Übersetzung für "Forminnendruck" in Englisch

The internal mold pressure thereby becomes low, and is kept at a uniform level.

This internal mould pressure is produced by lowering the piston in the measuring bore 12.

The arising internal mould pressure is thus diverted uniformly in the closed mould.

As this happens, the filling process is regulated by the cavity pressure.

The system closes the cold runner nozzles depending on the inner mould pressure.

It has been found that 37.3 bar of internal mould pressure is sufficient to avoid an oil coating.

US 2004/0142057 A1 makes known a device for measuring the internal mould pressure in an injection molding machine.

As a result, the cavity pressure and the required clamping force drop by about 30 percent.

In contrast to the cavity pressure, this significant signal can be utilised without additional sensors.

Eventually, the actual inner mould pressure is easier to be determined and to be repeated during vulcanization.

The addition of aromatic diamines makes it possible for molded articles with considerably improved heat resistance to be obtained. Lower internal mold pressures are also used for their production.

In that process, just as for example in accordance with GB-A-1 459 673, measurements are made in particular in respect of the internal pressure in the mold and the time at which it reaches a maximum, which indicates complete filling of the mold.

The addition of very small quantities of aromatic diamines makes it possible for molded products to be produced which have a high density, at only a low internal mold pressure and a considerably improved heat distortion temperature.

The high inner pressure of the mold caused by injecting the rubber is completely kept away from these locations so that a comparably low force defined by the spring force of the spring 30 is effective in the axial direction.

At the end of the volumetric filling process, it is known that the mould cavity pressure undergoes an abrupt rise, which is propagated as a compression front throughout the mould cavity within a few milliseconds.

The movable mold mounting plate 8 is urged toward the right during the injection procedure by means of the piston-cylinder unit 7 and the mold is thereby held closed against the internal pressure in the mold.

Preferably, therefore, the internal mold pressure during the introduction of the reactive mixture is at least 50% of the saturation vapor pressure of the total amount of originally dissolved CO2.

On the other hand, in the case of molds of simple design, especially where the bottom side of the mold cavity is flat and horizontal, the reactive mixture can be introduced fully unfoamed to no disadvantage, i.e., it can be introduced into the mold at an internal mold pressure which is above the saturation concentration for the originally dissolved CO2.

If the amount of reactive mixture predetermined for the foam molding is introduced into the mold, the internal mold pressure is reduced until the foamed reactive mixture fills the whole of the mold, optionally after the release of any other blowing agents used.

If the CO2 content of the polyol component is raised to 8 wt. % and the reactive mixture is filled into the mold at an internal mold pressure of 14 bar (9% full prior to expansion), a foam density of 38 kg/m3 is obtained.

A foam of about the same density is obtained if a polyol component containing 3.5 wt. % of CO2 and 2 wt. % of H2 O is used and the reactive mixture is filled into the mold at an internal mold pressure of 6 bar (4.5% full prior to expansion).

The accumulator 28 function continues after the injection by maintaining the mold pressure while the molded article cools.

The pressure supplied is measured by means of a pressure gauge 22 in the pneumatic line, and from which the internal mould pressure can be calculated by means of the above given ratio.

It is evident from the description of the apparatus having various probes and detectors, that the specific volume, temperature and pressure of the test piece as also the internal mould pressure and temperature of the measuring cylinder can be ascertained directly, simultaneously and independently from one another and under non-isothermal conditions.

So as to avoid the test piece body from losing contact with the cylinder wall after the gelling, either a specific internal mould pressure must prevail or the test piece must be coated with silicone oil.

In solving the above-indicated problem, it was first found that influencing the level of the post or back-pressure at a time when the internal pressure of the mold has already exceeded its maximum and the mold is therefore completely filled, has only a slight influence on the final result.

Furthermore, care is taken to maintain the internal pressure in the mold prior of the gelling point at a value being not lower than a minimum pressure, e.g., of 10 to 60 bar, and preferably of 25 to 35 bar, so that, by compression of the mass, a large portion of the shrinkage after the gelling point will be anticipated and already compensated while the mass is still in a liquid state.

The machine controlled itself independently, i. e. it individually finished injecting through the FlowControl cold runner nozzles as soon as a specific mould filling (detected by inner mould pressure) was reached.

The method according to claim 1, wherein the reactive mixture is inserted during step b) such that the inner mould pressure is between 10 bar and 100 bar.