IE41782B1 - A procedure and apparatus for the production of wired glass by rolling - Google Patents

Abstract

1513908 Rolled wired glass SOC ITALIANA VETRO SIV SpA 7 July 1975 [15 July 1974, 16 July 1974] 28490/75 Heading C1M Reinforcement wire (e.g. wire mesh) is fed into a glass melt, upstream of the forming rolls, at a rate higher than that of the glass issuing from the rolls until it forms a length of slack enough that it can freely float in the melt, whereby it is entrained without stress into the rolled glass, the feed rate then being adjusted to maintain the slack.

Description

The present invention refers to a procedure and an apparatus for the manufacture, by rolling, of reinforced glass ribbon, particularly of glass ribbon reinforced with wire netting.

Ih the known processes for the production of said rolled wire glass, the molten glass is fed from a furnace between the rolls of a rolling mill, immediately upstream of which the wire netting is introduced into the mass of fluid glass and entrained by the feed movement of the ribbon, which forms down10 stream of said rolls, into which ribbon said metal netting is incorporated.

Said process involves, however, various drawbacks. In particular, only a net with square or generally rectangular meshes may conveniently be utilized as a reinforcement, with the warp wires necessarily running parallel to the feed direction of the vitreous mass, inasmuch as any other geometric arrangement in which the wires would be at an angle with respect to this direction would be subjected to a considerable strain due to the pull to which the net is subjected. This would also lead to an increase in length and to a reduction in width of said net. After its emmission into the vitreous mass, the net must in fact pass through layers of molten glass upstream of the rollers, and these layers move at a speed lower than the ribbon formed downstream of the rollers and incorporating the net, and therefore the latter meets a considerable resistance However, even wire nets with square or generally rectangula meshes are subjected to a slight strain, with the result that these wires become curved.

Another disadvantage is that the material of the netting 5 suffers an alteration of its initial strength owing to stretching In order to obviate the above mentioned drawbacks, a known process for obtaining glass ribbons with reinforcement of any shape and arrangement consists in placing said reinforcement between two separately formed glass layers placed one ig atop the other and pressure welding them.

It is clear that this process is rather expensive and requires a considerable auxiliary equipment, which becomes particularly costly where large size glass sheets have to be produced.

It is the object of the present invention to supply a procedure and an apparatus which, although using the normal equipment for the manufacture of rolled glass sheets, permits the production of wired glass with nettings of any shape and arrangement, without any deformation of said netting or reduction of strength of their material. A further object of the invention is to provide a process and an apparatus which is manifestly cheaper than the processes so far used for this purpose.

According to the present invention there is provided a procedure for the production of wired glass ribbon by rolling, 17 8 3 comprising the steps of feeding the reinforcement for said glass into the molten glass upstream of the forming rolls of the rolling machinery, at a rate higher than the speed of the glass ribbon issuing from between said rolls, until said j reinforcement forms, in said molten mass, upstrem of said rolls,a length of slack sufficient to permit it freely to float in said molten glass, so that it is entrained, without stresses therein, within the glass ribbon issuing from between said rolls, and reducing said feed rate of said reinforcement to said speed of said ribbon, in order to maintain said slack in said molten mass.

In this manner., the reinforcement is entrained by the glass ribbon without any mutual displacement and strain between it and the reinforcement, with the result that wire netting of any desired mesh shape and warp direction may be used as a reinforcement for the glass.

According to a further aspect of the invention, there is provided an apparatus for carrying out the procedure of the method comprising a pair of variable speed, guide and drive, reinforcement feed rolls, located upstream of the forming rolls of said apparatus, and means driving said feed rolls independently of said forming rolls to feed said reinforcement into the molten glass upstream of the forming rolls, the arrangement being such that, in use, said reinforcement is fed into-said molten glass at a rate higher than the speed of the glass ribbon issuing from between said forming rolls, until, in said molten glass upstream of said forming rolls, said reinforcement forms a length of slack sufficient to permit it freely to float in said molten glass so that it is entrailed, without stresses therein, within the glass ribbon issuing from between said rolls.

The invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows schematically a conventional procedure for the production of wired glass; Figure 2 shows schematically a first embodiment of an apparatus and procedure for producing wired glass according to the invention; and Figure 3 shows also schematically a second embodiment of the apparatus and procedure for producing wired glass according to the invention.

With reference to Figure 1 there is indicated at 1 a mass of glass in the fluid state which issued from the furnace 2 and flows in the runner trough 3 towards the forming rolls 4 and 4‘ of a rolling mill which revolve in the sense indicated by the arrows. The mass of molten glass 1, when passing through said rolls, is reduced to a ribbon 5, which, supported by rollers 6, travels towards an area 7 of successive treatment.

