Dear Readers,
With growing interest and expansion in Asia, our quarterly DELO-Newsletter for Asia informs you about the latest trends around bonding technology. If you wish to receive our Newsletter regularly, please send a short e-mail to newsletter@delo.de or just click on "reply". Please contact our DELO Representative Office in Singapore at +65 6562-8013, singapore@DELO.de, for any queries.
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Intelligent dispensing
DELO has recently developed a world first in the form of a special foil cartridge that enables bubble-free dispensing
Process accuracy is one of the most essential criteria for standardized production processes. DELO has recently developed a world first in the form of a special foil cartridge that enables bubble-free dispensing. DELO-NEWS spoke about this with Dr. Wolf-Dietrich Herold, Managing Partner of DELO and inventor of DELO-FLEXCAP.
Dr. Herold, why do customers need a new small cartridge system?
Our DELO-FLEXCAP foil cartridge enables our customers to dispense adhesives by means of compressed air without bubbles being formed. At the same time, the dispensing accuracy is unrivaled. Before this, the market had not seen such a combination. We are a system supplier, so our goal is to provide not only high-quality adhesives that are perfectly adjusted to the specific application, but also the equipment to work with these adhesives. Our product range also includes LED lamps for curing light-responsive adhesives. That's how we configure optimized processes for our customers.
What does the cartridge consist of?
In DELO-FLEXCAP, the conventional cartridge piston is replaced by a flexible, hermetically sealed membrane. On top of that, we have developed accessories in the form of a special closure cap and retainer in order to enable convenient integration into production. The cartridge is available with a volume of 10 cc.
What is unique about it?
The membrane, by design, equalizes pressure fluctuations arising during air shipment as well as material shrinkage during extremely cold storage. Therefore, neither air nor contaminants can penetrate the container. As a consequence, the adhesive inside is hermetically sealed off and remains bubble-free until use.
How do customers benefit from DELO-FLEXCAP?
The bubble-free dispensing aspect isn't the only advantage of the new cartridge system. Our customers also benefit from maximum emptying of the cartridge. The reason is that, contrary to conventional cartridges with sliding pistons that are always susceptible to friction, the flexible membrane ensures consistent, steady pressure conditions for the adhesive in the foil container, and therefore consistent dispensing volumes. Therefore, the user has a higher available volume at his disposal. What's more, in many cases the adhesives can be transported cold in dry ice instead of being expensively tempered, without risking bubble formation. Thanks to this, logistics costs can be reduced considerably.
For which adhesives is it suitable?
The cartridge is suitable in combination with all one-component adhesives from DELO, such as the photoinitiated-curing DELO-PHOTOBOND and DELO-KATIOBOND adhesives, and heat-curing DELO-MONOPOX products. Our development engineers are also testing the cartridge's readiness for other adhesives in our labs. Nevertheless, the cartridge is only available in combination with our own adhesives.
What was the main challenge in the development of ELO-FLEXCAP?
In the beginning, we tested several approaches, one of them being a completely flexible tube container. The adhesive was indeed bubble-free, but neither residual emptying nor dispensing constancy were sufficiently controllable. Therefore, we designed a partly rigid and partly flexible sheathing in a continuous development process, in which all departments at DELO, such as R&D, Production and Engineering, worked shoulder-to-shoulder.
When was the foil cartridge launched?
DELO-FLEXCAP has been available for a few weeks and can be purchased directly from DELO in combination with our adhesives.
What must the customer consider when integrating the new cartridge system into his production process?
The conversion of an existing production process from small cartridges to DELO-FLEXCAP is trouble-free thanks to the standardized luer-lock connector. We know from talking to our pilot customers that the dispensing parameters don't need to be modified at all. Only the cartridge is switched out. Everything else remains unchanged.
How can adhesives be dispensed from DELO-FLEXCAP?
The cartridge is designed for automated production processes with compressed air.
Has the new cartridge system been already taken into use? What has initial user feedback been?
