New Opportunities and Challenges for Pressure Sensitive Adhesive in the Building

Products Market

by

Dipl. Kfm. Werner A. Hoermann

Custom Adhesive Technology, Inc.

Fallbrook, CA 92028

The four functions of a building

•Structural

•Aesthetic

•Moisture Management

• Insulation – thermal and acoustic

Function of Adhesive

•A. Attaching one layer to another

•B. Serve as a functional layer

Image of Adhesives in Construction

•Adhesives don’t work

•Tapes do

“Peel and Stick” Products for the Construction Industry

• “Peel and Stick” Single Ply Roofing Membranes and Walkways

• “Peel and Stick” Roofing Underlayments*

• “Peel and Stick” Below Ground Waterproofing Membranes*

• “Peel and Stick” Thru-Wall Flashings*

• “Peel and Stick” Window and Door Flashing Tapes*

• “Peel and Stick” Tile Underlayments

• “Peel and Stick” House Wrap*

• “Peel and Stick” Solar Panel Attachment Systems

* Product where the adhesive serves as waterproofing membrane

Fully Adhered vs. Mechanically attached

•Better Distribution of Stress

•Puncture does not create water entry point

•Adhesive provides secondary/primary water proofing

•Air and water tight seams

“Peel and Stick” vs. “In Place Applied”

•No waiting for adhesives to dry, No “dusting up” of exposed adhesive, No waiting for “good” weather

•No danger of missing the “open” window, No trapped solvents or water, Evenly applied adhesive coat, No special training needed

•No hot kettles, No open flames, No fire hazard, No heavy equipment, No special permits

•No protective clothing and breathing gear

•No offensive odors, No evacuation of buildings

•No VOC’s

What are the Challenges?

•Application Environment and Performance Window

•Exposure

•Changing Surfaces and Materials

•New requirements (e.g. moisture management, environmental)

•Cost

PSA Performance as a Function of Temperature

-50.0 -25.0 0 25.0 50.0 75.0 100.0 125.0 150.0

temperature (°C)

100.0

1000

10000

1.000E5

1.000E6

1.000E7

1.000E8

1.000E9

G' (P

a)

100.0

1000

10000

1.000E5

1.000E6

1.000E7

1.000E8

1.000E9

G''

(Pa

)

0

0.2500

0.5000

0.7500

1.000

1.250

1.500

1.750

2.000

2.250

2.500

|tan

(de

lta)|

Temperature Sweep, 10 rad/s

Butyl Hybrid

tan delta peak

Glass Region

Transition Region

Rubber Plateau

Melt Flow

G'

G"

Softening Point

Dahlquist Criterion - 300,000 Pa

tan delta minimum

tan delta = G"/G'

Effect of Outdoor Exposure on Adhesion

Loss of Flexible Flashing Adhesion to Housewrap after 2 week and 6 week exposure

RA Butyl Butyl Hybrid

2 weeks

6 weeks

The Problem:Deeply grooved OSB

How does the PSA bonding process work?

Best Case: Excellent wet-out, plenty of contact, high surface energy

Worst Case: Bad wet-out, little contact, low surface energy

The solution:

Moisture Management:How to achieve Vapor Permeability

• Formulation

• Coating process

• Post-Converting process

Cost

• How to sell a $2/lb. product into a $0.50/lb. market

Future of PSA in Construction

• Asphalt replacement

• New Functionalities in Construction PSAs

- moisture management

- insulation improvements through additives

- peel and stick bonding of structural panels

- seaming of geotextile application

- waterproofing of infrastructure products (tunnels, aqueducts)

- integration into prefab concrete and concrete textiles