In the world of tubes for the transport of liquids, with or without pressure, the market is crowded with many raw materials that compete for market shares and clash with no holds barred, showing the advantages in the duration of the materials produced, in the ease of installation, in the weldability of the elements or in the correct accessories for the connection, in the economy, in the sustainability and in compliance with regulations.
If we examine the pressureless pipes sector we see that in the past the use of cement and metal, in some situations, was the consequence of a step forward in the industrialization of transport products and the drainage of the water with respect to the pipes that were made of baked clay.
The spread of concrete pipes, which seemed eternal, collided with the birth of plastic polymers which represented a technical and economic improvement compared to canalization systems traditional.
Civil construction has begun to use PVC in household drains making the installation of liquid transport networks extremely simple and economical, and then extended to many other applications such as the irrigation, electrical and gardening sectors.
The PVC pipe has assumed a role of absolute importance also for its intrinsic qualities such as:
• The duration of more than 100 years based on pressure and aging tests
• Good resistance to chemical and oxidative corrosion
• The reduction of service disruptions
• Water repellency
• The resistance to internal and external pressure
• The resistance to abrasion
For many years virgin raw materials have been used for the production of all types of rigid and flexible pipes, until the sector began to collect waste and to reuse them according to the rules of the circular economy.
Today the production of PVC pipes, except for particular specifications, is largely made through the processing of recycled materials.
How is waste recycling done?
In the first place, the scraps may derive from the collection of used tubes or from the coupling sleeves but, according to the recipes required by the market, the raw material can be mixed to other PVC that comes from different supply chains.
For example in the rigid PVC sector, window profiles can dynamically enrich the recipe, thus the waste of the shutters or credit cards or profiles for the electricity sector, they attribute improving technical characteristics based on the percentage used.
In the Soft PVC sector, the sheaths of electric cable covers, gaskets, water containment sheaths and industrial processing waste make up the menu to make the right recipes.
However, these mixes must be precisely checked in the laboratory before the production of the recycled granule, in order to exactly match the technical characteristics required by the customer.
But to reach the verification in the laboratory you have to go through the recycling phases of the scraps that normally include:
• The selection of elements by type of application and by color
• Grinding of waste and deferization
• The micronization if required
• Granulation of the ground with the addition of the correct additives
What are the applications that can be realized through the use of Recycled PVC for pipes?
There are many sectors that the use of recycled raw material allows to reach, guaranteeing the customer the production of reliable, economical and long-lasting elements. Let's see some:
• Rigid pipes suitable for the discharge of non-pressurized water in civil construction with variable thicknesses and diameters
• Non-pressure field irrigation pipes with different sizes and diameters based on length and flow rate
• Tubular elements in the horticultural sector suitable for plant support
• Small flexible tubes suitable for tying plants
• Small diameter flexible corrugated pipes suitable for containing electrical cables
• Support tubes, called cores, of rolls of industrial materials such as plastic films, fabrics or other materials that are wound on reels.
• Solid bars suitable for industrial production for turning
• Flexible irrigation hoses for the garden
• Corrugated or smooth tubes to protect telecommunication cables
• Soil drainage pipes
There are obviously many other applications of pipes made with recycled PVC, as there are many other applications of recycled granule in the production of commonly used products of which we will have the opportunity to talk about later.
Automatic translation. We apologize for any inaccuracies. Original article in Italian.