SCRIMP process

The process allows panels measuring several meters in each dimension to be infused with resin quickly and thoroughly, to give more rapid and consistent production. It can be controlled more closely than open-mold wet lay-up, giving parts of higher consistency and reproducibility. Structures, which are both thick and complex, can be impregnated and 

Generally, the larger the part, the better the economics. Set-up costs are said to be modest and labor savings can be up to 50% of hand lay-up costs. There appears a consensus that it has a good future in styrene-free volume production of moldings with large relatively planar surfaces. 

The process has been licensed to some 30 organizations worldwide. The UK shipbuilder Vosper Thornycroft uses it for molding large bulkhead panels for minehunters and believes that laminates can be developed to meet stringent new regulations, such as the latest International Marine Organization (IMO) code (which some have feared would spell the end of TS polyesters in fabrication of primary marine structures). 

SCRIMP has been shown to be able to produce consistently high quality parts, including high-end military minesweepers, pleasure boats, windmill blades, marine fenders and piling, a 14.6 m (48 ft) all-RP flatbed trailer, utility poles for transmission lines, small temporary bridges. Lockheed has also used it for carbon fiber laminates. A noteworthy application was an insulated railcar, molded in two parts, with a 5-tonne body (fabricated from Dow s Derakane vinyl ester with Vetrotex E-glass fiber and Dow polyurethane (PUR) foam core for insulation, molded on a segmented FRP tool). 

In USA, SCRIMP fabricated large RP products such as a transportation bus weighs about 10,000 kg (22,000 lb) that is 3200 kg (7000 lb) lighter than steel units are. It fabricates a trial 75 ft high integrated mast structure for an amphibious warfare vessel. The RP structure, made up of infused panels, encloses and supports the forest of antennas visible on a normal warship, in a weatherproof, electro-magnetically tuned mast/ housing. 

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SCRIMP process This Seeman Composites Resin Infusion Process (SCRIMP) is described as a gas-assist resin transfer molding process. As an example glass fiber fabrics/ thermoset vinyl ester polyester plastic and polyurethane foam panels (for insulation) are placed in a segmented tool. A vacuum is pulled with a bag so that a huge amount of plastic can be drawn into the mold (Marco process approach). Its curved roof is made separately and bonded to the box with mechanical and adhesive fastening. It is similar to various reinforced plastics molding processes. 

SCRIMP See reinforced-plastic SCRIMP process, scrubber A device that is used to filter out unwanted pollutants, such as acid gas emissions at combustion fiicih-... 

For large structures such as boats, the SCRIMP process uses a vacuum bag instead of the two plates of a typical mold. Advantages for this technique are the one-sided mold, better control of and higher fiber volume, and lower porosity in the composite. It has been used for structures that need higher quality than can be obtained by other RTM processes. 

There are other variations of the RTM, VARTM and CRTM process which belong to the class of LCM processes such as RTM light in which a caul plate is introduced on top of the bag, resin infusion under flexible tooling (RIFT), resin film infusion (RFI) and vacuum injection preform relaxation (VIPR). In addition many of the same processes are known by different acronyms. It is useful to note that as the science base of RTM improved and led to better understanding of the variables and parameters that influence the flow and dry spot creation in RTM, it led to approaches and creative ideas to improve the process and cut down the cost. This learning continues today to evolve new modifications to the LCM family of processes. For example in VIPR one can now introduce flow control effectively to modify the flow front and create a part that is better than the SCRIMP process and is of consistent quality. ... 

SCRIMP process. (Source-. Adapted from reference 1.)... 

This study focuses on a new liquid molding process called VAP. The process adds a membrane to the SCRIMP process allowing uniform venting on the complete preform surface. It evaluates the flow behavior, membrane material and final material properties resulting from the process. Overall, the membrane approach provides a more robust process with the correct selection of the membrane material. 

Fig. 2. One-piece bridge deck made by SCRIMP process. Courtesy Hardcore Composites, New Castle, Del.

Lopez-Anido R, Fifield S. Experimental methodology for embedding fiber optic strain sensors in fiber reinforced composites fabricated by the VARTM/SCRIMP process, in 4th International Workshop on Structural Health Monitoring, Stanford, CA, 2003. ISBN 1932078207. 

Figure 4.17 RTM (SCRIMP ) process for injecting a boat hull. (Copyright Billy Black, courtesy ofSeemctnn Composites)...

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