摘要:
A film for stretch packaging comprising as a substrate a film of a linear low density polyethylene having a melt flow rate (190.degree. C.), as measured by an ASTM-D-1238E method, of 0.3 to 8 g/10 min., a density, as measured by an ASTM-D-1505 method, of 0.900 to 0.918 g/cm.sup.3, a molecular weight distribution (Mw/Mn) of 2 to 6, two or more melting points existing as measured by a differential scanning calorimeter, a maximum melting point Tm.sub.1 of 118.degree. to 125.degree. C. and a ratio of the height Tm.sub.1 H of the peak of the highest melting point Tm.sub.1 to the height Tm.sub.1 H of the melting point Tm.sub.2 adjacent thereto (i.e., Tm.sub.1 H/Tm.sub.2 H), of 1.3 or less.
摘要:
In a tandem rolling mill a control computer integrates the entry speed of a work strip having a gauge transition to determine the arrival of the transition at a first roll stand. At that time a screw-down on that stand is updated through a scheduling computer while roll speeds on all the stands remain unchanged. When the gauge transition arrives at each of the succeeding stands as determined by the control computer integrating a roll speed on the preceding stand, the scheduling computer updates a screw-down on the arrival stand and changes roll speeds so as to minimize the sum of the squares of changes in roll speed with the constant mass flow relationship fulfilled.
摘要:
An apparatus, for controlling the re-distribution of a load in a longitudinal direction of a single strip (which is called hereinafter within the plate) on a multistage continuous rolling mill, stores a standard expression of the distribution of the load for maintaining a product's shape constant within the plate. A screw-down correction computer system calculates deviations from this reference equation and controls a rolling force on each of the rolling mills. It thereby maintains the standard expression of the distribution of the load by iteratively correcting a roll opening on each of the rolling mills within the plate. The control of the load distribution among the roll stands is effected after the roll material has entered all of the roll stands.
摘要:
A thickness control device and method for maintaining the thickness of the rolled material which is passed between the rollers of a rolling mill, in which the rollers above and below the rolling material are rotated at different speeds V.sub.H and V.sub.L. A variation in rolling material thickness is detected and expressed in terms of a change in rolling load WF. ##EQU1## is also detected. The change in rolling load .DELTA.F and the differential peripheral speed rate X are used to derive the change in differential speed rate .DELTA.X which would cancel out the variation in rolling material thickness. This correcting differential peripheral speed rate .DELTA.X is then utilized to change the velocities V.sub.H and V.sub.L of the upper and lower rollers, respectively, such that the thickness variation is eliminated without changing the speed of the rolled material.
摘要:
A combustion apparatus (1) is generally composed of a principal part (5), a supplementary part (6) and a burner port assembly (3). Four metal plates (7,8,10,11) constituting the principal and supplementary parts (5,6) are pressed to have in them several protuberances and recesses. These metal plates are laid one on another to form in them some hollow spaces and sealed regions. These hollow spaces communicate with each other to form a thin gas passage (22) together with a thick gas passage (73) in this combustion apparatus (1) in such a manner that its condition of thick and thin fuel combustion is rendered more stable.
摘要:
There is described a method for compensating tail end of rolling materials for rolling shaped steel sections in an optimum manner. According to this method, in a continuous tension free rolling operation of a shaped steel section comprising a flat section and a flange section through a plural number of roll stands, the operating speed of a first roll stand is reduced by a predetermined amount as compared with a second or succeeding roll stand when the crop at the tail end of the rolling material enters the first rolling unit, thereby to prevent overfeeding.