Milk jugs are made from high-density polyethylene plastic (HDPE), which is one of the most versatile plastic resins and most valuable plastics for recycling.
The used jugs are baled and sent to the recycling facility where they are chipped and washed. The clean chipped plastic is then melted at high temperature and formed into pellets. The pellets are sold to plastic forming plants which use the material to manufacture of such items as buckets, pails and flowerpots.
Milk cartons are made from ‘polycoat’ – lightweight, high-grade paperboard sandwiched between two thin layers of polyethylene film. The result is a strong, rigid container that effectively maintains the integrity of the product inside.
Polycoat is a high-value material that can be converted into new material using a process known as hydrapulping. A hydrapulper is like an enormous blender, where a combination of heat, water and agitation break down the material to produce raw fibre, or pulp. The pulp is then used to make new paper products such as corrugated medium (the inner layer of corrugated cardboard), linerboard and household tissue products. The small amount of residual polyethylene can be screened off for use in other plastic and composite materials.