A Bopp Jumbo Roll is a large, master roll of Biaxially Oriented Polypropylene (BOPP) film. It is the primary form in which BOPP film is produced and sold by manufacturers to converters. These rolls are "jumbo" because they are enormous in both width (can be over 4 meters / 13 feet) and length (can be tens of kilometers long). Converters then use slitting and rewinding machines to cut these jumbo rolls down into smaller, customer-specific rolls for use in various packaging and printing industries.
Standard Specifications of a Jumbo Roll
When ordering, buyers specify these key parameters:
1.Film Type: This is the most variable specification. Common types include:
2.Plain/Standard: Clear, transparent film.
3.Metallized: Vacuum-coated with a thin layer of aluminum for a shiny, metallic appearance and enhanced gas barrier.
4.White Opaque: Contains pigments (like titanium dioxide) for a solid white background, often used for labels.
5.Pearlescent: Has a pearl-like shimmer effect for premium packaging.
6.Matte: Non-glossy, elegant finish.
7.Coated: e.g., Heat-sealable coating (for sealing bags), Acrylic-coated (for better ink adhesion), PVDC-coated (for oxygen barrier).
8.Thickness (Gauge): Measured in microns (μm) or gauges (where 1 gauge = 0.01μm). Common ranges are from 15 to 50 μm.
9.Width: The roll's width, which is the dimension that will be slit into smaller widths. Can range from 1 meter to over 4 meters.
10.Length: The total length of the film on the roll, typically measured in meters.
11.Core Inner Diameter (ID): The size of the cardboard core the film is wound on. Standard sizes are 3" (76mm), 6" (152mm), or custom sizes to fit the converter's machinery.
12.Outer Diameter (OD): The full diameter of the finished jumbo roll, which is limited by the handling capacity of the production and converting equipment.
Manufacturing Process (Simplified)
1.Extrusion: Polypropylene pellets are melted and extruded through a flat die to form a thin sheet of cast film.
2.Orientation (Stretching): This is the critical "BO" step. The cast film is stretched:
3.Lengthwise (Machine Direction - MD) over a series of heated rollers.
4.Widthwise (Transverse Direction - TD) in a heated oven called a tenter frame.
5.This biaxial stretching aligns the polymer molecules, giving the film its signature strength and stability.
6.Treatment & Coating: The film may undergo a corona treatment to increase surface energy for printing. It may also receive functional coatings (e.g., for sealing or barrier properties).
7.Winding: The finished film is wound onto a large cardboard core at high speed, creating the massive Bopp Jumbo Roll.
