Ask Dr. Dave

Ask Dr. Dave

Question: I make both thermoplastic and thermoset plastic parts, and I want to start using structural adhesives to bond pieces prior to supplying my customers. Should I be aware of any potential problems?

Answer: There has been a tremendous increase in recent years in the use of plastics and composites to replace metals in component design. Since plastics do not always lend themselves to traditional fastening methods, the demand for adhesive bonding of these materials has increased.

From the adhesives technologist’s perspective, plastics are something of an anomaly: on one hand, bonded joints can be made where the plastic falls before the adhesive; on the other hand, certain plastics are very difficult to bond. Structural adhesives for plastics typically include epoxies, cyanoacrylates, polyurethanes or reactive acrylics. Epoxies often work but are sometimes too rigid and brittle. Rubber-toughened systems have improved this problem to a certain extent, and many successful applications have been reported in bonding thermoset plastics and repairing fiberglass panels.

Two-component polyurethanes are extremely versatile in plastics bonding and are used widely for polyester sheet-molding compound (SMC) bonding, where their good adhesion and high flexibility are key properties. Cyanoacrylates provide excellent adhesion and are probably the most versatile adhesives for plastics. Limitations include gap filling to only 0.5 mm, temperature resistance to about 100

Did you enjoy this article? Click here to subscribe to Adhesives & Sealants Industry Magazine.

Recent Articles by Dave Dunn

You must login or register in order to post a comment.



Image Galleries

ASI April 2014 Photo Gallery

Our April 2014 issue is now available!


ExxonMobil Tackifier Expansion

Dwight Tozer, vice president of ExxonMobil’s Adhesion Industry business, discusses the company’s latest tackifier expansion project with Editor-in-Chief Susan Sutton.

More Podcasts

Adhesives & Sealants Industry Magazine

ASI May 2015 cover

2015 May

You won't want to miss our May issue, with a special packaging-focused Adhesives at Work section, as well as coverage of pressure-sensitive adhesives (PSAs), biorenewable feedstocks, and more!

Table Of Contents Subscribe

Better Jobs

Is the economy prompting you to consider leaving your job for a better one?
View Results Poll Archive


Handbook of Sealant Technology

The Handbook of Sealant Technology provides an in-depth examination of sealants, reviewing their historical developments and fundamentals, adhesion theories and properties, and today’s wide range of applications.

More Products

ASI 2014 Buyers GuideASI's Buyers' Guide

Annual purchasing resource for equipment used in the manufacture/formulation of adhesives, sealants, pressure sensitives, tapes and labels and for application of finished adhesives. 


facebook_40px twitter_40  youtube_40pxlinkedin_40 google+ icon ASI 30px

Clear Seas Research

With access to over one million professionals and more than 60 industry-specific publications, Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.