We have tested the foil cartridge with pilot customers. Customer feedback has been positive, without exception. The dispensing accuracy is better, the quality of the products is better, and the cartridge resolves other issues as well.
New Chief Representative in Shanghai office
Edward Newsom will support DELO in China
From now on, Edward Newsom will support DELO as the new Chief Representative in DELO’s Shanghai Representative Office in China. Before, he had worked as the UK Regional Sales Manager for about three years. “I’m very enthusiastic about this new challenge”, says Edward Newsom, who started his new job in October 2010. The former Chief Representative Torsten Uske, who had managed the office for about 7 years, will work for DELO in the USA.
DELO entered the Asian market in 2004, opening its own Representative Office in Shanghai. The company sees great potential in Asia. Today, 27 percent of DELO’s sales revenues are gained in Asia. The main tasks include strong technical support and the development of further market sectors, especially in the fields of RFID, display and electronics. In the financial year 2009/2010, DELO had a growth in turnover of 19 percent in Asia. Further Asian Representative Offices of DELO are located in Singapore and Taiwan.
In China, DELO will continue to focus closely on the use of adhesives in key niche applications such as: RFID, smart card and electronics. "We have already established a good reputation in these industries. Our customer base includes many large German companies with branches across Asia as well as local Chinese companies”, explains Edward Newsom. "Our idea is to give our customers excellent technical support and the best customer service.”
Politics and business in dialog
DELO Managing Partner Sabine Herold exchanges opinions with German Chancellor
Sabine Herold feels at home in the political arena. “Interacting with politics and trade associations is important for medium-sized businesses, so that they can gain attention for their concerns,” says Sabine Herold. Accordingly, in addition to her duties for the company, she is also active on a great variety of committees and associations on an honorary basis, and represents the interests of entrepreneurs and medium-sized companies. Last spring she and ten other representatives of medium-sized companies were invited to an informal discussion with German Chancellor Angela Merkel (see picture).
DELO is portrayed in the "Growth Champions" book
Thanks to its continuous and above-average growth over the past years, DELO Industrial Adhesives is one of the companies that were chosen in the “Growth Champions” book.
The "Growth Champions" book deals with success factors of German businesses by portraying 22 outstandingly growing and mainly medium-sized companies to which DELO also belongs. Those who want to pave new ways to its company or intend to check and optimize the status quo will find precise and exemplary ways for systematic growth, such as DELO's approach, in the "Growth Champions" book.
Reliable adhesives for COB encapsulation on PCBs
RAFI Eltec uses DELO adhesives
Encapsulants contribute to the flexible, efficient and reliable protection of the sensitive electronic parts for packaging from aggressive environmental influences such as oil, fuel, vibrations or elevated temperatures. The manufacturer of industrial adhesives DELO has developed special encapsulants on the basis of anhydride-curing epoxy resins. Thanks to their special flow behavior they can be evenly dispensed. On top of this, they cure significantly faster than comparable products. This combination enables fast and stable production processes. As a consequence, the efficiency of electronic production can be ramped up. What’s more, they are highly resistant to many media such as oil or fuel, and resistant to elevated temperatures.
Application example: COB encapsulation on PCB by RAFI Eltec
RAFI Eltec GmbH, Überlingen, Germany uses the DELO-MONOPOX GE785 and DELO-MONOPOX GE725 anhydrides as Dam&Fill. The company produces electronic assemblies and systems for diverse lines of business as a pure manufacturing service provider. RAFI Eltec combines standard assembly technologies with special techniques such as chip-on-board and flip-chip.
DELO develops new dual-curing adhesives
Light-curing adhesives with humidity curing mechanism for shadowed areas
DELO has developed new adhesives that can be cured with both light and humidity. In some applications, pure light curing is not possible, especially when bonding components with shadowed areas. The new DELO-DUALBOND adhesives are perfect for these cases, since they allow reliable curing even where little or no light is available.
