Polyurethane is a type of polymer that first came about in Europe in 1937. Polyurethane adhesives belong to a group of chemicals called reaction polymers (which also include Epoxy Resins), they are a varied group of chemicals with a lot of different subcategories.
Some polyurethane adhesives are catalysts making chemical reactions happen faster, while others require external catalyst like heat, water or chemical curing agents
Polyurethane adhesives are adhesives that use several types of polyurethane. Like epoxy resins, polyurethane adhesives are 'structural adhesives', they are designed to create very high strength bonds. They also prove very versatile as they are good at bonding diverse kinds of materials together with a long-lasting strong bond consistently. This makes them hugely useful for a vast number of different industrial applications which range such as: -
- Refrigerated Lorry Trailers.
- Cold stores.
- Sandwich Panels.
- Structural insulated Panels (SIPS).
- Modular Homes.
- Potting, moulding & encapsulation.
- Protective Coatings.
- Insulated Panels.
- PU Edgings.
?Polyurethane Industrial Adhesive - Application Equipment
As with the varied types of Polyurethane Adhesives there are also many diverse types of application systems. These range from basic “pump in a drum” type systems all the way up to fully automatic metering, mixing and dispensing systems with Mass flow and temperature control systems for control of ratio and open times.
Our types of systems and equipment:
- Static Mixers and 2 component Cartridges.
- One Component Manual Systems.
- One Component Automatic string bead Systems on a bed or with conveyors.
- One or two Component Continuous lines (diamond bead (indexes Y and Z at the same time).
- Two Component metering, mixing and dosing systems for manual application or spreading.
- Two Component automatic metering, mixing and application machines (for large panels these systems can move on a track to access vacuum press tables).
- Multi Component (3 part) Manual Systems are designed specifically to reduce press times, this is achieved by metering and mixing two base adhesives and one catalyst at varying ratios from 100:0 and 0:100, this is managed by its precise measuring systems, flow controls and ratio temperature compensation system (see image below).
- Multi Component (3 part) Automatic application Systems are generally for very large panels running on tracks to access vacuum press tables. These are designed again specifically to reduce press times and increase production (see image below).
Handling & Cleaning and Polyurethane Adhesives
Polyurethane adhesives can be very volatile and it is advisable to clean as you go, however with many applications cleaning of equipment needs to be done. Diffident solutions fit the varying types of Polyurethane and equipment used such as.
- Prevention is best if possible, one component spreader heads and dispensing tools should be kept submerged in a plasticiser such as Mezamol (automatic machines should do this for you).
- Where still wet solvent flushing is advisable to clean equipment, using a diaphragm pump, connections and a solvent flush box.
- Dry 1 component can be scraped out with brute force and then flushed, although it is expensive it is advisable to send parts away for baking, if possible.
2 & 3 - Component: -
- Prevention is minimal for 2 & 3 component adhesives because the catalyst is not mixed until it leaves the meter mix valve manifold, the static mixer is detached and the manifold outlet is wiped clean.
- Manual Systems, are usually supplied with a solvent flushing station for use with the steel or stainless-steel mixers, spreaders and extension pipes (for large panels).
- Automatic Systems do not need a solvent flushing system as we use disposable plastic static mixers and compatible disposable plastic spreaders (above image), this proves to be much less hazardous/time consuming than using solvents and generally more cost effective when you consider cleaning times, insurance and disposal.