Various methods of binding light agricultural byproducts
A lot of porous agricultural byproducts have few valorization possibilities and are mainly used as animal litter. In order to propose more valuable applications for these byproducts, research is being carried out to use these resources in particleboards for application as building materials for insulation or flooring underlayer, or as molded cushioning for packaging or horticultural support medium for example.
The objective of this study is to investigate the potential of low density materials obtained from corn pith. At industrial scale this type of material is generally obtained by adding synthetic binder. To obtain totally biobased materials, corn pith particles are bound by different methods:
- without addition of any binder. In that case water is sprayed on the vegetal particles before the forming process. The lignocellulosic compounds contained in the agroresources can act as binders. Rate of sprayed water must be optimized in order to minimize the process time.
- with various biosourced binders, based on vegetal resins or animal proteins to improve particleboards resistance.
The particleboards are made at a laboratory scale by thermocompression of the vegetal raw particles with densities range from 50 to 200 kg/m3 according to the target application.
The corn pith particles highlight interesting properties, such as a low density as well as a hygrometry control capacity due to their alveolar structure. Particleboards are characterized by their thermal insulation properties, their mechanical properties by bending tests according to the densities and the different binders and by their resistance to water. Several applications can be considered according to the properties obtained.