GETTING STARTED WITH MANIFOLD DESIGN
WHAT ARE PLASTIC MANIFOLDS?
Plastic manifolds are used for precision control of liquids and gasses. They have many applications from medical and life sciences to aerospace and industrial. Manifolds are the response to the need for more compact, easier to maintain devices. They allow a design engineer to take what are originally discrete components connected together with tubing and consolidate them into a single integrated assembly of plastic.
Controlled Fluidics produces plastic manifolds as a single layer orĀ multilayer assembly. Single-layer manifolds (SLMs) utilize common machining operations like drilling and milling to produce a simpler and internal straight network of channels. However, special features, such as curved channels or rounded bends, become near impossible to machine in SLMs. A plastics drilling or milling machine simply cannot create them ā even with the most talented machinists. Multilayer manifolds (often used interchangeably with ābonded manifoldsā) take on this challenge. They make these more complex internal geometries possible. Created layer by layer, theĀ multilayer manifolds are bonded together with heat, pressure and time. Using the next sample of images, you can see the differences in either of these types of manifolds.
SINGLE LAYER MANIFOLD EXAMPLES
MULTILAYER (BONDED) MANIFOLD EXAMPLES
WHY USE A MULTILAYER BONDED MANIFOLD?
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To understand the need for multilayer manifolds, we must understand from where the need arose. In the case of fluidic manufacturing, the need starts much like anything else: a challenge calling for an answer. Teams begin experimenting with hypotheses on a breadboard that involves connecting pumps, valves, and/or sensors with tubing to complete a potential testing circuit the serves as an answer.
Historically, the breadboard served as a layout where the physical prototype retained much of that breadboardās original internal fluidic circuits. After the prototypeās development, teams then work on testing in real time to investigate their previous hypotheses.
They connect other adjoining discrete components together with tubing in hopes of honing and developing the device further. This supports design in a few ways. The process here not only makes changes easier to address but also works to create multiple variants to investigate optimal functioning. It also aids in devising potential upgradable components for future revisions. However, bear in mind that most tubing and components here are external to the manifold, which creates some other challenges teams need to address.
While this design approach for traditional fluidic systems and tubing offers a working solution, it has some important limitations. For example, assembly time is high and often complex. It can take some time to connect the necessary components and have a complete fluidics system function properly. Some try to answer this challenge with more tubing. However, when this happens, it not only adds a layer of complexity but also impedes seeing the fluidic systemās function in real time. The tubing dominates the entire visual field within and around the device, hindering ideal function and purpose.
Another disadvantage in these traditional fluidics systems concerns field servicing. As more tubing or other components get added, overall device size grows and gives more opportunity for potential maintenance issues. For example, each tubing run requires two connection points. Each of those connection points can become a leak if not assembled or maintained properly. With more points like these, more problems can arise and create an unnecessarily difficult, painstaking situation.
Specialized plastic manifolds solve these common issues easily as they decrease size and ā with that ā the amount of potential failure points. In todayās fluidic device design, teams create either a drilled manifold or bonded manifold to reduce that tubing or even outright eliminate their need of it.
Kong Lo, āComplete Manifold,ā 2019. Used with creatorās permission.
In manifolds that need specific components, manufacturers can mount or install those directly on a single monolith of plastic with most (if not all) connections internal to the manifold. This makes use of the deviceās size to organize its internal construction and make use of its internal volume. With what was once external tubing now lies within the device, clearing the fluid circuit for observation and creating a more simplified experience.