Understanding Adhesive Viscosity and Rheology
Most adhesive manufacturers list the viscosity of the uncured adhesive on their literature to help engineers determine which product is most suitable for a specific application and can be integrated into their production line most effectively. Temperature and shear (stirring or agitating) can affect adhesive viscosity and flow behavior, therefore it is important to take these factors into consideration when selecting an adhesive product.
Viscosity is the measure of resistance to gradual deformation by stress. For the purpose of liquid adhesives, viscosity corresponds to the thickness of the liquid. Water has a viscosity of 1 cP (or mPa.s) at 20°C. Liquids that have a viscosity less than water are mobile liquids and those with viscosity higher than water are viscous liquids. Click Here To Read More
Structural Acrylic Adhesives are easy to source from Permabond!
Permabond Engineering Adhesives offers a wide range of structural acrylic adhesives including the popular aerospace-approved TA4246 resin & brush on initiator, which cures to a high strength rapidly and offers excellent shear strength, peel strength and impact resistance. 
Structural acrylic adhesives can be used for bonding many different substrate materials such as steel, aluminium and other metals and alloys, composite materials such as GRP and carbon fibre, wood, magnets and ferrites, glass and plastics. They are used in industries such as aerospace (aircraft bonding), automotive exterior, sign bonding, electric motor magnet bonding, sports equipment, lifts, shopfitting and many more diverse applications. Structural acrylic adhesives can be used to replace welding, brazing or mechanical fasteners giving a much easier manufacturing process, a better finish and improved bonded performance e.g. better stress distribution, bond strength and no damage to substrate materials.
Permabond’s structural acrylic adhesives come with a range of packaging and mixing options and are easy to apply – either manually or via automated dispensing equipment on high speed production lines.
Permabond can offer excellent technical support during your design and development stage as well as provide assistance with introducing adhesives into your production line. Samples and trial material can be provided and purchasing is easy – with low minimum order quantities, short lead times and a network of local distributors, your production line can be kept moving.
Please contact Permabond for free technical consultation or for purchasing / stockist information at http://www.permabond.com/en/en-contact-all.php
New UV Curable Adhesives from Permabond
Permabond Engineering Adhesives is pleased to announce the launch of two new additional UV-curable adhesives to complement the existing UV product range. The new UV-light cured adhesives have been developed to offer maximum optical clarity – even in high stress situations (some adhesives can turn white under high stress when in a structural bond) and enhanced resistance to harsh environments e.g. long term exposure to sunlight and contact with water. Permabond UV6160 has been developed to remain “invisible” even under high stress joints and in intense sunlight; UV6231 offers exceptional durability performance in harsh environments.
UV-curable adhesives offer excellent long term durability and good adhesion performance on a wide range of substrates – in particular glass and metal. Typical applications where these new adhesives could be beneficial include: structural bonding applications such as glass balconies, walkways, staircases and furniture; bonding glass kitchenware; bathroom applications such as handles and hinges on shower screens and cabinets and other items such as glass artwork / sculptures in harsh outdoor environments (where there is long term exposure to rain, strong sunshine, frost etc.). Please contact Permabond for further information, technical datasheets and brochure for these new products via our enquiry page: http://www.permabond.com/en/en-contact-all.php
New Permabond Epoxy Adhesives for Food Processing Equipment
Permabond is pleased to expand its epoxy adhesive line with a new range of two component epoxies formulated with FDA approved ingredients. These toughened epoxies are manufactured in compliance with the FDA CFR 175.105 and 175.300. The excellent shock and impact resistance coupled with environmental and temperature resistance make these epoxies ideal for food processing and food packaging equipment. Typical food contact applications include bonding filter components, bonding and sealing appliances and food handling equipment. They cure at room temperature or can be heated for a faster cure. The range includes various viscosities, gap filling capabilities and working times to suit most applications, and Permabond custom formulates to suit individual manufacturing needs.
