Polybutene is typically used with linear low-density polyethylene (LLDPE) resins for agricultural films.  KEMAT polybutenes Polybut™ and Polybol™ are selected on their narrow molecular weight distribution to avoid non-controlled migration and to optimise the cling properties.  LLDPE has the capacity of straining and having elastic recovery.  Stretch film needs to have good tensile strength, strain, high retention forces, tack, adhesion, puncture or tear resistance and a high elongation at break.

Agricultural stretch film is used to preserve cut grass.  The grass is compressed into bales, tightened with net and rolled up into stretch film.  The stretch film is wrapped around in several layers, each one attaching to each other due to the tacky characteristics of the film.  This tacky surface can be fabricated by the addition of polyisobutene (PIB) as a tack agent during the production process.

The grass is preserved by fermentation.  An anaerobic environment, ie without oxygen, is necessary. The presence of air would eventually cause putrefaction, therefore, secure wrapping is of the utmost importance.

Properties

  • excellent cling for better seal efficiency
  • exceptional puncture resistance to help reduce silage spoilage from film damage
  • increased resistance against UV radiation
  • thermal resistance
  • high resistance to most chemicals
  • excellent adhesive strength
  • improved elasticity

End User Applications

  • silage wrap
  • pallet wrap
  • bale wrap