Reliable primer application

Economy, quality and health: contact dispensing vs. non-contact dispensing

In practice, opinions differ on the use of primers - but this does not change the fact that their use in many applications, for example in the electronics and automotive industries, is currently without alternative. However, many criticisms of primers can be invalidated with the optimal - in this case non-contact - dispensing technology.

In electronics manufacturing, many surfaces are pretreated with primers. These agents improve the adhesive properties of surfaces and coatings that are subject to high stress or are difficult to bond. The better adhesion of adhesives or lacquers increases resistance to water and chemicals as well as corrosion protection and thus product quality. Classic applications include bonding glass to plastic, metal to plastic, smartphones and tablets, AR/VR lens bonding, speaker bonding, sealing mobile devices and batteries.

Classically, primers are applied with a sponge, spray or by time/pressure contact dosing, depending on the degree of automation of a production. However, manual application is rarely an option from a quality perspective. Since automated processes predominate in the electronics and automotive industries, the question of the optimal dispensing method arises. The choice of dispensing system or method also determines process reliability, economic efficiency and product quality. 

The solution - non-contact dispensing 

Application with the PDos X1 jet valve solves almost all primer problems in practice. Due to its high dispensing volume accuracy - the repeatability of the jet valve is usually 99% - errors caused by deviating primer quantities are almost impossible. The optimal use of material not only saves money, but also serves to protect health. Lines are created in this dispensing process by setting one dot next to the other at a very high frequency - up to 300 Hz. Among other things, this allows easy programming of the dispensing system for ramps or curves. With jetting, the adjustment stroke and the additional movement of the applicator are also omitted, which leads to significantly shorter cycle times than with contact dispensing. Component and position tolerances are also less critical with this method. Since the valve can be controlled directly from the system controller, users have a high degree of flexibility with regard to the variety of assemblies to be produced. This is a key aspect, especially in electronics production in Europe.

In addition, simple and optimal process monitoring can be realised with photoelectric sensors in the case of jetting. This is not possible with contact dosing. There, expensive optical process control must be used. The laser light barrier from perfecdos monitors every droplet that passes the barrier - even transparent, extremely small and/or extremely fast droplets. The sensors of the light barrier are automatically cleaned so that contamination does not cause malfunctions.

"Precise contactless dispensing with the PDos X1 jet valve applies the primer where it is needed," explains Julian Greiner, Marketing & Sales at perfecdos GmbH.  "This not only saves money with increased product quality, but the lower health risk due to the avoidance of overspray and thus lower investments in health protection are also becoming increasingly important.

 

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