| 摘要 |
The invention relates to a heating foil as a heating system for buildings. The heating conductor of the heating foil is formed by a narrow layer of an antimony-alloyed hard lead core (15) with a tin coating (17, 17a) on either side and has at least one heating conductor path formed in sandwich-like manner from a narrow layer (20) of tin- lead-antimony alloy or a low melting point lead-bismuth alloy and a further equally narrow layer (25) located thereon and formed by an antimony-alloyed hard lead core with a tin coating on the free side of the first layer and on the free side of the further layer. The depth of the layer (20) is equivalent to 10 to 100% of the total thickness of the heating conductor and the tin coatings in each case <IMAGE> based on the weight of the hard lead core. The first layer of this sandwich-like conductor path functions as a safety device, since it will melt and thus interrupt the current supply at a temperature sufficiently low to avoid the danger of setting fire to, for example, a wooden building incorporating the heating system. <IMAGE> |
