Gluing & Bonding

Advances in material engineering and the continued drive to reduce the weight of products have led to the growing use of adhesives as the method to join thinner and lighter substrates together.

Adhesive bonding also enables the joining of dissimilar substrates and composites.

As the use and variety of applications for bonding increases, so too does the need for dispensing equipment.

The two broad categories of Glues (adhesives) are:

• 1-Componenet (typically moisture curing/RTV).
• and 2-Component (reaction of a base material with a hardener/catalyst).

1-Component dispensing equipment is less complex and lower cost than 2-Componet dispensing. Because with 2-Components, not only are two pumps (feeding the material) required, but also both components must be dispensed (metered) in the correct ratio.

The material viscosity also has a big effect on the equipment specification. To dispense high-viscosity products greater forces are needed, so larger actuators and heavier-duty parts are required.

Low-viscosity products can be gravity or suction feed. Whilst Higher viscosities need positive pressure from Follower/Ram Mounted Pumps. For example, some 2-component Polyurethane Assembly Adhesives use a Polyol Paste (Base) and a Liquid isocyanate (Hardener) so have a Follower/Ram Mounted Pump feeding the A-Component and a Dip Tube Suction Pump feeding the B-Component, but most commonly A-Component and B-Component viscosities are fairly well matched.

All the fluid contact (wettable) parts and seals within the dispensing equipment must be compatible with the Glue/Adhesive to be dispensed.

Different applications required different outputs – applying bonding paste the length of a Wind Turbine Blade clearly requires a lot more output than bonding small inserts or brackets – so dispensing systems are sized according to the required output.

Dispensing equipment for gluing and bonding can be integrated with, or supplied as part of an automated application system.