Plastic Recycling Machines: Regeneration

Plastic Recycling Machines: Regeneration

Washing and crushing of plastic objects is the main part of creating recycled plastic that is suitable for further use. Still, it is not the end. Many production processes have higher requirements to the recycled plastic. To create again the original virgin plastic material further processing is necessary for which we have a few solutions available.

Agglomerator


This machine can be an economical solution for creating hard plastic raw material out of plastic foil and film. The rotating blades of the agglomerator squeeze the film scraps together. During this process, heat is created and the thin film melts together to small chunks that are better suitable to use in further production processes than the light and fugitive film scraps.

Packing Silo


After all processes are finished and the desired final recycled product is produced, the product has to be packed. Mostly this is done in big-bags. With the packing silo this packing process is convenient and when the bag is full, the bag can be changed by closing the silo for a while and changing the bag. Like this the recycling process doesn’t have to be interrupted while changing the bag.

Granulation Extruder


The most professional way of regenerating virgin material is a granulation extruder. The extruder melts the plastic completely and squeezes it through a mold with defined holes. After cooling down the plastic strings can be cut into pellets with defined dimensions looking the same as the original virgin pellets. Granulation extruders are available with water and air cutters.

Plastic Recycling Machines: Drying

Plastic Recycling Machines: Drying

Using wet plastic flakes for further processing can cause many troubles. In most processes, the water content should be very low in order to be able to do anything at all with the plastic. Furthermore, the water content causes the plastic to be heavier and can increase transport costs. For this problem, we have different solutions available to dry the wet plastic effectively.

Vertical Centrifuge


Based on the high-speed rotating principle, the vertical centrifuge works in a similar way as the horizontal centrifuge. Except the different position of the drum as the name already reveals, the vertical centrifuge works with higher speeds and a drum that is narrower. At the end, the result is dryer than with the horizontal centrifuge but disadvantage is that the vertical centrifuge is only suitable for hard plastics.

Pipeline Dryer


When the material is already relatively dry, for example after it went through a centrifuge, the last part of the water can be removed with a pipeline dryer. A hot airflow blows the plastic flakes and scraps round and round through a pipeline while absorbing the water. This simple method is very effective and increases the quality of the recycled plastic eminently.

Horizontal Centrifuge


The horizontal centrifuge is a basic solution to dry any recycled plastic flakes. With its big drum, it is suitable for hard and soft plastics and for plastic film material. In a similar way as a washing machine, the perforated drum rotates with high speed and spins out the water while the flakes that are bigger than the holes in the wall of the drum remain inside the drum and come out much dryer.

Plastic Recycling Machines: Washing

Plastic Recycling Machines: Washing

When thinking about waste most people will think about the dirty content of their waste bin at home or of the big waste dump areas and their unendurable smell. Indeed, no matter where the waste is coming from, in most cases it is dirty and has to be cleaned before it can be reused in any way. We have different machines available for different purposes to wash the waste effectively and efficiently.

Label Remover


It can be a hard job to remove all labels from plastic bottles and containers. At the same time these labels are the number one contaminant in the recycled material and can impair the quality significantly. The label remover is able to remove most of the labels already before cutting the bottles or containers into small pieces. The rotating drum of the label remover causes friction that rips off the labels from the materials.

Pre-Washing Drum


Waste can be very dirty. Often it is so dirty that dust and dirt make even appropriate sorting impossible. The Pre-washing drum washes off dirt, dust and mud before any other process. In a perforated drum, the waste is rolled over while cleaned by water. The dirt and dust can leave the drum through the holes in the drum wall while the waste gets out at the much cleaner.

Sink-Float Tank


With not only a wash function but also a sorting function, the sink-float tank is indispensable in the recycling of plastic waste. The flakes are paddling in the tank slowly pushed forward by the paddle shafts. While swimming in the water the flakes are cleaned and at the same time, lighter plastics that float on the surface are separated from the heavier plastics that sink to the bottom.

Friction Washer


In a similar way as the label remover, the friction washer works with a friction drum as well. Just in case of the friction washer the rotation speed is much higher and it is suitable only for plastic that is already cut into small plastic flakes. Besides labels, remaining dirt is rubbed away from the recycled plastic flakes as well. Depending on the purpose rotation speed, length and inclination angle of the friction washer can vary.

Hot Washer


When talking about household waste like PET bottles, the amount of dirt can be high. To remove effectively all dirt from the plastic flakes, it is essential to not only wash them in cold water but also wash them with hot water and preferably with some cleaning additives added to the water. Similar like a dishwasher, the hot washer has rotating paddles that create a whirlpool and effectively washes off the dirt from the PET flakes.