Reliable curing in shadowed areas is accomplished by brand-new humidity-crosslinking polymers. This eliminates the need for heating to cure shadowed areas, as frequently required by other dual-curing adhesives available on the market. This makes it possible to bond temperature-sensitive components without any problems. Furthermore, process costs can be cut down, since investment in a curing oven is not necessary. Only an appropriate UV/VIS light source is required for primary curing.
The new adhesive combines the advantages of acrylates, such as fast light curing, with reliable curing in shadowed areas within 24 hours. Thus, production rates can be ramped up thanks to the adhesives' high initial strength after fast light curing and fixing. In the subsequent process steps, the components can be handled without requiring additional mechanical fixtures. The strength of the adhesives can be individually adjusted from highly flexible to rigid, in line with the customer’s needs. The adhesives have been comprehensively scrutinized in DELO's labs, and give good resistance to temperature shocks and humidity.
The dual-curing adhesives are used in electronics, for example, to cast pins. In addition, they can be used for sealing the edges and frames of displays. DELO-DUALBOND with combined light and humidity curing mechanisms are suitable for use with a wide range of materials, such as plastics and metals.
Adhesives for compact camera modules
The new DELO-DUALBOND adhesive is suitable for "active alignment"
The mobile phone market is experiencing unabated growth. A current study by Gartner revealed that the number of phones sold increased by 17 percent in the first quarter of 2010 compared to the prior year's quarter. This is accompanied by great growth rates and unparalleled innovations in the compact camera modules used not only in mobile phones, but also in PCs, PDAs and industrial camera systems. DELO has developed new dual-curing adhesives to bond these high-tech components.
Low-temperature curing is the key advantage of the new DELO-DUALBOND mCD adhesives. They cure at a temperature of +80 °C, and can therefore be used for bonding temperature-sensitive materials. However, they are also ideal for fast processes with high throughput, as they cure in almost no time. After fast light curing the adhesives give high initial strength, so the components can be fixed in position. Afterwards, final curing is effected by heat. The adhesives are used for bonding compact camera modules, such as image sensor chips to PCBs, or for bonding housings.
Applications are mainly in "active alignment" processes. Optical components like mirrors, lenses or prisms are aligned on the substrate during fixing with the help of the adhesive. During alignment, the adhesive must remain liquid, but as soon as the component has taken its correct position, fast initial strength is required. At the same time, adhesive shrinkage must be as low as possible in order to keep the component in its position. The new DELO-DUALBOND adhesives are characterized by low water absorption and low shrinkage. What's more, they retain their properties even during exposure to temperature stress. DELO cooperates with many machine producers worldwide in order to further develop upcoming solutions in this field.
Adhesives for electric motors
EBM-Papst bonds stators with dual-curing DELO adhesives
The trend towards miniaturization never stands still. Even the latest generation of electric motors cannot meet an ever-growing demand for increasingly compact and more efficient designs. In turn, electric motor design and component layout present continuously growing challenges in terms of small size, low weight and high reliability. Efficiency also means that the energy density of smaller motors is steadily increasing, and thereby temperatures. As a consequence, the tensions to be equalized between components are also rising. Adhesives make a valuable contribution here, as they can create light, tension-equalizing connections between components of dissimilar materials. In particular, special light-curing adhesives cure quickly and give immediate firmness to touch. Thanks to this speed, production processes can continue without interruption.
A great variety of adhesives for electric motors
Adhesive bonding has many benefits in electric motor manufacture. For example, adhesives lend themselves to bonding stators into housings, and are also suitable for magnet bonding. The magnet surface is protected against corrosion. Therefore, the surface is usually passivated, lacquered, nickel-plated, chrome-plated or otherwise protected. Electric motors are found in ever more varied and versatile applications, including cars (such as motors for seat or window adjusters), toothbrushes and even elevators. It is also possible to use the shrink-joining method, in which one component is heated so that it expands, and the second component then inserted. However, this method can cause problems if temperature fluctuations occur, as high tensions arise and the component may crack. Bonding, or a combination of bonding and shrinking called "shrink-bonding", has proven its effectiveness. The key advantages of bonding include excellent equalization of tensions, high impact resistance and outstanding reliability.
