Contact welding heating component and automatic welding machine

A contact welding heating component for plasticizing the edges of thermally fusible/meltable material sheets disposed so as to overlap at least partially, which can be inserted between an overlapped lower material sheet and an overlapping upper material sheet and can be moved along the same, comprising an upper side of the heating component for making contact with the upper material sheet and a lower side of the heating component for making contact with the lower material sheet, including a front leading-material side of the component in the direction of movement of the contact welding heating component during the welding operation, and a rear trailing-material edge of the heating component, for the material sheets that are joined to one another by way of the upper side of the heating component and the lower side of the heating component, forming a wedge-shaped contour, and comprising at least one roughening device for the material sheets that are disposed upstream of the trailing-material edge of the heating component in the direction of movement of the contact welding heating component, which protrudes beyond the upper side of the heating component and/or the lower side of the heating component and extends transversely to the direction of movement of the contact welding heating component, adjoining the trailing-material edge of the heating component, and comprises a number of sharp-edged raised roughening elements extending in the direction of movement of the contact welding heating component, wherein the roughening device and the roughening elements have a variable height in the direction of movement of the contact welding heating component.