Featured Research

from universities, journals, and other organizations

Adhesive bonding with pre-applied adhesives

Date:
May 22, 2014
Source:
Fraunhofer-Gesellschaft
Summary:
In industrial production, bonding plays an increasingly important role. Researchers have now succeeded in separating the processes of applying the adhesive and the actual joining, which opens up a new world of applications.

In industrial production, bonding plays an increasingly important role. Researchers have now succeeded in separating the processes of applying the adhesive and the actual joining, which opens up a new world of applications.

Adhesive bonding technology is an effective and inexpensive means of seamlessly joining two parts, even two made of different materials. Especially in lightweight construction, adhesive bonding is the preferred technique because many of the materials used can hardly be joined otherwise. However, since liquid adhesives need time to cure, they cannot be applied in every production step. In hopes of finding a way to eliminate the need for regularly applying liquid adhesive while joining fasteners, the automotive supplier STANLEY Engineered Fastening -- Tucker GmbH in Gießen turned to the researchers at the Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Bremen. Their solution was a two-step process in which adhesive is initially deposited on one of the parts and then dried to form a non-sticky layer. During a subsequent production step, the adhesive is hardened and the two parts are bonded together.

Although two-step bonding techniques aren't new -- early postage stamps were coated with an adhesive that would only stick to envelopes once moistened -- using them for industry is. Fraunhofer IFAM researchers have successfully developed the technique to allow for a high-strength adhesive bond suitable for industrial use -- no easy task, since the adhesives must fulfill different and sometimes contradictory requirements. "Once the adhesive is applied, it can't be tacky and it has to withstand long storage times," explains chemical engineer Andreas Lühring from Fraunhofer IFAM. But the adhesive has to do more than that. "The adhesive also has to be very reactive and harden quickly during joining." The researchers' concept combines resins and hardening agents that melt at different temperatures. "We use micro-dispersion to finely distribute hardening agents with considerably higher melting points throughout the resin base," adds Professor Andreas Hartwig.

The resulting reactive, hot melt adhesive is used in the manufacture of fastening bolts, for instance. First the material is heated and then applied onto the fastener. After it cools, it solidifies again. The fastener can then be transported and stored without difficulty. To harden the actual adhesive, it must be heated to more than 150 degrees Celcius in a controlled way. "Only then is the actual hardening agent melted and the adhesive activated," explains Lühring. In this way, two parts can be bonded to each other within seconds.

"There is one disadvantage to reactive adhesives like these -- they can be stored for a long time, but not indefinitely," says Dr. Matthias Popp, group manager at Fraunhofer IFAM. That's why the researchers had added an additional, visual means of monitoring the adhesive -- if the substance has lost its functionality, it changes color.

These pre-applicable structural adhesives (PASA®) are also suitable for other applications, including a variable "construction kit" that offers adhesives based on different materials and hardening principles. The IFAM experts have altered the composition of the adhesives so that they yield the best possible productivity and characteristics for a wide variety of applications. For this development, Andreas Lühring, Andreas Hartwig and Matthias Popp received one of this year's Joseph von Fraunhofer prizes.


Story Source:

The above story is based on materials provided by Fraunhofer-Gesellschaft. Note: Materials may be edited for content and length.


Cite This Page:

Fraunhofer-Gesellschaft. "Adhesive bonding with pre-applied adhesives." ScienceDaily. ScienceDaily, 22 May 2014. <www.sciencedaily.com/releases/2014/05/140522074453.htm>.
Fraunhofer-Gesellschaft. (2014, May 22). Adhesive bonding with pre-applied adhesives. ScienceDaily. Retrieved September 3, 2014 from www.sciencedaily.com/releases/2014/05/140522074453.htm
Fraunhofer-Gesellschaft. "Adhesive bonding with pre-applied adhesives." ScienceDaily. www.sciencedaily.com/releases/2014/05/140522074453.htm (accessed September 3, 2014).

Share This



More Matter & Energy News

Wednesday, September 3, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Halliburton Reaches $1B Gulf Spill Settlement

Halliburton Reaches $1B Gulf Spill Settlement

AP (Sep. 2, 2014) — Halliburton's agreement to pay more than $1 billion to settle numerous claims involving the 2010 BP oil spill could be a way to diminish years of costly litigation. A federal judge still has to approve the settlement. (Sept. 2) Video provided by AP
Powered by NewsLook.com
Google Teases India Event, Possible Android One Reveal

Google Teases India Event, Possible Android One Reveal

Newsy (Sep. 1, 2014) — Google has announced a Sept. 15 event in India during which they're expected to reveal their Android One phones. Video provided by Newsy
Powered by NewsLook.com
Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) — Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) — Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins