System and method for fire-polishing glass containers

Abstract

A system and method for fire-polishing glass containers includes at least one fixed structure positioned on each side of a conveyor belt, in the forward movement direction of the glass containers; a structure that can move via each of the fixed structures, which moves with a forward movement in relation to the forward movement line of the conveyor belt, and with a backward movement in relation to the forward movement of the conveyor belt; a series of burners coupled to each of the moveable structures; sensors positioned on one side of the conveyor belt to determine the speed of the carrier belt and the distance or separation between containers; and a controller connected to the sensor and moveable structure, for adjusting and synchronising the speed and distance of the containers.

Claims

1. A system for fire-polishing glass containers includes: at least one fixed structure positioned on each side of a conveyor belt in a forward direction of the glass containers; a movable structure for each fixed support structure, which moves with a forward movement relative to the forward direction of the conveyor belt and with a backward movement in the opposite direction to the forward direction of said conveyor belt; a plurality of burners coupled to each of the movable structures, which travel together with each of the movable structures at the same forward speed of the conveyor belt, to provide a flame or heat flow to the surface of the container; sensing means positioned in proximity with the conveyor belt to determine the conveyor belt speed and distance between containers; and control means connected to the sensing means, movable structure and burners, to adjust and synchronize the speed and distance of the containers, with respect to the burners and to absorb any dephasing of the conveyor belt.

2. The system for fire polishing glass containers, as claimed in claim 1, where at least one fixed structure and a movable structure are placed on either side of the conveyor belt, in opposed facing manner, which are separated or offset with a spacing or distance to simultaneously move with a forward and backward movement.

3. The system for fire polishing glass containers as claimed in claim 1, further including: flame presence sensors for automatic on/off burners in case of: equipment start-up, emergency shutdown and absence of containers on the conveyor belt.

4. The fire polishing system for glass containers as claimed in claim 1, wherein burners are located at different heights to project the heat flow or flame in steps to predetermined areas of the container, while advancing said containers continuously on the conveyor belt, such movable structure, and such burners having several forward and backward movements to project the heat flow to all areas of each container until a predetermined forward distance is reached.

5. The fire polishing system for glass containers as claimed in claim 1, wherein the burners are automatically adjusted by the control means, to project the heat flow according to different areas of the container, as they continuously move forward on the conveyor belt until a predetermined forward distance is reached.

6. The fire polishing system for glass containers, as claimed in claim 1, where the control means is a programmable logic controller.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of the production and handling process for glass containers showing the location of the system of the present invention;

(2) FIG. 2 is a schematic diagram showing a side view of the system for fire polishing glass containers of the present invention;

(3) FIG. 3 is a schematic diagram, in a plan view, of the fire polishing system for glass containers of the present invention;

(4) FIG. 4 is a schematic diagram showing the side part of the system for fire polishing glass containers of the present invention and, also showing the burners at different heights, in accordance with a second embodiment of the present invention; and,

(5) FIG. 5 shows a schematic diagram (according to FIG. 4), showing in the form of horizontal bars, the different forward and backward movements of the fire polishing system for glass containers, according to a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

(6) Referring to FIG. 1, in the glassware forming process such as for vessels or containers, the molten glass is fed from a feeder D in a gob form G, which are distributed by a distributor DG to the individual forming sections of an I.S. machine. The products formed by each of the still hot sections S are first laid on a dead plate (not shown) in the respective section. Then the containers are pushed from there onto a conveyor belt (A) that moves the containers of all sections to a transfer mechanism T at the end of the section, which controls the flow of the products by separating them evenly and changing the flow direction by 90 and placing them one by one on a cross conveyor BT in an evenly spaced row. Once a complete row of formed containers has been formed, a pusher E simultaneously transfers all containers in the row of the cross conveyor belt BT, through transition dead plates PM of a linear conveyor belt BL into an annealing furnace HT.

(7) The location of the fire polishing system SP for glass containers in accordance with this invention is schematically shown in FIG. 1.

