4.3.6.3 Flame Treatment

Flame treatment increases the bondability of plastic by oxidising the surface through brief exposure to flame. The oxidation proceeds as a free radical mechanism, accompanied by chain scissions and some crosslinking. The functionalities introduced by oxidation are hydroxyl, carbonyl, carboxyl and amide groups, with a typical oxidation depth of approximately four to nine nanometers. Wettability is improved by increased surface energy. The chain scissions on the surface contribute to higher interfacial diffusivity.

4.3.6.4 Thermal Surface Treatment

Thermal treatment increases the bondability of plastics by exposing the plastic to a blast of hot air (approximately 500°C/932°F), which oxidises the surface. This method mainly introduces carbonyl, carboxyl and amide groups to the surface, but some hydroperoxide groups are also formed. Very similar to flame treatments, this process also utilises a free radical mechanism accompanied by chain scission and some crosslinking. The improved bondability results from increased wettability due to the introduction of polar groups and interfacial diffusivity caused by chain scissions.

Table of contents

Already have an account? Sign in

+33,000
professionals

have already
signed up

Award winning manual

Platinum Award for LOCTITE®X Digital Manual

The Digital Manual is for professionals by professionals

The manual is made entirely for you. However, if you’re still not convinced that free industry knowledge is for you, take a look at these user testimonials from the users of the manual.

"The topics are such that I can help take design related decisions very well at work. It's an interesting and knowledgeable read, I recommended my other colleagues to have a look at the manual as well."

Hanumant, Production Incharge

"The manual's chapters significantly enhanced my comprehension of various engineering topics. The manual adeptly presents explanations and examples of concepts, showcasing a high level of clarity and effectiveness in its content."

Tejas, Mechanical Engineer from a renowned Engineering College

"The release of this manual by a renowned brand such as Loctite has proven to be highly motivating for students. Its authentic content serves as a source of inspiration, encouraging students to engage actively in reading and learning."

Padmakar Deshmukh, Professor at an Engineering College