Don’t glue Polypropylene, BOND Polypropylene PP

Glue Polypropylene?  No, “bond” Polypropylene, with the Bonding Poly Process (patented)

Conventional wisdom used to be that you can’t glue polypropylene, which is a polyolefin. Nowadays, you type in glue polypropylene and you get everything from gorilla glue to Elmer’s glue and little pre-packaged one and done at best, super glues. Everyone is now claiming to be able to easily glue polypropylene. Why? Simple. It is currently the most prevalent plastic. When we switch over to biodegradable plastics like PLA, everyone will be claiming to be able to easily glue PLA, but for now the material of the day, is PP or polypropylene.

The fact of the matter is you might be able if you are lucky, to get Elmer’s to stick two pieces of polypropylene together. And you might even be able to get gorilla glue to ‘stick’ two pieces of polypropylene together, but they will not be bonded together. Bonding is the fusion of the two substrates at a molecular level, creating unmatched sheer and tensile strength. ‘Gluing’ simply works by being sticky and works on the same principle of a piece of gum, wedged between two objects, holding them together. For any amount of strength or performance with polypropylene, you simply need more than crazy or super glue, because polypropylene has the common problem that most poly’s share; low surface energy. These type of low surface energy materials are even referred to as ‘non-stick’.

Over glues and epoxies.

Materials with high surface energy have attractive forces which make them easy to bond or even glue. Materials with low surface energy like polypropylene, have inherent repulsive forces, which make it virtually impenetrable. This is especially true for glues and epoxy’s which do no even attempt to break through the surface to begin with. They work by forming a sticky glue join. Our Process however, results in cohesion at the molecular level. The Process allows you to repair polypropylene parts, devices, toys, etc., quickly, easily and permanently – provided there is adequate surface area. Besides surface preparation, adequate surface area is the second key component for bonding/repairing polypropylene (PP). Heat is the third. The steps of our Process are outlined below. While it is not as easy as most crazy glue companies would have you believe, that you can just glop on some goo and then it is good to go………the Bonding Poly Process is not difficult either. The steps are more involved than slopping on some sticky paste, but the results are far superior. The Process uses the laws of chemistry and physics to form deep and permanent bonds.


Wherever and wherever we state that we can bond polypropylene or any other poly the universal reaction is skepticism.  Skeptics are the reason why we have a 100% customer satisfaction money-back guarantee.  If any of our kits do not perform to your expectations, we will refund your purchase price.  Simply return the kit.  After selling thousands of kits, we have not had to make a refund.  In the years since we developed the Process, we have only had to make one refund.  The case is outlined at the bottom of the page.

To bond polypropylene to itself or to any other polymer.

The Process always works.  Below are the step-by-step instructions for bonding polypropylene to itself or to any other polymer.

  1. Use a medium to fine grit sandpaper to rough the polypropylene (poly) surfaces.
  2. Clean with a liquid that will not leave a residue. 
  3. Wipe the polypropylene (poly) surfaces with a soft cloth.
  4. Saturate the polypropylene (poly) with our Poly Prep, an adhesion promoter for polymers.
    When you do NOT need worktime.
  5. Spray one of the polypropylene surfaces with our Activator/Accelerator (AA).
  6. Warm both surfaces with a hair dryer or heat gun.  Warm to very warm but not hot.
    1. By touch, just below hot.
    2. By temperature, about 120 degrees F.
  7. Apply an SI Structural Structural Adhesive to the opposite surface from where you sprayed the AA.
    1. Apply the SI adhesive using continuous circles.
    2. Make sure the edges are covered.
  8. Align and firmly press the polypropylene surfaces together for 10-15 seconds.
    When you need worktime.
  9. Warm both surfaces with a hair dryer or heat gun.  Warm to very warm but not hot.
    1. By touch, just below hot.
    2. By temperature, about 120 degrees F.
  10. Apply an SI Structural Cyanoacrylate to one of the polypropylene surfaces.
    1. Apply the SI adhesive in continuous circles making sure there is no break in the adhesive.
    2. Make sure that the adhesive will reach the edges.
  11. Firmly press the polypropylene surfaces together for 6-8 seconds.
  12. Spray the AA on the seam.

As a result of this process, the two polypropylene surfaces will be bonded.  Operational strength is achieved within an hour.  Full strength will take at least as month.

*Our Surface Insensitive (SI) Structural Adhesives, in conjunction with our Poly Prep Adhesion Promoter, will bond 98% of all materials.

To bond polypropylene to steel. To bond polypropylene to aluminum.

  1. Rough the polypropylene and the metal with a low-grit coarse sand paper.
  2. Saturate the polypropylene surface with an adhesion promoter designed to work with poly’s.
  3. Spray a solvent based Activator/Accelerator (AA) on either the polypropylene or metal.
  4. Warm the polypropylene surface with a hair dryer or heat gun.  Warm to very warm, but not hot.
  5. Apply an SI Structural Adhesive to the opposite surface from where the accelerator was sprayed.
  6. Firmly press for ten seconds.
  7. Warm the bond for twenty seconds

As a result of this process, the polypropylene and metal surfaces are bonded.  Operational strength is immediate.  Full strength will take at least as month. Don’t glue polypropylene, bond polypropylene.

Polypropylene Video 

We are working on a Polypropylene video.  As shown in the above video, Polypropylene is often the polymer of choice for small parts.  For an appropriate polypropylene video, we will have to collect a number of small broken polypropylene parts to illustrate the best techniques for repairing those poly items.  In the meantime, our Teflon® video is best example of how to use the Process to repair polyethylene or other poly parts.  The steps of the Process are essentially the same whether you repairing/bonding polypropylene or Teflon® items.

Our patented Bonding Polymer Process

What is the secret of the Bonding Polymer Process?  There are actually two, Chemistry and Physics.  Our Poly Kit that combines the Laws of Chemistry and Physics to create the bonds needed :

  • a polymer-enhanced, Surface Insensitive Structural Cyanoacrylate  
  • our standard Activator/Accelerator, (chemistry at work)
  • the Poly Prep (more chemistry)
  • and heat (the Laws of Physics part of the Process.)

When working with polypropylene, Teflon®, nylon, Delrin®, polyethylene or any other poly, it is extremely important to understand that polymers are very slow curing.  Bonds may take thirty days or more to fully cure.  However, in most cases, the item can be put into use within an hour.

The Case Study

As stated above, we have only had to make one refund with one of our Poly Kits.   Here is the case study of that refund.  

An individual purchased a Professional Kit to bond two halves of polypropylene balls together.  The polypropylene balls were about one and a half inches thick.  The walls were about one sixteenth inches thick.  Using the Process, our client successfully bonded the two halves together and allowed the creation to cure for 24 hours.  To test, the polypropylene balls were dropped from a height of ten feet.   First time.  No problem.  Second drop.  No problem.  Third drop.  The ball came apart. That breakage did not meet the customers hopes. Ergo the refund. 

Because polypropylene has exceptional strength, it is used to make small and thin constructs.  What about when those items break?  Can you create the same strength in the repair?  Quick answer?  No. You can, however, make a repair using the Process that will withstand normal wear and tear.  An explanation is needed.  The amount of strength created depends of the amount of surface area.  If there is adequate surface area, repairs will withstand normal wear and tear. Bond strength is always dependent on the amount of surface area available for the repair. 

Final question. Can surface area be added to increase strength?  Yes it can. Use of our Filler can increase bond strength by about five percent. Though five percent is not usually enough to make a critical difference. The filler is best used for surface repairs, a crack in the dashboard of a car, drilling and tapping and threading screws. You can even you it to make missing pieces or parts. The completion of a melted blower motor wheel. There are many uses for the filler and it can provide extra surface area and strength, though nominal.

In all the almost 20 years we have been offering our unconditional performance guarantee, this is the only refund we have ever issued. Our track record with polypropylene and poly’s in general is impeccable. And unless you are planning to bond one tenth of one millimeter thick bouncing balls together and drop them from the roof of your house, that one blemish is a non-issue. As with any material, the more surface area there is, the stronger the polypropylene bond is. Often times the bond is stronger than the material itself. If any failure occurs it is usually substrate failure; breakage of the material in places other than the bond.

Bonding Polymers

To bond polymers, you need one of Poly Kits.  Our Basic Poly Kit includes;

  • an SI Structural Cyanoacrylate,
  • our standard Activator/Accelerator,
  • the  Poly Prep,
  • a detailed step-by-step instruction sheet.    

Save 15% With Tech-Bond Kits

Our Poly, Deluxe or Professional Kits will bond Polypropylene to itself and any other substrate; except stainless steel and glass.

*If you have any questions, feel free to call 877-565-7225.

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Poly Molecular Bonding Kit- For Bonding Polypropylene
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