There was a time when every design, development and production need demanded precise hand-crafting skills. With the advent of technology, we have successfully created several 3D designing software programs for computer-aided design and production. It has reduced the labor-intensive nature of most manufacturing processes including composites materials. Today, composites materials find extensive use in automobiles, aerospace, military and security, sports, and construction. You come in contact with hundreds of such productions of the composites technology every day during your commute to and from work, gym hours, entertainment and recreation, and even shopping.
The high demand in health, communications, security, transport, and entertainment sectors has led to complete computerizations of the design and cutting process. However, the strength and texture of the reinforcement textiles and dry fabrics ensures that it is impossible to cut them without special machinery. Moreover, each of the resulting composites is parts of a bigger system. They need to be precise by dimension and design. They need to fit together to create functional, structural and cosmetic units. That is why the reputed composites manufacturers and suppliers have entirely computerized and automated the standard cutting processes.
Why is the computerization of fabric cutting necessary?
The computerized knife cutter is the latest fabric cutting system. Fabric refers to any form of prepreg material or dry fabric that can reach up to 25mm in thickness. Several CNC cutters can precisely cut through Kevlar fabric as well. Depending on what your needs are you should check their cutting options, available technology, and machinery for preparing the composites. If a manufacturer cum supplier has state-of-the-art technology at hand, they can also ensure the optimal use of resources. That means you will be paying for exactly what you get. The overheads will be considerably low since computerized designing and cutting will minimize the wastage. Many manufacturers use a combination of static, oscillatory and dynamic blades for achieving the best results, closest to the design.
What is a round knife cutter?
One of the most common machines you will find in this domain is the round knife cutting machine. It has a round-ish cutter with a slightly octagonal shape due to the flattening of the blades. It is a compact, small and flexible machine that can handle small volumes of production. It also requires a manual grinder for function. The rpm of the motor depends on the device and its needs. Three types of knife edge including a toothed edge, waved edge and circular edge influence the kind of cut. The flexible movement of the knife allows natural non-linear motions as per the design template. Since a compact machine has the power to produce all kinds of cuts, a round knife cutting machine is always in high demand in the composites manufacturing industry.
Almost all-round knife cutting machines are suitable for cutting multilayer reinforcement fabric including prepreg. In fact, they are ten times more efficient than straight knives with the same r.p.m. However, they are not as suitable for cutting small parts or high curve lines accurately. They require periodic manual lubrication, and they are unsuitable for larger productions that demand high throughput. In spite of its low productivity, it is popular among composites suppliers due to easy handling and maintenance. Check out sparteccomposites.com/services/kit-cutting/textiles/to learn more about the advanced fabric designing and cutting techniques available now.
What are the prepreg systems that require the CNC cutters?
That brings us to the use and advantages of prepregs in all industries. These are reinforcing fabrics that include a resin system. They typically contain an epoxy resin system that eliminates the need of laying any more resin in the mold. They combine the strength and endurance of several components to exhibit the maximum durability of the content. Their properties are very different from the inherent properties of the ingredients. In the hand layup, it is almost impossible to reach a 50% resin and 50% fabric content. Even with vacuum sealing or closed molds, it is impossible to achieve this consistency. However, prepregs come ready with 35% resin, which is ideal for reaching the maximum cured properties.
What are the advantages of using CNC cut prepregs?
Here are some of the salient advantages of using CNC fabric cutter prepregs –
- They eliminate the need for human lamination techniques. The distribution of the components is uniform, and it eliminates overly dry or resin-rich spots. The fabrics have uniform strength and composition throughout.
- Prepregs bring forth the possibility of repeating and recreating the same fabric design without human intervention. The complete computerized system can store the initial models and execute them as long as the initial raw materials are consistent as well.
- They take less curing time. In case of hand lamination, you need to wait for about 48 hours minimum for the cure to dry. The heat curing process takes only a couple of hours when you have a machine-cut prepreg ready for use.
- Almost all companies are looking towards a sustainable existence. They want to minimize the wastage of raw materials and other resources. Use of CNC cutting machines and the availability of ready-to-use prepregs ensure the maximum utilization of all the resources.
- Many of these composites become cosmetic parts of automobiles, sports equipment, fitness equipment, and construction. Mold preparation and release via manual intervention rarely impart the smooth finish and gleaming texture necessary for cosmetic parts. However, the use of prepregs can create glossy, uniform surfaces essential for the cosmetic parts in multiple industries.
Right now, there are several popular types of composite fabrics. Prepregs get their name from pre-impregnated, that refers to the backing fabric that alreadyhas thermoset polymer fabric or a thermoplastic resin in between the two layers. It is a B-stage material that is ready-to-cure. Hence, it requires cold storage that prevents final curing.
The complete curing requires autoclaving or oven processes. The advances have resulted in the out of autoclave curing processes that have increased their popularity among the final-stage manufacturers. The elimination of the autoclaving process can save energy and resources, along with optimization of the production procedures. According to a recent publication, the out of autoclave techniques for the curing process can save millions. The Air Force Research Lab has led the study that saved over $100 million at NASA by avoiding the installation of large volume autoclaves.
