DE2431933A1 - HEATABLE PLATE MADE OF FLEXIBLE PLASTIC - Google Patents

Description

Swiss cable, rubber and plastics factories

Altdorf / Switzerland

Heatable plate made of flexible plastic

The invention relates to a heatable plate made of flexible plastic, in particular a plate of the type and Size that is used for swing doors. Such flexible swing doors are used in factories, warehouses, cold stores etc. are used because they can be easily pushed open by vehicles without the driver having to get off; they close again automatically after the vehicle has passed through.

In cold stores, in order to avoid cold losses at the transition from rooms with different temperatures as much as possible, Connecting doors used. To be able to do so in busy traffic Such swing doors are used to maintain small opening times

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particularly suitable here.

The plastic swing doors available on the market, however, have two major disadvantages that are becoming more widespread have prevented these doors in cold stores up to now, namely the insufficient cold flexibility of the plastic and the icing over of the door surface. The insufficient cold flexibility leads to the slow destruction of the doors in use. The icing of the surface reduces another advantage of such doors, namely their transparency, so that accidents while driving with forklifts or transport vehicles can arise.

The cold flexibility can be achieved through the use of suitable plasticizers be improved. However, there are limits to the use of plasticizers, as they are at the same time an optimum mechanical properties of the plastic, in particular Abrasion resistance, must be sought.

The use of de-icing fluids and the like, that are supposed to prevent freezing is not a long-term satisfactory solution.

"The present invention overcomes these disadvantages. It is characterized in that a heating grid is arranged in the plate, which has essentially the same flexibility how the plastic possesses.

The invention also relates to the use of such a plate as a door plate of a swing door.

Embodiments of the heatable plastics according to the invention are shown in the accompanying drawings; show it

Fig. 1 shows a swing door leaf with a fully heated door panel,

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FIG. 2 shows a cross section through this plate, FIG. 3 shows an only partially heated door leaf, and FIG

4 shows a door leaf in which the heating grille is divided into several fields.

Fig. 1 shows one wing of a swing door for average Cold stress, i.e. for temperatures that are not too low and for moderate humidity, i.e. for conditions in which massive icing of the swing door must be expected. An electric heater grille 1 here covers practically the entire surface of the plastic plate 2, but has only one connection 3 that is assigned to a distribution box 4 leads. The connection 3 is expediently in a frame 5, which the plastic plate 2 above and laterally and is known as a door gantry because of its shape, is hidden away and leads over one of the hinges 6 of the door gantry 5.

Plastic sheets, mostly PVC sheets, for the one shown here Intended use are usually pressed in multiple layers. The heating grid 1 is therefore, as FIG. 2 shows, with Advantage inserted between the layers 7, 8; this figure shows a plate pressed from only two layers.

The embodiment according to FIG. 1 is also particularly suitable for swing doors made entirely of clear plastic are. The heating grid, which preferably has a mesh size of 5mm, hardly reduces the view so that a vehicle approaching the rear of the door can still be seen. The heating grid consists of wires from of such a thickness that the grid has the same flexibility as the plastic plate in which it is inserted.

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This occurs when the swing door is pushed open by vehicles and the resulting bending of the door only low stresses between the grille and the material of the Plate on.

So-called visible swing doors are a little less complex in terms of material, in which the door panel is made of opaque plastic, but in which a window 9 is made transparent plastic is arranged. This window, which can also be extended across the entire width of the Plate can extend, must of course not freeze, and it then depends on the conditions in the cold storage rooms whether the embodiment of FIG. 3 is sufficient, in which only this window 9 receives a heating grid, or whether here too the embodiment according to FIG. 1, at most even the one according to Fig. 4, must be used.

This latter embodiment is for extreme conditions thought. The heating grid 1 is expediently divided into individual, here in three fields la, Ib, Ic, of each of which receives its own connection 3a, 3b, 3c to the distribution box 4.

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Claims (6)

Claims 1. Heatable plate made of flexible plastic, characterized in that that a heating grid is arranged in the plate, which has essentially the same flexibility as the plastic owns. 2. Plate according to claim 1, characterized in that it is laminated from at least two layers, between where the heating grille is located. 3. Plate according to claim 1 or 2, characterized in that that the grid has a mesh size of 5 mm. 4. Plate according to claim 1 or 2, characterized in that that the grid extends only over part of it. 5. Plate according to claim 1 or 2, characterized in that the grid is divided into several fields of each of which is connected to an electrical feed line by means of its own connection, and the together have approximately the total area of the plate. 6. Use of the plate according to claim 1 as a door plate of a swing door. Sb / lf 6/12/1974 * 509809/0691 Blank page