Hot-Plate vs IR Welding: The Epic Showdown

This webinar compares hot plate welding and IR welding, emphasizing that both technologies require heat and pressure, but differ in how heat is applied [06:12].

Hot Plate Welding

• Process: Involves touching plastic parts to a heated tool, allowing heat to conduct into the weld rib [06:38]. This method ensures weld surfaces are parallel, even if parts are warped, leading to strong, consistent joints [11:36].
• Parameters: Heat is controlled by tool temperature, melt depth, and time. Pressure (seal and weld phase) is controlled by depth, force applied, and hold time [10:03].
• Materials: Great for polypropylene, ABS, polycarbonate, and materials with fillers like glass or talc. Not recommended for sticky materials, such as nylon and PBT [13:29].
• Advantages: Creates strong, robust, and hermetic seals with no particulate generation, making it suitable for clean room environments [24:36]. Can achieve 80-100% parent material strength [23:13]. Effective for stack welding multiple layers [31:28].
• Applications: Engine degas bottles, automotive interior trim (glove boxes, center consoles, armrests, etc), batteries, and medical blood cartridges [21:12].
• Equipment: Extol offers the Rapid Conductor (three sizes for various working areas), Compact Fusion (smaller, benchtop unit), and custom large hot plate welders for big parts like pallets [33:01]. A new, more cost-effective welding platform with multiple technology options is also being launched [34:52].

IR Welding

• Process: A non-contact process where an IR emitter radiates energy absorbed by the plastic part [06:52]. Heat and pressure phases are similar to hot plate welding, but heat is applied via radiation [07:15].
• Types:
  • InfraGuide: Unique to Extol, uses individual bulbs for focused, efficient, and tunable energy. Air cooling minimizes flare-ups by pushing gases away from the emitter [43:09]. Can weld clear polysulfone.
  • Quartz IR: Uses quartz emitters, which can be challenging to achieve uniform energy and may have a medium flare-up risk [45:00].
• Materials: Suitable for materials that may be sticky for hot plate welding, such as nylons and PBTs [48:25].
• Advantages: Non-contact process prevents sticking. InfraGuide allows fine-tuning power across the weld surface [43:09]. Can be used for applications requiring airtight and particulate-free welds [48:25].
• Considerations: Part size affects cost; InfraGuide can become costly for very large parts [46:43]. Weld rib design needs to be different from hot plate welding, often requiring less height [19:03].

Key Comparisons

• Material Compatibility: Main consideration when choosing between the two [07:49].
• Particulate: Both hot plate welding and IR welding produce flash but no particulate [24:36].
• Warped Parts: Hot plate welding excels at normalizing warped surfaces due to material displacement [11:51]. IR welding does not displace material, so initial part flatness is more crucial [19:20].
• Energy Consumption: Hot plate welders, once on, remain stable but continue to consume energy. Designs are evolving to minimize thermal mass and reduce power [29:35]. For very large parts, the energy consumption of IR welding can sometimes exceed that of a hot plate [31:15].
• Flexibility: Hot plate welding offers geometrical freedoms for contoured parts that vibration welding might not [22:27].