Whether you are a business that offers products to customers or you are a consumer who purchases products, if you’ve ever received goods in a box, you’ve come in contact with wet strength resins. These resins help make paper and paperboard more durable and water resistant. They are widely used in the corrugated industry to enhance the durability of boxes and containers, and they add strength to tissue, paper towel and other paper products.
How Resins Work
Resins are liquid plastics. They are applied wet and harden as they set. Drying time can take anywhere from 4-6 hours, but once they dry, they are solid and extremely durable. wet strength resins are added to starch adhesives used in the production of corrugated boxes and containers. When a corrugated box is made, the heat of the corrugating machine helps the resins to set, providing the adhesive with a water-resistant shield. This makes the box stronger and resistant to cold and humidity.
Three Levels of Wet Strength for Corrugated Boxes
The higher the level of resin used in a product, the more water-resistant it becomes. Products can be made to keep simply moisture out, or they can be designed to be fully waterproof.
* MRA (Moisture Resistant Adhesive) — this is the lowest level of wet strength, used to pack products that will not be exposed to water or humidity.
* WRA (Water Resistant Adhesive) — the mid-level of wet strength is most commonly used by packaging manufacturers. This level is ideal to ensure that boxes remain strong in all shipping and storing conditions and that the adhesive does not come unglued due to moisture.
* WPA (Water Proof Adhesive) — the highest level of adhesive is primarily used in products that cannot come into contact with water. This level is specifically used for shipping and storing meat or fresh produce.
The next time you receive a product that has been shipped in a corrugated box, think about how far that box may have travelled. Perhaps it was sitting in storage, on a boat, plane or truck before it made its way to your home or office. It has endured the conditions of the journey, and this is largely due to the wet strength resins in the adhesive that have contributed to the box’s performance.
rapidbond is an innovative leader in the manufacturing industry. They proudly supply some of the largest corrugated packaging companies in the country with premium wet strength resins of the highest quality. Visit rapidbond.net to learn more.
