Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Hopper color

With few exceptions, thermoplastics are marketed in the form of pellets. They are shipped in containers of various sizes, from 25-kg bags to railroad hopper cars. Resins are conveyed to silos for storage and from there to the processing equipment. Colored resins are available, but frequentiy it is more convenient and economical to buy uncolored resins and blend them with color concentrates. Using concentrates avoids handling dusty pigments and ensures uniform color distribution. [Pg.136]

The extrudate samples and the solidification experiment clearly show the importance of the melting process on the mixing quality of the extruder discharge. The cases shown here are for color masterbatches in natural or white resins, but the concept applies to any solid mixture or blend added to the hopper of an extruder. Color masterbatches were used here because it is much easier to visualize than other compositional variations or thermal gradients. [Pg.352]

Explosive B T No 21 (Victorite). A compn ptepd by mixing flour (18.8), sulfur (1.9) KCIO3 (75.1%) in a soln of resin (4.2%) in an org solv, and then removing the solv by evaporation. This process is designed to coat the expl particles with resin, thereby waterproofing them and reducing their, sensitivity. The product may also be dyed different colors. The compn was unsatisfactory for military application because of its sen si tivity, hygroscopicity low brisance Ref J.D. Hopper, PATR 481(1934)... [Pg.268]

Another device often used with liquid color is the intermixer (see Fig. 20.3.). An intermixer is installed between the resin hopper and throat of an injection molder or extruder. The main parts of an intermixer are a mixing chamber and a motor-driven impeller. One end of the chamber is usually transparent, so the mixing process is visible. The resin falls into the chamber of the intermixer from the top, and liquid color is pumped into the chamber from the side. The impeller turns at a rate of about 60rpm and distributes the liquid color uniformly on the surfaces of the resin pellets. [Pg.292]

Wax concentrates may be in the form of prills, bars, flakes, or granules. Prills are very small spherical pellets, usually made from a pigment blend and wax. They may be blended, like dry colors, or dispensed by a metering device at the throat of the extruder. If they are blended, it is best to use a powder resin, such as polyvinyl chloride (PVC), so they do not sift to the bottom of the container. The other physical forms are applied in different ways some are designed to be metered in at the hopper, the rest to be blended in before reaching the hopper. The carrier may lubricate, so letdown ratios are limited. [Pg.297]

The mixing process for concentrate pellet product production via Leistritz-type extrusion equipment is essentially identical to that of dry color product mixing. Once weigh-out has been completed, the formula is usually transported to a mixer where the ingredients must be mixed to uniformity. The ingredients are usually manually dumped into the mixer, after which the lid is sealed and the mixer is operated until the formula reaches the desired uniformity. After mixing, the formula is manually removed from the mixer and placed into a hopper or container with a controlled outlet and is ready for the next operation. [Pg.304]

Add the resin/color blend to the hopper and then mold plaques until the color first appears. [Pg.324]

Via a plant hopper and honeybees, partly metabolized picrotoxanes from Coriaria spp. growing in New Zealand are found in toxic honey. The rather difficult isolation of picrotoxanes from honey has been described several times 2,3,10,99,100) and even now the procedure seems not entirely satisfactory (700). Originally, the isolation of picrotoxanes was achieved by extraction of honey with acetone. Later, ethyl acetate was the preferred solvent. In the late 1960s, the two main picrotoxanes were identified as tutin (11) and hyenanchin (15). Originally, the detection was governed by the physical properties of crystals obtained, color reactions, and bromoether formation. Palmer—Jones then developed a method... [Pg.113]

Fast color change developments have recently been made that utilize a two-canister system to apply color-specific powders for automotive applications. While one canister is used for powder coating, the other one is getting ready for the next job. This allows a continuous operation with 8 sec claimed between jobs. Another recent development consists of a color-changing manifold that uses automated valves to control color change. Powders from the different feed hoppers are attached to the manifold. The powder of choice is fed into the manifold that consists of a central channel. Air is used to purge the hose and block between colors, which allows for a color change of usually less than 8 sec. ° ... [Pg.2414]

The pellets of plastic are first transferred from storage to the hopper on the extruder, which serves as a reservoir to feed the solid particles into the barrel. The hopper can be a simple one like the one shown in Fig. 7.1. Most extrusion operations are automated at least to the point of having a vacuum hopper loader to bring material to the hopper. Specialized equipment is available to mix in color and other... [Pg.214]

Designed to sort compacted bottles, the Poly-Sort system employs conveyors for singulation, and two devices for color and chemical composition identification. A vibratory conveyor singulates bottles a read conveyor transports bottles to an ultrasonic sensor that detects their position a near-infrared system detects the resin type a camera detects the color of the container a computer integrates data and makes an identification air jets divert bottles to the appropriate segregation conveyor or hopper. [Pg.709]


See other pages where Hopper color is mentioned: [Pg.159]    [Pg.159]    [Pg.304]    [Pg.159]    [Pg.159]    [Pg.304]    [Pg.257]    [Pg.1769]    [Pg.4]    [Pg.196]    [Pg.330]    [Pg.349]    [Pg.418]    [Pg.494]    [Pg.79]    [Pg.482]    [Pg.677]    [Pg.958]    [Pg.87]    [Pg.287]    [Pg.257]    [Pg.131]    [Pg.298]    [Pg.476]    [Pg.1701]    [Pg.162]    [Pg.556]    [Pg.283]    [Pg.297]    [Pg.297]    [Pg.1529]    [Pg.126]    [Pg.744]    [Pg.268]    [Pg.365]    [Pg.709]    [Pg.108]    [Pg.1773]    [Pg.217]    [Pg.107]    [Pg.113]   
See also in sourсe #XX -- [ Pg.304 ]




SEARCH



Hopper

© 2024 chempedia.info