Fillers do not cause mechanical abrasions to dispensing systems

Technical Specifications

Two dispensers with two different elastomer stators each
Six epoxy resins with filler content between 25 – 50%
24 combinations, each with 300,000 dispensing cycles

Sudbury, MA January 2019 – DELO, one of the world’s leading manufacturers of industrial adhesives for automotive, consumer and industrial electronics applications, recently partnered with ViscoTec, a dispensing company that manufactures systems and components required for conveying, dosing, applying, filling and emptying medium- to high-viscosity fluids, to perform experimental tests analyzing adhesive abrasions to systems. The tests confirm that even highly filled adhesives can be dispensed reliably and precisely over the long term without causing mechanical abrasions to dispensing systems.

Are fillers difficult to dispense?

Automotive and electronics industries have a constant need to meet the ever-increasing demands found in temperature stability and media resistance. Because of this, and because properties like electrical or thermal conductivity or adapted expansion coefficients need to be achieved, adhesive manufacturers fill their products with additional raw materials like metal or minerals. These robust materials are considered abrasive and have been thought to be difficult to dispense. The recent tests done by DELO and ViscoTec has proven that assumption wrong.

ViscoTec used two of its dispensing units in the testing, eco-PEN and RD, with two elastomer stators each. Six epoxy resins from DELO with filler content between 25 – 50% were used.

The stators were placed in the adhesives for 168 hours. General chemical suitability for long-term contact was observed as well as the change in mass, the dimensional accuracy and the hardness and elasticity of the elastomers. No abnormalities or deviations from the tight production tolerances were found, eliminating the idea that chemical reactions between two components would affect results.

Testing dispenser resistance

Twenty-four long-term tests that included cyclic dispensing operations were performed. Each included two seconds of dispensing, followed by a one-second pause to simulate typical dispensing behavior of an automated manufacturing process. Just under 300,000 dispensing cycles make up each test series, corresponding to approximately 30 kg of dispensed adhesive for the eco-PEN dispenser and approximately 240 kg for the RD dispensers. Every 20 hours, three dispensing shots were weighed and compared over time. The test results confirmed accurate and repeatable dispensing for all test pairs.

Karl Bitzer, head of product management at DELO, said, “The tests show what we have seen in the field, that even hard fillers in combination with high filler contents do not impede reliable and reproducible dispensing of our high performance adhesives.”

Before and after the endurance tests, the rotors, made of hard chrome-plated stainless steel, and the elastomer stators of the dispensing units were measured. After 300,000 dispensing cycles, there was no sign of wear on the rotors and a miniscule sign of wear on the stators that fell within the tight manufacturing guidelines.

Manuel Paintmayer, relationship management material manufacturing at ViscoTec, said, “Permanently reproducible and accurate dispensing was possible for all dispensers and stators. This is made clear by the fact that despite the abrasive test media and the high number of dispensing cycles, our dispensing units did not reach the end of their lifetimes within the testing period. That is a really positive result for our customers that rely on these units to perform reliably for many cycles. The longevity of our units directly translates into longevity of our customers’ systems, keeping maintenance low and reducing replacement costs over time.”

About DELO:

DELO is one of the world’s leading manufacturers of industrial adhesives used within the automotive, aviation, optoelectronics and industrial electronics industries.  Headquartered in Windach, Germany, DELO has subsidiaries in the USA, China, Singapore and Japan. In fiscal year 2017-2018, DELO generated sales revenues of nearly $192 million.

About ViscoTec:

ViscoTec Pump and Dispensing Technology GmbH manufactures systems for handling, dispensing, application, filling, and withdrawal of medium- to high-viscosity media. The technological market leader is headquartered in Töging (upper Bavaria, near Munich). ViscoTec has subsidiaries in the USA, in China, Singapore, and India, employing around 200 people worldwide. In addition to technically sophisticated solutions, even for the most complicated tasks, ViscoTec offers all components for the entire application from a single source, including media withdrawal, processing and dispensing. This guarantees successful interaction of all components. All media, which in individual cases have a viscosity of up to 7,000,000 mPas, are conveyed and dispensed almost pulsation-free and with extremely low shear: in the fields of food processing, e-mobility, aerospace, medical technology, pharmacy, and many other industries.

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