What does the knife cord do?
In double-cloth velvet weaving, the pile yarns binding the two cloth layers are split by the knife travelling on the knife carriage. The knife cord is the drive element that pulls that carriage back and forth along the slide. Cord tension and surface condition directly affect cut quality and therefore pile height.
Our catalogue lists dry and oiled knife cords in 4, 5 and 6 mm. If you are not sure which diameter your loom takes, a photo of a piece of your current cord is enough.
Three signs of wear
1. Fuzzy cut edge
A stretched cord stops the carriage short of its end position, the cut line drifts and the pile surface shows uneven fuzz. If fuzz persists after changing the grinding stone, the cord, not the knife, is the problem.
2. Uneven pile height
When some sections of the cord are more worn than others, carriage speed varies from pick to pick. Regular light and dark bands across the fabric are the typical result.
3. Glazed cord surface
On oiled cord, a glassy shine on the braid means the end of its life; on dry cord, look for raised fibres.
Dry or oiled?
Rule of thumb: dry cord on graphite slides, oiled cord on bearing slides. On light and white velvet, dry cord is preferred to avoid oil marks. If you are unsure which slide your loom has, send a photo of the knife bed.
Note: Cord life varies a great deal with loom speed, shifts and dust. That is why we recommend replacing on the three signs above rather than on a calendar.
Five-minute check
- Stop the loom and bring the knife carriage to mid position.
- Press the cord between drum and pulley with your thumb; noticeable give means it has stretched.
- Slide a metre of cord through your hand and look for glazing or raised fibres.
- Check the pulley housing; built-up cord dust accelerates wear, clean it out.
- Check the grinding stone surface too; changing cord and stone together shortens setup time.
FAQ
Can I splice the cord? A splice stretches differently and brings the fuzz back. We recommend a single-piece replacement.
What should I keep in stock? One spare cord and one grinding stone set per loom is enough for most mills.
For prices on knife cord, grinding stones and knife beds, just send the part code on WhatsApp.
