What is granulated polyethylene and where it is used?

In our article, we will talk about the peculiarities of granular polyethylene and its use. Let us dwell on the methods of its production and second-hand.

Peculiarities

Granulation is the finish stage of any technological stage of manufacturing polymers of ethylene. The overwhelming majority of all polyethylene are produced in the form of granules, that is, solid particles of certain dimensions.

Granulation technique helps to solve three tasks at once:

  • By bringing polymers – removal of residues of additives and chemical solvents, improvement of the mechanical characteristics of the material, degassing, as well as homogenization;
  • Giving the product of operational characteristics, necessary for the more rational use of polyethylene in the creation of plastic products;
  • creating materials with all sorts of additives capable Change the parameters of chemical stability, density, optical, as well as dielectric features of polyethylene.

What is granulated polyethylene and where it is used?

What is granulated polyethylene and where it is used?

What is granulated polyethylene and where it is used?

Polyethylene in the form of granules has significant advantages in comparison with scales and powdered.

  • Reduced volume (The density of polyethylene in powdered and granulated forms – respectively, 0.20-0.25 g / cube. cm and 0.5-0.6 g / cube. cm.). This allows you to significantly reduce the cost of warehousing, movement and packaging of the product.
  • High flowering – The use of granules does not create any problems during packaging, as well as transportation. Plastic granules do not adhere to the walls of the equipment, are not assembled in the nodes of transport mechanisms, do not electrify and do not form “dead zones”, causing instability of production processes and stopping technological equipment.
  • Minimizing freight loss – Polyethylene granules are pumped from tanks and boot mechanisms in full.
  • Low Low Steepery and Destruction. Minding to zero of dust formation in the production process and, as a result, improving working conditions.

What is granulated polyethylene and where it is used?

What is granulated polyethylene and where it is used?

What is granulated polyethylene and where it is used?

After drying and all the tests for compliance with product quality requirements, granulated polyethylene is packaged in bags of 25 kg and is subject to labeling. In accordance with the gtales, the granules from the party must have a single geometry and the amount in all directions ranging from 2-5 mm to be the same painted. In each batch, the presence of the granules of 5-8 mm and 1-2 mm in volume is not higher than 0.25% and 0.5%, respectively. Elements with pronounced defects (extensive inclusions and coarse surface due to polymer destruction) are subjected to rejection.

What is granulated polyethylene and where it is used?

What is granulated polyethylene and where it is used?

What is granulated polyethylene and where it is used?

Use of use

The scope of application of granular polyethylene covers more than 80% of all directions for the use of polyethylene in general. List the most common areas.

  • Production of films of different shapes and sizes. For this, the granules are loaded into a special bunker, heated and mixed. As a result of all manipulations, melted mass is obtained. From it, the extrusion method produces a film of a given thickness. Wide demand in industry Extruder with a round head. This method allows you to get a sleeve that can be used to further manufacture packages.
  • Production of Tara. With casting and other molding techniques, packaging materials such as pots, drawers, bottles and similar products are manufactured. In this case, granulated polyethylene is subjected to vacuum molding – this method is considered the most economically justified and practical.
  • Creating electrical insulation from polyethylenes of special cable brands. This method is similar to the first: the granules are melted and stirred to a homogeneous state. Then with the help of an extrusion method, an insulating material of the required form is performed.
  • Making foamed polyethylene (polyethylene foam). This is one of the most popular thermal insulation materials. It also uses the melt of granular polymers.
  • Production of elements of vehicles and other products requiring high strength. For this, polyethylene granules of special brands are subjected to molding with injection casting.

What is granulated polyethylene and where it is used?

What is granulated polyethylene and where it is used?

What is granulated polyethylene and where it is used?

Granulators and other equipment

The manufacture of granular polyethylene includes several stages.

Initially, raw materials are trained, that is, grinding. Depending on which the category includes the material being processed, several types of grinders are distinguished:

  • Samples for polymer films – optimal for polypropylene residues, acrylic, as well as nylon, PVC and other similar products in film form;
  • Mill – suitable for processing thin products from plastic, for example, PET bottles;
  • Crusher – need to grind massive products, such as balcony PVC and other overall designs.

Prepared raw materials are sink, for this use “wet crushers”,

Functionally they can combine the grinding of raw materials with its wash.

What is granulated polyethylene and where it is used?

What is granulated polyethylene and where it is used?

What is granulated polyethylene and where it is used?

Excessive moisture is removed with the help of drying units, as a rule, go to move:

  • centrifuges;
  • drying with heated air;
  • drying with compressed air;
  • press presses;
  • Water separators of auger type.

Crumpled, purified and dried plastic may contain polymers residues, since Initial sorting manual way does not provide 100% separation. To bring all the extra elements, specialized separating mechanisms are introduced into the structure of production lines for plastic processing.

What is granulated polyethylene and where it is used?

What is granulated polyethylene and where it is used?

What is granulated polyethylene and where it is used?

We describe the most common technologies for the separation of plastic crumb.

  • Flotation separation. The method is based on the difference in the parameters of wetting of shared materials. To perform separation, the prepared mixture enters a container with water enriched with oxygen. Particles of hydrophobic material are immediately covered with air bubbles and pop up. Hydrophilic materials accumulate at the bottom of the reservoir.
  • Electrostatic separation. This method is based on the difference in materials on electrical conductivity and predisposition to the accumulation of static surface electrification. In the course of processing, the particle of the material is subjected to intense stirring, as a result of friction, their surface is strongly electrified and thus acquires an electrical charge of a certain value. Separation allows you to divide materials with different characteristics in the electroopol.
  • Photometric separation. The basis of the operation of this mechanism is the separation of plastic on optical characteristics, that is, reflective ability and color.

Installations of this type are equipped with special emitters of electromagnetic signals, as well as high sensitivity sensors.

What is granulated polyethylene and where it is used?

What is granulated polyethylene and where it is used?

What is granulated polyethylene and where it is used?

The final stage in any process of manufacturing granulated plastic is directly granulation, for this, use polyethylene granulator. This equipment allows you to solve several tasks at once:

  • Posted by finished products;
  • Get composite materials with a variety of additives.

Polyethylene granulator acts similarly to extruder. Plastic blanks in it are stirred by means of special moving screws, and also pass through zones that are characterized by warm-up temperature. Under the action of elevated values ​​and from the friction arises during the mixing, the mass begins to melt, and fibers with specified cross section parameters are obtained at the output. To prevent them from bonding among themselves, they are irrigated by water. After they are cut by a special device, sticking to a certain length. It is these segments that got the name of the granules. For cooling, preheated granules are placed in water filled with water, from there they move to a centrifuge, where the mass is getting rid of the liquid component. Then the raw material enters the chamber for drying, and at the final stage, the dried material is transported to the packaging unit.

Polyethylene granulator allows you to turn the bulk polymer into durable and dense material. Granules at the exit have a single shape and size, a homogeneous structure.

At each stage of granulation, monitoring the quality of the material obtained.

What is granulated polyethylene and where it is used?

Process processing

In recent years, the number of production companies engaged in plastic processing has increased markedly. And the point here is not only in environmental issues, but also in the prospects of such a business. Polyethylene becomes an ideal base for creating garbage containers, all kinds of household tanks, plastic panels and other items.

Recycling films and packages practically does not cause special difficulties, since their structure does not change. But about the quality of the product obtained, it is impossible to say this – with each processing cycle, the transparency parameters and the color of the granulate significantly deteriorate.

Accordingly, the areas of further use are reduced.

What is granulated polyethylene and where it is used?

About how the processing of plastic granules at home, you can learn from the video below.

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