POLYMER CROSSLINKING WITH IONIZING RADIATION

Nowadays, plastic production continues to grow daily, driven by its diverse applications. Among these are pipes, sleeves, heat shrink tubes, couplings, and cables, which require exceptional durability. The technology of ionizing radiation plays a crucial role in enhancing their robustness, ensuring they meet the demands of modern use.

BEAMCOMPLEX EQUIPMENT FOR POLYMER CROSSLINKING
Beamcomplex manufactures compact size complexes for electron beam crosslinking of finished polymer products. Complexes may be placed directly at polymer plants.


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IONIZING RADIATION TECHNOLOGY FOR POLYMER CROSSLINKING

Crosslinking of polyethylene is the process of formation of transverse and longitudinal bonds between long polymer molecules under the influence of intense electron bombardment. In the case of physical cross-linking, the polyethylene pipe is irradiated with hard
X-rays. This process is very productive; its speed is 80 m / min. Polyethylene obtained as a result of physical cross-linking is marked as PEX-C.
Under the influence of accelerated electrons and secondary gamma radiation, chemical bonds break down, facilitates formation of free radicals which, in turn, recombine creating cross-links between macromolecules.

Radiation modules with electron accelerator and built-in product feed system

The complex is equipped with various systems for supplying products to the irradiation zone. Depending on the supply systems, the complex can produce the following products:
1. Cable
2. Heat shrink sleeves
3. Shrink wrap
4. Heat resistant pipes for heating and hot water
5. Polyethylene foam sheets
6. Film for greenhouses, resistant to ultraviolet
7. Heavy-duty polymer products
8. Other materials

CROSSLINKING OF PIPES AND SLEEVES

Beamcomplex modules are designed for radiation cross-linking of polyethylene pipes. The module has unique equipment that allows to cross-link polymers simultaneously along the whole circumference of a pipe. The uniformity of the received dose and, consequently, the uniformity of the cross-linked material are guaranteed by the technology employed.
According to this method, the production of pipes is divided into two separate stages: the production of pipes on conventional pipe lines and the subsequent processing by high energies from electron accelerators.
The pipe diameter can be up to 400 mm and the thickness of the wall can reach up to 25 mm.
IONIZING RADIATION TECHNOLOGY FOR PIPES AND SLEEVES CROSSLINKING

In order to obtain uniform cross-linking of the pipe along both the thickness and perimeter, the accelerator must have special outlet windows for electron beams. For pipes with a wall thickness of 10 m accelerators with an energy of 3 MeV are required, for 5 mm thickness it is advisable to use accelerators with the energy of 5 MeV and electron beam power of 50-100 kW.

BENEFITS OF ELECTRON BEAM PROCESSED PIPES AND SLEEVES

Metal-plastic pipes become resistant to the effects of various chemical solutions.
After bending the metal-plastic pipes retain the initial shape, which facilitates and accelerates the assembly of fittings and further work with the pipe.
It allows employing pipes for the installation in hot water systems.
Due to the aluminum layer, the coefficient of linear expansion of the metal-plastic pipes is 0.025 mm / (mChK).
The inner layer of metal-plastic pipes is made of high-strength cross-linked polyethylene. This ensures virtually no deterioration even at high flow rates. High resistance allows carrying out water supply pipelines with high internal pressure. Also, metal-plastic pipes are resistant to multiple, sharp pressure and temperature drops.
The special design of the fittings allows terminate electrical contact and put a barrier for premature destruction of the system due to the impact of electric fields.
Metal-plastic pipes have no contra-indications for use in any type of drinking water pipelines. Due to the fact that the outer layer of the pipe is also cross-linked polyethylene or polypropylene, there is no need to protect the pipe the outside against the corrosion, and there is no need to paint it.

CROSSLINKING OF HEAT SHRINK TUBES AND COUPLINGS



The use of heat shrinkage is based on the shape memory effect. It is achieved by radiation exposure. For instance, if the polymer is placed in a powerful beam of electrons there is a connection of neighbouring macromolecules with each other at the molecular level.
This technology is called crosslinking. After this process the polymer becomes more elastic, and the product, when heated, acquires its original shape and initial dimensions.

BENEFITS OF ELECTRON BEAM PROCESSED HEAT SHRINK TUBES AND COUPLINGS

Isolation from the corrosive environment of metal and water pipes.
Improvement of the ergonomics of the tool handles and sports equipment, by using ribbed tubes.
Longitudinal sealing of bundles of cable. In addition to external insulation, due to a special tape, the space between the cores is completely filled and isolated.
Advanced chemical qualities that prevent imflammation of cable

CROSSLINKING OF CABLE



Crosslinked polyethylene (PEX) is one of the most used materials for insulation manufacturing for power cable and signal cable.
Its unique strength properties, water resistance, heat resistance, resistance to mechanical stress, enable us to create materials having higher reliability and durability comparing to traditional materials.
IONIZING RADIATION TECHNOLOGY FOR CABLE CROSSLINKING

The module is designed for radiation crosslinking of polyethylene cable. The module has inbuilt equipment that allows cross-linking of polymers simultaneously over the entire circumference. Thanks to the technology used, the uniformity of the dose obtained is guaranteed and, as a result, the uniformity of the crosslinked material.

BENEFITS OF IONIZING RADIATION TECHNOLOGY

High reliability.
Lower costs on reconstruction and maintenance of cable lines.
Low dielectric losses (dielectric loss factor 0.001 instead of 0.008).
Greater throughput due to an increase in the permissible heating temperature of the conductors.
Environment friendly cable laying and maintenance (absence of lead, oil, bitumen).

BENEFITS OF ELECTRON BEAM PROCESSED CABLES

Minimum bend radius during cable laying (at least15 Dn), lower weight, which makes it easier to lay on difficult routes.
Ultraviolet radiation resistance.
Increased resistance to heat pressure.
Low moisture absorption.
Higher flame resistance.
Better resistance to oil and chemicals.
Better resistance to hydrolysis.
Higher flexural strength (alternate bending strength).
Better abrasion properties.
Improved resistance to stress cracking.