Dave Dunn Ph.D.

Ask Dr. Dave is written by Dave Dunn, Ph.D., of F.L.D. Enterprises, a technical consultancy and full-service industrial market-research firm specializing in the adhesives, sealants, specialty rubbers and plastics fields. Dave is a former vice president and director of Loctite Corp. and has spent many years in troubleshooting adhesive and sealant problems. Questions for publication should be directed to him at 242 Trails End, Aurora OH 44202; phone (440) 477-5164; fax (330) 247-1690; or email DrDave242@windstream.net .

Ask Dr. Dave

Is handling one-component polyurethane adhesives and silicone sealants difficult?

Dave Dunn's October 2017 column

Dave Dunn Ph.D.

October 2, 2017

It sounds like you sell to several different markets. Although there is some overlap of silicone or polyurethane markets, they are often used in distinct applications.

Ask Dr. Dave

What is the best way to store my epoxy and acrylic adhesives?

Dave Dunn Ph.D.

August 3, 2017

We use an acrylic UV adhesive to bond and coat a complex medical device, and get areas where there is incomplete curing. How can we improve this?

Ask Dr. Dave

How do we get rid of the mess created from using fumed silica?

Dave Dunn's June 2017 column.

Dave Dunn Ph.D.

June 1, 2017

Can you help us to get rid of the mess created from using fumed silica in our silicone and polyurethane adhesive manufacture? It is so lightweight that it covers the entire factory.

Ask Dr. Dave

Is there a PSA that can be removed and reapplied a number of times without losing adhesion?

Dave Dunn's May 2017 column.

Dave Dunn Ph.D.

May 4, 2017

We have a customer who wants to use an adhesive-backed expanded PTFE gasket strip on a steel substrate. However, the customer wants to be able to remove and reapply the strip without losing adhesion. We do not make ePTFE gasket strips, but we have imported some samples for the customer to test. They are not satisfied with the results. I must admit, I am not surprised. Is there such a thing as a PSA that can be removed and reapplied a number of times without losing adhesion?

Ask Dr. Dave

I see a lot of job advertisements for polyurethane chemists. Why the sudden interest?

Dave Dunn Ph.D.

April 3, 2017

Polyurethanes can be one- or two-component systems. The single-component systems comprise a polyester or polyether polyol that has been end-capped with an isocyanate.

Ask Dr. Dave

Do reactive acrylics and anaerobics behave like epoxies in terms of curing?

Dave Dunn's March 2017 column.

Dave Dunn Ph.D.

March 1, 2017

Do reactive acrylics and anaerobics behave like epoxies in terms of curing and properties like heat resistance?

Ask Dr. Dave

What is the difference between a hardener, a primer, an accelerator, and an activator?

Dave Dunn's February 2017 column.

Dave Dunn Ph.D.

February 1, 2017

What is the difference between a hardener, a primer, an accelerator, and an activator for adhesives and sealants?

Ask Dr. Dave

What has been your experience using silicone caulks, both interior and exterior?

Dave Dunn's December 2016 column.

Dave Dunn Ph.D.

December 1, 2016

Longtime readers of this column may note that I have always been a fan of silicone sealants; however, I worked for a manufacturer of these materials for many years, so I hope I can be totally objective. I have no doubt that the durability and longevity of silicones cannot be exceeded in most applications. However, I can offer you several observations from my personal experience using them at home.

Ask Dr. Dave

What tips can you provide for bonding plastics and composites with adhesives?

Dave Dunn's November 2016 column.

Dave Dunn Ph.D.

November 3, 2016

Adhesives are often a better way to assemble plastics than by using mechanical assembly with fasteners. For example, fiberglass composites are routinely bonded with epoxy or reactive acrylic adhesives in the automotive and marine industries because they give high strength and durable bonds.

Ask Dr. Dave

Why use pressure-sensitive tape adhesives in the assembly of electronic devices?

Dave Dunn's October 2016 column.

Dave Dunn Ph.D.

October 3, 2016

What are the pros and cons of using pressure-sensitive tape adhesives in place of liquid adhesives in the assembly of electronic devices?

Dave Dunn Ph.D.

ARTICLES

Is handling one-component polyurethane adhesives and silicone sealants difficult?

What is the best way to store my epoxy and acrylic adhesives?

How do we get rid of the mess created from using fumed silica?

Is there a PSA that can be removed and reapplied a number of times without losing adhesion?

I see a lot of job advertisements for polyurethane chemists. Why the sudden interest?

Do reactive acrylics and anaerobics behave like epoxies in terms of curing?

What is the difference between a hardener, a primer, an accelerator, and an activator?

What has been your experience using silicone caulks, both interior and exterior?

What tips can you provide for bonding plastics and composites with adhesives?

Why use pressure-sensitive tape adhesives in the assembly of electronic devices?

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