Heat sealer used to prepare plastic bag of lettuce for shelf life testing. A heat sealer is a machine used to seal products, packaging, and other thermoplastic materials using heat. This can be with uniform thermoplastic monolayers or with materials having several layers, at least one being thermoplastic.
KDNK (88.1 FM) is a community access station broadcasting an eclectic format of music and local news in western Colorado in the United States.
There were a number of stations on the air before KDKA, including stations in Medford Hillside MA (1XE, later WGI) and Detroit (8MK, later WWJ). Up in Canada, XWA (later CFCF) was on the air in 1919, and I recall reading that a station in Argentina also broadcast in 1919.