A03 - Finishing machinery
Establish a unique general for the finishing procedure of the product is very difficult; the steps of those operations are frequently reserved and part of the single tannery competence. However, the common elements of the finishing process are: 1) Dray milling for softening 2) Staking to make the skin flexible 3) Coating surface for final look. The last stages finishing are a combination thermal and mechanical action (heat and pressure) for the grain plating. Film Application on surface as well as polishing and grinding are performed on skins with any particular defects on grain allowing the product recovering.
Drums for dry milling to soften the leather by mechanical shaking to controlled moisture and temperature. In addition to the simple action of softening, some cleaning chemicals recipes may be used to obtain desired special fashion effects; for which the drums may be equipped by chemical dosing devices.
Softening and spreading of leather are the main aim of the staking process and also contribute effectively its yield. The head type vibration staking machines concept are based on pin design for wet or dry hides processing; the mechanical and electric device provide the synchronised oscillation motion.
Softening and spreading of leather are the main aim of the staking process and also contribute effectively its yield. The rotative staking machines concept are based rotary cylinders of various types through which passes the product to be processed. Particularly apply for processing small size leather.
The splitting process of the hide in horizontal layers allows to reach the desired thickness and simultaneously to recover a byproduct (split) which is processed in a same way like the hide from which it derives; this operation can be done at different steps of the manufacturing process. The splitting in finishing phase is practiced on finished hides using the machines that are equipped with a circular band knife mounted on wheels, specifically designed to facilitate the hide introduction. Equipped with micrometric precision systems, such as the insertion table inclination and blade position, that ensure the thickness adjustment with very hight accuracy. The blades are automatically rebladed through grinding stones mounted on cart system.
The machines are working on the flesh side of the hides/skins which remove the excess material and make uniform the thickness of hides/skins through the use of sharp blades mounted on a spiral rotating cylinders while the grain side faced the pressing roller. The constant sharpening of the blades is ensured by a mobile carriage of grinding wheels.
Cylinder machines, equipped with sandpaper or emery for the processing of leather with nubuck or suede effect, or to correct any defects on the leather grain side. Control devices with hydraulic drive are used to quickly reverse the direction of rotation of the feed roller and make it easier the manual extraction of the leather. The systems are supplemented by specific elements of dust extraction and collection in the bags.
Through-feed end-less band buffing machines for both sides of the leather, and that may be suitable for vegetable tanned leather (sole leather, shoulders, flanks etc.), nubuk, pull up, greasy leather, splits, and chrome tanned leather. The product is introduced by means of conveyor belts which make complete automation of the working cycle. The systems are equipped with extraction systems able to collect the sawdust into bags for disposal.
Brushing and de-dusting machines designed for the cleaning of all types of leather. Versions of this type of machine are available for all cleaning requirements (air blast, multiple blowing heads, brushes etc.), sometimes also with vacuum system for soft leathers. The systems are complemented by specific elements for dust extraction in the collection bags.
Automatic spray booths for continuous production. Metallic structure equipped with spray guns on robotic arms and continuous feeding chain. The cabins are accompanied by tubs for containment and collections as well as systems that allow the dust coating. Sprayers may have various motion configurations of the spray-guns arm or rotating carousel systems. An important accessories of the spray booths are the economizer of chemical products.
Complete finishing lines with the drying, equipped with perlon threats or nylon cord transport conveyor, net conveyor or band conveyor. The dryers may be equipped with the heating system working by steam, hot water, diathermic oil, by gas, by catalytic gas heaters, the radiation which is produced by electricity, and others.
Padding and coating machines by roller finishing for color coat and top coat application, for effects and printing, impregnation, pigment coating waxing and fillers.
Transfer foils application devices; system based on calendering concept. Usually the film transfer action is specifically focused on fashion effects. This technique is developed for recover any bad quality leather.
Continuous rotary ironing, plating, embossing, polishing, and glazing machines for hide and skin leathers. The process consist in the continuous passage of leather between cylinders that press the surface, supported by through feed system. Time, temperature and pressure are adjustable according to the product to be made.
The embossing process is performed to impress on the skin surface a specific design. The pressing systems is essentially composed of two work plates, vertical movement of the lower is actuated by a hydraulic system. The plans themselves can be heated and maintained at the desired temperature by means of an electrical or heat transfer fluids.
Glazing machines for hide, by means of rod system with reciprocating motion of the glazing arm. scrubbing action, with a roller polishing of hard material (agate, glass), allows to obtain an effect of brilliance in particular of exotic skins.
Polishing machines, by means of the action of scrubbing action with a roller rotary polishing of various material (wool, linen, etc..) It acting on the finished leather to improve the appearance, particularly suitable for the polishing of "nappa".