Walki®Pack: Maximum Barrier – Minimum Material

 

Walki has developed a range of barrier boards for the folding carton market. Carefully selected boards are used to give the required strength and convertion characteristics. These can then be one or two side coated with a suitable polymer to achieve an economic barrier to meet the product requirements. Barrier boards reduce the need for inner wrapping of foodstuffs thereby reducing the amount of packaging used. All Walki products are tailored to meet customer requirements for cost effective and optimum packaging performance.

Depending on the end use application our customers can choose from a variety of baseboards. These are normally selected according to:

• Strength (stiffness, burst strength and tear resistance)

• Hygiene (suitability for food contact )

• Appearance (surface whiteness, print result, shade of reverse side)

• Cost

• Availability

For many applications, especially for frozen food, the base board should be hard sized, ie the centre plies will be chemically treated by the board mill to reduce moisture uptake (edge wicking) when used in the fridge or the freezer.

• Folding Boxboard (FBB or GC) Frozen, chilled and ambient food cartons, confectionary, medical and bakery products.

• solid Bleached sulphate (SBS)Cigarettes, paper cups, food packaging and ovenable trays and lids.

• Coated natural Kraft (CNK)Frozen food, bakery products, hardware and beverage multipacks.

• White lined Chipboard (WLC or GD) Used for packing household goods, secondary packaging and some restricted food products.

• Greyboard or Unlined Chipboard (ULC)Main uses include rigid boxes, lamination and divider.

Having decided on the best baseboard we then design the best functional or decorative barrier by using selected polymers such as LDPE, HDPE and PP or by using paper, film or aluminium foil as a secondary web layer. The polymers can be clear or pigmented and are given either a gloss or matt finish depending on the physical characteristics required.Minimum polymer coatweight is 10 gsm to a maximum of 50 gsm on either or both sides of the board. For printing and gluing of the polymer surfaces we apply Corona Treatment to improve adhesion of inks and adhesives. We are also able to offer renewable coatings as well as renewable and compostable coatings, which are compostable according to EN 13432 directive.

Walki®Pack products are generally used for direct contact food packaging. The polymers and any additives used are selected to comply with FDA and European national regulations. A copy of a certificate issued by Walki for individual applications to confirm compliance is available on request. The suitability of the boards and papers used is also likely to be of concern if the only direct food contact is on the exposed cut edges inside a carton. Virgin fibre grades are generally designed to have a wide range of food contact approval. Recycled grades have a limited or zero food contact approval. Our factories employ strictly controlled hygiene conditons during manufacture and we have recently gained the BRC/IOP Certificate of Hygiene for our Steinfurt factory. 

Walki has developed a standard range of functional, barrier and decorative laminates and coatings. By constant monitoring of the market demands and in partnership with many of our customers and using our extensive R&D facility in Pietarsaari Finland, we are developing new combinations and polymers to meet the requirements of economy and performance. 

Walki’s Walki®Pack range is intrinsically eco-friendly as it provides "Maximum Barrier with Minimum Materials". All boards used are produced either from fibre obtained from sustainably managed forests or from recycled paper fibre. Most of our products can be recycled to recover the paper and polymer content and our new products, soon to come on stream, will be fully compostable. A number of mills in various countries are equipped to use polymer coated board as a major raw material source. However, Walki®Pack products can also be recycled for energy recovery by incineration. The hydrocarbon polmers used burn without harmful emissions to give water and carbon dioxide only.