an apparatus for sealing cover attachments to the plastics couplers of multipacks of containers , comprising conveyor means for transporting a succession of the multipacks along a generally horizontal path , a reservoir for a plurality of the blanks , an applicator device operating in timed relation to the conveyor means to place blanks for the cover attachments individually upon the multipacks moving along the conveyor means so that tabs , which extend out from the plain portion of each blank , are disposed laterally in relation to the conveyor path and , along each side of the conveyor path , heating means for directing hot gas onto the tabs and onto the lateral surfaces of the coupler so as to render them heat - sealable together . the apparatus further comprises folding means for folding the tabs downwardly and pressure means for holding the tabs against the coupler to heat - seal the coupler and cover attachment together . the conveyor means comprises a locating side conveyor disposed to receive the multipacks with the blanks thereon downstream of the applicator means and having dog members arranged to engage individual multipacks between adjacent containers thereof , so as to locate the multipacks as they are carried in succession through the heating means , folding means and pressure means , each dog of the locating side conveyor being arranged to engage both a multipack and the respective blank thereon so as to locate the blank in relation to the multipack until the heat - seals have been made .