Injection delay time

Water-assisted injection molding experiments were carried out on newly developed equipment in our lab. The effects of four processing parameters, short-shot size, melt temperature, water injection delay time, and water pressure, on the water penetration length and residual wall thickness of water-assisted injeetion molded polypropylene curved pipe were investigated. The crystallization behavior difference between the beginning and the end of the water channel of the eurved pipe was analyzed using differential scanning calorimetry. 

Figure 3. Effects of (a) short-shot size, (b) melt temperature, (c) water injection delay time, and (d) water pressure on water penetration length.

In this work, an inverse nemal network model was proposed. That is, measured residual wall thicknesses at five different positions of molded parts as shown in Figure 2 are the input variables. The output variables consist of fom processing parameters, including melt tenperature, water injection pressure, water injection delay time, and short-shot size. Among 31 data sets obtained from experiments by changing processing parameters, 26 sets of data (data 1 26 shown in Table 1) were used as training patterns to train the LMBP neural network to ascertain its... 

Once trained, the neural network model has been identified and can be utilized to forecast the processing paramrters expected for new levels of residual wall thicknesses at five positions of molded part. For exarrtple, inputting thicknesses 3.75, 3.72, 3.48, 3.65, and 3.00 mm at positions PI to P5 to the model, it can predict the processing parameters as follows melt temperature 232.3°C, water injection pressure 8.6 MPa, water injection delay time 3.4 s, and short-shot size 88.1%. While the actual measrrrements are melt temperature 230°C, wato-injection pressme 9 MPa, water injection delay time 3 s, and short-shot size 85%. 

Water-assisted injection molding experiments were carried out on newly developed equipment in our lab to investigate the influence of melt temperature, water injeetion pressure, water injection delay time, and short-... 

The cetane engine is a variable compression single cylinder engine very much like the octane engine. The engine is mn at 900 rpm and injection is timed to start at 13° before top dead center (BTDC). The compression ratio is adjusted so that the test fuel starts to ignite at exacdy top dead center (TDC), for an ignition delay of 13° or 2.4 ms. Reference fuels are chosen which bracket the sample and the cetane number of the sample is estimated by interpolation between the two reference fuels. 

OS 44] ]R 4a] ]P 33] 4-Bromobenzonitrile plugs (5 s) were inserted into a continuous phenylboronic acid stream for time intervals of5,15,25, 30,40 and 55 s (25 min reaction period) [6, 7]. For a 5-20 s delay, catalyst saturation occurs owing to the high injection rates rendering the phenylboronic acid concentration too low. In turn, for delay times of 30-55 s, the effective concentration of 4-bromobenzonitrile becomes too low. At 25 s, optimum performance with a yield of 62% was achieved (Figure 4.67). 

One interesting concept mentioned in the literature to reduce cycle time is that of backflushing.60 In this method, the column flow is reversed just after the product of interest has eluted. After a delay time, the next injection is made at the opposite end of the column from the first. This is designed to minimize the time spent eluting strongly retained contaminants. 

If the sample contains more than one species with different retention times, the effect of the column will be to transmit the same version of the switching code but at different delay times, according to the retention times of each of the components. This can be visualized then as a number of delayed versions of the sampling pattern transmitted through the column simultaneously — all originating simultaneously from the same injection code. 

Koelling et al. (70) conducted nonisothermal, pressurized gas-bubble Newtonian fluid-displacement experiments. The fluid used was PB H-300. It was injected into a capillary tube maintained at 60°C. The tube was then transferred in a different temperature bath at 0°C. The penetrating gas was then injected after different delay times, t. The longer the delay time, the deeper the cooling penetration thickness will be, since it is dependent on the Fourier number,... 

Fig. 13.36 The fractional coverage during nonisothermal gas-penetration experiments in PB-300, where the gas was injected after different F0 = at/R, that is, dimensionless delay times, following the step bath temperature switchover from 60° to 0°C. [Reprinted by permission from K. W. Koelling, V. Gauri, M. Tendulkar, R. Kaminski, and O. Becker, Understanding the Controlling Mechanisms of Gas-assisted Injection Molding through Visualization, SPE ANTEC Tech Papers, 43, 3697 (1997).]...

Each method is performed under constant flow conditions and uses the same temperature/carrier gas pressure program (see Annex 1). This ensures that the retention times of analytes are unchanged and the RI calibration table used for the calculation of RI by AMDIS is valid for each run. The solvent delay times vary between methods to adjust for the type of solvent used for a particular injection. The preparation run is different the temperature program heats faster and no data are acquired. This run is used only for the preparation and/or baking/cleaning of the system. 

Injection-type laser diodes based on GalnN active layers have now been demonstrated by a number of different groups [2,25-30], The threshold current densities range from 1.5 kA/cm2 [31] to about 50 kA/cm2 [26], From measurements of the tum-on delay time Nakamura et al [32] have also estimated the threshold carrier density to be about 1 - 2 x 1019 cm 3. 

Shallow Traps. In the presence of traps, the nm mobile and nt trapped carriers contribute to the space charge. Shallow traps mean that the delay time in the trap is considerably shorter than the transit time of the injected carriers. Under these conditions, Child s law (5.3) remains valid, if an effective mobility peft = s used instead, weighted by the percentage of mobile carriers 6 = nm/(nm + nt). 

In the most general case of the nonresonant fifth-order light scattering measurement, five off-resonant optical pulses are injected, as shown in Fig. 1. Two pairs of pulses are used to create two consecutive vibrational coherence states, and the fifth pulse is scattered by the temporal and spatial grating thus created. The controlled delay times between the first two pairs of pulses and between the second pair of pulses and the final pulse are... 

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