Marking off
Causes: Excessive quantities of brightening dyes or organic pigments inefficient amount of binders in the pigment finishes or top coats which have been applied too thin may result in making
Off of the finish.
Remedy: Avoid the causes
Cracking off
Causes: Use of polymer binders which are not cold resistant very hard pigment finisher or top coats inadequate content of plasticizers or impaired adhesion of the individual finishes coats
Remedy: Avoid the causes
Powdering of Surface layers
Causes: Occurs in very hard causes finisher which have been applied in a very thick coat
Powdering of the entire finish coat
Remedy: Reduce the thickness of coat. It is recommended that several thin coats be applied with intermediate drying. Addition of small amounts of polyacrylate dissolved in alcohol to the base coating agent prevents powdering of the finish coat.
Stripping of the finish
Causes: impaired adhesion of the individual finish layers caused by an insufficient absorption capacity of the leather when applying the base coat and by inadequate reswelling of the preceding finish.
Remedy: If the absorbing capacity is not adequate, use a penetrative pretreatment primer. Reduce the use of sealing, water-resistant binder. If using cross-linking binders continue processing without storing the leathers for a longer period as otherwise the film becomes insoluble by subsequent reaction.
No comments:
Post a Comment