Suggestions on Selecting Geomembrane Materials
Material production technology
In terms of the production process of HDPE geomembrane imported from Europe and the United States, there are currently two production methods at home and abroad, including the blown film process and the flat extrusion process. At present, 85% of the existing HDPE geomembrane production lines imported from Europe and the United States and most of the new geomembrane production lines are blown film production lines. This is because compared to the extrusion process, the blown film process has the following features: Point advantages:
(1) For smooth geomembrane:
The two different production processes have different requirements for imported HDPE textured geomembrane for sale resin raw materials from Europe and the United States. The melt index of the resin material for the extrusion process is generally 0.11 g / 10min (test method ASTM D1238 Cond.E), and the melt index of the resin material for the blown film process is generally 1.0 g / 10min (test method ASTM D1238 Cond.E).
This is because the blown film process has higher requirements for resin raw materials and a higher melting index of raw materials. The HDPE geomembrane products imported from Europe and the United States produced in this way have better tensile elongation properties. In other words, the HDPE geomembrane imported from Europe and the United States with better tensile and ductile properties can better bear external load (landfill waste, heavy machinery, etc.).
(2) For rough surface geomembrane:
The film blowing process is a one-step forming method. The rough surface of the geomembrane is formed by adding nitrogen blowing during production. The finished product is a whole, and the rough spots are not easy to peel off. The flat extrusion process is a two-step forming method. After the production of the smooth high quality textured geomembrane is completed, the rough surface is formed on the smooth surface by spraying rough particles. The finished product is not an integral material, and the rough spots are easy to peel off, which greatly increases the possibility of landslide accidents, The consequences could be disastrous.
In addition, more importantly, according to the different terrain and terrain requirements of different landfill projects, the blown film process can adjust the pressure and direction of nitrogen blowing to produce HDPE rough surface geomembrane products imported from Europe and the United States with a higher height. Product friction is greater, slope stability is better, the safety factor is higher, so it can better meet engineering requirements.
For example, in the standard specifications, the height of the rough surface of the HDPE geomembrane imported from Europe and the United States is required to be 0.25mm. The blown film process can produce 0.5mm (commonly used) and 0.75mm (commonly used) roughened geomembrane products. However, due to the defects of the process itself, the flat extrusion process makes the products produced have great limitations, and the height of the rough surface geomembrane is uncontrollable. In addition, the rough spots of the HDPE rough surface geomembrane imported from Europe and the United States produced by the flat extrusion process and the membrane itself are not integrated, and the rough spots are easy to peel off. From the perspective of past experience and engineering quality assurance, it is recommended to use a blown film process (such as Soma textured geomembrane factory price) is not recommended to use HDPE geomembrane products imported from Europe and the United States using the flat extrusion process.
From the past many construction experiences, it is generally recommended to use a wide range of imported HDPE geomembrane materials from Europe and the United States for landfills and similar projects with large laying areas.
The main reason is that the wider the width of HDPE geomembrane imported from Europe and the United States, the fewer welds will be generated during the actual welding construction, and the weld is a high incidence location of high quality LDPE geomembrane leakage. The less likely it is to leak, the better the barrier effect.
In addition, the increase in width and the reduction in welds also bring two other favorable conditions to the project. One is to reduce the overlap loss during welding construction. Comparing the 8-meter-wide HDPE geomembrane imported from Europe and the United States with the 7-meter-wide geomembrane, the theoretical loss rate can be reduced by 14%, which is beneficial to the cost of the project. reduce. Another point is that it can reduce the construction cycle of the project and the corresponding labor costs. The following two figures are data statistics and comparisons conducted by Soma Canada based on actual project construction.