3-Layer Co-extrusion Fully Automatic 7000L Large Capacity Blow Moulding Machine Extrusion Blow Molding Machine for HDPE Water Storage Tanks

The HUAYU 7000L 3-layer co-extrusion blow moulding machine is a heavy-duty industrial hollow forming equipment independently developed and manufactured for large-volume plastic tank production. It is engineered to produce high-performance 7000-liter HDPE hollow containers widely used in water storage, chemical liquid containment, environmental protection sewage treatment, agriculture irrigation and industrial raw material storage. Compared with single-layer and double-layer blow moulding solutions, the three-layer co-extrusion structure brings obvious advantages in barrier property, anti-aging performance and structural strength, making finished tanks suitable for long-term outdoor service and medium-corrosion working conditions.

This machine adopts a three-channel co-extrusion die head design. Each layer can be equipped with different raw material formulas according to customer requirements. The inner layer can use food-grade HDPE for drinking water storage; the middle layer can add anti-ultraviolet, anti-static or barrier masterbatch to enhance functional performance; the outer layer adopts high-strength weather-resistant HDPE to resist sunlight, rain, temperature difference impact and surface scratch damage. Independent extrusion control for each layer ensures stable melt flow and consistent layer thickness ratio. The wall thickness control system monitors and adjusts the parison in real time during extrusion, effectively avoiding thin spots and uneven distribution on large tank bodies, greatly improving the pressure resistance and service life of finished products.

The whole machine is fully automatic with stable cyclic operation. After raw material feeding, plasticizing, parison extrusion, mould clamping, blowing, cooling, mould opening and product unloading, one complete forming cycle can be finished without frequent manual intervention. The clamping unit uses heavy-duty linear guide structure and high-response hydraulic drive system, providing large and even clamping force to fit huge mould tightly and prevent flash on tank seams. The hydraulic system is equipped with precision proportional valves and energy-saving servo pump, which lowers power consumption while keeping clamping and moving actions smooth, reducing production cost for long-time continuous running.

The control interface adopts user-friendly touch screen operation. Operators can set and save all key parameters including extrusion speed, parison curve, clamping pressure, blowing pressure, cooling time and cycle time. Multiple groups of product recipes can be stored inside the system. When switching to different tank specifications or material formulas, workers can call preset data directly to shorten trial adjustment time and lower the risk of defective products. Alarm monitoring function covers temperature anomaly, pressure overload, position deviation and lubrication reminder. Clear fault prompts help maintenance staff locate problems quickly and minimize production downtime.

Cooling system is specially optimized for 7000L ultra-large containers. Independent internal and external cooling circuits are configured for mould and parison. Fast and balanced heat exchange shortens the cooling period and improves moulding efficiency, meanwhile reducing internal stress inside plastic products so tanks are not easy to deform after leaving the mould. The machine body frame is welded with thick steel plates and processed by stress relief treatment, which guarantees high rigidity and anti-vibration capacity under long-time heavy-load operation. All core transmission and moving parts adopt high-quality accessories with reliable wear resistance.

This model supports customized mould development according to customer drawing requirements. Finished tanks can be designed with different openings, manholes, flange seats and bottom structures to match customers’ assembly and pipeline connection demands. It can adapt to HDPE, MDPE and other modified polyethylene materials. Finished containers meet common industrial inspection standards for storage equipment.

HUAYU provides complete after-sales support including machine installation guidance, on-site commissioning, operator training, spare parts supply and regular technical consultation. Our technical team helps customers optimize material formula and production process to get stable product quality and higher output. This 7000L three-layer blow moulding machine is an ideal investment for manufacturers who pursue high-quality large plastic storage tanks, helping users gain competitive edges in chemical, environmental and water storage container markets.