Extrusion Lines: How do They Work?

Extrusion Lines: How do They Work?

Extrusion lines are used for a continuous production of plastic or wood plastic composite (WPC) pellets, pipes, profiles or sheets. Thickness and diameter can vary depending on the specific needs of a company.

The process of extrusion starts when plastic flakes or powder are fed into a hopper. Different types of plastics can be used as a raw material, for example PE, PP, PS, PET, ABS, WPC and PVC.

Immediately after going into the hopper, the raw material comes in contact with a rotating screw. The screw forces the material through a barrel in which temperature is gradually rising. Heating zones are necessary to prevent overheating of the polymer and its degradation. The heat is generated by an electric motor, as well as by friction and pressure inside the barrel. In some cases the electric motor can be even shut off, as the temperature generated by friction and pressure is high enough to melt the plastic flakes. Extruders also have cooling fans that keep the temperature under control. However, it is important to always keep an eye on the temperature control meter. The machine operator should be present to make sure the extruder functions within established parameters.

At the end of the barrel one can find a screen pack, which is designed to remove any contaminants, and a breaker plate. The latter represents a metal puck with holes. It reinforces the screen pack.
When melted plastic goes through the screen pack and the breaker plate, it reaches a die. The die is made from steel and gives the plastic its final form. In order to ensure a smooth process, the flow of the molten plastic should be even.

The next step is cooling. It can be done with water or air depending on the properties of the profile. Then the final products can be cut and packaged. Another option is to connect the extruder to a thermoforming or a blow molding line. In this case, you can continue the process and produce various plastic consumer goods (e.g. containers, cups, bags, bottles, plates, cutlery etc.)

Single- and Twin-Screw Extruders

Single screw extruder is a basic machine for plastic processing. It works best when there is one type of a polymer involved.

Twin-screw extruders have higher production rate. They are also much more suited for mixing polymeric materials. There are several types of twin-screw extruders: co-rotating intermeshing, counter rotating intermeshing and non-intermeshing. The first type is the most commonly used one.

Energy and maintenance costs are comparable for single- and twin-screw extruders. However, the latter have larger functionality and cost more. Twin-screw extruders are more flexible, productive and offer higher output quality. With them it is easier to control the temperature of materials, and their transportation is very stable. As a result, little residual is left, and you can change production material without interrupting the machine for cleaning.

Extruder Maintenance

Extrusion lines can serve a long time with a high productivity and a minimum downtime if the right maintenance is performed. Regular inspections of the equipment is a must. They will help you to prevent any problems and schedule downtime if necessary, so you won’t find yourself in a situation when the line has to be stopped in the middle of the process.

Regular inspections mean that extrusion lines should be checked on a weekly, quarterly and annual basis. Weekly checks are performed while the extrusion line is running and imply verification of pressure and temperature indications, oil flow, condition of plugs and guards. Quarterly and annual checks are performed both while the extruder is running and while the scheduled downtime is taking place. Usually the machine operator visually inspects the lines, records noise levels, searches for oil leaks, changes filters and other parts if needed. A detailed description of the maintenance recommendations and requirements can be found in the extruder manuals.

 

BOMAC Industries strives to provide innovative solutions for recycling plastics and offers a wide range of plastic recycling lines and machines for most common plastics and rubber, for example PET bottles, plastic film, car tires, PVC profiles etc.

Plastic Recycling Machines: Crusher

Plastic Recycling Machines: Crusher

PET bottles, HDPE packaging and other types of plastic waste can be transformed into valuable resources trough a recycling process. Shredding or crushing is an important part of it. In this article we are going to focus on crushers (also referred to as granulators) and see how they work, what are their advantages and disadvantages.

Basically, crushers perform the same function as shredders. They crumble plastic waste into small particles. They also can work with a variety of other types of waste: aluminium, paper and carton, copper cables, wood, fabric, foam, rubber, and electric devices. However, shredders and crushers operate in a different way and perform better in different conditions.

Crushers are more compact than shredder machines. Some of them are portable which means that you can crush plastic waste virtually anywhere, pack the particles densely and transport them to your facility. Though in the portable crushers motor power is usually lower than in the stationary machines. For example, BOMAC Industries offers portable crushers with a motor power ranging from 2.2 kW to 11 kW. In universal crushers the motor power is up to 4 times higher (reaching 45 kW), and in industrial – up to 15 times higher (reaching 110 kW and 160 kW respectively). You can’t have both high productivity and portability.

Crushers (or granulators) also differ by type of input material they can crumble. Portable and universal crushers can easily work with smaller items like PET bottles, HDPE bottles (milk, detergent and shampoo containers), film or CD\DVD cases. Industrial and heavy-duty crushers are suitable both for small and bulky objects. Besides, they are designed to handle high capacities and operate continuously.

