HATS tapes and PSA tapes speed gasket installation and provide reliable attachment. Adhesive tapes that use a heat-activated taping system (HATS) require curing but provide permanent fastening. Pressure-sensitive adhesive (PSA) tapes don’t require heat or curing. They’re used mainly for temporary fastening and with screws, bolts, staples, or pins.
For engineers and product designers, both types of tapes offer advantages over mechanical fasteners and liquid adhesives. Mechanical fasteners are durable, but they’re susceptible to loosening from vibrations. Liquid adhesives are messy and can raise environmental health and safety concerns. Adhesives tapes won’t vibrate loose and are easy-to-install, but is a HATS tape or a PSA tape the better choice?
This week’s article, the first in a two-part series, compares HATS tapes to PSA tapes in detail. Next week’s article, our last of 2018, will guide you through the tape selection and gasket installation process.
HATS tapes provide excellent adhesion and holding strength but require up to 24 hours of curing after gasket installation. Once these tapes are fully-cured, however, the bonds are permanent. They also keep out moisture during dynamic sealing. As weatherstripping attachment tapes, HATS are a good choice for bonding rubber gaskets to the cabin doors on mobile equipment.
With their superior strength and environmental resistance, HATS tapes are suitable for both indoor and outdoor use. The heat-activated adhesive (HAA) flows readily into highly-porous materials and bonds to flexible or rigid substrates, including painted metal surfaces. HATS tapes adhere readily to gasket materials such as EPDM rubber, PU foam, and PVC plastic.
HATS tapes adhere to a wider range of materials than PSA tapes, but HATS won’t stick to silicone – a synthetic rubber. Otherwise, these adhesive tapes can increase production efficiencies because parts stick and stay in place. HATS tapes also bond well to larger surfaces.
It’s important to understand that HATS tapes won’t become tacky until the adhesive is activated by a heat source such as flame lamination. Gasket fabricators can source rubber profiles that come with HATS tape, or they can perform flame lamination in-house. At Elasto Proxy’s manufacturing center near Montreal, we can source the taped gasket materials you need or use our taping machine to meet your requirements.
Pressure-sensitive adhesives (PSAs) are permanently tacky substances that stick to surfaces when light pressure is applied. With gasket tapes, these adhesives hold the rubber part in place until workers can install mechanical fasteners for more permanent attachment. There are three main types of PSAs: rubber, acrylic, and silicone.
Rubber-based PSAs consist of elastomers that are made tacky by the addition of compounds. They are economical, provide high initial strength, and are suitable for short-term, non-critical use. Rubber-based PSAs are used mainly with indoor applications because they won’t withstand ultraviolet (UV) light. Exposure to chemicals or solvents can cause these adhesives to swell, soften, or dissolve.
Acrylic-based PSAs are made of acrylic monomers or compounds and are formulated to be tacky. They have a lower initial adhesion than rubber-based PSAs but provide greater stability at higher temperatures. Unlike rubber-based adhesives, however, acrylic-based PSAs are recommended for applications that require resistance to chemicals, solvents, and UV light.
Like acrylic adhesives, silicone-based PSAs can also resist chemicals and sunlight. Silicone PSAs cost more than other types of adhesives but support the widest temperature range. They provide high-temperature resistance and can withstand cold-temperature conditions. Importantly, adhesive tapes that use silicone-based PSAs are required for silicone gaskets and silicone substrates.
Elasto Proxy can source rubber extrusions that come with PSA tapes or use our in-house taping equipment during gasket fabrication. To learn more about our custom fabrication capabilities, request the Super Gasket – a unique educational tool with features that include high-bond adhesive tape.