Chlorinated polyolefin (CPO) adhesion promoters for polyolefins
Tramaco Trapylen adhesion promoters bond paints, inks, and adhesives to polypropylene, polyethylene, and TPO. Solid, solvent-borne, waterborne, and UV-curable forms.
Tramaco Trapylen adhesion promoters bond paints, inks, and adhesives to polypropylene, polyethylene, and TPO. Solid, solvent-borne, waterborne, and UV-curable forms.
Polypropylene, polyethylene, and TPO are low-surface-energy plastics. Their surfaces are non-polar, so paints, inks, and adhesives have nothing to grip and will not bond to them on their own. A coating that looks fine when it goes on can peel, flake, or fail a tape test in service.
The usual fix is physical surface treatment: flame or corona pre-treatment to oxidize the surface before coating. That works, but it adds a process step, equipment, and a treatment window that has to be managed before the surface relaxes again.
A chlorinated polyolefin adhesion promoter does the same job chemically. The workhorse Trapylen grades are maleic-anhydride-grafted chlorinated polypropylene. The chlorinated polyolefin backbone is compatible with the untreated polyolefin surface and anchors into it, while the polar maleic-anhydride-grafted groups give the next layer something to bond to.
Applied as a thin tie-coat or blended into the coating or ink itself, the promoter becomes the bridge between the plastic and the topcoat, ink, or adhesive. Bond strength comes up, tape-test and peel failures come down, and in many cases the flame or corona step can be reduced or removed.
Two chemistries run through the Trapylen range. The chlorinated polyolefins (CPO) are the classic promoters, at 2.5 to 43 percent chlorine depending on grade. The chlorine free modified polyolefins (APO) do the same adhesion work without chlorine, in solvent, in water and as solid resin, for specifications that exclude chlorinated material. Chlorine content is a first column in every grade table in our Tramaco catalog. If the specification you are working to excludes chlorine, the thirteen chlorine free grades and what changes when you convert are set out on chlorine free adhesion promoters for polyolefins.
Tramaco organizes Trapylen by application case, and the catalog follows it. Each page carries the current grades for that case with chemistry, chlorine content, form and solids.
| Application case | What it covers | Grades |
|---|---|---|
| Printing ink additives | Adhesion additives for solvent-based and UV-curable inks on PP, PE and BOPP film | 186 EAC, 187 EAC, 196 X, 5650 UV, 5800 UV, and the solid 118 S to 196 S range |
| Primers for molded plastics | Painting and coating molded polyolefin parts, in solvent, waterborne and solid form | 130 X, 777, 6600 W to 6800 W, the solid 112 S to 146 S range, and the chlorine free 900-series |
| Primers for films, foils and sheets | Ready-to-use primers for coating TPO and FPO film, foils and sheets | T 4121, 8000, X 8280, X 9100 M, 9352 W, 9703 W |
Trapylen comes in four carrier forms so the promoter fits the system it goes into. Choose the form to match the coating or ink, then we narrow the grade to the substrate and the bond you need.
Neat polymer that the formulator dissolves into the carrier of their choice.
Ready-made solutions for solvent coatings, inks, and primers.
Aqueous dispersions for waterborne and low-VOC systems.
Polymer carried in a reactive acrylate monomer for energy-cure inks and coatings, with no solvent.
If you run PP, PE, or TPO substrates and you are seeing paint, ink, or adhesive peel or tape-test failures, or you are told the part needs flame or corona treatment, that is a CPO adhesion-promoter application. Read more in how chlorinated polyolefin adhesion promoters bond coatings to polyolefins.
Low-surface-energy polyolefins, mainly polypropylene, polyethylene, and TPO. These plastics resist bonding by paints, inks, and adhesives, and a chlorinated-polyolefin promoter gives the coating a surface it can grip.
In many applications it can reduce or remove the physical pre-treatment step, because the promoter provides the polar bonding surface chemically. Whether it fully replaces treatment depends on the substrate and the coating, so trial it on the real part. Samples are available on request.
Match the carrier to your system: solvent solution for solvent coatings and inks, waterborne dispersion for low-VOC systems, UV-curable for energy-cure inks, or solid resin if you prefer to dissolve it into your own carrier. Tell us your system and we will narrow the grade.