woodworkingnetwork.com/redbook | April 2019 | RED BOOK 42 |
• PUD - (Polyurethane Dispersion) is a water-based system that
is catalyzed for best performance. The PUD is sprayed on the
base/core substrate, left to dry, then reactivated with heat.
PUDs are used in vacuum or membrane pressing. Vacuum
pressing is done by heating the overlay and creating bottom vacuum pressure to form the laminate material over the part. The
heat and vacuum pressure create an intimate contact between
part and laminate material that then activates the adhesive.
During the membrane process, the membrane is heated
by an upper platen and the overlay drawn to the membrane to
be softened by heating. Vacuum and upper positive pressure is
applied, causing the membrane and overlay to form around the
parts. This process ensures heat to all sides and contours within
the part for proper activation of the adhesive.
Poor bond at the lowest edges of a part is a common issue.
Cures might include adjusting the membrane temperature,
moderating the press cycle, slightly higher application quantity
of PUD adhesive or a combination. Parts in a press will need bot-
tom support from pedestals or pins for the laminate material to
be applied on all appropriate areas. Common pedestals should
be 1/2 inch smaller all around the part being pressed for prod-
uct support so as to not break the corners. The PUD adhesive
must be applied to see a minimum 50% sheen on part edges
once dry to achieve proper bonding.
• EVA – Thermoplastic Hot Melt. Can be reheated/softened.
• Polyolefin – Thermoplastic Hot Melt with higher heat resis-
tance vs. EVA. Can be reheated/softened endlessly.
• PURHM – Thermoset Hot Melt. Once cured, it will not soften.
Most edgebanding processes are similar regardless of the ad-
hesive. A hot melt is applied to the edge of a core substrate and
the edgeband is applied almost immediately to ensure contact.
Once married together, the adhesive must cool and set within
seconds to ensure the banding holds to the part as it is trimmed
The adhesive will need to be matched to the products be-
ing bonded. Once an adhesive is chosen, and the application
amount is set, the rest is mechanical.
• EVA Hot Melt – Used for speed of initial set.
• PURHM – Used to achieve superior heat and water resistance
with a non-softening glue line.
Wood, plastics, and metals are among the materials that
are typically profile wrapped. The key is talking with suppliers
of the various components that make up the final product to
ensure choosing the right adhesive. Also, depending on the core
substrate, there could be the need for a primer to be applied on
Always utilize your suppliers as a resource to provide the sup-
port needed to get your product offerings off to a great start.
This information should only be used as a guide. Each lami-
nation process will need its own application method. If you have
any questions, please contact your suppliers for specific recom-
Source: Gene Weathersbee is an account manager with Daubert
Chemical Co. For more information call 866-311-8574 or visit
GLUING, PRESSING & MATERIALS