BEST PRACTICE GUIDE FOR

ADHESIVE SEAM JOINTING

Brian Spencer Chairman

ESTO Adhesives Working Group

SOME BASIC GUIDANCE TO START WITH…

• Correct choice of adhesive • Correct installation conditions • Correct installation techniques

Designed to last a lifetime!

• Adhesives are formulated to extend the season but limitations exist…

Whatever the weather?

• Moisture tolerant adhesives are available but…

• If it’s really wet the adhesive will try to bond to the water on the surface rather than the surface itself…impossible for any adhesive!

How wet is wet?

• Temperature & storage • Mixing • Application • Seam joints • Curing process • A recommended check list

The effective use of two component adhesives and considerations of:

• Before use try to protect the adhesive from temperature extremes Store before use at 10 – 25°C

• Mix will lose some structure • Mix will cure more rapidly and give shorter working period • Mix will absorb more into textile faced jointing tapes.

EFFECTS: Use of adhesive at high temperatures

• Store adhesive components at the recommended storage temperature

• Compensate for loss of structure by increasing amount of adhesive

• Reduce time from mixing to application • Mix less sets of adhesive in advance of

application • Work efficiently as a team to apply the adhesive

and make the seam joint promptly • Do not install in conditions above 35°C

35°C

To compensate:

• Adhesive will be “thicker” and more difficult to mix components

• Adhesive will cure more slowly after mixing • Slow cure gives more time for bad weather conditions to

affect bond

EFFECTS: Use of adhesive at low temperatures

• Store adhesive components at recommended temperature

• Ensure thorough mixing of the two components

• Use the 3rd component accelerator to promote faster cure time

• Do not install if temperature is below 3°C • Allow 4 hour window to cure before

temperature drops to 0°C

3°C

To compensate:

• Products available where: • Structure more stable at high & low temperatures • Application easier and more consistent • Mixing is easier at uniform viscosity

New technology is improving consistency...

MIXING

Ensure complete mixing of the two adhesive components

• Adhesive will not cure to a consistent tough film • “Soft spots” will give rise to a bond failure points

EFFECTS: Poor mix consistency

• Use an effective mechanical mixing device whenever possible • Pay close attention to dispersing adhesive from sides and base

of container • Observe uniform colour consistency through the mix • If in any doubt that mixing of entire contents is not uniform,

pour into another container and remix

REMEDIES:

Apply the correct quantity of adhesive appropriate to the carpet backing

Application

• Bonding will be less than 100% to back of carpet • Bond strength is reduced • Future bond failures are highly likely

EFFECTS: Not enough adhesive applied

• Apply sufficient adhesive to fill the spaces between stitch rows on the back of the carpet

• Use correct applicator setting that will give consistent application

• Ensure notches on applicator are clean • Test the carpet before installation to determine the correct

coverage

REMEDIES:

BAD PRACTICE

GOOD PRACTICE

SEAM-RITE

POOR TOOLS ADHESIVE APPLICATOR

• Adhesive will extrude at seam joint causing hard glue line • Danger of raised seam joint affecting performance

EFFECTS: Too much adhesive applied

• Apply sufficient adhesive to just fill the spaces between stitch rows on the back of the carpet

• Use correct applicator setting that will give consistent application

• Ensure notched applicator tray is level over tape • Test the carpet before installation to determine the

correct coverage*

* Test by applying adhesive to tape and pressing carpet into the adhesive. Remove carpet and you need to see adhesive transferred over whole area of carpet backing.

REMEDIES:

SEAM-RITE

HEAVY COAT – Too much adhesive applied

SEAM JOINTS Correct Use of Adhesive With Seaming Tape

• Too narrow a width of adhesive applied to tape • Carpet joint not positioned down centre of tape

Both effects can lead to reduction of seam strengths

EFFECTS: Common errors in combining materials

• Apply minimum 24cm adhesive across width of tape 30cm • Position carpet seams centrally

REMEDIES:

For cut in line installation it is advisable to use a wider tape to allow for extra seam joint width. This particularly applies to inserted curved lines.

SEAM JOINT

• Adhesive will not bond to the plastic backing of the jointing tape, where joints cross or lines are cut in

• Bond in this area will be weak and may be future point of failure

EFFECTS: Non removal of tape backing at cross joints

• Remove the tape backing that will be in contact with the new bond area, i.e. • Remove the film backer from the tape; • If tape has a sealed plastic coating or reinforcement,

then remove this portion of tape by abrading.

REMEDIES:

The yellow area represents the section of horizontal tape where it is necessary to remove the film backer or tape section before bonding to

the vertical seaming tape.

• Jointing tapes available that eliminate the need to remove backing on cross joints (not suitable for all specifications)

• Jointing tapes available with secondary laminates to impart high strengths to tape structure

• Cross joints with these tapes necessitate removal of backing laminate as previously described

New technology of seaming tapes

Apply uniform pressure to bonded area during adhesive curing process

Light even pressure is required immediately after making bond.

Curing process

• Adhesive may not transfer evenly to carpet backing • Extreme edges of carpet may not be “bedded” into adhesive • Stiffness of carpet may cause seams to open in some areas

EFFECTS: Poor pressure

• Use light roller to transfer adhesive • Apply light even pressure to seam joint several times until

adhesive solidifies • Use one of the following methods to consolidate bond:

• Flat planks with weights • Frequent use of light roller.

REMEDIES:

POOR PRESSURE

On-site check list

• Are external conditions suitable for seam bonding? • Was the adhesive stored at the recommended temperature

range? • Is mixing of adhesive components consistent? • Are application tools clean and set correctly? • Is amount of adhesive adequate for carpet being installed? • Is adhesive applied to tape uniformly? • Is procedure correct for cross joints? • Is pressure on seam applied adequately and frequently?

Finally check standard of bond being achieved!

Check list:

For further information visit

www.envirostik.com