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Nip distance

The top and the bottom rolls should be adjustable to keep the nip distance for taking out sheets of precise and uniform thickness. The central roll is fixed. [Pg.214]

The nip distance during mastication and initial addition of chemicals should be at a minimum and then increased slowly during addition of fillers and finally during cross folding, blending and homogenising, it is again reduced. The nip distance can be varied... [Pg.88]

Taylor (1961) studied experimentally the bubble problem described while, at about the same time, Bretherton (1961) analyzed both theoretically and experimentally the slow motion in a capillary of a long bubble, where differently shaped interfaces at the front and rear menisci have to be considered. If, however, only the front meniscus and the film thickness to a point sufficiently far back of the front are examined, then the configuration is essentially the same as Taylor s. In the bubble problem the characteristic length scale is the tube radius a, and this length corresponds to the half-nip distance in the roll coater problem. Except for the appearance of a natural length scale, all of these problems may be recognized to have the same character as the Landau-Levich... [Pg.305]

Gauge length n. On a dog bone-shaped, tensile-test specimen before stress is applied, the distance between two marks on the narrow part ( waist ) of the specimen, perpendicular to the direction of pull that will be used to measure elongation. If the specimen is of uniform thickness and width, gauge length may be taken as the nip-to-nip distance between the clamping fixtures. [Pg.453]

Various new designs of intermeshing rotor internal mixers have been proposed since the 1970s [33, 67 to 69]. In a 1987 patent application, Passoni [69] describes a design wherein the nip distance between the rotors may be varied. This allows the intensity of inter-rotor shearing to be varied during the mixer cycle for any particular compound and the shear intensity to be varied for different compoimd formulations. This machine is manufactured by Techint Pomini. [Pg.247]

Sheet can be produced by melt extmsion, but in this case a three-roll stack of quenching roUs is generally used (Fig. 2). More than three roUs may be used where necessary. The roUs may be mounted vertically or horizontally. The web is extmded through a slot die in a thickness close to the desired final thickness. The die is in very close proximity to the first chill roU or chill-roll nip. The web may be cast horizontally directly onto the upper chill roU of the stack as shown (Fig. 2), or it may be extmded into the first nip directly. The roUs quench the sheet and provide the surface polish desired. In some applications, matte or embossed roUs maybe used to impart special surface characteristics for certain functions. Where the utmost in optical (glazing) quality is desired the trend has been to mount the roU stack horizontally. The hot melt is then extmded vertically down into the first nip. This avoids problems associated with sag of a horizontal hot melt no matter how short the distance between die and quench. [Pg.379]

The distance upstream of the nip at which the pressure is a maximum is given by equation (4.38)... [Pg.317]

The nip is the radial distance or V formed between rolls on a line of centers. In-going safety devices in the nip areas are built into these machines. They protect the hands of operators. An emergency stop device is placed in an accessible location on the upstream side. [Pg.525]

Let p(x) be the pressure as a function of the distance x from the calender nip perpendicular to the calender axes. The coordinate y describes the distance from the center of the clearance to the roll axis. The equation of motion in this case can be reduced to... [Pg.1002]

The pressure through the calender nip is determined with this equation. The distance from the calender flow centerline to each roll surface is given by... [Pg.1002]

Fig. 2.30 Comparison of antiparallel hairpin structures in / -peptides 120-122. (A) / -Pep-tides 120, 121 with a 12-membered R/S dini-pecotic (Nip or/ -HPro) turn segment (gray color). Summary of backbone-backbone and side-chain-side-chain NOEs collected in CD2CI2 and X-ray crystal structure of 121 (stereo-view) [154, 193], The intramolecular H-bond N" 0 distances are shown. The angles (N-H -O) are 170.8° (inner H-bond) and 1 72.3 ° (outer H-bond). (B) jS-Peptide 122 with... Fig. 2.30 Comparison of antiparallel hairpin structures in / -peptides 120-122. (A) / -Pep-tides 120, 121 with a 12-membered R/S dini-pecotic (Nip or/ -HPro) turn segment (gray color). Summary of backbone-backbone and side-chain-side-chain NOEs collected in CD2CI2 and X-ray crystal structure of 121 (stereo-view) [154, 193], The intramolecular H-bond N" 0 distances are shown. The angles (N-H -O) are 170.8° (inner H-bond) and 1 72.3 ° (outer H-bond). (B) jS-Peptide 122 with...
The distance between adjacent rolls of a mixing mill or calender the term is often applied also to the space between the rolls, leading to the nip proper. [Pg.43]

A calendering process in which rubber compound (suitably warmed) is passed through the nip between two bowls set at a specified distance apart to produce a comparatively thin sheet of rubber. The name sheeting is also given to the vulcanised product. [Pg.57]

You would like to analyze the atomic structure of Pd by grazing incidence X-ray diffraction. After penetrating a distance x, the intensity of the beam is decreased by I = J0 e x. Your diffractometer uses photons of 10 keV energy. Is the wavelength sufficiently small to analyze atomic structures At this energy a handbook tells you that the photon attenuation coefficient, nip, is 691 cm2/g. The density is 12.0 g/cm3. Assume you want 20% of the incident X-rays to be scattered within the topmost layer of 1 nm thickness. Which angle do you have to choose ... [Pg.176]

