Reference - An Overview of the SCRIMP ™ Technology
| Type | Journal |
|---|---|
| Title | An Overview of the SCRIMP ™ Technology |
| Abstract | SCRIMP ™ (an acronym which stands for Seemann Composites Resin Infusion Molding Process) is a resin transfer molding process that uses a vacuum to pull liquid resin into a dry lay-up and is used for making very high quality, repeatable composite parts with almost zero VOC emissions. SCRIMP ™ technology was invented by Bill Seemann, as a means to meet the demanding requirements of projects for the U.S. Navy. The first of ten U.S. patents owned by TPI Technology, Inc. (TPI) was issued on February 20, 1990 and the latest was issued on December 12, 2000. The SCRIMP ™ technology serves a variety of applications and is compatible with all types of fiber reinforcements and resin matrices commonly used today. It is uniquely suited to build large-scale structural composite parts where high strength, durability and light weight are critical. NOTE: This overview is not intended to provide a comprehensive review of all of the technology, trade secrets, and related patents and intellectual property held by TPI, but it is intended to communicate the key elements of the SCRIMP ™ technology. For a detailed understanding of the patented technology, a review of the individual patents is required. In the basic SCRIMP ™ process, fiber reinforcements, core materials and various inserts are laid up in a tool while dry, followed by a vacuum bag that is placed over the lay-up and sealed to the tool. The part is then placed under vacuum and the resin is introduced into the part via a resin inlet port and distributed through the laminate via a flow medium and series of channels, saturating the part. The vacuum pressure compacts or debulks the dry fibers. For this reason, parts made with the SCRIMP ™ process have high fiber volumes, typically about 60-75% fiber by weight (50-65% by volume), depending on the type of fiber, the fiber architecture and the type of resin used. The vacuum removes all of the air from the lay-up before and while resin is introduced. The pressure differential between the atmosphere and the vacuum provides the driving force for infusing the resin into the lay-up. |
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| Date | 2001 |
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Welcome
Welcome to the CKN Knowledge in Practice Centre (KPC). The KPC is a resource for learning and applying scientific knowledge to the practice of composites manufacturing. As you navigate around the KPC, refer back to the information on this right-hand pane as a resource for understanding the intricacies of composites processing and why the KPC is laid out in the way that it is. The following video explains the KPC approach:
Understanding Composites Processing
The Knowledge in Practice Centre (KPC) is centered around a structured method of thinking about composite material manufacturing. From the top down, the heirarchy consists of:
- The factory
- Factory cells and/or the factory layout
- Process steps (embodied in the factory process flow) consisting of:
The way that the material, shape, tooling & consumables and equipment (abbreviated as MSTE) interact with each other during a process step is critical to the outcome of the manufacturing step, and ultimately critical to the quality of the finished part. The interactions between MSTE during a process step can be numerous and complex, but the Knowledge in Practice Centre aims to make you aware of these interactions, understand how one parameter affects another, and understand how to analyze the problem using a systems based approach. Using this approach, the factory can then be developed with a complete understanding and control of all interactions.
Interrelationship of Function, Shape, Material & Process
Design for manufacturing is critical to ensuring the producibility of a part. Trouble arises when it is considered too late or not at all in the design process. Conversely, process design (controlling the interactions between shape, material, tooling & consumables and equipment to achieve a desired outcome) must always consider the shape and material of the part. Ashby has developed and popularized the approach linking design (function) to the choice of material and shape, which influence the process selected and vice versa, as shown below:
Within the Knowledge in Practice Centre the same methodology is applied but the process is more fully defined by also explicitly calling out the equipment and tooling & consumables. Note that in common usage, a process which consists of many steps can be arbitrarily defined by just one step, e.g. "spray-up". Though convenient, this can be misleading.
Workflows
The KPC's Practice and Case Study volumes consist of three types of workflows:
- Development - Analyzing the interactions between MSTE in the process steps to make decisions on processing parameters and understanding how the process steps and factory cells fit within the factory.
- Troubleshooting - Guiding you to possible causes of processing issues affecting either cost, rate or quality and directing you to the most appropriate development workflow to improve the process
- Optimization - An expansion on the development workflows where a larger number of options are considered to achieve the best mixture of cost, rate & quality for your application.
