Which glue to use for plastic bonding?

To guarantee effective bonding, it is crucial to ensure the surface preparation of the plastics to be assembled. For example, Samaro and its partner Socomore recommend the use of Diestone DLS, a non-greasy, fast-evaporating solvent degreaser, ensuring optimum adhesion during assembly.

Types of adhesive suitable for plastic

Plastic bonding is common practice in many industries, offering robust and durable assembly solutions. However, choosing the right adhesive for the job is crucial to ensuring the quality and reliability of the joints. Here we will cover 4 types of adhesive used for plastic bonding: epoxy adhesives, cyanoacrylate adhesives, UV adhesives and methacrylate (MMA) adhesives.

Epoxy adhesives for plastics

Epoxy adhesives fall into two categories: single-component, which cure between 100 and 175°C, and two-component, which cure at room temperature. These adhesives are renowned for their high mechanical strength and remarkable chemical resistance, enabling them to form solid joints on a variety of plastic surfaces.

They are often preferred for bonding different types of plastics, including thermosets and thermoplastics. ARALDITE® 2011 PL, a standard two-component epoxy adhesive that is versatile, fluid and has a long open time, is an excellent choice for a variety of applications.

Cyanoacrylate adhesives for plastics – the “super glues”

Cyanoacrylate adhesives, often referred to as “super glues”, are popular for their polymerisation in seconds and instant adhesion. They are ideal for bonding plastics such as polystyrene, polycarbonate and PVC. Cyano PERMABOND 737 “Black Magic”, offers fast curing from 5 to 20 seconds, increased flexibility for better shock and vibration resistance, as well as excellent adhesion to difficult plastics such as polyamide.

UV adhesives for plastic bonding

UV adhesives, also known as light-curing adhesives, cure quickly under exposure to ultraviolet light. They are popular in many industries due to their ability to offer transparent joints, fast setting and high strength. PERMABOND UV645 is a UV adhesive specially designed for bonding acrylic plastics, offering instant set and suitable for PMMA parts.

Methacrylate (or MMA) adhesives for plastics

Methacrylate adhesives are renowned for their strength, reliability and ease of use, requiring little surface preparation. These adhesives, often referred to by the abbreviation MMA, are versatile structural adhesives perfectly suited to a variety of plastics, including even ABS (acrylonitrile butadiene styrene). ARALDITE® offers a variety of methacrylate adhesives suitable for different applications. For example, ARALDITE® 2023 offers a long pot-life of up to 60min, while ARALDITE® 2050 and ARALDITE® 2051 guarantee ultra-fast setting in just 6 minutes, making them ideal for emergency repairs and extreme environments.

Advantages and applications of MMA adhesives

Methacrylate adhesives offer several significant advantages in the plastic bonding industry. Their long working time allows precise adjustment of parts before curing, which is particularly useful in complex applications. In addition, their ability to bond a wide range of plastic materials makes them a versatile choice for a variety of industrial applications.

ARALDITE® 2053 is a popular choice for harsh environments because of its outstanding resistance to impact, vibration and adverse weather conditions. Its ability to form flexible joints compensates for material stresses and movements, an essential feature in many applications.

ARALDITE® 2081 is specially designed for bonding plastics. Its main advantage is its low odour emission during application. With up to 90% less odour than conventional MMA, this is a crucial factor to take into account when applying in confined or difficult-to-ventilate spaces.

Some examples of common applications for methacrylate adhesives in different industry sectors:

Railway :

• Assembly of interior and exterior components for wagons and locomotives.
• Fixing panels and interior linings.
• Repair of plastic parts on trains.

Marine :

• Bonding structural components on ships and boats.
• Repair and maintenance of plastic hulls.
• Fixing underwater accessories and lighting systems.

Wind power :

• Assembly of plastic wind turbine blades.
• Repair of nacelle and tower parts.

General industry:

• Manufacture of plastic storage tanks and containers.
• Assembly of industrial machinery and equipment parts.