Wet milling from Erretre11 March 2010
Italian milling and finishing machinery experts, Erretre have upgraded their wet milling Inox range of machines. New types of leather finish and grain effects can be achieved by tumbling wet leathers. The higher moisture content, heat and the mechanical action allows the tanner to achieve special effects such as grain pebbling and other surface effects through a controlled shrinkage.
Following the retanning steps in the drum, leathers can be milled directly using Erretre’s Inox drums for various effects such as ‘vintage’. Depending on the effect required wet milling may also take place after sammying and setting out or after vacuum drying.
Erretre have upgraded the drainage system on the smaller models and improved the sealing/insulation while the machine is in operation across the whole size range. Inox drums also have a more powerful heating system than the traditional dry milling machines and have more electronic controls to avoid any unwanted shrinkage of the leathers during processing. The computerised system also optimises the wet milling and subsequent drying phase, avoiding loss of heat while the machine is periodically vented to reduce the excess of moisture.
Erretre say that tanners have used their wet milling equipment at temperatures between 35°-60ºC depending on the final effect and the tannage used. The machines have also been used to provide a ‘used’ and natural look to finished products such as leathergoods and garments to enhance the seams, the edges and surface which are exposed to a rubbing action to create a warn look. The equipment has been used on chrome or vegetable tanned leathers and is ideal for tanners that wish to create the ‘tuffato’ or dipped leather effects.