In chemical, coating and food packaging industries, 20L large-capacity HDPE plastic pails are universal storage and transportation containers for hazardous chemicals, grain oil and paints. Characterized by deep cavity and wide mold projection area, the mold cavity generates huge opening force during high-pressure filling, which has been a stubborn molding problem troubling the industry for decades. Conventional toggle injection molding machines transmit clamping force through connecting rods, with stress concentrated on both sides of the mold and insufficient platen rigidity. During long-term 24-hour three-shift continuous production, platens keep elastic deformation, widening gaps on parting lines, causing flash on pail edges and thread sealing surfaces. Excessive wall thickness deviation at pail corners and bottoms leads to leakage when filled with liquid chemical raw materials or paints, resulting in high reject rates and rising costs including material waste, manual trimming and after-sales compensation. LISONG GT series pail-dedicated injection molding machines are specially developed for high-pressure molding of 20L large pails, equipped with central direct mechanical clamping system to eliminate molding defects from fundamental machine structure, stabilize yield rate and greatly extend mold service life.

      On traditional toggle machines, clamping force is indirectly transmitted via multiple toggle links, stress gathers on left and right sides of the mold while the mold center bears insufficient pressure. High-pressure melt filling pushes the mold center apart, creating gaps on parting lines and mass flash waste. In contrast, LISONG GT direct clamping structure applies vertical and uniform clamping force to the mold center with four-point balanced pressure distribution, eliminating eccentric wear of toggle mechanisms. The machine is equipped with thickened high-temperature tempered high-rigidity platens, greatly reducing platen deformation under high-pressure filling and keeping parting lines tightly fitted all the time, fundamentally eradicating flash defects.

      The machine adopts integrated thickened tempered steel platen with four symmetrically distributed tie bars for balanced full-area pressure, perfectly matching the installation of large single-cavity 20L pail molds. Mass production tests in factories prove that the direct clamping structure requires 15% lower clamping force than ordinary toggle machines for identical 20L pail molds. Molds endure long-term high-pressure melt impact without easy deformation, and cavity abrasion is greatly slowed down, extending overall mold service life by over 30% and cutting heavy maintenance costs on frequent mold polishing, cavity repair and insert replacement.

      Mandatory anti-leakage standards for national hazardous goods packaging impose strict regulations on wall thickness uniformity of 20L pails. The thickness difference of pail body, bottom and thread must be controlled within an extremely small range; local thin wall will cause rupture and leakage under liquid pressure. LISONG GT’s four-point balanced clamping design stabilizes the wall thickness tolerance of complete 20L pails within ±0.05mm, free of sink marks at pail bottoms, uniform thickness at four corners and smooth flat thread sealing surfaces. Finished products fully meet sealing standards without secondary manual trimming, directly reducing scrap volume.

      Large single-cavity molds for 20L pails cost a huge amount of money and act as core fixed assets of packaging factories. Falling plastic scraps and residual impurities during production may scratch the cavity and cause irreversible damage. LISONG GT machines come standard with ultra-sensitive low-pressure mold protection system, whose protection pressure is only 1/30 of rated clamping force. It monitors cavity resistance throughout mold closing, automatically opens the mold and triggers sound-light alarm once foreign objects are detected, preventing mold collision damage and minimizing downtime for maintenance to ensure continuous stable production. The machine frame is integrally formed with thickened steel plates, high-temperature tempered to eliminate internal stress and spray-coated for rust and corrosion resistance. It adapts to year-round non-stop three-shift production of packaging factories, free of resonance and structural deformation under long heavy loads. Its stability and durability fully surpass general injection molding machines, serving as core hardware guarantee for mass 20L pail manufacturers to steadily deliver qualified products，For export orders and food-grade 20L pails with strict hygiene requirements, the clamping area of the machine has no exposed hydraulic pipelines, so no oil drips to contaminate pail blanks. No extra protective baffles are required, fully meeting domestic and foreign food packaging safety inspection standards, and supporting stable mass production for cross-border packaging enterprises with large export orders. In summary, relying on clean hydraulic circuit, servo energy saving, low maintenance and intelligent control, LISONG GT pail machines lower comprehensive production costs for 20L pail manufacturers in long run, expand profit margins amid industrial competition and deliver a stable, efficient, green integrated molding solution for 20L plastic pails, Compatible with all domestic & eco-friendly plastic materials.