Gum edging is an important part of the tire manufacturing process. The gum material is a rubber strip that adheres to both edges of the steel-belt layers in a tire, either placed on top, or wrapped around the edges. Gum edge material is also utilized in some textile body ply components. Gum material is used to reduce or eliminate friction between the various tire components, which if not addressed, can lead to larger problems with tire quality. Gum material also helps to create a durable, strong bond between the belt and body ply components and other components in the tire.
Hot and cold gum edging systems use different processes, and understanding their differences and applications is key to choosing the right gum edging system for your tire manufacturing process.
Hot Gum Edging System
A Hot Gum Edging System uses an extrusion-based process to extrude the gum profile, before it is applied to the steel belt or textile body ply material. The gum material has increased tack being still warm from the extrusion process which aids adhesion to the semi-finished material
Benefits Over the Cold Gum Edging Process
- Eliminates the cost to calender, slit, and handle the cold gum material
- Eliminates the material cost and disposal cost of poly liner
- Eliminates the possibility for the poly liner to get into a tire and contaminate it
- Direct application of hot material onto the belt reduces the possibility of air entrapment
- Easy to change gum profiles on an as needed basis
Steelastic Hot Gum Edging System Capabilities
- Gum application can be flat or wrapped
- Belt Width Range:100mm (4in) to 1270mm (50in)
- Belt Gauge Range: 0.8mm (0.03in) to 2mm (0.08in)
- Gum Width Range: 13mm (0.5in) to 48mm (1.9in)
- Gum Gauge Range: 1mm (0.04in) to 3mm (0.12in)
- Line speed: 3m/min to 25m/min
Cold Gum Edging System
A Cold Gum Edging System, on the other hand, does not use an extrusion-based process to form the gum profile. Instead, the cold gum material is produced by slitting calendered rubber material, applying a liner, and then winding the material into stock rolls. Those rolls are then unwound and applied directly to the steel belt of textile body ply material by the cold gum edging system. This method relies on the natural adhesive properties of the rubber. The rubber gets applied at room temperature, making the process simpler and faster.
Benefits Over the Hot Gum Edging Process
- Ease of frequent stops and starts
- Faster line speeds
- Single gum strip can be slit into two strips
- Single or dual let off stations, with accumulation for continuous processing during changeover
- Active guiding of gum strip onto belt
Steelastic Hot Gum Edging System Capabilities
- Gum application can be flat or wrapped
- Belt Width Range: 100mm (4in) to 355mm (14in)
- Belt Gauge Range: 0.8mm (0.03in) to 2mm (0.08in)
- Gum Width Range: 13mm (0.5in) to 36mm (1.4in)
- Gum Gauge Range: 0.5mm to 3.0mm
- Max Gum Stock Roll Diameter: 610mm (24”)
- Gum Stock roll core ID: 76mm (3”)
- Line speed: 3m/min to 25m/min
Explore Steelastic’s Gum Edgers
Both types of gum edgers have their place in the tire manufacturing process. Choosing which method is right for you depends on what application is most effective. Check out this introduction video to learn more about the systems or visit the Tire Gum Edging Systems page for more information.