Wax Coating for Packaging Applications
Wax coating is applied to paper to enhance the functionality during packaging. Wax will make the paper more durable and moisture resistance. Wax will keep the paper together when it comes into contact with moistures like grease or water. That’s how you are able to enjoy your greasy hamburger without getting grease onto your hand and unwrap your candy without it sticking to its packaging. Wax coating is all around us.
How is wax applied onto paper?
Wax can be applied onto paper for packaging through three main ways. One way is to immerse the paper in wax. Another way is to spray wax onto the paper. The most common way is to apply wax onto paper through rollers. Using rollers is a fast, effective, and precise way to get the job done. Where the paper is set up on a roll-to-roll machine and is run through different rollers. Some rollers are to control the amount of wax that goes onto the paper, some are to apply the wax, and some are to cool off the wax to turn it from liquid into solid form. Some common roller methodologies include direct gravure coating, reverse gravure coating, offset gravure coating, micro gravure coating, flexo coating and four roller coating. The different coating methodologies are suitable for different coating viscosity, coating thickness, coating speed and coating width. Click here for more information on the different coating methodologies.
Amount of wax used in coating
According to the different packaging applications, different wax amounts are applied to produce the functionality needed. For instance, a butcher paper application to hold greasy food will have a thicker wax coating when compared to candy wrapper. On average the wax coating weight is in the range of 3 to 5 gsm.
The type of wax used in coating
Different wax types are used for different applications. Two common food grade wax include the paraffin wax and the carnauba wax. These two waxes are safe to ingest and provide benefit for food quality and protection. Paraffin wax is the main wax used for corrugated packaging. A corrugated box protected with wax can be three times stronger than non-wax coated corrugated box. Carnauba wax is often used in the protein packaging to address the fluids produced by protein products. Carnauba wax coating can help to improve tensile strength of packaging materials by 175% and lower the water vapor permeability by 65%.
Wax coating can be found in many places, packaging is just one of the applications for wax coating. Wax coating can also be applied to tissue paper to form waxed tissue paper that is stronger and grease resistant. Wax coating can be applied to paper cups to keep the liquid from breaking down the paper. Contact KYMC to learn more about how you can apply wax coating to your products.