(8) The following will describe in detail each part and operation of the system of this invention according to FIGS. 2 and 3, which includes: a fixed support structure 10 placed on each side of the conveyor belt (A), in the direction of the glass containers' advance. A movable structure 12 is coupled to slide on the fixed support structure 10, which moves with a forward movement at the same forward speed as the conveyor belt (A) and with a backward movement in the opposite direction to the feed rate of the conveyor belt (A). The movable structure 12 includes a lengthwise bar 16 coupled to the movable structure 12, which is fixed by means of cross support bars 18, 20, at each of its ends. The lengthwise bar 16 is coupled to a magnetic linear motor 22, which produces a straight line movement, on which the lengthwise bar 16 and consequently the movable structure 12 slide, with a forward and backward movement. At least one series of burners 24 are coupled on the movable frame 12, which are arranged toward the front of the conveyor belt (A) to provide a flame or heat flow to each side of containers 26. Burners 24 are mounted on burner holders (not shown) on the movable support structure 12, which allow the height or angle of flame projection to be adjusted according to the height of items 26.

(9) As shown in FIG. 3, the polishing system SP of this invention is placed on both sides of the conveyor belt (A), which are placed in a counterposition to each other, which are separated or offset by a certain distance. According to the layout shown, both movable structures 12 move simultaneously, with a forward movement, up to a predetermined feed distance DA in the direction of continuous movement of the conveyor belt (A) providing during its advance run, a flame on both sections of the containers 26. For example, the movable structure 12 can have a maximum run of 200 cm, but this may vary depending on the shape and size of the articles.

(10) Once the movable structure 12 and burners 24 have completed the advance run, the structure returns to its starting position (DI distance) to perform a new polishing step for containers 26 that are continuously moving on the conveyor belt (A). The polishing speed can be adjusted up to 2 m/s with a maximum reverse speed of 2 m/s.

(11) Since burners 24 travel at the same speed as the conveyor belt (A), containers 26 require less exposure to fire, therefore, reduce the number of burners 24 allowing a considerable saving of gas and oxygen. According to the mode shown and based on the previous art, it was possible to reduce the number of structures (SP) from 3 to 2, i.e. from 18 to 12 burners.

(12) Sensors 28 are placed on one side of the conveyor belt (A) to determine the conveyor belt (A) speed and the distance or spacing (DE) between containers 26; and, flame presence sensors 30, located in proximity to burners 24, allow the automatic on/off of the equipment in the following cases: equipment start-up, emergency shutdown and absence of containers on the conveyor belt (A).

(13) A programmable logic controller (PLC), connected via lines 32, 34, to the magnetic linear motors 22 to move each movable structure 12. This controller (PLC) is also connected to sensors 28 through line 36 and to flame presence sensors 30 through line 38, to calculate and synchronize the speed and space (DA) of containers 26, in real time, to achieve a better positioning of burners 24 and to absorb any offset of the conveyor belt (A).

(14) In a second embodiment of this invention, burners 24 are placed at different heights, to project the flow of heat or flame towards different zones of the body of the glass containers 26, while they continuously advance on the conveyor belt (A). However, the advantage over the previous art is that the movable structure 12 is backed up several times before reaching its predetermined advance stroke (DA) (see FIGS. 4 and 5) i.e. in a container line 26 on the conveyor belt (A), burners 24 and movable structure 12 advance a certain distance (d1), for example, in a line of six containers, the first burners 24A project the heat flow to the bottom of the containers (1 and 2), the second burners 24B project the heat flow to the middle of the containers (3 and 4) and the third burners 24C project the heat flow to the top of the containers (5 and 6). Once the different areas of the containers 26 have been exposed to the heat flow (e.g. ten to fifteen seconds), the movable structure 12 moves back a second distance (d2), and now the first 24A burners project the heat flow to the middle part of the containers (3 and 4), the second 24B burners project the heat flow to the upper part of the containers (5 and 6) and move forward again, in that position, at the same speed of the conveyor belt (A) at a distance (d2n) projecting the heat flow to each container 26 areas. Since this is a continuous process, the third burners 24C start projecting the heat flow to the next row of containers 26, i.e. the bottom of the containers (1 and 2).