X-ray diffraction analysis can be used to characterize the crystallites themselves.15,68 First, it is possible to obtain information about the chain conformation adopted by the polymer chains in the crystallites. Many polymers crystallize in helical conformations. These can be defined by the following helical parameters. The designation pn tells how to rotate and simultaneously translate along an axis to generate the specified helix. First a point of reference is rotated around the proposed axis by nip times a complete rotation of In. Simultaneously, there should be a translation of nip of the crystallographic repeat distance, a quantity that is also obtained from diffraction data. Repetition of this scheme gives a helix having p repeat units in n turns of the helix. [Pg.35]

A 15 cm diameter, 2 m wide calendering system is used to produce a PVC sheet with a Newtonian viscosity of 10,000 Pa-s. The roll speed, U is 6 m/s and the distance between the nips is 5 mm. [Pg.334]

Fig. 44. The structures of NiAs, CoP (MnP type) and NiP. Shortened T—T and P—P distances are emphasized... Fig. 44. The structures of NiAs, CoP (MnP type) and NiP. Shortened T—T and P—P distances are emphasized...
Another distorted variant of the NiAs structure occurs in NiP which is stable only above 850° C (159). In the orthorhombic NiP structure the distortions are stronger than in the MnP type (Fig. 44) but like in MnP the metal atoms form zig-zag chains with Ni—Ni = 2.53 A. The coordination of the nickel atoms is modified insofar as they are shifted towards a comer of the distorted anion octahedra. As a result there are only five phosphorus atoms in contact with the central nickel atom. The anions themselves are arranged in pairs with a P—P distance of 2.43 A, which roughly corresponds to the length of a half bond. In the absence of cation-cation bonds the P—P pairs would lead to divalent Ni and non-metallic properties would be possible. In the actual structure the Ni—Ni bonds exclude semiconductivity which, moreover, cannot be expected in a high-temperature phase. [Pg.147]

Distance through the nip is important because time is needed for the film to... [Pg.65]

The same treatment applies to the regenerated nip surface film, dc. The velocity gradient would be zero at the surface, except perhaps when elastic forces predominate. The surface exposure time may be approximated by 0 = distance dc/irDN sin(f)y where screw helix angle measured from the cross-sectional plane. [Pg.238]

The Flow Equation. Consider a differential cross-sectional slice, dx, at distance x from the feed end of the devolatilizer. A volatile component material balance across this slice will include net inputs due to mean axial flow and axial dispersion (the latter arising from the nip mixing action), and depletion through the regenerated surface films. In addition to the three assumptions made above, it is assumed that uniform conditions prevail throughout the length—i.e., constant Uy p, S, Wy D y etc.-and that the effect of axial dispersion may be characterized by a constant axial eddy diffusivity, E. The steady-state material balance for a volatile component across dx reduces to ... [Pg.238]

For mechanical reasons the gap between rolls cannot be less than 10 am and it is usually ranges from 40 to 50 J,m. Small particles will not be affected as they pass through the nip, but agglomerates smaller than the distance between rolls will be disintegrated due to the shear stress imposed on the material... [Pg.224]

As already noted, however, in lithography we are not operating at equilibrium we are not waiting for spontaneous wetting action we are forcing the wetting action. The pressure and shearing forces at roller nips are purposely far in excess of the ink s viscous resistance to flow, to assure that the ink will move a small but finite distance at the ink-to-ink roller couples, within 10 2 to 10 second dwell times. [Pg.348]

Fig. 8.123 describes the compaction of a particulate solid in the nip between two gravity fed counter rotating rolls. For clarity, the roller diameter D and the distance between the rolls are not to scale. In reality the roll gap is much smaller as compared with the roller diameter (e.g. D/Iia 100/2 to 100/5). Compaction between two smooth rolls may be explained by dividing the nip area into three zones The feed zone, the compaction zone, and the extrusion zone. [Pg.340]

Fig. 6.9-8 depicts three typical hot briquetting systems for DRI. Hot feed in the form of reduced pellets and/or lumps and/or fines is forced by a vertical screiv feeder into the nip between two counter-rotating rollers with matched pockets [B.48, B.97]. The briquettes are pillow shaped, 90-140 mm long, 50-60 mm wide, about 30 mm thick, and weigh 450-800 g each (Fig. 6.9-9). Although the rollers are set closely together, a distance of 2-3 mm is maintained between their surfaces to make sure that there is... Fig. 6.9-8 depicts three typical hot briquetting systems for DRI. Hot feed in the form of reduced pellets and/or lumps and/or fines is forced by a vertical screiv feeder into the nip between two counter-rotating rollers with matched pockets [B.48, B.97]. The briquettes are pillow shaped, 90-140 mm long, 50-60 mm wide, about 30 mm thick, and weigh 450-800 g each (Fig. 6.9-9). Although the rollers are set closely together, a distance of 2-3 mm is maintained between their surfaces to make sure that there is...

See other pages where Nip distance is mentioned: [Pg.216]    [Pg.386]    [Pg.290]    [Pg.216]    [Pg.386]    [Pg.290]    [Pg.512]    [Pg.294]    [Pg.267]    [Pg.490]    [Pg.251]    [Pg.192]    [Pg.115]    [Pg.94]    [Pg.152]    [Pg.198]    [Pg.165]    [Pg.864]    [Pg.65]    [Pg.3663]    [Pg.2480]    [Pg.342]    [Pg.733]    [Pg.3662]    [Pg.305]    [Pg.281]   
See also in sourсe #XX -- [ Pg.386 ]




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