HOT-MELT ADHESIVES FOR UPPER-SOLE BONDING
Hot-melt adhesives constitute an alternative to organic solvent based adhesives currently employed in footwear manufacturing, which are in turn more and more subject to legal restrictions. This is a new generation or environmentally sustainable adhesives with technical and financial benefits.
Hotmelts are solid adhesives. They do not contain water or solvents. They melt down by the action of heat and only need to be applied to one side (sole material). They do not require drying time, and do not need additives for upper-sole bonding as they are single component adhesives.
Additionally, the use of robots for hot-melt adhesive application implies savings in time and costs for the footwear industry.
INESCOP is currently working on several projects related to the use of hot-melt adhesives for upper-sole bonding in footwear manufacturing, as a feasible alternative from the environmental and process-based point of view.
BENEFITS DERIVED FROM THE USE OF HOT-MELT ADHESIVES
CO2 AS A FEEDSTOCK
The use of carbon dioxide as a feedstock for the chemical industry is an interesting alternative to oil because CO2 is inexpensive, not flammable and abundant in the atmosphere. In this sense, CO2 can be used to produce sustainable polymeric materials not dependent on non-renewable fossil resources. INESCOP is working on the development of a new generation of CO2-based polyurethanes. These polyurethanes are regarded as a sustainable alternative for application in various sectors: footwear, textile, automotive, etc. with significant technical, financial and environmental benefits.
ADHESIVES FUNCTIONALISATION BY MEANS OF NANOTECHNOLOGY
Nanotechnology is paving the way for the production of new materials with enhanced performance and novel functionalities. In this sense, INESCOP goes for nanotechnology as a tool to confer added value and a competitive advantage on the Spanish footwear industry. The possibility of adding nanofillers to footwear components opens a wide range of innovative solutions for our industry.
Some of INESCOP’s projects are researching into the incorporation of nanoparticles in footwear components with the aim of conferring new functionalities on these materials, such as:
- Electrical conductivity
- Flame retardance
- Antimicrobial effect
- Hydrolysis resistance
- Improvement of mechanical, rheological, thermal etc. properties
The materials that can be added in adhesive formulations include: carbon nanofibres and nanotubes, graphene, metal nanoparticles, etc.