Liquiguard waterproof cardboard coating
If you use or sell waxed cardboard boxes to your customers, Liquiguard waterproof cardboard sheets are a cost-effective, environmentally friendly alternative.
Liquiguard coating creates a translucent, water-resistant film when applied to corrugated cardboard. The waterproof cardboard coating provides resistance to oil, grease and moisture. Applications include waterproof cardboard boxes for greasy industrial components, wet and oily foods such as fish (being FSA-approved for food contact), and products that retain moisture, such as cut flowers.
GWP Coatings has supplied UK sheet plants with water-resistant cardboard and other high-quality coated board for more than 35 years. We can provide a completely confidential trade service, low volumes (from as little as 200 sq. metres) and lead times under 48 hours.
Benefits of Liquiguard waterproof corrugated cardboard
Liquiguard waterproof cardboard sheets (or fabricated packaging) provides the following benefits:
Technical and conversion information
Cobb test
The Cobb and 3M tests measure the endurance of oil and water-resistant cardboard.
These tests determine water absorption. There are three exposure times used: 1 minute, 3 minutes and 30 minutes.
The test involves pouring a known volume of water (100 ml) onto a specific area of the water-resistant cardboard’s surface (100 cm²). Weighing the board before and after exposure allows the difference between the two to be expressed as the weight per unit area of water absorbed in that given time. Therefore, the lower the Cobb value, the better the result.
Typical test results obtained on Liquiguard material are below:
Cobb: 3 minutes = 2.0
Cobb: 30 minutes = 10.0
3M Kit test
This test involves putting five separate drops of various solvents onto the board’s surface and inspecting it after 15 seconds to see if any pinholes appear (visible as dark specks).
The solutions range from thick vegetable oil to thinner substances, such as white spirit. Each solution is numbered up to a maximum of 12, and the higher the number achieved, the more resilient the surface.
Typical test results obtained on Liquiguard material are:
3M Kit Test: = >12
Conversion information
Liquiguard waterproof cardboard coating is a blended waterborne acrylic lattice that creates a totally non-hazardous, inert, translucent film when coated and dried onto paper or corrugated cardboard, while containing only water as the carrier system with no halogenated compounds or hydrocarbon co-solvents.
The materials used to manufacture Liquiguard coating are acrylic emulsions, which are fully biodegradable and recyclable on standard paper materials.
Liquiguard is FSA/FDA approved for direct contact with food. Care is required when applying it to test liners, as it is typically not possible to guarantee the composition of the test liner.
Liquiguard is excellent for storing frozen foods and does not separate from the liner. Converters can also use it for ‘cook in the box’ products.
Paper mills readily accept Liquiguard-coated material, preferring it over poly-lined or wax-impregnated cardboard, both of which are not environmentally friendly and difficult to repulp.
The minimum run usually is 200 sq. metres onto any fluted board grade, with a maximum board size of 1500 x 3000 mm.
Coating onto pure kraft or white top kraft liners achieves the optimal results. It is possible to use Test liners; however, these are not certified.
Liquiguard can be applied to either one or both sides of corrugated board, providing a clear finish, but it tends to darken the underlying paper.
It can generally be overprinted with water-based Flexographic inks or used over the top of Spectrumcoat-coloured or other pre-printed boards to give an enhanced visual appearance.
Liquiguard waterproof cardboard coating requires special PVA adhesive for cold glueing or a hot melt adhesive. Our coatings and packaging experts can advise on suitable glues.
FAQs
Is waterproof corrugated cardboard really waterproof?
Whilst cardboard cannot be completely waterproof (due to exposed fluting), Liquiguard coating allows treated surfaces to become highly water-resistant. These properties make packaging manufactured from waterproofed cardboard sheets more durable and suitable for packaging wet, oily, or greasy products (such as fish or greased industrial components).
Why should I use Liquiguard waterproof cardboard sheets?
GWP coats corrugated material with Liquiguard in an ISO-accredited environment using 17kg of coating per 1,000 sq. m of board. The weight of the coating compares favourably to alternative solutions, which can use as little as 7kg. Liquiguard is also more sustainable than wax-coated boards, which are challenging to repulp and recycle.
Can I purchase waterproof cardboard boxes?
GWP Coatings typically supplies coated material to trade customers, who then convert it into packaging products according to their specific customer requirements. However, the Packaging division of the GWP business can offer custom packaging boxes and products utilising Liquiguard material. GWP can supply both material and fabricated packaging to sheet plants and box factories as part of a confidential trade agreement.
Can I source low volumes of waterproof cardboard sheets?
The efficiency of the coating equipment used at GWP Coatings allows you to specify runs from as low as 200 sq. metres. With a stock holding of various board grades and efficient processes, you can also benefit from lead times that are typically within forty-eight hours. GWP are happy to coat any board you supply to us as well.
Is Liquiguard coating suitable for carton boards?
Whilst Liquiguard works on carton boards (and paper), due to the equipment used at GWP Coatings, we are not able to coat material of this type.
Disclaimer: Application images on this page may have been enhanced or created specifically to illustrate a products features and/or potential uses. Please see our content policy for further details.
Why GWP Coatings?
Confidential trade supply
We can supply any coated cardboard material you need as part of a confidential agreement, and at competitive trade pricing.
Flexible volumes
We can coat a wide range of corrugated boards – supplied by us or by you – from as little as 200 square meters and typically within 48 hours.
UK-based experts
With over 35 years of experience in coating corrugated board, our UK experts can provide both technical advice and conversion information.
Quality guaranteed
Coating all board in-house enables us to have complete control over quality, guaranteeing exceptional coverage and performance.
Quotes, technical info and advice
Speak with our UK-based coating experts
The information on this page has been collated, checked and approved by several of our corrugated coating experts:
