The splitting band knife (or band knife or bandknife) is a kind of

knife A knife ( : knives; from Old Norse 'knife, dirk') is a tool or weapon with a cutting edge or blade, usually attached to a handle or hilt. One of the earliest tools used by humanity, knives appeared at least 2.5 million years ago, as evidenced ...

used in several fields including:

tannery Tanning may refer to: *Tanning (leather), treating animal skins to produce leather *Sun tanning, using the sun to darken pale skin **Indoor tanning, the use of artificial light in place of the sun **Sunless tanning, application of a stain or dye t ...

EVA Eva or EVA may refer to: * Eva (name), a feminine given name Arts, entertainment, and media Fictional characters * Eva (Dynamite Entertainment), a comic book character by Dynamite Entertainment * Eva (''Devil May Cry''), Dante's mother in t ...

rubber Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, and ...

foam Foams are materials formed by trapping pockets of gas in a liquid or solid. A bath sponge and the head on a glass of beer are examples of foams. In most foams, the volume of gas is large, with thin films of liquid or solid separating the reg ...

cork Cork or CORK may refer to: Materials * Cork (material), an impermeable buoyant plant product ** Cork (plug), a cylindrical or conical object used to seal a container ***Wine cork Places Ireland * Cork (city) ** Metropolitan Cork, also known as G ...

shoe A shoe is an item of footwear intended to protect and comfort the human foot. They are often worn with a sock. Shoes are also used as an item of decoration and fashion. The design of shoes has varied enormously through time and from culture t ...

and

leather Leather is a strong, flexible and durable material obtained from the tanning, or chemical treatment, of animal skins and hides to prevent decay. The most common leathers come from cattle, sheep, goats, equine animals, buffalo, pigs and hogs, ...

goods,

paper Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distributed ...

carpet A carpet is a textile floor covering typically consisting of an upper layer of pile attached to a backing. The pile was traditionally made from wool, but since the 20th century synthetic fibers such as polypropylene, nylon, or polyester hav ...

and other soft sheet materials. It is a

power tool A power tool is a tool that is actuated by an additional power source and mechanism other than the solely manual labor used with hand tools. The most common types of power tools use electric motors. Internal combustion engines and compressed ...

which is very similar in operation to a

band saw A bandsaw (also written band saw) is a power saw with a long, sharp blade consisting of a continuous band of toothed metal stretched between two or more wheels to cut material. They are used principally in woodworking, metalworking, and lumb ...

, with an endless loop

blade A blade is the portion of a tool, weapon, or machine with an edge that is designed to puncture, chop, slice or scrape surfaces or materials. Blades are typically made from materials that are harder than those they are to be used on. Historic ...

; the material to be cut is supported by a flat table.

Technical characteristics

A splitting band knife can be produced in different sizes (length x width x thickness) according to the splitting machine on which it has to be fitted. Different technical characteristics define the quality of the product (blade) The blade can be welded and bevelled, toothed not rectified, rectified on both edge and surfaces, with pre-sharpening made by tools or grinding stones. A splitting band knife can be produced in several dimensions, usually with a length from , a width between , and a thickness from .

Sectors and use

Tannery sector

In the tannery sector the splitting band knife allows to divide/split leather and textile in its thickness. The final products of this operation are Split and Grain (internal and external parts) of the leather. Blades can be used to split every kind of material which has to be split in the thickness: * leather * fur * non-woven material * velvet In the tannery sector, splitting band knives can be used in following working: wet blue, lime, dry, wet white and other tannings. The blades which are mostly used in this sector are rectified on both edge and surfaces in order to guarantee the best splitting, that means a constance in the thickness of the leather that is produced/split (rectification of surfaces), and also to guarantee the maximum linearity during the splitting process ( back edge); the blade must run as stable as possible without oscillations at all, which could create defects on the leather. Moreover, blades are used to be provided pre-bevelled in order to save time to start the blade running up once it is fitted on the splitting machine.

Rubber, cork and foam sectors

In the fields of rubber and cork, splitting band knives can be used on every kind of material that needs to be split in the thickness such as: * rubber (except vulcanized rubbers) * cork * foam In this sector blades can be used according to their application, to the splitting machine, to the material and to the cut/split precision required by the final product.

