Investigation of the feasibility of using powder coating for leather finishing

The feasibility of using powder coating technology, a process involving dry solid particulates, has been investigated for leather finishing for the fi rst time. Results showed that powders can be applied to leather successfull y using conventional electrostatic spraying facilities, provided that the l eather is properly wetted with water. Powders can also be successfully appl ied to leather using non-electrostatic application methods, after pre-treat ing the leather surface with a tack agent, such as a soft resin, that makes the leather surface tacky and therefore receptive to powders. Finishing trials on leather using currently available commercial powder coa tings have shown that a surface coating with an appearance no different to a conventional pigmented finished leather can be achieved without loss of a rea or softness, provided that stoving conditions are controlled (160 degre es C for 10 minutes). Although the coating was incompletely cured, it still provided excellent wet and dry rub fastness, sufficient dry adhesion and a dequate wet adhesion properties. However, the coating was not completely sa tisfactory due to the occurrence of surface cracking and poor flexing endur ance. This was because the powder coating used had not been specifically fo rmulated for leather finishing.