Not building, roofing paper or felt preparation.  

Code 4250 and Code 4244 “Corrugated or Fiberboard Container Mfg.”  shall not be assigned to the same employer unless the operations described by these classifications are conducted as separate and distinct businesses.

Code 4250 applies to employers engaged in paper coating, corrugating, laminating, creping, oiling, paraffining, parchmentizing or waxing.

Coatings of various kinds and colors are mixed in mixers or agitators and then run into troughs or coating machines.  Rolls of paper are coated as they pass over rolls revolving through this mixture.  Some products are printed with advertising material before the coating.  Paper is dried on rolls or stacks, some are polished or embossed, finished by calendaring, slitting to width and rewinding or sheeting to size, then labeled and packed.

Paper is corrugated by being slowly passed over a steam or gas heated uniformly ridged metal drum, then revolved around a roll covered with silicate of soda which is deposited on the tips of the corrugation.  It is then moved along until it meets a paper liner, both travel, under pressure, over heated plates where they are combined and dried.  If double facing is desired, the single faced paper travels back again to the silicate roll and a second liner is applied by the same process.  It is then trimmed on a slitter and then wound into rolls or cut into sheets, tied and packed.

The process of laminating paper involves paste that is mixed or agitated.  Laminated paper is produced by feeding a paste or glue between layers of paper, pressing them together, drying and finishing by winding into rolls or sheeting to size, or else cutting, slitting or die cutting to size and shape, wrapping and tying into bundles.