Shoes and leather goods sectors

In the production linked to shoes and leather goods, the splitting band knives allow to divide/split and equalize or “reduce” the leather in the thickness in order to improve the quality of the finished product. The final product of this working, equalization or “reduction” is a leather ready to become a shoe or leather goods (for example bags, wallets, belts, etc..) The hides used in this sectors are always finished leathers and in dry. In this field, splitting band knives can be used on every kind of material that needs to be split in the thickness such as: * leather *

textiles Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, different fabric types, etc. At first, the word "textiles" only referred to woven fabrics. However, weaving is not the ...

– linings * rubber – insoles *

cardboard Cardboard is a generic term for heavy paper-based products. The construction can range from a thick paper known as paperboard to corrugated fiberboard which is made of multiple plies of material. Natural cardboards can range from grey to light b ...

components The blades which are mostly used in this sector are rectified on both edge and surfaces in order to guarantee the best splitting, that means a constance in the thickness of the leather that is produced/split (rectification of surfaces), and also to guarantee the maximum linearity during the splitting process ( back edge); the blade must run as stable as possible without oscillations at all, which could create defects on the leather. Moreover, blades are used to be provided pre-bevelled in order to save time to start the blade running up once it is fitted on the splitting machine.

Paper sector

The splitting band knife can be used also in paper sector and allows to divide/to split the material in the thickness, for example paper reels (from toilet paper to the reels for industrial use, paper towel rolls for domestic use, etc..) In this production, the final product obtained by the splitting is: * paper for industrial sector: big rolls, reels, etc.. for hygienic uses: handkerchiefs, toilet paper, kitchen rolls In this sector blades can be used according to their application, to the splitting machine, to the material and to the cut/split precision required by the final product

Band knife machines

Band Knife blades are used on two types of machine (vertical and horizontal) depending on the material being cut/processed.

Vertical

On a vertical band knife machine usually a narrow width band knife blade is used, the most common width being . The length of the band knife blade depends on the supplier of the band knife machine. The dimensions are indicated on a small metal tag pasted or riveted on the machine. The vertical machine band knife blade is most commonly a "double bevel, double edge DBDE" execution to enable cutting while advancing the table and also while retracting the work table, while as the "double bevel, single edge DBSE" execution cuts only in one direction. Productivity is enhanced when the operator cuts both while advancing and also while retracting the work table after adjusting the foam block after each pass for cutting. The DBDE execution blade can have a parallel or twisted 180 degrees welding. The twisted welding execution saves a grinding unit, as both edges pass the same grinding unit after two turns. It has been observed that a narrow width on a vertical band

machine gives better dimensional accuracies on the foam block. The wider the vertical machine band knife - more the deflection and size variation from one end to the other extreme end.

Horizontal

Horizontal band knife blades are wider usually wide for foam converting is popular, for leather goods wide blade is popular, width is popular for the

splitting band knife. There are other widths depending on the machine manufacturer. The horizontal machine band knife blade is supported by a guide to give dimensional accuracies while cutting/splitting. Therefore, only blades that have passed as one main manufacturing step a surface grinding process reach the necessary thickness tolerances of less than . A higher tolerance would lead to marks on the surface of the split material like leather or rubber. Blades are available in different grades of exactness depending on the required exactness on the material to be cut/split. On modern machines in combination with a high grade blade a splitting thickness of for material width is possible.

Blade sharpening

For both the vertical and horizontal band knife machines there is a grinding attachment which continuously sharpens the band knife while it is cutting. It is possible to find a nonpowered grinding attachment for the vertical machines but for the horizontal band knife machine the grinding attachment for continuously sharpening the blade is powered by

electric motor An electric motor is an Electric machine, electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a Electromagneti ...

History

* 1808 W. Newberry patent No. 3105 London, including "machinery for ... splitting skins", * 1854 J.F. Flanders and J.A. Marden with a patent for a bandknife machine, * 1912: Foundation of blade manufacturer Rudolf Alber, Before WW II: several machinery brands on the market: Turner, Clasen, USM, BMD, * 2011: Known Polish pneumatic lifting table manufacturer REXEL started producing Vertical Band knife machines. At the moment there are models: R1250, R1150, R1000, R750, R500 (The number e.g. 1000 is the arm length in cm).

Images

File:Lama a Spaccare.jpg, Splitting band knives for tannery sector, tested before packing File:Lama a Spaccare Fase Di Collaudo.jpg, testing phase of splitting band knives File:Lama a spaccare.jpg, Splitting band knives File:Lama a nastro.jpg, splitting band knife

References

{{reflist Knives Power tools