Know more about Methacrylate.

What is a Methyl Methacrylate Adhesive (MMA)?

MMAs or Methyl Methacrylate Adhesives are 2 component structural grade acrylic adhesives that comprise of an Adhesive (Part A) and an Activator (Part B). When Adhesive and Activator are combined and mixed the product cures rapidly at room temperature exothermically to form a tough, thermoplastic adhesive capable of withstanding extreme stress, vibrations, impact forces and having excellent shear and peel strength. While the above description may sound similar to an epoxy adhesive but in reality, a Methyl Methacrylate adhesive cure profile and ultimate bond performance is much different and, in most cases, more stronger and fatigue resistant than an epoxy adhesive. The progress of curing reaction in a methyl methacrylate adhesive is slow until it reaches its pot life/open time and subsequently the fixturing strength is reached rapidly in very short time duration reducing the need for expensive fixtures and saves time before the parts can be assembled. Surface preparation requirements are not as stringent with Methacrylate adhesives.

What makes Scott Bader CrestaBond Methyl Methacrylate Adhesives (MMA) a preferred choice for Structural bonding applications?

The term Structural bonding refers to joining parts with an adhesive capable of withstanding high levels of stress and their ability to transfer load for long time period. Scott Bader MMA adhesives are one of the widely used structural bonding adhesives because they are formulated using impact modifiers to provide tough yet flexible bond lines that can withstand high shear, peel, cleavage and impact forces. Due to their toughness and high peel force resistance, they can replace mechanical fastening such as riveting, welding and bolting in a variety of applications.

Key advantages of Crestabond Methyl Methacrylate (MMA) adhesives over others

  • Universal Bonder: Due to their unique chemical nature Crestabond methyl methacrylate adhesives bond equally well to metals, composites, plastics and ceramics. While an epoxy can have as high a structural strength but they do not generally bond plastics as well as methyl methacrylate.
  • Versatile: Crestabond MMAs can be used in off mixing ratios. They are very well tolerant to off mixing and yet produce tough and strong bonds. In contrast a 2C Polyurethane or epoxy adhesives require near perfect mixing ratios of Resin and Hardener.
  • Surface Preparation: Due to the unique nature of Crestabond’s acrylic monomers, our Methyl methacrylate adhesives are fairly tolerant of poor surface conditions (small amount of oil or an imperfect cleaning) without much loss in final results. In contrast the final strength of an epoxy and PU is greatly affected by the surface condition and high level of surface preparation is critical to their successful performance.
  • Speed of cure: Methyl Methacrylate Adhesives cure rapidly after they reach their pot life and fixturing strength is obtained fairly quickly ranging from 5minutes to an hour. Because of this they are preferred in a high production environment. In contrast an epoxy or a 1 component polyurethane adhesives need prolonged periods of fixturing that can range from 6 hours to 12 hours.
  • High strength: Methyl methacrylate adhesives offer higher shear and peel strength as compared to an epoxy or 2C PU adhesive. While typical shear strength of a high strength epoxy adhesive is about 22-25 N/mm2 and lesser for PU, a Methacrylate adhesive can reach upto 30 N/mm2 and beyond.

What substrates can be bonded using Scott Bader Crestabond Methyl Methacrylate Adhesives?

Our methacrylate adhesives can bond a variety of substrates making them an ideal adhesive to bond two different substrates.

PlasticsMetalsComposites
ABSStainless SteelGRP / FRP
AcrylicAluminiumCarbon fiber
PolycarbonatePowder Coated SteelPolyester
PVCCold Rolled SteelGelcoat
NylonGalvanised surfaceEpoxy
PP/PE TPOCarbon steelVinyl ester

Preferred Joint Designs and forces for successful bonding with methacrylate adhesives:

Lap Joint

Lap Joint

Double strap Joint

Double lap Joint

Strap Joint

Strap Joint

Double Lap Joint

Double Strap Joint

Scarf Joint

Scarf Joint

Sheer Force

Tensile Force

Peel Force

Forces and Joint Designs to be avoided

Cleavage Forces

Stepped lap joint

Butt joint

Butt Joint

Types of Methacylate Adhesives from Scott Bader:

Our Crestabond Methacrylate adhesives come in three types

M7 Series:

Are 1:1 mix ratio rigid methacrylate adhesives especially formulated to bond metals and plastics such as Galvanised steel, zinc coated metals, chrome plated metals, SMC, BMC, Poltruded GRP and Nylon.

They offer high strength but limited elongation. Due to their rapid curing they are very good for small surface bonding applications such as brackets, hinges, bigheads. Class NK and EN45545 accreditation is available for M7-05 and M7-15

M1 Series:

Are 10:1 mix ratio tough and flexible methacrylate adhesives. They offer high strength and high elongation. Can fill larges gaps upto 50mm and are non-sag on vertical applications. M1 series products are excellent for large bonding surfaces in commercial vehicles, transportation and marine. DNV-GL approvals on M1-30 M1-60HV & M1-90HV is available. EN45545 accreditation is available for M1-05 and M1-20.

PP Bonder:

Especially formulated for bonding low surface energy plastics such as PP, PE, HDPE, LDPE et al to themselves or to other substrates such as metals, plastics and composites. Variants for ultrafast curing to very slow curing available to meet suit most application requirements.

Application Areas:

Transport and automotive:

Methacrylate adhesives are being successfully used in the automotive and transport industry for bonding both metal and composite assemblies such as bumpers, instrument panels, spoilers, wheel arches, glove boxes, door panels, plastics headlights, tail gate, structural body parts, grille, roof assemblies, E-coated parts and other composite components.

Marine:

In boat manufacturing methacrylate adhesives are widely used for Bonding of deck to hull and stringer bonding, deck liners, ski boats, internal fixtures, canoes and kayaks. They save time and provide a strong and reliable bond which is not susceptible to cracking or brittleness.

Electric Vehicles:

Methacrylate adhesives reduce weight and help in even stress distribution in Electric Vehicles where these are highly desired properties. Some of the key applications of methacrylate adhesives in electric vehicles include battery enclosure bonding, battery pack sealing, bonding of liner to frame.

Wind Energy

Even though epoxies are traditionally used in a large variety of applications in wind applications, methacrylates due to their flexibility and strength are being preferred in a number of applications such like Shell bonding, Nacelle, drill and fill repair and blade accessories

Solar rooftop Installations:

Methacrylate adhesives are widely used for bonding of Aluminium brackets to roof panels for installation of solar panels. Due to non-penetrating joints, it enhances joint strength and eliminates chances of water ingress through rivet holes.

Building Construction:

Methacrylate adhesives are used extensively for bonding in external signage and UPVC door applications, displays, anchoring and architectural components.

 

Other newer areas of applications of methyl methacrylate adhesives are coming up in new technology manufacturing such as Drone manufacturing, IOT, Electric Vehicles and others.