Why the joint decides your belt's life
On a teflon (PTFE) coated glass belt, the joint is almost always the first thing to fail — it is the one place where the smooth, non-stick surface is interrupted. Choosing the right joint type for your dryer or conveyor is therefore a maintenance decision, not a detail.
The four standard PTFE belt joints
- Bullnose overlap — both ends folded into a rounded nose that overlaps. Fast to fit, easy to re-lace on the machine; slight thickness bump at the joint. The everyday choice for medium duties.
- Scarfed (bias) overlap — the overlap is planed to a taper so the joint stays close to belt thickness. Smoother running over rollers and knife edges; the standard for solid belts and product-marking-sensitive duties.
- Pin / alligator joint — metal or plastic pin hinges joining the ends. Strong, openable for cleaning, good for mesh belts; the metal pin must suit the temperature.
- Endless (seamless) — woven or welded with no joint at all. The smoothest and strongest option for vacuum belt dryers; needs the belt made to final length.
Which joint for which duty?
- Vacuum belt dryers, food & pharma: endless or scarfed — anything that minimizes marking and product trap points.
- Tunnel dryers, general drying: bullnose or pin — quick to fit, tolerant of temperature cycling.
- Mesh belts for high-air drying: pin joints — they preserve the open area.
- Frequent clean-downs: pin or bullnose — both can be opened for cleaning.
Specifying joints with Aurora
Tell us the dryer type, temperature, product and whether the belt passes over knife edges or vacuum plates — we will match joint type, thickness and edge treatment across our PTFE-added spiral belts, dryer fabrics and food & pharmaceutical drying belts.
Need this specified for your machine?
Our engineers match construction, CFM and seams to your duty.