The feeding process is different for crushers and shredders. Due to a hydraulic push block, the shredder needs little supervision and can process dense, heavy scrap even if it is just dumped into the hopper. However, if you try to dump the same kind of plastic waste into a crusher, you can seriously damage it. The scrap should be fed ‘portionwise’ in order to avoid rotor’s jam. A smooth operation of the crusher is achieved through the usage of conveyors or other feeding mechanisms. Angle of feeding is also important.

Cutting mechanism of a crusher consists of a rotor with mounted durable hard-metal knives, and stationary knives mounted within a chamber.

As for the cutting mechanism, it is similar for all types of crushers. They have:

  • a rotor with mounted durable hard-metal knives which rotates with a high speed
  • stationary knives mounted within a chamber.

Together they grind the plastic waste into small particles. You decide what is the desired size. The manufacturer produces a screen with holes of the respective diameter and embeds the screen into your crusher. The plastic waste, which you load into the crusher, goes though the cutting process as many times as needed before it becomes small enough to fall through the holes. This way you can be sure that you will always get a uniform size of the particles.

Crushers have electric motors. Energy costs can eat into your budget if you don’t pay attention to energy-efficiency levels. It is also the case when buying second-hand crushers may be financially attractive in a short-term, but less so in a long run. BOMAC Industries provides all crushers with energy-efficient cutting and constantly works on improving it in order to minimize operational costs of your business. In order to save on energy consumption also make sure that the crushers you buy have a motor of the correct size, i.e. the one that matches your specific needs.

Talking of maintenance of the crushers, it is relatively easy. You want to make sure that the knives aren’t getting blunt and the belt – loose or warn. If they do, not only will it reduce productivity of your machine, but also increase energy consumption. You also want to have an easy access to the cutting chamber in order to clean it and change the knives easily and with a minimum downtime.

With the right recycling machines you can crush a large variety of soft and hard plastic. If you have any questions, do not hesitate to contact BOMAC Industries. Our specialists in recycling will be glad to help you!

 

BOMAC Industries strives to provide innovative solutions for recycling plastics and offers a wide range of plastic recycling lines and machines for most common plastics and rubber, for example PET bottles, plastic film, car tires, PVC profiles etc.

Recycling Technologies of the Future

Recycling Technologies of the Future

Recycling technologies develop very fast, especially when it comes to recycling plastics. About a half of all plastic garbage cannot be recycled today because of its initial design and composition. As a result, millions of tons of garbage end up in landfills, rivers and oceans, and represent an enormous ecological problem. For instance, plastic waste kills seabirds and turtles, and releases harmful chemicals into the soil. Many companies like BOMAC Industries try to solve this problem. They come up with innovative ideas, design new recycling machines, develop new technologies, and thus open a new market for recycling with billions of dollars of possible revenue.

Turning polystyrene into oil

Polystyrene is a very common material. It is used for producing test tubes, razors, yogurt containers, and food packaging (think of the boxes in which you get food in the fast food restaurants) etc. Polystyrene foams are also widely used in construction as they are good thermal insulators. However, available technologies for recycling polystyrene are not economically feasible. An American start-up came up with a new technology that can convert polystyrene back to crude oil. The company did it successfully before the oil crises. The main challenge for this technology is that it needs large amounts of the material, and some countries aim to minimize usage of polystyrene.

Undisclosed opportunities of recycling polyethylene

Polyethylene is everywhere. It’s the most popular type of plastic. It is used for producing bottles, plastic bags etc. Most of polyethylene trash ends up in landfills like polystyrene for the same reason – it is too expensive to recycle it. Some of the main issues are collecting small plastic items and then separating them from other types of garbage or unwanted chemical additives. Current technology doesn’t allow to efficiently sort items that are smaller than 60mm.

Another important issue is that it is hard to get rid of colour. Yes, all the logos and product information that you usually see on plastic packaging is one of the main reasons why your plastic bag goes to ocean instead of recycling loops. The Ellen Macarthur Foundation report says that colouring plastics reduces the value of the recycled materials up to US $300 per ton. Some companies already refuse from colouring bottles in order to use them in next production cycles.

These are just a few examples of what issues the recycling industry faces and how technology can resolve them. No doubt, if technologies ever allow us to recycle 100% of plastic waste, they will become the technologies of the future.

BOMAC Industries strives to offer innovative solutions for recycling plastics and offers a wide range of plastic recycling lines and machines for most common plastics and rubber, for example PET bottles, plastic film, car tires, PVC profiles etc.