Milk containers are made from paperboard coated with a waterproof plastic[plastic?:Plastic sample cutting machine], generally polyethylene. The wood pulp that is used to make paperboard for milk cartons is a blend of softwood and hardwood. Softwood is usually a type of pine, though the actual trees used vary depending on the location of the paper[paper?:paper sample maker cutting machine] mill. Softwood produces long wood fibers that provide strength to the paperboard. Hardwood comes from deciduous trees such as oaks. Hardwood has shorter fibers that make for a better printing[printing?:printing cutting finishing solution] surface. Pulp for milk carton[carton?:carton box sample cutting machine] board is usually 60% hardwood and 40% soft.
Several other chemicals are used to make milk cartons. One is oxygenated chlorine, which bleaches the wood pulp. Other chemicals specific to each manufacturer are added to the paper to add strength. Chemical pigments in the ink are used for the printing process as well.
