Adhesive Types and Characteristics

In many cases, the use of pressure sensitive and ST adhesives can eliminate mechanical fastening systems (staples, nails or retaining clips), and the inherent problems associated with them, such as cost, weight, and breakage. PSA and ST frequently improve productivity during the final assembly process by providing a faster, more efficient way of attaching seals and gaskets to the end product.
To begin the adhesive selection process, it is important to have the answers for several basic questions:
1. To what type of substrate will the adhesive be attached?
2. In what temperature range will the adhesive be expected to perform, and with what chemicals will it come into contact?
3. Will the adhesive come into contact with moisture or sunlight?
4. Will the adhesive be functional after installation?
The PSA and ST adhesives each offer specific benefits depending upon the surfaces to be joined, the strength of the bond required, and environmental factors such as temperature and chemical resistance.

Acrylic Based Adhesive – H2
Acrylic adhesives are polar in nature, and tend to stick well to polar substrates such as metals, glass, polyesters, polycarbonates and neoprene's. Conversely, acrylics do not bond well to non-polar surfaces such as polyethylene, polypropylene (olefins), EPDMs and silicones. Acrylics are thermoplastics by nature; they soften when exposed to heat and harden when cooled. They are inherently soft at ambient temperatures. Being soft at room temperature permits them to flow under light pressure and make good intimate contact with the substrate. This ability to flow is very important when bonding to an irregular or rough surface .Acrylics age very well in the presence of ozone, ultraviolet light and corona due to the saturation in the polymer backbone.

Rubber Based Adhesives – H3
Rubber based adhesives are very thermoplastic. The addition of heat will soften the adhesive and directly affect its function. These types of adhesives have a high initial bond to the substrate. This is unlike acrylics, which can take 48 to 72 hours to achieve their ultimate strength. Rubber Based Adhesives – H3
Rubber based adhesives are very thermoplastic. The addition of heat will soften the adhesive and directly affect its function. These types of adhesives have a high initial bond to the substrate. This is unlike acrylics, which can take 48 to 72 hours to achieve their ultimate strength.

HATS/ST Adhesive
The heat bonded adhesives are medium density, heat activated acrylic foam tapes used to attach gaskets to a wide range of substrates. These adhesives are characterized by high adhesion and holding strength, and form durable, long lasting bonds on most substrate surfaces. They feature an instant adhesion and provide a continuous seal against moisture, dirt, and noise intrusion. They are thermally bonded to the extruded profile using specially-designed heat laminating equipment. When properly applied, a permanent bond between the tape and the surface of the extrusion is obtained, providing an attachable profile that can be bonded to a large variety of surface materials. Gaskets utilizing these tapes provide excellent performance at both high and low temperature conditions. The tapes are high performance formulations designed to meet a variety of requirements including holding power, ultraviolet light stability, moisture resistance, salt spray resistance and more.

Double-Coated Paper and Film Tapes

H2 - Acrylic, H3 - Rubber - Based

*Advantages: Acrylic adhesives are cross-linkable and deliver good resistance to varying temperature ranges, chemicals, ultraviolet light and oxidation. They are very color stable and can easily be removed and reinstalled in the application if done incorrectly.
*Disadvantages: Generally, they have poor adhesion to polyolefins. The initial bond or tack strength of acrylic adhesive is low.

Heat Activated Tapes

HAT - Neoprene Profiles ST -EPDM Profiles

*Advantages: Rubber based adhesives will adhere to a wide range of materials and they have a high initial "grab" or tack.
*Disadvantages: Poor resistance to elevated temperatures, fair to poor resistance to chemicals, and generally poor resistance to ultra violet light and oxidation.