a heat - seal type wrapping apparatus which operates by wrapping successive pieces of candy at regular intervals in a plastic film being unwound from a reel and being formed into a cylinder , subjecting the cylinder of plastic film to longitudinal heat seal along its overlapping margins and then to transverse heat seal between adjacent wrapped pieces of candy , and centrally severing the transversely heat - sealed regions . the apparatus comprises a device for preheating the overlapping margins of the film to a suitable temperature prior to the longitudinal heat seal and a device for preheating transverse heat - seal regions to a suitable temperature prior to the transverse heat seal , thereby ensuring satisfactory heat seal both longitudinal and transverse . the preheating device for transverse heat seal comprises a plurality of units arranged on a rotatable disc so that their radial positions can be adjusted , while the rotation of the transversely heat - sealing device is made adjustable to enable the spacing of transverse heat seal to be adjusted .