Production line for HDPE dimpled sheet
The extrusion line for dimpled sheet is undoubtedly one of the most technically complex applications in the field of thermoplastic extrusion systems, especially when the goal is to combine high performance of the finished product with the use of low-cost raw material derived from post-consumer recycling. BG Plast has developed specific solutions to meet this need, addressing the typical challenges of this process in a structured manner.
Those involved in the production of dimpled HDPE membranes know how much of an economic competitive advantage the use of washed and ground material represents. At the same time, it is well known that this type of raw material contains significant percentages of oils, fats, soaps and contaminants, elements that complicate the extrusion process and jeopardize the quality of the final product. For this reason, our dimpled sheet line is the result of an in-depth study of the entire production cycle, from feeding to forming.
Applications of dimpled sheets
Dimpled sheets are widely used in the civil engineering sector, where they serve as water drainage systems, provide protection and insulation for exterior walls, and act as separation layers between construction elements. The unique dimpled geometry creates air gaps and drainage channels, improving moisture management and extending the lifespan of structures.
Another application involves elastic under-tile membranes (uncoupling mats), used to absorb movement and stress between the substrate and the tile covering. In all these applications, uniform thickness, surface integrity and compressive strength of the membrane are fundamental requirements, achievable only through extrusion lines specifically designed for this type of product.
Technical specifications of the BG Plast dimpled sheet line
The BG Plast dimpled membrane extrusion line is designed to deal with HDPE in the form of pellets or flakes derived directly from post-consumer waste and to effectively address the challenges associated with the material’s high level of contamination. The process begins with an accurate feeding system for the flakes, followed by intensive degassing stations operating at high vacuum levels, supported by high-capacity pumps.
The extrusion screw is designed with a specific profile capable of handling the high flow rates required while maintaining process stability. Since the presence of impurities can cause micro-holes in thin-gauge membranes, rendering them unusable, the filtration of the molten polymer plays a central role. For this reason, the line incorporates automatic self-cleaning filtration devices and a filter-changing unit capable of removing even the smallest particles.
A gear pump completes the plasticizing unit, providing a constant flow rate to the flat die, which can reach widths of up to 6000 mm. The standard widths of the produced membranes generally range from 2000 to 5000 mm, with thicknesses between 0.5 and 0.9 mm, but different specifications can be provided upon request.
The extruded material is deposited onto a forming cylinder made of a special aluminum alloy, featuring thousands of dimples made of highly conductive material. This cylinder, equipped with vacuum suction circuits and a high-performance cooling system, is the true heart of the dimpled extrusion process. The thermal control of the calender cylinders has been the subject of specific development by BG Plast technicians, as it directly affects the geometric and mechanical quality of the product.
For the same production capacity – approximately 500–1100 kg/h – we are also able to manufacture dimpled membrane systems using either virgin or post-industrial material, thereby simplifying the plant’s architecture and reducing installed power and initial investment.
End product examples
Discover some examples of end products made with our solutions. Each result is the outcome of a precise, flexible, and highly technological process, designed to ensure performance, quality, and reliability in every application.
BG Plast technology for dimpled sheet
Thanks to our experience as a manufacturer of extrusion lines, we offer reliable, flexible systems for the production of HDPE dimpled sheets that are optimized for the use of recycled materials. Our engineering approach transforms a production challenge into a tangible opportunity, enabling us to provide the market with efficient, sustainable and competitive solutions.
New opportunities, with BG Plast.