In said conventional procedures, in order to provide the glass ribbon with a reinforcement, such as a metal net 8, the latter, which is fed from a not shown source, comes in contact with the fluid mass of glass 1 in the vicinity of the upper roll 4 through a guide means 9, which is shaped and directed in such a manner that said net 8 is passed by the feed movement of the glass mass 1 through the rolls 4 and 4', thereby remaining incorporated within the ribbon 5, whose movement causes the entrainment of said net 8. 417 8 2 As previously mentioned, owing to the tensile stresses to which said net is subjected, this process permits only to used nets with square or generally rectangular meshes, with the warp wires arranged parallel to the feed direction of the glass.

In the procedure according to the invention shown in Figure 2, the wire net is introduced into the glass mass 1 at a point which lies further upstream of the point at which it is introduced in the conventional processes as shown in Figure 1.

Furthermore, while in the conventional procedure the rate at which the meta! net is introduced into the glass mass 1 is equal to the speed of the ribbon 5, inasmuch as it is determined by the entraining action of said ribbon 5, in the procedure according to the present invention the rate at which the net 8 is introduced into the glass mass 1 is varied, by a suitable feed apparatus, so as to be initially higher than the speed of the ribbon 5, with the consequence of forming a given slack 10 in the reinforcement net 8 within the fluid glass mass 1. Once said slack 10 has been formed, the rate at which the net is fed into the fluid glass mass 1 is reduced to the speed of the ribbon 5.

Thereforethe net 8 moves together with the mass of molten glass 1 at the same speed reached by the latter in the space between the rollers, without any displacement and stress between the glass and its meshes and therefore without being subjected to a tensile stress, thereby permitting the use of wire nets shaped and arranged in any desired manner, without any deformation of the latter.

A device with entraining and guide rolls 11 is used as a feed device for producing the desired variation of feed rate of the net into the mass of molten glass 1. This device is located upstream of the forming rolls 4, 4' at a distance therefrom to produce a length of slack sufficient to permit it freely to float in said molten glass, so that it is entrained, without stresses, within the glass ribbon issuing from between said forming rolls.

The net 8 may be fed into the glass mass 1 either vertically, as shown in the drawings, or at a given angle with respect to the vertical.

In the embodiment shown in Figure 3, the point at which the reinforcment 8 is introduced in the molten mass of glass 1 is selected in the vicinity of the upper forming roll 4 of la the rolling mill and precisely in the region where said mass 1 forms’ a whirl 12, in such a manner that the revolving motion of said whirl 12 acts in the sense of imparting to the reinforcement a thrust in the feed direction. This contributes to avoid that upstream of the rolls tensile forces are caused in the elements forming the reinforcement 8, due to the entraining action of the ribbon 8 and involving a deformation of said reinforcement.

It is clear that even existing equipment for the production of wired glass may be adapted for carrying into practice the hereinbefore described procedures, on the condition that they are completed with a device by which the feed rate of the reinforcement into the molten mass upstream of the rolls may be varied in the above described manner, in order to produce and maintain a slack in the reinforcement upstream of said rolls.

It is also clear that the invention comprises also the wires glass produced according to the above described procedures, since in the wired glass produced by them the deformation of the net and the stresses between glass and wire net are completely absent.

Claims (10)

1. A procedure for the production of wired glass ribbon by rolling, comprising the steps of feeding the reinforcement for said glass into the molten glass upstream of the forming rolls of the rolling machinery, at a rate higher than the speed of the glass ribbon issuing from between said rolls, until said reinforcement forms, in said molten mass, upstream of said rolls, a length of slack sufficient to permit it freely to float in said molten glass, so that it is entrained, without stresses therein, within the glass ribbon issuing from between said rolls, and reducing said feed rate of said reinforcement to said speed of said ribbon, in order to maintain said slack in said molten mass.

2. A procedure according to Claim 1, wherein said reinforcement is a wire netting of any desired mesh shape and warp wire direction.

3. A procedure according to Claim 1, wherein the reinforcement is introduced vertically into the molten glass upstream of said rolls.

4. A procedure according to Claim 1, wherein the reinforcement is introduced obliquely into said molten glass. 5. Between said rolls.

5. A procedure according to Claim 1, wherein the reinforcement is introduced into the mass of molten glass at the location of a whirl produced in said mass by the rotation of said rolls within said molten glass upstream and in the vicinity of them.

6. An apparatus for carrying out the procedure as claimed in Claim 1, comprising a pair of variable speed, guide and drive reinforcement feed rolls, located upstream of the forming rolls of said apparatus, and means driving said feed rolls independently of said forming rolls to feed said reinforcement into the molten glass upstream of the forming rolls, the arrangement being such that, in use, said reinforcement is fed into said molten glass at a rate higher than the speed of the glass ribbon issuing from between said forming rolls s until, in said molten glass upstream of said forming rolls, said reinforcement forms a length of slack sufficient to permit it freely to float in said molten glass so that it is entrained without stresses therein, within the glass ribbon issuing from

7. Wired glass produced by the procedure of Claim 1.

8. A procedure for the production of wired glass substantially as hereinbefore described with reference to and as shown in the accompanying drawings. 10

9. · Apparatus for the production of wired glass Substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

10. Wired glass substantially as hereinbefore described with reference to the accompanying drawings.