Infusion process

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 (Seeman Composites Resin Infusion Process) 522 ... 

Decoction is a variation on the general infusion process in that the herb is steeped in boiling water to which heat is then supplied to keep it at boiling point, simmering gently rather than boiling vigorously. 

Percolation is an alternative to infusion processes whereby the solvent is trickle-fed on to the top of the herb or spice material and collected as it emerges from the bottom of the percolation vessel, which is traditionally conical in shape. This process is sometimes used in the production of natural flavours. 

Rather than an in-depth technical description of the mechanics of extraction, this section presents briefly a typical infusion process, focusing on the factors that make extracts different from single-chemical components. Extracts by then nature are complex mixtures of (often) diverse active compounds contained within a plant matrix which are brought into solution by the extraction process. The aim of the extractor is to produce, over a period of time, batches of an extract meeting a customer s individual specification with as little variation as possible. There are parameters over which the extractor has some control, and these can be used to help achieve product consistency and also to fine-tune an extract to a particular customer s needs. 

Epoxy vinyl ester resins are a special class of unsaturated resin. This resin is made by capping an epoxy resin with methacrylic acid and then dissolving in styrene monomer to the desired viscosity. This gives mechanical properties similar to epoxy resins, but the processibility (low viscosity allowing for resin infusion processes) of an unsaturated polyester resin. As with unsaturated vinyl esters, the most common fire retardant vinyl ester resin is based on a resin made from a halogenated system, tetrabromobisphenol A. The level of bromine in the resin and the presence of antimony will determine the fire performance of the resin. These resins are normally used for corrosion resistant equipment or when fire performance and high mechanical properties are required. It is very difficult to get a low smoke value with a brominated vinyl ester resin again due to the fact that bromine... 

Apart from wine, several other works involving multielemental characterization of beverages have been carried out with different scopes, for example, origin assessment of orange juices [28, 60], study of the tea infusion process [61], and investigation of the interdependences among trace elements in beer [62]. 

Comparisons between the different intra-arterial thrombolysis trials and between intraarterial thrombolysis and intravenous thrombolysis is hampered by differences in methodology and type of thrombolytic therapy. In addition, within the intra-arterial thrombolysis trials, thrombolytic deUvery has varied between regional into a parent vessel of the thrombosed vessel, local into the affected artery and into the thrombus itself, or combinations of these methods. In addition, the infusion process has been variable, ranging from continuous to pulsed infusion. Some studies have allowed physical clot dispersion using the tip of the microcatheter while this was prohibited in others, for instance in the PROACT trials. 

Firmness of segments was substantially reduced by the pectinase infusion process. Vesicle compression values for pectinase derived segments ranged from 38 to 69% of the value for water infused control segments. Of the pectinase derived segments, those produced with Pectinase 1 were the firmest, and also had the least fluid loss during storage. 

Solid-infusion processes Emulsion liquid membranes Solid-supported liquid membranes Fnam fractionation Bubble fractionation... 

These processes are well suited to the production of very large parts ranging from turbine blades and boats to rail cars and bridge decks with relatively low equipment investment. Compared to the conventional composite fabrication methods used in the aeronautical field, these infusion processes are an ideal technique using low cost materials without prepregs and autoclaves. 

Resin Transfer Molding Resin transfer molding (RTM) is a closed mold infusion process in which reinforcement material is placed between two matching mold surfaces (Fig. 28.7). The matching mold set is then closed and... 

The VARTM is a hquid resin infusion process and is currentiy considered by the aircraft industry to be the favoured low cost manufacmring process for the future. It is an autoclave-free process that has been identified as reducing the cost of component processing. It is reported that dimensional tolerance and mass measurements are comparable with stitched RFI autoclave panels. A conventional blade stiffened test panel (3 X 2 ft with 4-in-high blades 0.5 in thick) has been manufactured recently at NASA by using the VARTM method, achieving a reasonable quahty. 

Advantages of resin-infusion processes (sometimes referred to as out of autoclave processes ) include ... 

Two of the most popular of these processes are CRTM which is reviewed by Bickerton and Kelly (2012) [22] and VARTM which is discussed by Hsiao and Heider (2012) [23]. The use of vacuum to develop resin-infusion processes has been one of the most successful developments in reducing the problem of voidage as well as speeding up the process. Vacuum-based processes have enjoyed enormous growth in popularity... 

At the upper end of the glass technology scale, GRP is the basis for Sandown class mine hunters built by Vosper Thornycroft for the UK Royal Navy using a proprietary infusion process. A number of navies have selected FRP for the structures of mine countermeasures vessels since it provides immunity to magnetic influence mines. 

This Seeman Composites Resin Infusion Process (SCRIMP) has been used to manufacture corrosion resistance bus shells (Chapter 5). North America Bus Industries (NABI) of Anniston, AL uses glass fiber-polyester plastic material from TPI Composites of Warren, RI. These new buses weigh about 10,000 kg (22,000 lb) that is 3200 kg (7000 lb) lighter than steel units. Lighter weight results in reduced axial loads, brake wear, etc. and improved fuel efficiency. 

Outside Emope and North America, a one-step "infusion process is reportedly becoming more popular for lowa-cost silane aosslinking of cable coverings. This process uses a aossUnkable PO compound that already incorporates a aosslinking catalyst. The complete formulation is mixed in a separate machine near or in-line with the cable extmda, where the grafting... 

In the vacuum infusion process, the fibre sheets are placed in a dry state with a plastic sheet laid over the entire form to create a vacuum. Resin is introduced at one end. The vacuum enables the flow of the resin and an even distribution of the matrix through the fibres. In comparison with the hand laminating process, a higher volume of fibre can be achieved in the composite material. However, it is difficult to control the flow of the resin along edges, comers, etc. It is also not possible to vacuum-infuse honeycomb materials for a sandwich structure. 

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