Bladders

Bladders are best described as self-contained flexible enclosures. They are typically very specific configurations of plastic films or Polymer coated fabric-cells with one or more entry-exit points that enable gases or liquids to be input and evacuated.

Sizes range from a few cubic centimeters to flotation chambers for watercraft. Configurations can be uniform accordion type bellows, sensory pads that fit on the tip of a finger or mattress pads that inflate and deflate in multi zone combinations to prevent bed sores.

As important as the air or liquid bladder is, connecting and regulating the flow, the contents level and internal pressure must be addressed.

Bellows air and liquids

Some of the most common arrangements for facilitating flow into and out of a flexible bladder are:

  • Medical tubing welded directly to the bladder. Either into a seam or through a sidewall.
  • Barbed fittings or Luer fittings inserted into short tube segments that are welded into the seam of a bladder.
  • Two-piece compression fittings (sometimes referred to as bulkhead fittings) installed through the side of the bladder.
  • Ports for tubes or threaded caps welded to the sidewall.
  • Dual function squeeze bulb pressure and flow control units connected to a tube.
Miniform

A few unique functions of bladders include:

  • Sealed accordion type bladders used as ballast tanks in mini submersibles.
  • Dual chamber bladders used for simultaneous displacement-replacement applications. Which is best described as having a flexible dual chamber bladder use the same space for two different mediums at different times. This is a space saving concept used in healthcare and medical equipment. The two or more different mediums do not intermingle but can utilize the same space in displacement-replacement type arrangements.
  • Deployment upon inflation or filing with other medium. Flotation and collection applications. Like and automotive airbag neatly tucked away until it is needed.