What is a PVC geomembrane sheet

Polyvinyl chloride or PVC is one of the thermoplastic polymers that are produced in hard and flexible types. PVC is considered one of the most valuable and widely used products in the petrochemical industry, and its uses are unlimited. PVC is widely used in the construction industry due to its reasonable price and easy use. Today, PVC has become a suitable alternative to traditional materials such as wood, cement and clay in construction.

PVC geomembrane sheet is a product of the geosynthetics category, which refers to soft and flexible plastic sheets with very high tensile strength.
PVC geomembrane sheets are produced in rolls with a width of 1.6 meters and a length of 15 meters in thicknesses of 1 to 4 mm.
These sheets are completely waterproof and water and moisture do not pass through its surface.

PVC Flexible sheets of polyvinyl chloride, commonly called PVC, have been used for geomembrane applications for over 60 years. PVC geomembrane layers are a combination of PVC with softening additives. These softeners make PVC soft and flexible.

PVC geomembrane is an elastic layer that can easily conform to irregular shapes and different settlements. PVC is one of the most widely used plastics available with a special formulation that can withstand oil, low temperature, and UV rays.

The standard formulation of PVC geomembrane materials is designed to be suitable for long life and low production cost. Acceptable PVC materials must comply with the requirements of ASTM D 7176 Specification for Polyvinyl Chloride (PVC) Geomembranes.

PVC geomembrane

PVC geomembrane formulation

PVC is a rigid plastic that has little thermal stability and due to heating, its surface color tends to be metallic. For various reasons, it is necessary to combine the mixtures of this plastic with other additives in order to obtain a useful collection.
By accepting such an attitude, it is possible to produce a wide range of products such as hard pipes to soft foams.

In examining the formulation of PVC compared to other thermoplastics, we find that the formulation of PVC consists of more additives and is more similar to the formulation of rubber.
Common additives in PVC formulation
1- Stabilizer
2- Lubricant
3-     filler
4- Softener
5- Expander
6- Process assistance
7- Impact improver
8- Pigment

The multiplicity of additives participating in the mixture of this polymer is due to compensating the weaknesses of PVC and the possibility of using this material to produce different products; Including:

1- Compensating for the weaknesses of PVC geomembrane in order to protect it against all kinds of damage during mixing and blending, melting, extruding and turning into granules and finally turning the granules into the final form.

2- Changing the color of the plastic and getting ready to accept the final process.

3- The strange talent of PVC geomembranes

In turning into a wide range of products with different characteristics, which makes it necessary to push the properties of plastic with the help of suitable additives.

Choosing the base polymer:

Choosing the right grade of PVC polymer is of special importance to Khordar. In Iran, PVC is produced in two grades, E and S. Another point is to ensure that the selected grade is suitable for the process by which the plastic is intended to be formed. One of the parameters that helps with this problem is knowing its K-VALUE value. This parameter shows the relationship between viscosity and molecular weight.

For example, PVC grade S-70 shows:

First, this polymer is obtained by suspension method
Secondly, its K-VALUE is equal to 70, which indicates the high molecular mass of this polymer
As a result, this grade is suitable for extrusion.

Meanwhile, PVC S-50 grade is suitable for injection purposes due to its low molecular mass.
In terms of volume and price, the largest amount of additives in the PVC formulation is related to softeners and fillers, and fillers and anti-UV have the lowest amount in the formulation.

PLASTICIZER softener
Plasticizers are small molecular substances with a high boiling point, whose main role is to reduce the glass transition temperature, as a result of softening plastics, by which some fragile plastics can be softened and flexible.

The presence of a plasticizer or a rubber substance in the continuous phase of a plastic reduces the elastic modulus and increases the toughness. The second role of plasticizers is the ease of the molding process, because by reducing the viscosity of the melt, it reduces the temperature and pressure required for molding it. provide

The use of a softener is for the following reasons:

Reducing the process temperature to less than the destruction temperature

To simplify the process and application

Improving the properties of the final product

A mixture of 30 parts of DOP with 70 parts of it lowers the glass transition temperature to 10 degrees, while unhardened and unsoftened polyca tubing has a glass transition temperature of about 90 degrees.

In addition to the main task, the added softeners can change the flammability, odor, biodegradability and reduce production costs.

Types of soft pulp based on the amount of dissolution:

If the softener is compatible with PVC, the ratio of softener with polymer is 1:1.

If the softener has a ratio of 1:3 with PVC, it means that it is a secondary softener.

If the softener has a ratio of 1:20 with PVC, it is an expander.

Common types of softeners:

DOP: It is used for general PVC purposes, such as bathroom curtains, tablecloths, slippers and car dashboards

.

DOS: It is used for products that are used at low temperatures.

TCP: It has flame retardant properties but it is toxic.

Applications of  PVC geomembrane sheet:

PVC geomembrane is a product that mainly has civil applications such as tunnel sealing, underpass sealing, roof garden sealing, etc.

tunneling

Dams

Roof garden and green space

Water transfer channels

Docks and ports

Pools and storage tanks for water and materials

roof top

rain walls

Construction pit and elevator pit

Containers and prefabricated houses

Home pools

These membranes are used in subway tunnels, railways and roads, pits and foundations of buildings, pools and lakes, canals, reservoirs, landfills, covers and valves or similar facilities where the membrane is inaccessible after construction. has it.

Advantages of PVC geomembrane sheet (PVC sheet) Arian Khak

Resistant to tearing and puncture

Very high reliability and ensuring that water and moisture do not pass

A life of over 50 years and maintaining the flexibility of the sheet during this period

High flexibility and no need for infrastructure and the ability to insulate all geometric surfaces

Easy and quick installation without the use of glue and the ability to weld with an industrial hair dryer

Simple repairability by using the super weldability of the sheet pieces on the holed or torn area

Economical and competitive in terms of economic cost

⇐ In moisture insulation applications where the membrane is exposed to sunlight, it is recommended to use polyethylene geomembrane sheets.
⇐ In moisture insulation applications that are in direct contact with drinking water or agricultural water, polyethylene geomembrane sheets are recommended.

The price of PVC geomembrane sheet

Arian Khak Iranian Company is a representative for the sale of all types of geomembrane sheets, HDPE and PVC, please inquire about the purchase price and get the technical specifications. It is worth mentioning that the sales of all types of geomembrane sheets available in Arian Khak Iranian Company are over 1000 square meters. The price inquiry will also be based on this size.