Thermoplastic Adhesives
Thermoplastic adhesives are fusible, soluble and poor heat and creep resistant.
They are normally used for low/medium load assemblies under reasonable service conditions
In general, thermoplastic adhesives have low/medium shear strength and suffer from
creep at high loading. They have good resistance to oils but poor
resistance to water. Thermoplastic adhesives include polyvinyl acetate (PVA),
polyvinyl alcohol (PVA), polyacrylates, polyester acrylics, acrylic solvent cement,
cyanoacrylates (superglue), silicone resins, polyamides and acrylic acid diesters.
Over the last 35 years, properties of thermoplastic adhesives have been enhanced by
toughening such that variants are available suitable for structural duties. There is
widespread use of thermoplastic adhesives (anaerobic) adhesives for radial fit
assemblies, and screw locking assemblies.
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| Type |
Notes |
Materials Bonded |
| Polyvinyl Acetate (PVA) |
Supplied as an emulsion in water, for porous materials, especially wood. Shear strength is good. Resistant to oil . Poor resistance to water. Low heat tolerance. ( White glue) |
Wood, Metal, glass, ceramics, |
| Acrylic solvent cement |
Polymethyl methacrylate (PMMA) dissolved in methyl chloride. |
PMMA,styrene,Polycarbonate, UPVC |
| Toughened Acrylic |
Toughened acrylics( 2 part) are relatively fast curing and offer high strength and toughness, plus have more flexibility than common epoxies. They tolerate minimal surface preparation and bond well to a wide range of materials. High peel strength adhesive. Flexon variant single part -24 hours full strength. |
Most materials , very good for metals. |
Toughened Acrylic
Flexon |
As above bu single part - Requires 24 hours for full strength. But good wet tack allowing rapid assembly. |
Most materials , very good for metals. |
| Cyanoacrylates |
Harden quickly in seconds based on catalytic action of surface moisture. Good for rubber. Care needed when used with metals in moist warm conditions. "Superglue" |
Metal, ceramics, plastics etc. |
| Silicone resins |
Two part thixotropic adhesive provides electrical insulating properties. Low strength but high working temperatures |
Fluorocarbons |
| Polyamines |
Applied hot and set on cooling. Same properties as nylon. |
Metal, wood, plastics , laminates |
Anaerobic
Acrylic acid diesters |
Sealant, locking compounds set in the presence of metals and the absence of atmospheric oxygen. In use this hardens when used in a completed assembly. Used to lock , seal, retain all types of turned threaded, fitted parts., |
Metals,. |
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