Concrete Block Machine Middle East: Sizing and Cost

Concrete block machine Middle East shortlists are usually a ladder of five or six models, and every rung is set by six numbers: pallet face, cycle time, vibration force, rated pressure, installed power and machine weight. A buyer who compares only the daily output printed on a quotation ends up arguing about price, because two machines quoting the same total can differ by 22 t of steel and 70 kW of connected load. Read the pallet first. The rest follows from the mould face it can carry into one press.

Each rung is bought with mass. The QST6-15 weighs 12 t and draws 34.4 kW. The QST1800 weighs 34 t and draws 104 kW. Across the same range the pallet grows from 980 x 680 mm to 1400 x 1400 mm and the vibration force climbs from 68 kN to 280 kN. Nothing in that progression is styling. It is what a bigger mould face demands.

The model ladder, read as six numbers

List the machines in order and the tiers separate without argument. Read each line as a limit, not as a feature list.

• QST6-15: pallet 980 x 680 x 20 mm, cycle 15 to 23 s, vibration force 68 kN, rated pressure 25 MPa, installed capacity 34.4 kW, weight 12 t. Six hollow blocks of 390 x 190 x 190 mm per mould, or 32 to 36 standard bricks.
• QST8-15: pallet 980 x 860 x 22 mm, cycle 15 to 23 s, vibration force 95 kN, rated pressure 31.5 MPa, installed capacity 44.9 kW, weight 14 t. The 27 kN of extra vibration and the higher pressure are what the money buys here.
• QST1000: pallet 1100 x 880 x 25 mm, cycle 15 to 23 s, vibration force 105 kN, rated pressure 31.5 MPa, installed capacity 48.9 kW, a pallet 120 mm wider than the QST8-15.
• QST1200: pallet 1350 x 880 x 25 mm, cycle 15 to 25 s, vibration force 150 kN, rated pressure 31.5 MPa, installed capacity 57.6 kW, weight 17 t.
• QST1500: pallet 1350 x 1150 x 30 mm, cycle 15 to 23 s, vibration force 220 kN, rated pressure 31.5 MPa, installed capacity 69.1 kW, weight 20 t. The pallet grows in depth, not in width.
• QST1800: pallet 1400 x 1400 x 30 mm, cycle 15 to 25 s, vibration force 280 kN, rated pressure 31.5 MPa, installed capacity 104 kW, weight 34 t.

Where does a 400 x 200 x 200 mm block force you up a tier?

The mould face decides the cavity count, and the cavity count decides whether the machine can serve your market at all. Laid one way, a 400 x 200 mm block fits two across the 980 mm width of the QST6-15 pallet and three down its 680 mm depth. That is six cavities, before you allow for the partition walls between them. On the 1350 x 880 mm pallet of the QST1200 the same block fits three across and four down, which is twelve cavities from one press.

That step is arithmetic, not preference. A buyer who needs 400 x 200 x 200 mm blocks in volume cannot buy cavities the pallet does not have, and cannot reach them by running the machine faster. The QST1000 sits between the two: its 1100 mm width takes two blocks across, so eight cavities, and the next 250 mm of width is worth four more.

Why does the QST6-15 stop at 25 MPa?

Rated pressure is the cleanest tier marker in the range. Every model from the QST8-15 upward is rated at 31.5 MPa, and the QST6-15 at 25 MPa. That gap is not a valve setting on the same frame. Pressure multiplied by cylinder area gives the force that closes the mould, so frame, guide columns and hydraulic manifold are sized for the pressure they are sold at. Ask for 31.5 MPa on the smallest frame and you are asking for another machine.

Vibration force draws the same line. The QST6-15 delivers 68 kN, the QST8-15 95 kN, the QST1200 150 kN and the QST1800 280 kN. A 200 mm deep block with thin walls, or a dense kerb mix with little water, needs the higher figure to fill the mould and close its corners. Mix that is under-vibrated does not fail a test. It arrives chipped, with weight drifting across the pallet.

Can a shorter cycle make up for a smaller pallet?

No, and the published cycle times show why. The QST6-15 runs 15 to 23 s, the QST1200 runs 15 to 25 s, and the QST1800 runs 15 to 25 s. The cycle is set by the time the mix needs under vibration and pressure, not by frame size, so a bigger machine buys almost no seconds. What it buys is pieces per cycle. The QST6-15 makes six hollow blocks of 390 x 190 x 190 mm per mould, which is 8,640 to 11,520 in an 8 hour shift.

To pass that total on the same product you need more cavities in the press, and more cavities need a larger pallet, which is the next tier. Solid brick moves the argument to the other side. The QST6-15 carries 32 to 36 standard bricks per mould, which is 46,080 to 61,440 in 8 hours from a 12 t machine, so a plant selling solid units can stay on the small tier for years if pallet handling keeps up with it.

What each tier adds to the building, the power and the crane

Four structural items move with the ladder. Machine mass goes from 12 t to 34 t. Connected load goes from 34.4 kW to 104 kW before the stacker's 3.7 kW is counted. Footprint goes from 9,450 x 3,300 x 2,700 mm to 15,500 x 5,500 x 3,200 mm, and the pads under the feet have to take the dynamic load of a 280 kN vibration unit instead of a 68 kN one.

The hydraulic side scales with pressure and flow. A 31.5 MPa circuit on a heavy frame needs proportional valves, fine filtration and oil cooling that hold setpoint through a long shift, and those parts are imported on every model in this range. The 25 MPa circuit on the QST6-15 is simpler and cheaper to keep running, which matters on a single shift with two maintenance hands.

Two items usually miss the first budget. The crane: a mould set for a 1400 x 1400 mm pallet is a heavier lift than one for a 980 x 680 mm pallet, and it must clear the machine at every product change. The pallets: each one in circulation is steel, a repair and a square metre of curing floor, and the fleet you must own follows curing time and shift pattern.

Which numbers should you settle before you talk to a supplier?

Four inputs come from your plant, and they fix the tier before any quotation is written.

• Product dimensions, exactly, including the 400 x 200 x 200 mm unit if it is in the plan, because that number decides whether a 980 mm pallet is enough.
• Target output per 8 hour shift, product by product, as a figure for an ordinary day rather than a good one.
• Floor area for the machine, the pallet return and the curing racks, measured in metres before the layout is drawn.
• Lifting capacity available above the machine, in tonnes, for mould changes and for pulling a cylinder.