Every fiber, every gram of resin is the result of a defined engineering calculation.
Composite manufacturing is based on combining two or more materials with different physical and chemical properties at a micro level to achieve superior performance at a macro scale.
Reinforcements such as glass, carbon or aramid fibers provide structural strength, while matrix systems including polyester, vinylester or epoxy resins ensure load transfer and environmental resistance.
The correct combination of these components, through optimized ratios, orientations and curing parameters, enables high strength-to-weight performance, corrosion resistance, thermal stability and design flexibility.
At Otostech, these parameters are optimized for every project:
- Fiber orientation engineering
- Resin viscosity and gel time control
- Lamination design and stacking sequence optimization
- Curing profile control
Vacuum Infusion Process
“High Fiber Ratio with Vacuum-Controlled Resin Flow”
OTOSTECH’s infusion capability enables the production of large-scale composite parts in a single mold with high precision and paint-ready surface quality. Each production cycle is supported by quality control data, ensuring reliability in industries such as marine, defense and energy.
Technical Description:
Vacuum infusion is based on impregnating dry fiber reinforcements with resin under controlled vacuum conditions. This method enables high fiber volume ratios between 55 and 65 percent with reduced resin consumption, especially for large and complex geometries.
The system operates as a fully closed process. Resin flow, temperature, vacuum level and gel time are continuously recorded. This eliminates operator dependency and ensures repeatable production based on engineering parameters.
Technical Advantages:
Fiber volume ratio (FVF)55–65%
Void ratio<0.5%
Weight consistency±1.5%
Thickness tolerance±0.3 mm
VOC emissionsUp to 90% reduction (compared to open molding)
L-RTM (Light Resin Transfer Molding)
Closed-Mold Serial Production with Repeatable Quality
Otostech delivers hybrid manufacturing solutions by combining infusion and L-RTM technologies according to project requirements. While infusion enables large, complex single-piece production, L-RTM ensures efficient and repeatable serial manufacturing in closed systems.
“Surface aesthetics on the outside, engineering performance on the inside.”
Process Steps:
- Preparation and placement of fiber preforms
- Vacuum generation and resin injection
- Gel time monitoring and curing
- Demolding, trimming and dimensional control
Advantages:
- Suitable for serial production with consistent process window
- High-quality surfaces on both sides
- Closed system with near-zero VOC and styrene emissions
- Reduced labor dependency through controlled resin flow
Technical Description:
L-RTM is a low-pressure resin injection process performed in a two-part closed mold system. This method combines the precision of infusion with the efficiency of serial production.
Temperature control circuits, resin pressure sensors and vacuum ports ensure full process traceability. The result is smooth surface quality, consistent thickness, minimal tolerances and a clean production environment.
Technical Advantages:
Mold pressure0.3–0.7 bar
Vacuum level-0.9 bar
Cycle time20–45 min
Surface quality (Ra)0.3–0.5 µm
SurfacesDouble-sided A/B surface
“L-RTM is not only a process, but an industrial standard for composite quality.”