ADHESIVE SCIENCE 101 for the FLOOR COVERING INSTALLER Jeffrey B Johnson FCIS & DIY Business Marketing Manager MAPEI Corporation
The SCIENCE of BONDING What is the function of a flooring adhesive? Gravity Assist Structural support
The SCIENCE of BONDING Types of adhesive bonds Mechanical Chemical Ionic Covalent Van Der Waals
The SCIENCE of Bonding Adhesive Failure Modes Cohesive Adhesive As a general design rule, the material properties of the object need to be greater than the forces anticipated during its use. (i.e. geometry, loads, etc.).
Types of ADHESIVES Non-Reactive Reactive Drying Adhesives Pressure Sensitive Adhesives Contact Adhesives Hot-Melt Adhesives Reactive Two Component One Component
CURING Mechanisms Non Reactive Drying Adhesives Evaporation Coalescence Pressure Sensitive Adhesives Tapes Contact Adhesives Hot-Melt Adhesives
CURING Mechanisms Reactive Two Component One Component Chemical reaction between two (or more) chemical compounds One Component Chemical reaction between a prepolymer and moisture (H2O) Anaerobic adhesive cures in the absence of O2.
ADHESIVE Chemical Bases Natural Plant based, animal based Solvent Based Nitrile, Neoprene, SBR, Asphaltic, Acrylic, PVA Latex SBR, Acrylic, PVA Thermoplastic Ethylene Vinyl Acetate Reactive Epoxy, Urethane
ADHESIVE Chemistry Components for solvent based adhesives consist of: Rubber Solvent Filler “mummy dust” Performance attributes: Fast drying Flammable Moisture resistant Contact cements, construction adhesives
ADHESIVE Chemistry How solvent based adhesives work Dry by solvent evaporation As solution concentrates due to evaporation the adhesive mass builds viscosity and develops green strength. Excellent wetting characteristics Things that effect solvent based adhesive performance Temperature Moisture Ignition sources
ADHESIVE Chemistry Components for SBR Multipurpose Flooring Adhesives SBR Latex Hydrocarbon Resin Process Oil Filler Water Performance Attributes: Leggy Durable Inexpensive Designed for felt backed and fibrous backed flooring FILLER LATEX OIL HYDROCARBON RESIN
ADHESIVE Chemistry How SBR latex adhesives work Dry by water evaporation and coalescence Resin solution emulsion breaks destabilizing the blend which results in “leg” development Things that effect SBR adhesive performance pH of substrate Contaminants Excess shear Temperature Moisture Plasticizer Migration
ADHESIVE Chemistry Components for an acrylic adhesive: Latex acrylic polymers Fillers Water “Mummy Dust” Performance Attributes Plasticizer resistant Alkali resistant Oxidation resistant Expensive Designed for vinyl backed flooring Non-legging SOFT SET / PSA HARD SET
ADHESIVE Chemistry How acrylic latex adhesives work Dry by water evaporation and coalescence Polymer structure and Tg determine final performance Hard set Pressure sensitive Things that effect acrylic adhesive performance pH of substrate Contaminants Temperature Moisture
ADHESIVE Chemistry Components for hot melt adhesives EVA resin Wax Tackifiers Plasticizers Performance attributes Solid at room temperature but become fluid at temperatures above 180F Cool quickly to solid phase Can be brittle at very cold temperatures Can soften at higher temperatures
ADHESIVE Chemistry How hot melt adhesive work Performance attributes Become fluid with heat and cool to a solid Performance attributes Rapid bond performance Things that effect hot melt adhesive performance Temperature Moisture Surface contaminants Plasticizers
ADHESIVE Chemistry Epoxy Adhesives Performance Attributes Reactive adhesives by the combination of an epoxy resin and a basic (pH) hardener (amine) Performance Attributes Extremely high bond strengths 100% solids Bonds to many types of materials EXOTHERMIC! Can cause allergic reaction No “green strength” Mass dependent for curing (temperature)
ADHESIVE Chemistry How epoxy adhesives work Cure by chemical reaction Epoxy resin reacts with amine based hardener to create thermoset adhesive Things that effect epoxy adhesive performance Temperature Moisture Improper mixing
ADHESIVE Chemistry Urethane Adhesives Performance Attributes Reaction of isocyante group (NCO) and hydroxol (OH) Releases CO2 when reaction occurs with water. Performance Attributes 100% solids, no solvents, no water Superior bond and tensile strengths Very resilient Moisture resistant when cured Expensive Can be hazardous
ADHESIVE Chemistry How urethane adhesives work Cures upon exposure to moisture or Cures when mixed (Part A/B) Things that effect urethane adhesive performance Moisture (excess or lack thereof) Contaminants Temperature
RULES that Regulate Adhesives
RULES that Regulate Adhesives PROP 65 Proposition 65, the Safe Drinking Water and Toxic Enforcement Act of 1986, was enacted as a ballot initiative in November 1986. The Proposition was intended by its authors to protect California citizens and the State's drinking water sources from chemicals known to cause cancer, birth defects or other reproductive harm, and to inform citizens about exposures to such chemicals. PAGE 1 of 22
STANDARDS for Adhesives ASTM D7799-12 Standard Specification for Tufted and Woven Broadloom Carpet Adhesives Without Homogenous PVC or Non-PVC Backings
When to USE WHAT, and Why
When to USE WHAT, and Why
READ THE INSTRUCTIONS! When all else fails, and preferably before things start to fail, please read the instructions provided by the adhesive manufacturer.
“Bond, James Bond” Thank you for sticking with me on this tacky subject!
QUESTIONS? I’m all ears.