Lamination is a manufacturing process where two materials are joined together using adhesives, heat, pressure or all of these. Experience counts in the design of industrial laminating equipment for this complex process, and you can trust Radiant Energy to understand the requirements and design the right heater or dryer for the job.
Industrial Laminating Equipment Applications
The purpose of lamination can be purely decorative, purely functional or a combination of both. We see laminated products every day, such as:
- vinyl wallcovering in our offices or homes
- interior panels of air planes
- synthetic leather used for bags, purses and office furniture
- sound deadening panels inside printers and mass transit cars
- door and instrument panels in our cars
- other automotive surfaces, including the roof, seats and under the hood
Even the bulletproof vests worn by our troops are made from laminated materials. The manufacture of these materials calls for carefully designed process heating equipment.
Radiant Energy’s Industrial Laminating Equipment Designs
Here at Radiant Energy, we have learned from years of experience what works in the laminating process and what does not. Our IR heaters for lamination feature these important design characteristics:
- Multiple zones to ensure that products are uniformly heated.
- Heaters located as close to the laminator as possible, sometimes literally into the laminator, so that the web does not cool off after being heated.
- Heating the second web for a better bond.
Web handling for lamination
Roll supported. For continuous web-to-web lamination, webs are roll-supported, heated and fed into the laminating nip for bonding. Our process heaters for lamination can be designed for webs with a pre-coated adhesive that’s activated by heat, or a wet adhesive that is dried, or partially dried, for lamination.
Belt laminators. When the lamination process takes longer than the time available in a two-roll nip, belt laminators are used. In this process, the two webs are preheated and brought together in between two heated and pressurized belts, providing a longer residence time for a better laminating bond.
The challenge of wet lamination
Wet lamination can present a particularly difficult drying challenge. If you’re not careful in planning your process and choosing the right industrial laminating equipment, you can end up with bubbles and blistering in the coating.
The difficulty with drying a wet laminated product is that the wet coating is trapped between the two webs. That means the moisture needs to pass through one of the substrates to be removed from the coating. As a result, the drying rate slows down significantly as compared to most drying processes where the coating is directly exposed to the heat.
The problem is compounded when one of the webs is non-permeable film or foil, so no moisture can come out from that side. The coating has to be dried in such a way that all the moisture comes out from the paper side. If you try to dry too fast by applying too much heat, the moisture boils in place and the coating starts to blister, resulting in a defective product.
The goal of drying a wet laminated web is to reduce the rate of heat transfer and increase the residence time to match the rate that the moisture can be safely removed through the paper web. At the same time, you want to use as much heat as you can in order to minimize the dryer size.
Depending on how much heat the product can handle without damage, you can successfully dry a wet laminated coating using the following types of process heating ovens:
- Hot air convection
- IR with room temperature air impingement
- Combination IR and hot air
At Radiant Energy, we understand the need for extensive testing to get the best results when drying a wet laminated coating. We don’t rely on computer models that focus strictly on heat load and fail to account for the slower drying time needed for the moisture to pass through the web.