Nylon system Injection rates

The net effect is to permit lower injection rates to be used in nylon RIM. This permits use of smaller pumping units and produces less part anisotropy when fiber-reinforced systems are used. Injection rates as low as 0.1 lb/second are common on 3-4 lb parts, although rates as high as 1.0-1.4 lbs/second can be used. 

The immobilized lipase (0.1 g) in pH 7 phosphate buffer (25 mL) was added to 25 mL (20 mM) of ester stock solution in a 250 mL Erlenmeyer flask (reaction flask). The reaction flask was incubated in an incubator shaker at 40 °C with the agitation speed set to 200 rpm. Samples from the organic phase and aqueous phase were withdrawn at 24 h intervals over a 5-day reaction period. The samples collected were filtered using 0.45 pm nylon filter and injected into the HPLC system to determine the rate of resolution by monitoring both substrate ((/ ,5)-2-ethoxyethyl ibuprofen ester) and product (5-ibuprofen acid concentration). 

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