The Secret to Perfect Overmolding: Bonding Polyamide with SEBS-based TPE.

Image Credit to The Spruce / Kelsey Hansen


If you’ve ever worked with multi-material injection moulding, you know the struggle: getting a soft, flexible TPE to actually stick to a rigid Polyamide (PA) substrate. Without the right chemistry, you’re often left with peeling edges or the need for expensive adhesives.
 
Phon Tech has understood your concern. Our latest PA bonding grade is specifically engineered to solve this. It creates a seamless, high-strength bond with PA6, PA66, and Glass-Filled Nylon, ensuring your product feels premium and lasts longer.
 
Our new TPE alloy grade does not need to be bonded with PA material through more physical Interlocks; the chemical bond does the heavy lifting, so it is great for overmolding and 2K injection moulding.
 
After you use our new TPE alloy grade, you can discover a clean, flush finish between the soft-touch grip and the hard plastic frame.
 

In the competitive business world, every industry prefers to get the most suitable material sourcing for their business profit. TPE industrial also facing this issue, so most producers are tempted to look toward low-cost suppliers promising "excellent PA bonding" at a fraction of the price. However, as many manufacturers have discovered, there is a massive gap between a salesperson's claim and the reality of a 2K injection moulding cycle.
 
Polyamide (PA) is notoriously difficult to bond with because of its high polarity and thermal requirements. Many budget SEBS-based materials from aggressive low-cost exporters use "fillers" or weak modifiers to mimic adhesion.
 
Therefore, the parts might look okay when they come out of the mold, but they fail shortly after due to imperfect assembly, or the part encounters heat, moisture, or vibration.
 
However, we don't rely on "temporary and fake bonding" claims for promoting our product. Our PA bonding grade is specifically formulated with active functional groups that create a true chemical bond with the PA substrate.
 

Comparing PA bonding TPE: Engineering vs. Budget

 

	Our Engineered TPE		Budget "PA-Bonding" TPE
Bonding Mechanism	Molecular chemical grafting		Simple physical suction/interlock
Consistency	High-purity SEBS base		Variable recycled content/fillers
Reliability	Tested for PA6, PA66, and GF-Nylon		Often only works on specific grades
Total Cost	Lower scrap rates and zero returns		High hidden costs due to failures

 

 

Finding the "Sweet Spot": High-Performance PA Bonding Without the European Price Tag

 

When it comes to bonding TPE to Polyamide (PA), the market usually offers two extremes. On one side, you have low-cost suppliers whose materials often fail in the field. On the other hand, you have premium European grades that work beautifully but come with a price tag that eats your most profitable margin.
 
We got your curious point, so we’ve focused more of our R&D on the molecular science of polar-modified SEBS, and our new PA-bonding TPE that bridges this gap. It provides the true chemical bonding required for PA6 and PA66; this ensures that it creates a permanent graft to the Polyamide substrate, matching the peel strength of the industry's " top standard" brands. but at a price point that makes sense for high-volume manufacturing.

 

Comparison at a Glance

 

	Low-Cost "Budget" Grades		European Competitors		Our SEBS-PA Series
Bond Strength	Weak / Unreliable		Excellent		Excellent
Chemistry	Simple Blend		Specialized Polar-Grafting		Specialized Polar-Grafting
Price	Very Low		Very High		Competitive / Mid-Range
Value	High Risk		Low Margin		Optimal Balance