Opening force

Alifdocken, v.t. wind up, roll up bundle, shock. (Ulfdfirren, v.t. dry, desiccate, anfdrkngen, v.t. press open force upon, anldrehen, v.t. screw open, untwist turn on (as gas) turnup (Ceram.) throw. 

Closing Force = P x Areo A + Spring Looding Opening Force = P x Areo "B"... 

Clouing Forco = P i (Areo A -Ana C ) +Spring Loading Opening Force = P Area"B ... 

Closing Force P x reo An + Spring Loading Opening Force = P x Aren "B"... 

Closing Fores = P x (Areo"A"-Ar o"c") + Spring Loading Opening Force = P1 i Arta"B"... 

Carton opening force. The method that is often used is to hold the flat carton, as delivered, by its creases between thumb and first finger and press. The carton should spring open into the square position without a need for unreasonable force. If the carton does not spring open, or buckles in on itself, then it is reasonable to assume that those particular cartons will cause problems on any cartoning machine. This can be measured by instrumentation. 

It must be possible to open a door coming from the normal direction of egress without using a key. Draw bolts, hooks, bars, or similar devices cannot be used. An essential element of a door is that it cannot be too difficult to open. The opening force for most interior doors must not exceed a force of 5 pounds. To open a door that is normally power assisted must not require more than 50 pounds with the power off. Panic hardware must require no more than 15 pounds force to release, and a door not normally provided with power assistance cannot require more than 30 pounds force to initiate motion and swing to a full-open position with apphcation of a 15-pound force. These restrictions on the force required to operate a door can easily be exceeded should the ventilation system be modified without taking this concern into account. A very moderate atmospheric pressure differential of just over 0.3 inches (water gauge) would result in a force of more than 30 pounds force on a door of the minimum acceptable size. Addition of hoods to a laboratory, without provision of additional makeup air, could easily cause this limit to be exceeded on a more representative 3 foot by 7 foot door. 

Voluntary closing devices require an opening force to be overcome before the terminal device will close (default to open position). Pinch force in a voluntary closing terminal device is directly proportional to the force qyplied to the device through the control cable. 

Imposition of transverse or opening forces at the edge of adhesive... 

Fracture toughness. The orthotropic nature of wood also affects its fracture mechanics. Actually, timber fractures along the grains irrespective of the opening force and original notch geometry. 

To cope with the production of quite large parts, this unit incorporates multiaxis robots to demold and transport the molded part. The whole twin unit, which features a combined injection rate of 18 Ib./sec., is managed by a Unilog 90(X)B control system that made its debut at the 1989 Dusseldorf Plastics Fair. The mold alone weighs 127 t (140 tons) for the 1.5 m (2 yd. ) container, measures 305 x 153 x 216 cm (120 x 110 x 85 in.), and has an opening force of 545 t (600 tons). The top and bottom tie bars are 9h ft. apart and the side-to-side platen space is 18 ft. at a maximum mold thickness of 8i ft. 

Inclined bolt has to be sufficiently dimensioned to withstand the opening force. 

The projected area of a mould includes cavities and feed systems. The injection pressure is a function of part thickness, melt temperature, and mould temperature. It can vary within the mould. The three-zone reciprocating screw should achieve good plasticisation of the material. The estimation of the clamping force needed to keep the mould shut is a complex function of the projected area and the injection pressure. A rule of thumb for the clamping force required for PE is 0.2-0.5 tons/cm of projected area. A large safety factor of 25-50% is advisable. Computer simulation of flow will provide a more accurate estimation of the injection pressure and mould opening force. 

Most of the theory developed to date has been concerned with the behaviour of cracks or crack-like defects produced by opening forces (Figures 2.12,2.13) applied to linear elastic brittle materials. More complex analyses have been developed for cracks induced by shearing or tearing, but these are beyond the scope of this text. On first consideration, the relevance of a fracture mechanics approach to plastics which are predominantly ductile may be questioned, but further reflection confirms that most unexpected failures are brittle in nature. 

Figure 2.13 Further analysis of a crack subjected to opening forces...

When opening with increased opening force (high pressme opening) the control piston closes the main piston. The main piston and opening piston now open the mould with 50 bar pressme. 

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