Crystal-clear part

Edges, over which the plastic has to glide when forming, can be roughened in the slide direction of the plastic part. Edges of high positive molds can be polished. Surfaces can be polished when no air can be trapped. An exception is the manufacture of crystal-clear parts because an air trapping is mostly wanted. 

Dry mineral powders must be fed using some type of bulk handling system, preferably totally enclosed to prevent contamination of non-filled parts. If a molder, for example, is making filled parts and also polystyrene chandelier lights, one or two specks of filler are enough to ruin the crystal-clear parts. 

BASF AG Luran SAN Applications Crystal clear parts, refrigerator parts, cassettes, bathroom fittings, cosmetic containers, headlamp housings, instrument covers. ... 

Part of the North Branch of the Potomac River runs crystal clear through the scenic Appalachian Mountains, but it is lifeless—a victim of acid drainage from abandoned coal mines. As the river passes a paper mill and a wastewater treatment plant near Westemport, Maryland, the pH rises from an acidic, lethal value of 4.5 to a neutral value of 7.2, at which fish and plants thrive. This happy "accident comes about because calcium carbonate exiting the paper mill equilibrates with massive quantities of carbon dioxide from bacterial respiration at the sewage treatment plant. The resulting soluble bicarbonate neutralizes the acidic river and restores life downstream of the plant.1... 

Colorless crystals, clearly soluble in 25 parts of cold water. The aqueous solution sliould be neutral to litmus paper. 

Small, while crystals, clearly and completely soluble, in 20 parts id cold wafer. 

Fig. 1.48.1. Results of annealing (thermal treatment) on the formation of ice in (1) 60% fructose and (2) 60% glucose solution. (A) After cooling at 30 °C/min to -100 °C the DSC plots were recorded during rewarming at 5 °C/min.Tg—85 and-88 °C, respectively. At = 48 and-44 °C, respectively, ice crystallization clearly starts, followed by the beginning of melting of ice (during freezing only part of the water has been crystallized). (B) After cooling...

I was impressed and inspired by Charles Coulson (1910-74), the evangelical teacher of quantum chemistry. Quantum mechanics was not taught to chemistry students when I was an undergraduate, and Coulson s Summer Schools introduced some 35 to 60 chemistry graduate students, postdoctoral fellows and university lecturers to the subject each year from 1955 to 1973. His lectures were crystal clear, and his communication went beyond the power of his words, for one had to work hard at the problems he set, as part of the course, to really understand what he had said. 

Iodoform can be recognized by its odor and yellow color and, more securely, from the melting point (119-123°C). The substance can be isolated by suction filtration of the test suspension or by adding 0.5 mL of dichloromethane, shaking the stoppered test tube to extract the iodoform into the small lower layer, withdrawing the clear part of this layer with a Pasteur pipette, and evaporating it in a small tube on the steam bath. The crude solid is crystallized from methanol-water. 

An important alternative type of crystallizer is the fluidized bed. One fluidized bed design is shown in Fig. 6-6. As shown, the supersaturated solution enters at the bottom of the crystallizer and the clear, partly or fully depleted solution exits at the top of the crystallizer. The slurry is suspended in the crystallizer by the upward liquid flow, which usually lies in the... 

Cytisine (12, 38). The ground tops and seeds of Laburnum vuLgare were air-dried and extracted in a soxhlet with 50 % aqueous ethanol to which had been added 2 % of acetic acid. The extract after concentration was cleared with lead acetate, concentrated, made alkaline with sodium hydroxide, and extracted six times with an equal volume of chloroform. This left only a trace of cytisine in the aqueous layer. When the chloroform was removed, the residual alkaloidal material crystallized in part. No clear-cut separation of components was accomplished by fractional crystallization of the free base or the crude picrate. The isolation of cytisine as the benzenesulfonyl derivative was effected according to the method of Ing (5), and benzenesulfonyl-cytisine was collected and recrystallized from ethanol as glistening prisms, m.p. 261 . Microchemical tests and picrate formation and identification were also used to establish the presence of cytisine in a particular plant. 

It is a different story with the three-part CD case base and lid are of crystal-clear PS, whereas the insert part, which retains the CD, is of colored PS. 

Senior management must make it crystal clear to its employees that harassment and threats will not be tolerated. Garry Mathiason, a San Francisco lawyer who specializes in workplace liability law, stated, If you have a policy or plan in place, then what is tolerated and what is not become part of the culture (Dunkel, 1994, p. 70). This is especially important with verbal threats. Company policy must be firm that verbal threats will not be tolerated. Mathiason goes on to say, If you doubt me (ask yourself) when was the last time you made a joke going through an airport metal detector (Dunkel, 1994, p. 70). 

Many parts of this book are certainly incomplete. This is due partly to a lack of sufficient insight, partly to insufficient data. The reader should, therefore, not look at this contribution as a crystal clear definition of facts and problems, but instead as an impetus to possible developments. 

Crystal-clear technical parts are manufactured best using skeleton molds without using vacuum or compressed air. Skeleton molds are molds which are built like a scaffold on which only the contour forming edges are shown. 

Polyoxymethylene (POM) is used as an assisting piug material for crystal-clear molded parts. 

To a freshly prepared solution of 2 parts of d-isolysergic acid azide in 300 parts of ether is added an ethereal solution of 2 parts of d-2-aminobutanol-1 and the mixture is left to stand at room temperature during 12 hours. The yellowish clear solution is then washed several times with some water, dried over sodium sulfate and the ether evaporated in vacuo. The crystallized residue is treated with a small quantity of acetone and filtered. Yield ... 

Parts of diallyl-barbituric acid are added to a precooled mixture of 1 5.5 parts of concentrated sulfuric acid and 0.5 part of water while stirring intensively, the mixture being cooled so that its temperature does not exceed 25°C. The honey-colored viscous solution Is stirred vigorously and all at once into 45 parts of water, whereupon the mixture warms up to 35°C to 40°C and, after several seconds, solidifies into a thick pulp, which Is then heated as quickly as possible to 95°C, at which temperature a clear solution Is formed. This is cooled slowly until the 5-allyl-5-((3-hydroxypropyl)-barbituric acid begins to form coarse-grained crystals, after which the mass is cooled rapidly to 20°C. 

The thus-washed crude product is dissolved in a mixture of 12 parts of ethanol and 20 parts of benzene, with mild warming if necessary. 1 Part of sodium chloride and 1.5 parts of saturated aqueous sodium chloride solution are added to the obtained solution in ethanol-benzene, and whole thoroughly admixed. When the brine layer has settled. It is separated and the afore-described washing repeated. The clear solution is concentrated under reduced pressure until incipient formation of crystals and is then poured into 30 parts of benzene, whereupon a thick crystalline pulp is forthwith formed which, after being cooled to room temperature, is centrifuged off. The so-obtained 5-allyl-5-( 3-hydroxypropyl)-barbituric acid is dried at 70°C under reduced pressure and can be used for therapeutic purposes without further purification. Melting point 164 °C to 165°C. Yield 5 parts. 

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