New anaerobic adhesives: Improved equalization of tensions without oven curing
A wide range of adhesives is available for use in electric motors: But many components cannot withstand oven curing. The new generation of dual-curing DELO-ML adhesives is suitable for these temperature-sensitive components, as they cure by anaerobic reaction at room temperature and/or by irradiation with light of the suitable wavelength. The adhesive leaking from the bonding gap is cured by light in a few seconds. This provides prompt firmness to touch, so processing of the components can continue right away. Unlike conventional dual-curing adhesives with combined light/heat curing, shadowed areas cure anaerobically, in other words, by metal contact without the heat curing step. Thus, the components do not need to be subjected to elevated temperatures, and a complex and cost-intensive process step can be omitted. On top of that, dual-curing DELO-ML adhesives lend themselves to bonding metals with dissimilar coefficients of expansion thanks to their tension-equalizing properties. As regards larger magnets, previous adhesives were often not able to equalize the high tensions. This is now possible. It is now also feasible to bond metal to plastics, such as polyamide. The dual-curing DELO-ML DB135 shows clearly higher strengths than conventional products in tensile tests, especially on bare steel and aluminum. There are three adhesives in the DELO-ML family, DB133, DB135 and AD170. The feature that the three adhesives have in common is that their excellent resistance to substances used in engine compartments, such as oil, gasoline and diesel fuel.
The dual-curing DELO-ML DB135 is already used by German drive manufacturer EBM-Papst. "We use this adhesive in our electric motors. We bond the steel stator to an aluminum housing", explains Daniel Rauer, EBM-Papst Industrial Drive Development Project Team Leader. "We switched to this adhesive as it gives better strength in torque testing than the adhesive we used previously." The motor is used in the new modular ECI drives series. These high-performance, multi-pole drives reach a very high torque in a small space. The company found DELO-ML AD135 to give reliable and durable joins even at high torque. In addition, the adhesive is ideal for automotive applications where a very wide temperature range of use must be covered and very high forces must be transmitted. High tensions arise in the temperature range of use from -40 °C to +150 °C between two metals with disparate coefficients of expansion. "Our new, tension-equalizing adhesive has a competitive edge over conventional non-flexibilized anaerobic adhesives", says Thomas Bauer, Sales Engineer at DELO Industrial Adhesives.
In order to verify that the new products could withstand harsh conditions, numerous tests were performed in DELO's labs and by the customer. For example, the bonded electric motors were aged in temperature change tests (-40 °C to +120 °C, 15 cycles). Finally, the choice fell to DELO-ML DB135 for this bonding task. The adhesive combines an elongation at tear of 30 % with a temperature range of use up to +180 °C. What's more, it has higher extruding forces and adheres very well to smooth metal surfaces. Therefore, the complex process step of surface roughening was omitted.
Competitive edge of the new dual-curing adhesives
Further advantages of DELO-ML DB133 and DB135 over conventional anaerobic products include the option of additional light curing. Even opaque components can be fixed in a few seconds using the right UV lamps, if a little extra adhesive leaks from the gap in the form of a fillet and is accessible to a light source. It is then not necessary to fix the components to prevent misalignment until the completion of the actual anaerobic curing process required for final bond strength. Another special feature of the new adhesives is their excellent adhesion to bare metal. Surface roughening or groove milling become unnecessary, and helps save further process steps and costs. Further application areas include screw securing, magnet bonding, electric motor bonding and component fixing.
New: Light-curing adhesives with dry surface
DELO recently developed new light-curing dry-touch DELOPHOTOBOND adhesives. Their special features include excellent adhesion to plastics, and high peel strength on plastics and thermoplastic elastomers. Unlike conventional UV/VIS-curing acrylates, their surface is dry after just a few seconds of continuous light curing. Low outgassing is another outstanding property. These adhesives are suitable for a great variety of applications, such as bonding membranes and coils for mini loudspeakers, and bonding opaque plastic housings.