The interface between tanner and shoe manufacturer can be difficult because leather is a natural material with flaws and faults, of variable quality and irregular size – and traditionally needing a skilled craftsman to select which part of the hide or skin to use for which shoe components.
But the technology exists today to vastly improve this situation, according to Rui Guerreiro, of Inocam Ltda, Portugal, who said that completely automatic leather cutting systems are now available which offer flexibility, productivity and less need for human resources. Speaking on the subject of Fully Automated Leather Cutting at the UITIC conference, he raised the following issues on leather used in shoemaking:
* Tanneries use low or medium accuracy equipment, prone to errors, for measuring leather
* Tanneries do not really control, in a quantitative way, leather and its quality. The quality control is subjective and, once again, prone to errors
* A shoe manufacturer with several cutting facilities must replicate all necessary logistics and resources
* A shoe manufacturer only really knows the quality of the leather he has bought after the leather has been cut
* Leather is transported from the tannery to the shoe factory without full certainty that it conforms to the orders to be cut
* The time spent taking the leather from the tannery to the cutting facility is unproductive.
A new business model on leather supply to help overcome these problems was proposed by Guerreiro as follows:
* Leather is digitised at the tannery or at a separate unit after leaving the tannery
* The digitised leathers are placed in a virtual store where batches can be individually inspected and bought by shoe manufacturers before despatch
* Automatic nesting can be performed while the leathers are in transit from the supplier to the cutting unit. Alternatively, nesting could be carried out at the buyer’s head office, allowing absolute control over leather consumption
* After the leathers arrive at the cutting unit, automatic systems can cut them without the intervention of skilled operatives
* Automatic feeding of leather to the cutting machines and automatic sorting of the cut components complete the picture
Guerreiro said his company were committed to implementing this model and were developing all the required software to fully automate the leather supply and cutting processes.
The proposed new model obviated tooling costs and preparation time which are high in die cutting while the cutting time per piece would be 2-15 seconds in automatic cutting compared with 13 seconds in die cutting.
Workers involved to cut one piece would be one or two in automatic cutting compared with just one in die cutting. Maintenance he described as ‘medium’ for die cutting and ‘medium to high’ for automatic cutting.
