Fixed half

Test salons are often used to evaluate hair fixatives. Half-head studies are performed, with the test product appHed to one side of the head and a control product to the other in reaHstic use amounts. Similar properties as desctibed in laboratory tests are measured. Finished products are often sent to testers homes where they have an opportunity to evaluate the products in real use situations for extended pedods. 

Drugs with zero-order elimination have no fixed half-life (tl/2 is a variable). Graphically, zero-order elimination follows a straight-line decay versus time. 

The low-pressure die-casting process involves holding the molten metal to be cast in a crucible around which are arranged the heating elements necessary to keep the metal molten. The crucible and elements are contained inside a sealed pressure vessel in the top cover of which is a riser tube whose lower end is immersed in the molten metal. Low-pressure air (0.75 bar to 1.0 bar) is introduced into the crucible above the surface of the molten metal and forces the metal up the riser tube and out through the top end. This top end is attached to the bottom or fixed half of the die, which is designed to allow air to escape as the molten metal enters. When the metal has solidified in the die, which is aircooled, the air pressure is released and the remaining molten metal in the riser tube drops. 

The mould (see Figures 7.3,7.28,7.29) comprises two halves the fixed half attached to the stationary platen and the moving half attached to the moving platen. The impression is formed between the two halves. It is... 

Assuming that the decision has been made that the molded part must be ejected from the moving half of the mold (as opposed to the fixed half), then it is necessary to make provisions such that the part will not remain in the fixed half of the mold during mold opening, but will invariably remain with the moving half. 

The fixed and moving halves of the mould are supplied with water at different temperatures. The fixed half contains the presentation surface of the moulding, which demands the better visual finish. This requires somewhat slower cooling, to allow the mould surface to be accurately reproduced. 

Fixed half tool temperature = mains water ( 10 C)... 

In all cases the film is an external layer on the moulding, which means that the melt has to be injected through a core located in the fixed half of the mould. 

In an IML mould, the cavity is in the moving half of the mould because of the need to inject into the non-visible side of the piece. This means that both the ejection system and the HR system must be located in the fixed half of the mould. 

The function of the clamping unit is to move the one mold-half called clamp , movable or ejector half towards the stationary, fixed half and the application of clamping force to seal against the separating force of the cavity pressure. 

Basic injection molds are made of two halves Fixed half (often abbreviated as A) and Ejector half (often abbreviated as B), which are consisting of several plates (Figure 1.10). Due to an easier machinability and interchangeability, the cavity is formed by inserts which are tailored to the surrounding frame plates. 

Arrangement of the inclined bolt and the locking wedge on the fixed half, whereas the slider guidance is on the ejector half of the mold. 

Using restraining undercuts helps keeping the runner on the fixed half which leads to tearing off the pinpoint gate. Similar to the tunnel, the runner has to be demolded out of its undercuts using elastic deformation. 

FIGURE 1.56 Sealing of the cavity for applying vacuum before injecting On the left Ejector half with peripheral sealing ring On the right Fixed half with vacuum connection above the cavity [15]... 

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