CSS is your bridge to low cost high quality FRP composite products

Composite Bladder Inflation Molding (BIM) Support

"Tackle complex hollow composite structures with confidence ..."

CSS has more than 30 years of experience supporting the design and manufacture of complex hollow composite structures produced with Bladder Inflation Molding (BIM).   CSS' Composite Product Development Services help Clients produce challenging bladder molded prototypes from prepreg or resin infused preforms.   And though CSS does not manufacture or sell bladders we can certainly help you select the right bladder for your bladder molding application.

CSS also supports the transition from bladder molded prototype fabrication to bladder molded composite production via our Composite Production Support Services.



Bladder Inflation Molding Advantages/Benefits


Prepreg Preform Bladder Inflation Molding



Resin Infused Preform Bladder Inflation Molding


Bladder Inflation Molding (BIM) is suitable for a wide variety of hollow FRP composite part geometries including:

Bladder material selection is a function of part geometry, processing temperature, reusability requirements, and cost. Some common bladder materials include:

Stroller Frame
Case Study

Program Objective:   Replace constant 22 mm diameter 6061-T6 aluminum tube frame member with a FRP composite execution; Maximize weight savings and improve fatigue life without sacrificing bending stiffness or strength.

Composite Solution:   Bladder Inflation Molded (BIM) carbon/epoxy tubular frame member with an elongated 76 mm perimeter cross section near the highest bending moment and round 69 mm perimeter cross sections on either end to mate with existing frame members.   Discrete reinforcements were added for local stiffening, additional bearing strength around holes and cutouts, and for increased hoop strength at the ends.

Material:   75 g/mē FAW UD Carbon/Epoxy Hotmelt Prepreg

Cured Part:   58% Fiber Volume (32% Resin Content)

Part Weight:   66 g (48% Savings)

Performance:   53% Higher Bending Strength, 2X Longer Fatigue Life

Local Thickness Build-Ups Around Molded-In Notch Locations

Wrinkle-Free Inner and Outer Elbow Bends


Please contact CSS to discuss your Bladder Inflation Molding project challenges.