Upper Cutting Process flow chart
Cutting leather: The method of cutting “uppers” from a leather is a great importance, and is necessary for cutter to know the structure of the skin. The cutter must know which parts of the skin have better physical properties, the direction of the stretch and the nature and origin of the various defects. A good cutter will always be cost minded and get maximum utilization from a skin. A good cutter must know how to use to the maximum the various parts of the leather.
Cutting synthetic and fabric: Synthetic material & fabrics are cut in layer. Depending on the thickness and hardness of the material the number of layers is determined. Some times to maintain the design, particular direction need to be maintained.
Knives: The knives are manufactured from steel. Double edge cutting knives are in use wherever possible; this minimizes the number of knives required, so reducing cost.
Types of knife heights: 19 mm. for leather and 32 mm. for textiles and other multi layer cutting.
Cutting Block: The blocks on which leathers cut are made of poly propylene or phenolic resin block, the cutter should always use the entire surface area of the block to wear it uniformly, this saves knives and improves cutting quality.
Machine: Basically two types of cutting machines are in use
Swinging head cutting machine
Beam head cutting machine
2a. Fixed beam head
2b. Travelling beam head.
Normally the swinging head cutting machines are used for cutting leather and Beam head cutting machines are used for cutting synthetics & Fabric.
Safety on Machines: The double control system on cutting machines requires both the hands of the cutter to be on top of the machine, so ensuring that he cannot get his hands caught between the cutting head and the knife.
4 ) Prefabrication:
Shoe components particularly shoe uppers, must be prepared for the sewing together of the component pieces. Although the operations performed varies from style to style, some of the process are
Splitting to bring components to desired even thickness as per the requirement of style.
Lamination for reinforcing certain parts of the upper to give strength and comfort.
Embossing any decorative design, punching etc.
Stamping or Printing.
Cementing of socks etc.
Because of the number of processes involved in prefabrication it is important that there is as little handling between feeding and collecting the shoe components as possible. The quality of the prefabrication process can impact the quality of later processes.
Quality Inspection: After completion of all the operations in the cutting & prefabrication, each and every component are checked pair by pair, put in poly bag and store in the cutting dept. for delivery. In case of non conformity, respective components are replaced.