High production lines for polishing granite slabs
LEVIBRETON KG 4600:
THE EXCELLENCE IN GRANITE POLISHING
The Levibreton KG 4600 polishing lines for granite are the soundest investment for companies requiring a very high output, a top quality and programmed, low-budget operating and maintenance costs. Breton was the first company to develop machines for continuous polishing of granite slabs, revolutionizing the field and today, thanks to its unrivalled years of experience, concepts like automation, production, quality without compromise, user-friendliness, simple maintenance and low operating costs are quite familiar to Breton, who has masterly applied them to the outstanding Levibreton KG 4600. Levibreton KG is a worldwide success: more than 1.300 machines produced until today with nearly 100% customer satisfaction.
HIGH RESALE VALUE: thanks to their inherent quality, their ability to remain high-performance machines during all their service life and to the readily available spare parts guaranteed by Breton, Levibreton KG are much appealing to the used machine market and maintain a very high resale value even after several years (a fact not to be ignored when the purchase of a new polishing machine is considered).
Honing-Polishing Units
Made of anodized aluminium alloy, they are specially designed for weight reduction and stiffness increase. The raising-lowering system is perfectly balanced thanks to a pair of pistons with protected internal rods. Heads raise and lower in a flash, with a minimal lifting from the slab surface, therefore slab edges are perfectly polished and the operating speed is increased. Each head is equipped with a pressure regulator displaying the operating pressure on an analogue display (upon request, the machine can be supplied with metering valves for the PC dynamic and automatic management of the operating pressure of all the heads).
THE SPECIAL BRETON HEADS
Heads with 8 oscillating bricks
Levibreton KG 4600 are usually equipped with the more productive Breton heads Mod. SG/8 with 8 oscillating bricks, 510 mm in diameter and oil bath lubricated.
Upon the customer’s request, it is however possible to mount also the traditional Breton heads Mod. SG/6 with 6 oscillating bricks, 460 mm in diameter and oil bath lubricated.
The SG/8 heads derive from the SG/6 head project, but have obviously been adapted to hold 8 bricks; they offer the following advantages:
HIGHER OUTPUT thanks to the greater number of operating bricks (152 bricks for a Levibreton KG 4600 with 19 heads Mod. SG/8 against 126 bricks for a polisher with 21 heads holding 6 bricks each).
BETTER HONING thanks to the larger head diameter (510 mm for the SG/8 heads against 460 mm for the 6-brick heads) and heavier weight (140 kg for the SG/8 heads against 105 kg for the 6-brick heads) that gives them more “stability” when operating.
INSTALLED POWER REDUCTION 285 kW for a Levibreton KG 4600 with 19 heads Mod. SG/8 against 315 kW for a polisher with 21 heads holding 6 bricks each).
Beam
The arc-welded steel beam has a special box-type section design for weight reduction and stiffness increase. In particular, the beam is not drilled (and therefore weakened) to insert the honing units, which are fixed to the beam and contribute to increase its flexural strength. The spindle/beam assembly is therefore very dynamic yet rigid and enables fast acceleration/deceleration ramps.
Beam Drive
The beam is actuated by two rack and pinion systems driven by two gearmotors, which are fixed at each end of the beam and are mechanically synchronized. The gearmotors are driven by two brushless motors that are controlled by special drives enabling either a sine movement of the beam or to keep the number of the beam strokes constant even when the slab width changes; this ensures a better polish quality and uniformity on the whole surface of the slab, edges included. The system, reliable and well-tried, guarantees highly dynamic movements without stressing the mechanical components. The beam working speed reaches 70 m/min. During the beam motion slowing down, the energy generated by the braking is transferred to the electrical grid thanks to “energy recovery” drives: this means energy saving.
LEVIBRETON KG 4600:CLOSE TO PERFECTION
LEVIBRETON KG 4600 was designed on the basis of the extensive experience acquired on more than 1.300 “Levibreton” polishing machines sold throughout the world, using the latest design techniques.
Quality Function Deployment - QFDThe new Levibreton KG 4600 originated from the Customers’ needs, from what the Customer really expects from the ideal machine.
Finite Element Method - FEM
All the critical components of the machine have been checked out using the Finite Element Method (FEM).
Failure Mode and Effect Analysis - FMEA
Particular care was given to the early detection of all the potential defects/critical points which may occur during the service life of the machine, identifying and implementing the appropriate corrective actions.
The support structure consists of a distortion proof, arc-welded steel monobloc, provided with 12 sturdy supporting legs. The conveyor belt slides on a thick steel top, milled all at once to ensure a perfect flatness. The conveyor belt is driven by a brushless motor for a better speed control.
