KraftPak is a single-ply uncoated unbleached kraft paperboard that offers a consistent and uniform surface with an attractive natural brown appearance. The unique look and feel truly delivers the ideal combination of sustainability and durability to help stand out.
KraftPak is a versatile, sustainable fit in a wide variety of applications.
Suitable for die cutting, embossing, foil laminating, flexo, letterpress, paper laminating, screen printing and litho printing.
The CO2 emissions from this product can be mitigated through the Carbon Capture® programme, directly supporting the work of the Woodland Trust.
Kraftpak is typically used for automotive, beverage carriers, dry and prepared food, filter frames, foodservice / carry-out, gift boxes, health and beauty, slip sheets / partitions, wines and spirits and sporting goods.
Printing set up
- Printing is possible on both sides.
- Before printing for the first time on KraftPak, perform a press trial to ensure ink / varnish compatibility with the substrate. Involve the ink suppler to advise on ink series/optimum tack choice for the uncoated surface.
- An UV ink and varnish system with inter-deck drying assists with good adhesion.
- If using conventional inks, the use of sealer / varnish is recommended to help protect the print.
- Printing one or more hits of registered white ink first will lift the subsequent ink colour intensity printed on top. This applies to both solid and screen work.
- When possible, leave the first unit open and under pressure to scavenge and remove any loose fibre.
- Blankets should be packed to the press manufacturers specification. Quick release, compressible blankets should be used.
KraftPak creasing guidelines
- KraftPak™ is a stronger, medium density and more flexible substrate compared to most other coated and non-coated paperboard grades.
- As a result, scoring parameters need to be optimised to achieve adequate scoring and folding performance.
- Optimised scores on KraftPak are achieved mainly by rule width and channel width geometry. Penetration of the rule into the channel can also assist.
Scoring geometry guidelines
Rule width:
– 258 – 302 gsm (0.381 – 0.457 mm) caliper: 2 pt rule (0.71 mm)
– 332 – 410 gsm (0.508 – 0.660 mm) caliper: 3 pt rule (1.07 mm)
Channel width = 2 x (board thickness) + rule width
Rule penetration guide: 0.15 mm
Channel width example
Scoring 380 gsm (0.610 mm) KraftPak with a 3 pt rule (1.07mm)
Channel width = 2 x (0.610 mm) + 1.07mm = 2.29 mm
The recommendation would therefore be a channel width of 2.30 mm.
Rule penetration example
The rule penetration is calculated as:
Knife height – rule height – counter height
Scoring 380 gsm (0.610 mm) KraftPak with the following geometries:
Knife height = 23.80 mm
Rule height = 23.25 mm
Counter height = 0.70 mm
Rule penetration = 23.80 mm – 23.25 mm – 0.70 mm = -0.15 mm
The negative sign indicates that the rule penetrates into the channel.