Please contact Permabond for further information, technical datasheets and brochure for these new products via our enquiry page: http://www.permabond.com/en/en-contact-all.php
New Adhesives Improve Displays and Touch Panels
The search for a better adhesive in LCD displays and touch panels has led to the development of a whole new chemistry, involving dual curing by light and humidity. The new adhesives have been developed to help overcome problems associated with traditional adhesives used in displays and touch panels. They reduce the problem of poor readability in bright surroundings, such as direct sunlight, by allowing the glass plate to be bonded directly to the LCD and cured using a combination of light and humidity. Among other things, direct bonding also increases the display’s readability and reduces dust contamination and fogging caused by humidity between the glass plates. It also increases the display’s resistance to shocks and vibrations. The direct bonding made possible by these new adhesives is expected to have significant applications in large area displays used in the automotive, aircraft and military industries.
Source: http://www.adhesivesmag.com/articles/91369-industrial-displays-and-touch-panels
Frequently Asked Questions Regarding Dispensing of Adhesives
The following are some of the more common questions when it comes to the dispensing of adhesives, as well as a few tips for preventing adhesive dispenser tips from clogging.
Question
When dispensing adhesive around the opening of a large plastic container, it was found that adhesive had somehow splattered on the inside of the bottle in some of the assemblies. What could be causing this?
Answer
There are two main possible causes for this situation, the first of which is due to static electricity. Static electricity is caused by dry conditions, and could cause the line of adhesive to briefly jump to the other side of the bottle rather than continue to drop directly below the dispensing needle. The second possible cause is due to stringing, which is where the adhesive doesn’t stop coming out when the pressure from the dispensing needle stops, and this last little string of adhesive may then be free-falling into the wrong side of the container.
Things You Need to Know to Choose the Right Adhesive
When it comes to making the right decision, regardless of what it may be about, it is wise to always gather as much information as you can. This is especially true in the case of adhesives, where even one tiny detail can change the entire situation. When choosing the right adhesive, there is no such thing as looking into too much detail, so for starters, make sure you have the answers to the following questions.
What substrates are you bonding?
When trying to find the right adhesive, it is crucial that you know a little about the materials you will be attempting to bond. Every substrate has very different properties and will react in different ways depending on the substrate with which you are trying to bond it. So, before you start researching your adhesive, do a little research into the substrates you are hoping to bond. Don’t forget to take into account if the surface has been painted, lacquered or treated in any way, as this can have a big impact on how well adhesives will be able to effectively create a bond.
The Evolution of Instant Adhesives
When Harry Coover invented the original cyanoacrylate adhesive more than 50 years ago, it seemed he had created the ultimate fast-acting adhesive. However, when you look at all of the different adhesives available these days, it now seems the best is yet to come.
Cyanoacrylate adhesives were essentially made up of methyl cyanoacrylates and ethyl cyanoacrylates. There was a saying that you should use methyl on metals and ethyl on everything else.
While it is true that methyl will bond better with metals and ethyl better with almost everything else, cyanoacrylates have improved so much that there needs to be far more said about your options when it comes to fast-acting adhesives.
A Brief Guide to Surface Initiated Acrylics
Surface-initiated acrylics are able to form extremely strong, structural bonds to metals and other types of substrate. The following is a brief look at some of the best ways to use surface-initiated acrylics, as well as answers to some of the most frequently asked questions.
When working with surface initiated acrylics, the process of the ‘room temperature cure without mixing’ has been shown to have the best results, and it can be done the following way.
Using Permabond HL126 for Weld Sealing and Thread Locking
Permabond HL126 is an extremely versatile product that can be used for both sealing welds and as a threadlocker. It is able to do this primarily due to its low viscosity and impressive strength. The following is a brief look at using Permabond HL126 for both weld sealing and thread locking.
Weld sealing
- You need to be able to expose the metal surface first in order to seal it properly, so clean off any dirt, grime, rust or paint so that there will be nothing impeding the seal. It doesn’t have to be impeccable, though the cleaner the surface area of the metal is, the easier it will be for the sealant to get right in there and be effective.
- Ensure any sprinkler systems have been bled dry of water, as any water pressure in the pipes can prevent the sealant from being able to wick right into the area you are attempting to seal.