Beam slidingbridges
The beam ends are fixed to two shoulders sliding along sturdy, cast-iron bridges, which house hardened, ground and thick slideways with large diameter roller runner blocks in an oil bath,
and a micropinion. Slideways are protected by stainless steel labyrinth guards.
Slab profile and thickness readers
A photoelectric barrier reader detects the slab shape with 10x10 mm resolution, while a sonar reader senses its thickness. This system enables to process even slabs with a polished surface (such as already polished or resin-treated slabs).The system controls the automatic head lifting-lowering, ensures the self-adjustment of the beam travel to the slab width and guarantees that the front, anti-splash and sound-deadening barriers are positioned automatically to match the slab thickness.
Water plant
Water is supplied to the heads by common, large-diameter, PVC piping that is fixed behind the spindles and connected by flexible, rubber pipes.An ingenious system diverts water outside the spindle casing in the event of overflowing or clogging of the ducts, thus preventing excess water from coming into contact with the spindle internal components.
Automatic controlof abrasives wear
This system performs the continuous monitoring of the abrasive wear of each single head, with video advice notes and warning signals before tools are completely worn out. It also guarantees the minimal lifting of the heads at the forepart and rear end of the slab and their subsequent rapid descent, thus ensuring a better polishing of the edges and a higher operating speed.
Electric and electronic plant
The electric and electronic plant is wired with the “field-bus” technique that transmits digitally, through a single cable, all the PC signals to the different control units installed on the machine. Signal transmission is safe and identification of possible failures is greatly simplified. The stationary part of the machine is electrically connected to the mobile beam by a parallel sheathing system ensuring safer working conditions and longer cable life. All the electric and electronic equipment, including the PC, is supplied by world top-brands, therefore the user can freely get technical assistance and spare parts directly from the manufacturer, virtually throughout the world.
Head lubrication
All the Breton heads operate in an oil-bath system, thus minimizing the wear of mechanical parts. Each rotating head contains the required amount of oil.
Automatic centralized lubrication system
A centralized system, mainly consisting of a grease reservoir, a pump with double micrometer filtration system, sequential distributors and pipes for high-pressure, guarantees the automatic lubrication of both the spindle units and the other moving parts of the machine. The system is warned about possible malfunctions by pressure sensors that easily pinpoint where the circuit is clogged.
Slab cleaning
A rubber wiper fixed at the back of the machine removes water from the slab surface. A pneumatically controlled spindle, integral with the beam and equipped with a brush, cleans the slabs once they are polished. The spindle is raised and lowered automatically each time a slab passes through.
Accident-prevention, sound-deadeningguards
A pressure regulator is installed on each single spindle in an high, ergonomic and safe position. Pressure is displayed on an analogue pressure gauge (upon request, manual selectors for lifting/lowering each single head can be supplied). The frontal, sliding panels for accident-prevention and sound-deadening have a sandwich-like structure and are made of ABS and polyurethane. Sound-deadening splash guards with a stainless steel sandwich-type structure are installed on the beam, in front of the heads, on the same level of the heads. Their positioning is motorized, vertical and automatic in order to match the slab thickness and lift each time the abrasives need to be changed.
Management and programming
The colour touch screen video and advanced, user-friendly software enable the main processing functions to be managed, including:
• option to store (and recall) different work programs for various types of material;
• conveyor speed and synchronism of the whole line, including loaders and connection roller conveyors;
• beam movement (speed, customized programming of the acceleration and deceleration ramps);
• back-slipping correction on the anti-skid conveyor of badly-sawn or bent slabs, for both single slabs and packs of slabs;
• continuous automatic monitoring of the abrasive wear for each single head, with video advice notes and warning signals before the tool is totally worn out;
• option of excluding all, some, or just one slab, or even a portion of a slab (head, end, corner).
Remote diagnosis
Levibreton KG 4600 is equipped with an advanced software for remote assistance (subject to an Internet connection with Breton) enabling the remote trouble-shooting of any possible technical failure: a time- and cost-saving solution since technical service on the spot is no more required.
Statistics and maintenance scheduling
The PC allows to gather and organize statistical data relating to production and consumption, such as:
• production statistics (square metres produced on partial periods, per job order, per shift, progressive or total quantities);
• tool wear statistics (square metres produced with the operating tool, square metres produced with the last replaced tool, etc.);
• diagnostics of machine conditions (time of: machine turned on, machine operating, machine with alarms turned on, etc.);
• statistics of the alarms occurred;
• maintenance scheduling with video alarm when preventive maintenance has expired.
What are you waiting to ask for a quote?
Write to mail@breton.it and we will reply promptly.
It's all for today.
By-by
Sergio Prior
