HEAD REST

Semiflexible molded polyurethane foams are used in other automotive appHcations, such as instmment panels, dashboards, arm rests, head rests, door liners, and vibrational control devices. An important property of semiflexible foam is low resiHency and low elasticity, which results in a slow rate of recovery after deflection. The isocyanate used in the manufacture of semiflexible foams is PMDI, sometimes used in combination with TDI or TDI prepolymers. Both polyester as well as polyether polyols are used in the production of these water-blown foams. Sometimes integral skin molded foams are produced. 

Now, mistress, we must tie it around your belly, said Mother Goodier, bending down with a grunt to where I squatted on the stool, with my head resting on my arms where I gripped the bedpost. Up you get so that we may do it with reverence. ... 

The throne s incumbent is robed in white linen with a mantle of crimson silk falling from his shoulders. He bears a tall staff surmounted by the triple cross of Melchizadek. Upon his head rests the White Crown of Upper Egypt, encircled by three gold diadems. His face is as old as yesterday and as young as tomorrow. The mouth is generous and warm and the eyes are deep and dark to look into them is to see the starry wisdom mirrored therein. 

In the synthesis above styrene reacts with butadiene to form long chains while at the same time retaining a double bond per two molecules. Subsequently sulphur is added and sulphur bridges are formed between the remaining double bonds which interconnect the chains. These bridges are represented by small dashes. SBR is for instance used in the manufacture of car tyres. Another elastomer is polyurethane rubber PUR which is used as a foam in head rests. 

Slush Molding. This is the reverse of dip molding. A female mold is used to give any desired surface finish on the product. The mold is preheated, plastisol is pour into it, and gels onto the surface of the mold. The excess liquid plastisol is poured out, and the internally- coated mold is heated to gel, then cooled to solidify the rubbery product, and the product is stripped out of the mold. Typical products are arm rests, head rests, road safety cones, anatomical models, dolls, toys, and auto parts. 

The phenomenon of plasticiser migration into polyurethane foam, leading to hardening and cracking in arm and head rest applications, has been investigated and a mechanism proposed (215). 

Samples of plasticised PVC coatings backed with a thin polyamide fibre cloth used for arm and head rests of trains were analysed after both normal use in service and artificial ageing at 100 C. Two parameters were studied the effects of temperature inside the train and the influence of the polyurethane foam inside the rests. Plasticiser loss due to migration during ageing led to hardening of the... 

The six figures shown here are selected from a 1914 Paris reissue of the Mm-tus Liber. The title page (Figure 84) shows a picture believed to depict Jacob and the Ladder to Heaven and is totally spiritual. His head rests on a rock some say represents the Philosopher s Stone. The translation is as follows ... 

The largest-volume use of flexible foam is furniture and bedding, which account for nearly 47% of the flexible polyurethane foam market. Almost all furniture cushioning is polyurethane. Automobile seating is either made from flexible slabstock or poured directly into frames, so-called deep seating, using HR chemical formulations. Semiflexible polyurethane foams find use in crash pads, arm and head rests, and door panels. 

Arco Chemical s line of Arpro expanded PP and Arpak expanded PE bead resins are used for the interior components. Polyolefin foams provide a higher degree of chemical resistance, heat resistance, and cushioning as compared to foamed polystyrene. Potential applications include seat backs, head rests, and other critical energy-absorbing areas. 

MAJOR APPLICATIONS Polyurethane urea is useful in making interior automobile parts like armrests, head rests, gear shifts, knee protection pad, etc. Rigid integral PU foams are used in electronic and construction fields. 

Complete passenger seat Complete passenger seat including arm- and head rests, separate pillows, tip-up seats, and driver seat accessible to the passenger... 

Upholstery for passenger seats and head rest Upholstery for seats and head rest... 

Patient position prone, head resting on ehin and facing forward, arms either at the side or hanging down from table (Fig. 36-6). Physician position standing at the side of the patient, facing the patient s head. The... 

Patient position prone, head resting on chin, arms at sides. 

Education is probably valuable where there is evidence that unsafe behaviors are associated with ignorance rather than due to ulterior motives. This, for example is the case in the use of child booster seats, where most parents are unaware or misinformed of their importance and proper use, and for adjustment of head rests in car seats where most drivers do not know the proper adjustment (see Chapter 10). 

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