Kaman Composites' Production Cells all include integrated Quality Assurance:
|Hand Layup of Composite Component|
Manufacturing is also responsible for fabricating most of the Tooling and Fixturing used in production.
The fabrication of a composite part starts with the cutting of the material into precisely sized pieces that have the weave running in an appropriate direction. Carbon materials pre-impregnated with resin (prepreg) are used for autoclave processing and are kept in a freezer until thawed for cutting. Material is rolled onto a vacuum table where precise computer programs control the cutting to minimize waste. Once cut, materials are grouped according to the designated plan so that they can be mated with other plies to form the kits needed to create an individually designed part.
Foam and honeycomb cores are used in a wide variety of the composite parts that Kaman Composites makes. The foam cores must be conditioned prior to manufacture so that they have the proper level of humidity at the time of molding. Some cores are bent to proper shape, while others go through CNC operations to shape them or mill specific features.
Composite material which has been precision cut and organized into individual kits, laid into molds according to detailed assembly plans that determine specific placement and orientation of the material to achieve the desired physical characteristics each part. After the composite material is laid up and rolled to eliminate voids, it is covered with breather cloth and sealed with plastic material through which are inserted vacuum valves. A vacuum is pulled to compress the layers of composite material in preparation for autoclave processing.
The parts that have been laid up in the molds are cured under heat and pressure in the autoclave. Specifically, the uncured molded parts are placed into the autoclave and maintained under vacuum. Heat and and pressure are added to flow the resin and create structurally sound, strong, rigid, lightweight parts.
Resin Transfer Molding
RTM is another technology that Kaman Composites uses to manufacture parts. RTM is a low pressure molding process whereby a mixed resin and catalyst are injected into a closed mold containing a fiber pack, sometimes known as a preform. When the resin has cured, typically at room temperature, the mold can be opened and the finished component removed. A wide range of resin systems can be used. Fiber packs may be glass, carbon, arimid, or some combination of these and other fibers depending upon the characteristics desired in the finished part. Resin Transfer Molding produces parts to the desired shape with good surface finish, low void content and with the required levels of fiber volume. Raw material costs for the resin transfer molding process are typically lower than those associated with pre-impregnated materials. See our press release entitled Vermont Composites Announces Addition of Resin Transfer Molding Technology.
Our extensive in-house machining capabilities represent a significant strategic advantage over most of our competition. We use our machining center during the tool making process to efficiently produce our own molds in-house and as an integral process with much of our volume production. Vermont Composites has a wide variety of 3, 4 and 5 axis Computer Numeric Controlled (CNC) machines, as well as a highly skilled and experienced machining center staff. After a part has been molded, this precision equipment is used to perform close tolerance final finishing operations on completed parts. This can include: shaping, cutting, drilling, milling, etc.
Kaman Composites' assembly includes a wide range of capabilities, from skilled craftsman performing hand work for prototypes and small volumes, to semi-automated assembly for medium volumes, and full automation for high volume products. Assembly areas are organized by product family.
Finish, Prime & Paint
While many customers need the natural finish weave of carbon fiber composites, some customers enhance that appearance by a clear coat. Other applications/composite materials may require priming and painting. In all cases, Kaman Composites can handle the customers’ needs. We can also do screen printing, apply decorative labels, or a wide variety of other finishes.
More detail on our manufacturing capabilities can be found in our Facilities List.