1. Field of the Invention
This invention relates to a mechanized power assisted apparatus for applying tanned hides on a smooth flat plate preparatory to drying in the course of leather manufacture.
Tanning of leather is an ancient art. From the earliest times, man has changed rough raw animal hides into supple wearable materials. This involves mechanical and chemical treatment of the hide to remove blood, lymph, adhering flesh, hair, etc. and enzymatic and bacterial action to render the hide soft and supple. These are wet treatments. The leather is commonly dyed and treated with oils and fats for lubrication, softness, strength and water-proofing. After dyeing and fat-liquoring, leather contains about 45 to 60 percent water and is commonly dried to about 14 percent moisture. Chemical and physical reactions take place during drying. Loose tannins, dyes and oils spread uniformly, penetrate deeply and are firmly fixed. Uneven drying causes migration of unfixed tannin, dye and oil to the surface, resulting in undesirable dark stains and non-uniform appearance.
A common industry technique of drying wet hides is so-called "paste drying." Hides are literally pasted by the grain side to large flat plates of adhesive coated glass, porcelain or metal, and then are passed through a tunnel dryer. After drying to the desired moisture content, the hide is stripped off yielding flat, smooth grain, large area leather sheets ready for finishing and fabrication into various leather goods. Alternatively, the wet hides may be vacuum dried after being similarly spread out on a flat smooth polished plate. Vacuum drying is faster but requires costly equipment.
Whether to be paste dried or vacuum dried, it is essential that the wet hide be in intimate contact with the smooth planar surface without any entrapped air bubbles. The wet hide is applied to the surface and manually smoothed by means of a squeegee-type slicker element. This is most commonly in the form of a flat edged blade which is manipulated over the surface of the wet hide from the center to the edge working out any entrapped air or water between the hide and plate surfaces. At the same time, the hide is stretched somewhat increasing its area. This is tough, arduous work requiring great strength and staying power. Typically, in the course of a day's work, fatigue sets in toward the end of the day and productivity is materially reduced. The principal objective of the present invention is to provide a mechanical power assisted apparatus to perform this back-breaking task, with its attendant advantages of lessened fatigue, higher productivity, and more uniform product.
2. The Prior Art
No prior art pertinent to the invention is known.