✅ How Ultrasonic Welding Works

Ultrasonic welding joins materials using high‑frequency mechanical vibrations (typically ~20–40 kHz) combined with pressure.
There is no glue, no staples, no thread, no heat guns, and no burn marks on the fabric.

The process:

1. The slat material is placed between a horn and an anvil.

   • The horn = vibrating metal tool
   • The anvil = shaped tool that supports the material

2. The horn vibrates at ultrasonic frequency.
   These vibrations create microscopic friction at the exact weld line.

3. Friction generates heat inside the material (not from outside).
   This melts a thin layer of the plastic in the slat.

4. Pressure is applied as the melted layer cools.
   The material solidifies into a permanent weld.

Ultrasonic welding is fast—often 0.1 to 0.5 seconds per weld.

✅ How It Applies to Vertical Blind Slat Hanger Pockets

The top of a vertical blind slat often includes a pocket/loop that holds:

• The hanger clip, or
• The insert that attaches to the headrail carriers

✔ What the ultrasonic welder does:

1. The slat material is folded over to make a loop.
2. The ultrasonic horn presses the folded layers against a patterned anvil.
3. Vibrations melt the thermoplastic layers just at the contact points.
4. A welded pattern is formed.

✔ Function of this weld:

• Seals the fold securely so the hanger tab can’t pull out.
• Creates a clean and uniform seam with no needle holes.
• Resistant to UV and temperature, unlike adhesives.
• Maintains flexibility without delamination.

✅ How It Works on the Bottom Weight Pockets

Vertical slats need a bottom weight to hang straight.
Most slats have a bottom pocket created by:

1. Folding the material upward.
2. Ultrasonically welding along the fold line.

✔ Ultrasonic welding ensures:

• A clean, straight seam that aligns visually with the slat.
• A pocket strong enough to hold a PVC or metal weight.
• No chance of glue failure or stitching unraveling.
• No distortion or warping of the slat material.

✅ Why Ultrasonic Welding Is Ideal for Blind Slats

Vertical slats are usually made from PVC-coated polyester or pure PVC, which are excellent for ultrasonic welding because they fuse predictably.

✅ Quick Summary

Ultrasonic welding joins the folded sections of vertical blind slats (top hanger pockets and bottom weight pockets) by vibrating the material at high frequency to create frictional heat, melting the plastic layers internally, and bonding them under pressure.