Open molding composite manufacturing process
The open mold composite manufacturing process involves manufacturing composite parts in an open mold in order to facilitate access to the mold and direct application of the composite material. Unlike the closed molding process where the mold is sealed, the open molding process is more direct and usually results in less precise control of the material distribution of the part. This manufacturing process is usually used for production parts with lower mold costs, faster production times, and simple design.
Open mold manufacturing method:
- Sticky hands
This composite manufacturing method carefully positions the fibers on or in a mold and then wets them with a liquid resin. This is applied manually by our experienced laminating machines, which are then rolled out and placed in curing or vacuum bags. The fibers used in this process can be any material, as long as they are short strands of felt, woven, knitted, stitched or bonded fabric.
As you can imagine, hand pastes require great attention to detail and need to achieve lamination before the resin can begin to cure. This is a naturally time-constrained and high-pressure role that can limit the amount of detail and tailoring possible.
All in all, for composite materials that require shredding guns and rollers, hand paste (or wet paste) can be a cost-effective manufacturing process. Or, using vacuum bags and epoxy, it can be highly specialized and more expensive. If you want to learn more about these, just give our knowledgeable team a call to discuss your options. - Spray
As expected, this composite manufacturing process uses an airbrush to apply a mixture of resin and short glass fibers to the mold until the desired material depth is reached. In the hands of our skilled operators, these guns provide quick and tidy formation pressure, provided the operator pays attention to detail during the painting and rolling process. After spraying, the resin can be used after curing.
While this is a fast and cost-effective composite fabrication process, mechanical properties are generally low and high performance is not recommended.
The finished composite is often rich in resin, has a variable thickness and can be difficult to control. This is a desirable process for large, fairly simple structures such as hulls, bathtubs, and storage tanks.
- Fiber wrapping
This well-established and well-known industrial process is recommended for selected composite products. Fiber winding requires the use of a mandrel, usually an elongated outer mold. The part is made by threading a fiber bundle through a resin tank, where it is applied under tension to the mandrel.
To control the direction and Angle of this winding, we use a bracket with a winding guide that moves up and down the length of the mandrel as the spindle itself rotates. Using this synchronous movement, the fibers can be laid at a specific Angle to achieve the desired geometry. It is then cured at high temperatures as needed. For high-volume production needs, this composite manufacturing process can be easily automated and is often used for pipes or products with simple rotating shapes.
This may include pipes, pressure tanks, tapered rods and drive shafts, as well as specialized items including high-performance products such as bicycle frames. These typically use a combination of carbon fiber and epoxy resin with a mandrel wrapped prepreg to produce a lighter, stronger tubular structure.
While this can be a more expensive carbon fiber composite manufacturing process, we are the recommended choice for thicker, more engineered tubular shapes.
- Pultrusion molding
In the manufacturing process of the composite, the wet fiber strands are fed through a heated molding extrusion die. The fiber and resin are combined into one and then pulled out as fully cured parts.
As imagined, such a process results in long items with a consistent cross-section shape, axial reinforcement, and a consistent cross-section. Pultrusion is an excellent composite manufacturing process with high production accuracy, suitable for ladder parts, bridge parts and handrails. The process can be easily automated while using low-cost raw materials, which makes it ideal for high-volume output. - 3D printing/additive Manufacturing
3D printing, or additive manufacturing, is widely recognized as an innovation that is changing the manufacturing process for composite materials, and it is disrupting the industry in a good way! This composite manufacturing method uses 3D printing to produce functional components, such as tools and end-use production parts. Additive manufacturing builds geometric shapes by weaving raw materials such as filaments, wires, or powders. Then, depending on 3D printing processes and applications, additive manufacturing can tap into a growing catalog of materials and is arguably the most versatile manufacturing category.
Initially popular in the aerospace and medical industries, additive manufacturing is completely flexible and can be easily applied to many end markets, including dental, automotive, oil, gas, heavy equipment, and consumer goods.
Compared to reduction processes such as milling, additive manufacturing enables greater geometric freedom while using less material. In addition, 3D printing does not require any molds or tools to manufacture parts, so it is a good choice for applications with long lead times or associated costs.
