Study of Adhesive Strength in Polymer Plate Heat and Mass Exchanger

Open Cycle Liquid Desiccant Air Conditioner system is promising solution for air
conditioning in hot and humid climates like a tropical region South East Asia. The
system used cross flow type plate heat exchanger made by thin sheets of polymer for
both dehumidification and cooling. However leakage between the polymer sheets is
due to adhesive failure of joint between plastic sheet results in a decreasing of
regenerator performance. The objectives of this project are to fabricate and simulate
model of plate heat and mass exchanger and to study the adhesive strength used for
heat and mass exchanger. The methodology for this project is started with the design
of prototype plate heat and mass exchanger and material selection such as
cyanoacrylate adhesive, silicon sealant and EVA Hot Melt Adhesive based on their
properties and also polypropylene material as corrugated sheet and solid sheet
material. Prior to adhesive test, heat treatment and surface roughening are prepared
as surface preparation together with step to apply the adhesive to sample test. In
order to test the maximum strength of the adhesive, the Single Lap Joint Shear Test
is chosen for the adhesive test. After satisfYing with the performance of adhesive,
the fabrication of the heat and mass exchanger is started. Hydro testing of the model
is conducted to test the leaking problem and also HMX working principle. 2D
Design of Regenerator is designed to illustrate the model of plate heat and mass
exchanger. Material selection for each component of regenerator is summarized by
Bill of Material of Plate Heat and Mass Exchanger. From the single lap joint shear
test, PP sample with treated surface bonded with cyanoacryalate adhesive achieved
highest shear strength, 3.61MPa compared to untreated surfuce PP sample and other
adhesive sample test. Besides, the result of hydro testing are also discussing about
leaking problem of adhesive and also working principle of model. Most of leakage
problem occurred due to improper fabrication technique and improper sealant used.
Sealant of plastic joint is replaced from silicon sealant to EVA Hot Melt Adhesive.
This adhesive able to fill the gap between the joint and resist the water from leaked.
As a result, the leakage problem is minimized by using EVA Hot Melt Adhesive.