摘要:
A method for the production of elastomer and duromer molded items in an injection molding process using an injection molding machine with a respectively separately heatable filling unit, injection unit and cross-linking tool. The filling unit is heated to a temperature which is non-critical with regard to the cross-linking reaction of the plastic to be treated. The injection unit is heated to a temperature which is slightly below the cross-linking temperature of the molding material used.
摘要:
A method for the production of elastomer and duromer molded items in an injection molding process using an injection molding machine with a respectively separately heatable filling unit, injection unit and cross-linking tool. The filling unit is heated to a temperature which is non-critical with regard to the cross-linking reaction of the plastic to be treated. The injection unit is heated to a temperature which is slightly below the cross-linking temperature of the molding material used.
摘要:
A parison head for discharging a parison for producing capillaries, tubes or pipes, includes a sleeve-shaped housing into which the melt is fed, and which surrounds a core on all sides with a spacing, the core being firmly clamped in the housing, and also a likewise sleeve-shaped die, which likewise surrounds the core on all sides with a spacing, wherein the housing and the die surround the core in such a way that there is a closed flow channel between the housing and the core and between the die and the core, and at the end of the flow channel a peripheral closed outlet gap is formed by the die and the core, wherein there is between the housing and the die a low-cost, quickly exchangeable, trifunctional component, which securely seals off the flow channel between the housing and the die, and with which the angle between the housing and the die and also the length of the head can be changed, while retaining the flow resistance in the region of the trifunctional component and while retaining a flow channel that is free from dead spots, and so in this way the cross section of the flow channel gap at the end of the flow channel is variable.
摘要:
For producing a multi-extrudate of thermoplastically processable plastic, a coextrusion adapter block has a multi-part slide having a plurality of side-by-side slide sections mutually spaced in a direction transverse to the flow direction and slidably fitted in the adapter block for movement to adjustably protrude into a secondary runner for adjusting the thickness of a molten extrudate therein. A multi-layer extrudate emerging from the adapter block is further extruded in an extrusion die, and the thickness of at least one layer thereof is measured at a plurality of positions along the width thereof. The width measurements are used to control the positions of corresponding slide sections so that the layer thicknesses can be accurately controlled during an extruding operation.
摘要:
Method and apparatus for the continuous industrial production of tubular bodies in which coated or uncoated steel strip is formed to a slit tube and the opposite strip edges are longitudinally seam welded at high speed by a laser beam of high energy density under protective gas with or without supply of additive material, and after a preparation adapted to the narrow melt zone and bringing together of the strip edges a fusion welding with subsequent controlled cooling and upsetting is carried out which results in a seam geometry suitable for any further processing.
摘要:
A method for production of a multi-layer gap-less steel pipe. An inner pipe and an outer pipe are formed from thermomechanically rolled steel strip with high notched bar impact strength by welding. The individual helical welding seam steel pipes of about the same lengths are matched with a difference of less than about one percent between the outer diameter of the inner pipe and the inner diameter of the outer pipe. The matched inner pipe is inserted into the outer pipe and the pipes are mechanically expanded with diameter control to a preset outer diameter of the multi-layer steel pipe. The resulting multi-layer steel pipe has the inner pipe disposed under compression and the outer pipe layer disposed under stress. The presence of a compression stress in the inner pipe provides a means opposed to hydrogen sulfide stress corrosion. The advantages of the helical welding seam steel pipes can be combined such as economic production, advantages relating to crack formation and crack propagation stopping, and the availability of high internal pressure loads upon use of thin, economic steel strip of different yield strength.
摘要:
The geometry of a flow channel (1) can be varied within wide limits if at least one wall of the flow channel (1) takes the form of a sheet stack (2) which is pushed from the rear into the channel to a greater or lesser extent by means of adjusters (7). The adjustment may be effected either uniformly over the entire width of the flow channel (1) or only locally at certain points thereof. It is thus possible, while a medium is passing through the flow channel (1), to alter from outside the flow resistance either of the entire channel or only at certain points and thus alter the entire mass flow or the mass flow distribution as desired. New processing possibilities are given by the greater flexibility of the sheet stack (2) in relation to solid channel walls.
摘要:
The invention relates to an adjustable throttle with which to influence the mass flow within a rectangular flow channel or a flat flow channel with rounded marginal areas. Because of its special design, the throttle has no parting plane perpendicular to the fluid flow direction. The channel height may be modified by this throttle, so that the fluid mass flow may be influenced by changing the local flow channel resistance as a function of its width without creating discontinuities in the flow channel. Because of this continuous change in the geometry of the flow channel, both in the direction of its width and in the flow direction, the whole flow channel is totally free from dead spots.
摘要:
In a method for manufacturing a sealing ring with a sealing lip, the material forming the sealing lip is fabricated in plastically deformable condition into the shape of a column-like hollow body. Prior to solidification, the column-like hollow body is twisted between axially spaced cross-sectional planes. This forms return elements with hydrodynamic action. Subsequently, the hollow body is solidfied and its diameter is enlarged axially outside the region of the sealing lip and it is then secured in a sealing ring housing.
摘要:
Improved steel profiles having superior material characteristics are obtained by rolling a precipitation-hardenable fine grain steel, cooling it from a final rolling temperature above the A.sub.1 -temperature down to a temperature of about 400.degree. C. in an atmosphere in which it is allowed to overage, whereupon the steel plate or strip is then cooled down to room temperature and cold-processed to form an open profile which can thereupon be converted into a tube by welding together its longitudinally extending edges and which is then subjected to solution-annealing in order-to dissolve coarse precipitants and subsequently further cooled to form finely dispersed precipitants in the profile.