Problems of wrinkles and breakings.

1. Humect cuttings at 91% humidity and 23ºC, at least 12 hours.
2. Air off the stiffeners in order to avoid humidity excess before enter in the chain.
3. If you are using leather goard stiffeners humidity must be less or equal 5%. Add to the upper, mould and enter in the chain.
4. If you are using resines textile stiffeners after moulding you have to wait solvent evaporates.
5. Procure moulding let the shoe without any wrinkle.
6. The lasting in the drier must be at 90-95ºC and 6-9 minutes.
7. Don't use linings or backers with different behaviour to the pulling.
8. Relative humidity in the factory must be 60% in order to avoid uppers get dry during the process.
9. Don't abuse of water finishings.
10. Avoid the use of excess elastic backer ribbon.

Help links:

• Instituto Tecnológico del Calzado y Conexas. (spanish)
• SATRA Technology Centre. (english)