When we talk about hollow block making machine there are some different pictures in people’s head so we need to specify what we mean by hollow block making machine. It’s a machine that produces hollow blocks using pressure and vibration.
In modern construction practices, bricks are categorized according to materials used to form them and the method of production. Under this classification, there are five common types
Categorizing Bricks by Raw Materials:
- Burnt clay bricks
- Sand-lime bricks
- Concrete bricks(concrete hollow blocks)
- Fly ash clay bricks
- Firebricks
This article is about concrete Hollow block making machine so first concrete brick is defined, then we will pass to the Hollow block making machine.
First, let’s see what hollow blocks are.
Concrete blocks also called cinder blocks and cement blocks, come in a wide variety of shapes and sizes. They are made from a mixture of Portland cement, sand, gravel and water and produced in hollow block making machine. When the mixture is wet and paste-like it is cast into the form of the block. Concrete bricks are usually placed in facades, fences, and provide an excellent aesthetic presence. These bricks can be manufactured to provide different colors if color pigments are added during production. Note that Concrete bricks are not recommended to be used in below-ground applications.
The difference between concrete block and cinder block is that cinder block comprises fly ash as aggregate but the concrete block does not. there are also other additives that can be used in the hollow block making machine.
What is the standard size of a hollow block?
Normally the size of a standard hollow block is 20cm(width) * 40cm(length) * 20cm(height) this is a worldwide standard and the manufacturers produce their hollow blocks considering this standard. also, the size of the hollow block making machines is chosen with these blocks.
After describing the product we can now talk about the hollow block making machine, this machine has molds in the shape of hollow blocks and when the mortar is poured inside these molds, the machine uses vibration and hydraulic force to press the mortar into the molds. By this way, concrete hollow blocks are shaped.
the kind of mortar used in producing hollow concrete blocks:
the basic mixture of the mortar is 4-to-1 or 5-to-1 mixture. It means for every five parts of sand you need to add one part of cement and then you should add water until it you achieve the texture you want for your hollow block making machine. To produce a mixture which can be used in cement brick machine you generally want a thick, creamy mixture that will stick but also endure the blocks' weight.
When adding water, you need to be more careful because too much water will make it difficult for the sand particles to bond with cement in the concrete.
You should also be careful with the amount of cement you are using for your hollow block making machine. too much cement will cause cracks on the hollow concrete clocks when they are dried. you can sometimes go as low as three shovels of sand to one shovel of cement, anything beyond that does not provide you with a quality mortar that cures slowly and hardens the best.
Sand helps the hollow concrete blocks to withstand the weight of the wall. So make sure you use the right ratio in your mortar used in the hollow block making machine.
These days it is very important to make hollow blocks lighter in weight.
It can be achieved by mixing a lighter aggregate in the hollow block making machine, such as perlite, vermiculite or Styrofoam to reduce the overall weight.
Like always it has advantages and disadvantages. It is not as strong as the old mixture but it has better insulation than the traditional concrete.
This concrete is often used for countertops and rooftop decks, where a lighter weight is more important than a higher strength. it is also used for walls where insulation is more important than strength, such as offices
This machine is produced in two general forms as you see below
Mobile hollow block making machine is simpler easier to use and cheaper but most of the job like preparing concrete, transferring the mortar to the machine and operating the machine is done manually. The capacity of this machine is also low compared with the stationary hollow block making machine.
This machine doesn’t need pallets it lays the hollow concrete blocks on the floor, all you need to do is to prepare a suitable flooring for this machine. mobile hollow block making machine has wheels and it moves to the new place to lay more hollow blocks when it has finished the previous one.
You need about 1500m2 of land to operate Mobile hollow block making machine. suitable flooring should be provided as well. This machine also uses hydraulic power and vibration to form blocks but on a smaller scale compared with the stationary model.
Stationary hollow block making machine is a bigger and stronger machine and it also has different models, different automation levels and optional parts.
The smallest Stationary hollow block making machine produces 4.000 pieces of concrete hollow blocks or 12.000 pieces of paving blocks in on an eight-hour shift and the biggest Stationary hollow block making machine produces 24.000 pieces of concrete hollow blocks or 56.000 pieces of paving blocks in on an eight-hour shift.
How Stationary hollow block making machine works:
First, you need to prepare the mortar with the right ratio. usually, one unit of cement is added to four units of additives and sand. Then you need to add the right amount of water till the mortar becomes like a paste. This action is done in the mixer. Some Stationary hollow block making machines do the whole process of preparing the mortar automatically and some others do it semi-automatically. it depends on some facts like the budget or the capacity that the market requires.
Then the mortar is delivered to the hopper of the hollow block making machine by a conveyor belt. this action is also done automatically and in cement block machines with double hoppers.
there are two options for the conveyor belt:
- single conveyor belt with a changing position head to feed both hoppers
- two conveyor belts separately to feed both hoppers
the hollow block making machine will take care of the rest of the job, first the mortar is poured to machine called mortar cart and the mortar cart starts to fill the mold by going back and forth, when the mold is filled the vibration starts to vibrate the mortar so the tiny space between sands can be filled and when the hollow block making machine vibrates, the surface of the mortar shrinks. The mortar cart starts to fill the mold for the last time before the press starts its job.
Pressing takes place on the surface of the pallets with the bottom and top moulds. After pressing takes action both molds go up and the pallet is automatically delivered to the output of the hollow block making machine. Pallets are then delivered to the drying section or curing chamber. Delivering the pallets is optional it can be ordered as manual or automatic. It depends on your budget and production capacity.
pallet size differs according to the size of the machine and as the machine gets bigger the pallet also needs to be bigger and thicker as well. the quality of the pallet is so important because of the maintenance. the higher quality you use the longer you can use them and save money changing them.
there are alsodifferent choices for your pallets:
- plastic pallets
- wooden pallets
- metal pallets
Automatic pallet gathering system in the hollow block making machine is done by a forklift or a finger car system.
It is faster and it requires less space allocated to the drying part. It is because the pallets are stored in five levels then carried to be dried but in the manual hollow block making machine, they are delivered and stored one by one.
For hollow block plant, you need a maximum of 8 and a minimum of 2 workers. It only depends on your automation level. If you live in a country that labor cost and the land are cheap, the semi-automatic machine suits you the best. For higher productions, you are recommended to buy automatic hollow block making machine because of the smaller land needed and to handle higher capacities robots show better performance.
Pallet size differs in accordance with the production capacity of the hollow block making machine. For example, PRS-400 requires 100cm*50cm with 4cm thickness and PRS-800 needs 95cm * 110cm pallets with 4cm thickness.
This machine can also produce other concrete products by just changing the molds. There are almost 600 different molds available for this machine.
The products that hollow block making machine can produce are listed below
- Hollow concrete blocks
- Paving blocks
- Asmolen
- Curbstone
- Roof gutter
- Lego blocks
- Lawn stone
- Tile
As the conclusion, you need to have in mind to buy a high-quality machine for long term use if you are considering establishing a hollow block producing plant.
Other advantages of the machine can be low power consumption, a faster cycle of production, quality of the equipment used on the machine, after sales service, warranty of the machine and longer periods between maintenance.
