Finishing Defects:
★ Change of shade on finished leather
Causes:
- Faulty combination of pigment
Remedy:
- Use suitable combination and avoid using such pigments which fade on exposure.
★ Poor covering & showing of stained bottom
Causes:
- Dyed and finishing shade do not match.
- Improper brushing or spraying of the finish solution.
Remedy:
- Bottom dyeing must be matched to finish shade
- Check application of the finish solution.
★ Glazing difficulties
Causes:
- Use of excess or insufficient plasticizers.
- Insufficient drying.
Remedy:
- Adjust the quantity of plasticizers
- Dry properly.
★ Dry and wet rubbing of pigment film
Causes:
- Insufficient binder or plasticizer
- Excess of binder
Remedy:
- Increase the quantity as the case may be
- Reduce binder.
★ Top coat cracks:
Causes:
- Use of too thick top coat
- Too much of binder
- Inadequate plasticizer
Remedy:
- Dilute the top coat
- Reduce binder
- Increase plasticizer
★ Grayish undertone on finished leather
Causes:
- Optical effect due to low grain
- Too much use of chrome salts in fixing solution.
Remedy:
- Hot ironing before finishing
- Adjust the quantity in chrome in fixing solution,
★ Pigment coat peeling off:
Causes:
- Too much pigment or too little binder.
Remedy:
- Correct which is applicable.
★ Scratch marks on corrected grain finished leather
Causes:
- Buffing sores
Remedy:
-Changing abrasive paper to correct grit.
★ Streaks of color appearing after glazing operation (comet formation)
Causes:
Dust, soot, dye stuff powder or undissolved pigments on the pigmented leather
Remedy:
- Keep the finishing room clean and away from contamination with foreign particles.
★ Frequent change of shades with the same recipe.
Causes:
- Consistency of pigment past differs or the finish not sufficiently stirred before use.
Remedy:
- Check consistency before making finish solution.
-Stirring well before taking the solution every time.
★ Tackiness of finish surface with tendency to get finger marks.
Causes:
- Too much plasticizer and the finish surface hygroscopic
Remedy:
- Reduce plasticizer, wax emulsion may be used.
★ Poor rub-fastness
Causes:
- Improper fixing.
- Insufficient binder.
- Too much plasticizer.
Remedy:
- Fix with 10% formaldehyde & sprit solution.
- Increase binder.
- Reduce sulphated oil.