What co-injection molding methods create foam-core PVC outdoor tree boxes?

Foam-core PVC outdoor tree boxes are created using specialized co-injection molding methods that combine rigid PVC with a foamed inner layer. This process typically involves injecting two materials simultaneously—a solid outer layer for durability and a foamed inner core for lightweight insulation. Common techniques include gas-assisted co-injection, where nitrogen gas expands the core, and chemical foaming agents blended into the PVC melt. These methods enhance structural integrity while reducing material costs. The result is a sturdy, weather-resistant tree box ideal for outdoor use, offering improved insulation for plant roots and long-term durability against environmental stress. Manufacturers often optimize parameters like temperature, pressure, and injection speed to achieve consistent foam distribution and surface finish.