(15) Once the different areas of containers 26 have been exposed to the heat flow for a period of ten or fifteen seconds, the movable structure 12 moves back a third distance (d3) and again moves forward with the same speed of the conveyor belt (A) a new distance (d3n). As a result, the first burners 24A now project the heat flow to the top of the containers (5 and 6); the second burners 24B project the heat flow to the middle part of the containers (3 and 4) and the third burners 24C project the heat flow to the lower part of the containers (1 and 2). The movable structure 12 can have a maximum run of 200 cm, but this may vary depending on the shape and size of the items, so the movable structure 12 and burners 26 can back up and move forward three or four times, projecting the heat flow to all of the container areas before reaching its forward distance (DA). Considering that the container rows 26 have a continuous movement, the movable structure 12 and burners 26 travel a maximum advance, which would be represented by DA=d1+d2n+d3n, and once reached, move back to the starting distance D1.

(16) In a third embodiment of this invention and on the basis of FIG. 2, all burners 24 may be automatically adjusted during the movable structure 12 movement, i.e. all burners can direct a heat flow to all containers 26 from the beginning, in a first area of the container (e.g. the bottom) in a first time period t1 and distance d1. Then, as containers 26 move forward on the conveyor belt (A), burners 24 can be adjusted towards a second area (e.g. the middle part of containers 26) in a second time period t2 and distance d2n; and finally, adjust burners 24 towards a third area (e.g. the top of containers 26) in a third time period t3 and distance d3n, until they reach their displacement or maximum distance (DA) and start their rewind step. In this case, burners 24 travel all the time at the same speed of the conveyor belt (A) and its adjustment to each of the different areas of containers 26 is set by the programmable logic controller (PLC).

(17) From the above, the method for fire polishing glass containers comprises the steps of:

(18) moving continuously forward a row of freshly formed glass containers on a conveyor belt;

(19) providing a series of burners on at least one side of the conveyor belt;

(20) exposing the containers to a burner flame, directing the flame continuously to the surface of each container up to a first predetermined advance distance DA for polishing the containers, said burners travelling at the same forward speed as the conveyor belt (A);

(21) moving the burners back to a starting distance D1, once the polishing step of the containers has been carried out; and,

(22) adjusting the conveyor belt speed, in real time, to achieve a better positioning of the burners on containers 26 and to absorb any offset of the conveyor belt (A).

(23) The method of this invention can include the step of:

(24) sensing the conveyor belt (A) speed and/or spacing (DE) between each container (26) to adjust the burner tracking speed during polishing.

(25) The method of this invention further can include the step of: projecting each burner flame according to the shape of the container surface (26).

(26) The method of this invention further can include the steps of: advancing the movable structure 12 and burners 24A, 24B, 24C up to a distance (d1) to project the heat flow in a first predefined area of containers 26, which are continuously moving forward on the conveyor belt (A); moving back the movable structure 12 and 24A, 24B, 24C burners one distance (d2) to place them in a second predefined area of containers 26 and, again, moving the movable structure 12 and 24A, 24B, 24C burners forward at the same conveyor belt speed (A) until distance (d2n) is reached; moving back the movable structure 12 and 24A, 24B, 24C burners at a distance (d3) to place these burners in a third predefined area for each container 26 and, move the movable structure 12 and 24A, 24B, 24C burners forward again at the same speed as the conveyor belt (A), projecting the heat flow to said third pre-defined area of each container 26, until distance (d3n) that would be equivalent to the maximum advance distance (DA) of the movable structure 12 is reached;

(27) moving back the movable structure 12 and burners 24A, 24B, 24C to a starting distance, once the fire polishing step of the containers has finished.

(28) The method of this invention in a third embodiment includes the steps of:

(29) continuously moving forward a row of freshly formed glass containers on a conveyor belt;

(30) providing a series of burners on at least one side of the conveyor belt, such burners travel at the same forward speed of the conveyor belt until a predetermined advance distance is reached;

(31) adjusting the burners to direct a heat flow to all containers 26 in a first container area in a first time period t1 and distance d1;

(32) adjusting the burners to a second area of containers 26, to direct heat flow to the selected area in a second time period t2 and distance d2;

(33) adjusting the burners 24 towards a third area of containers 26, to direct a heat flow to a third selected area in a third time period t3 and distance d3, until the predetermined advance distance is reached; and

(34) moving the burners back to a starting distance, once the polishing step of the containers has been carried out.

(35) From the foregoing, a system and method for fire polishing glass containers has been described and it will be apparent to industry experts that other possible advances or improvements can be made, which may be considered within the field determined by the following claims.