSA Coating?
Pressure sensitive adhesives are viscoelastic materials that form a bond when light pressure is applied. Unlike structural adhesives, PSA does not undergo a chemical reaction or phase change during bonding — it remains permanently tacky.
Hot Melt PSA Coating Principle
Hot melt PSA is applied in molten form (typically 150–180°C), cools rapidly on the substrate, and retains its pressure-sensitive properties at room temperature.
PSA Coating Machine Types
Slot Die PSA Coater
- Highest precision: ±1–2%
- Best for: premium labels, medical tape, electronic tape
- Coating weight: 10–100 g/m²
Gravure PSA Coater
- Medium precision: ±5–10%
- Best for: patterned coating, standard labels
- Coating weight: 10–150 g/m²
Roll PSA Coater
- Moderate precision: ±5–8%
- Best for: high-volume, standard products
- Coating weight: 15–200 g/m²
Laboratory PSA Coater
- Desktop compact design
- Best for: formulation development, process validation
- Coating width: 100–300 mm
Key Technical Parameters
| Parameter | Typical Range |
|---|---|
| Coating weight | 10–200 g/m² |
| Line speed | 10–400 m/min (up to 400 for low-viscosity PSA) |
| Operating temperature | 150–180°C |
| Substrate types | Paper, film, nonwoven, foam, fabric |
| Adhesive viscosity | 2,000–30,000 cPs |
PSA Coating Applications
- Label stock: Self-adhesive labels for packaging, logistics, and retail
- Double-sided tape: Mounting, splicing, and bonding applications
- Masking tape: Painting, surface protection
- Aluminum foil tape: HVAC duct sealing, thermal insulation
- Medical tape & dressings: Wound care, transdermal patches
- Foam tape: Automotive mounting, construction sealing
- Protective films: Surface protection during shipping and processing
→ Medical coating machine applications for medical tape and patch production.
Process Control for PSA Coating
- Temperature control: PSA viscosity is highly temperature-sensitive; ±1°C control is recommended
- Coating weight uniformity: Cross-web and machine-direction consistency critical for tape performance
- Online inspection: Laser or optical gauges for real-time thickness measurement
- Tension control: Prevents web stretching and coating weight variation
- Chill roll temperature: Rapid cooling ensures proper PSA surface properties
FAQ
What is the difference between hot melt PSA and solvent-based PSA?
Hot melt PSA is 100% solids and requires no drying oven, offering zero VOC emissions and lower energy costs. Solvent-based PSA requires drying and solvent recovery, but can achieve higher tack and broader formulation flexibility.
What coating weight is typical for label stock?
Label stock typically uses 15–25 g/m² of hot melt PSA adhesive. Premium labels may use up to 30 g/m² for higher tack requirements.
What is the ideal chill roll temperature for PSA coating?
Typically 10–20°C depending on PSA formulation and line speed. Full parameters are in our PSA Process Deep Dive.
How does PSA viscosity affect coating weight?
Higher viscosity requires higher pump pressure and may limit minimum coating weight. Learn more in our 10 PSA Process Parameters article.
What online inspection methods are used for PSA coating?
Laser triangulation and optical gauges are most common. Details in our PSA Coating Deep Dive.
Can PSA be coated on heat-sensitive substrates?
Yes, but lower-temperature PSA formulations or UV-curable alternatives may be needed. See our PSA Process Deep Dive.