Sealing critical points in HDPE geomembranes—pipe outlets, angled corners, repair patches, and perimeter reinforcements—with filler welding rod that restores full structural integrity, without the limitations of hot air without added material, requires a handheld extrusion welding gun with a powerful motor and integrated air preheating. This extrusion welding machine—also called a handheld extruder, extrusion welder, or extrusion welding gun—is manufactured by MOLTEXO with 3400 W of power, designed for professional geosynthetic installers, chemical tank manufacturers, structural plastic ducts, and critical repairs in civil engineering.
Key Benefits
- Independent dual heating system: hot air prepares the surface of the base material while the filler rod simultaneously melts, ensuring molecular fusion in both areas and eliminating thermal stresses that compromise joint watertightness.
- 360° swivel head with adjustable shoe: allows welding at any angle and orientation, a critical condition for tank corners, pipe outlets in plants, and restricted access areas where the operator cannot maneuver freely.
- 3400 W motor for constant flow: the sized power allows continuous extrusion of filler rod without flow drop during long sessions, a condition for heavy industrial work with multi-meter seams without stopping.
- Safe cold start system: the motor does not activate until the melting chamber reaches temperature, preventing internal damage to the polymer and the motor itself, a condition that ruins generic extruders in a few months of careless use.
- Interchangeable Teflon shoes: different geometries (angle, overlap, fillet) according to the type of joint for the project, expanding versatility without investing in multiple tools.
Typical Applications and Uses
- Sealing critical details in geomembrane installation: pipe outlets, corners, perimeter reinforcements, structural interfaces.
- Manufacturing and repair of chemical tanks, water reservoirs, and structural plastic ducts with HDPE or PP.
- Repair of cracks and damage in installed geomembranes with filler rod that restores full structural integrity.
- Construction of special elements on site: containment ponds, sumps, sub-grade tanks, and custom non-standard elements.
Quality and Durability
An inexpensive extruder fails in two ways: the motor cannot withstand continuous extrusion of multi-meter rods (it burns out or loses torque within a few weeks) and the cold start system is absent or deficient (which leads to activations with unmelted material that break the motor). MOLTEXO works with a sized 3400 W motor and a safe cold start, which distinguishes a serious industrial-grade extrusion gun from a generic tool that fails in critical work.
What filler rod should be used with this extruder?
The filler rod (plastic electrode) must be the same polymer as the surface to be welded for consistent molecular fusion. Typically HDPE for geomembranes and high-density polyethylene tanks, polypropylene (PP) for ducts and PP elements, and PVDF for specific chemical applications. Welding HDPE with PP or LDPE rod does not produce structural fusion, and the joint fails in mechanical testing. Always verify that the surface and rod polymer match; serious geosynthetic suppliers include a data sheet declaring compatibility.
Why is integrated air preheating necessary?
Without preheating, the molten filler rod is deposited on a cold surface, and the fusion between the two polymers is not molecular but only superficial — producing a weak joint that fails under load or pressure in the short term. The integrated hot-air blower brings the surface to fusion temperature just before deposition, ensuring that both parts melt simultaneously and form a single structural piece. This condition is what differentiates a professional extruder from basic equipment without preheating that only applies the rod on a cold surface.
Can the bead geometry be changed for different joints?
Yes — with interchangeable PTFE shoes. Each shoe defines the bead geometry: 90° angle for corners and perpendicular junctions, overlap for horizontal lap of geomembranes, fillet for linear sealing with concave profile, and other specialized shapes. Interchangeability lets the same basic extruder handle multiple types of joint, optimizing investment and increasing on-site versatility. The shoes are consumables that wear with intensive continuous use; keep replacement stock.
Can it repair cracks and leaks in installed plastic tanks?
Yes — it is the ideal tool for structural repair of HDPE, polypropylene tanks and plastic vessels. Standard technique: empty the tank, identify and clean the crack zone, V-bevel the edges to create a fusion surface, preheat with the integrated air and deposit the filler rod along the crack. The result: a structural joint that restores the original mechanical strength of the material. For extensive cracks or multiple failure points, evaluate replacing the entire tank rather than repairing, since multiple repairs accumulate risk.
Still have questions?
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| Dimensiones y formato | |
|---|---|
| Dimensions | 64 x 53 x 20 cm (25.2 x 20.9 x 7.9 in) |
| Welding rod diameter | 3.0 mm - 4.0 mm (0.12 in - 0.16 in) |
| Gross weight | 18 kg (39.7 lb) |
| Net weight | 6.5 kg (14.3 lb) |
| Resistencias y rendimiento | |
| Structural resistances | High/low temperature, acids, and corrosion |
| Durabilidad y protección | |
| Protection | Dust shield |
| Sistema eléctrico y motor | |
| Voltage | 220V |
| Frequency | 50/60Hz |
| Integrated controls | Temperature regulation knob and power switch |
| Extrusion motor | Metabo (Germany) 1300W |
| Heating system | Bipolar (dual system for preheating and melting) |
| Hot air blower | Weldy (Switzerland) 3400W |
| Plastic melting temperature | 200 - 300°C (392 - 572°F) |
| Air temperature | 20 - 600°C (68 - 1112°F) |
| Welding speed | 1.8 kg/h (4.0 lb/h) |
| Funcionamiento y ergonomía | |
| Material inlet | Dual feed-hole design |
| Nozzle / shoe type | Rotating 360°, made of Teflon |
| Compatibilidad y uso | |
| Compatible materials | PP / PE |
| Machine: Weight | 18.0 kg |
|---|
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