摘要:
A unit and method are provided for conveying workpieces along a processing run, having at least one transport car (10), moving along the processing run in a conveying direction (FR) and a rotating shaft (20), mounted on the transport car (10), close to a first of the ends thereof, to rotate about the axis thereof at right angles to the conveying direction (FR) and on which a mounting (40) for the workpiece to be processed is provided. The rotating shaft (20) is only mounted close to the first end thereof on the transport car (10) and may thus be driven in the conveying direction (FR), the second free end thereof being passively transported along in the conveying direction (FR). It is thus possible to pivot the rotating shaft (20) in a plane running at right angles to the conveying direction, in particular, to permit a space saving return.
摘要:
The invention provides a process for continuously preparing polyether alcohols by adding alkylene oxides to H-functional starter substances using a DMC catalyst, comprising the steps of a) preparing a precursor by continuously metering an H-functional starter substance, an alkylene oxide or a mixture of at least two alkylene oxides and the required amount of DMC catalyst into a continuous reactor, b) continuously withdrawing the precursor from step a) from the reactor, c) continuously metering the product from step a), an alkylene oxide different from that in step a) or a mixture of at least two alkylene oxides different from that in step a) and, if appropriate, the required amount of DMC catalyst into a further continuous reactor.
摘要:
The present invention provides a process for producing low-emission flexible polyurethane foams having a reduced odor and reduced fogging by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms which are reactive toward isocyanate groups, c) blowing agents wherein polyether alcohols which have been prepared by addition of alkylene oxides onto compounds derived from renewable raw materials using DMC catalysts are used as compounds b) having at least two hydrogen atoms which are reactive toward isocyanate groups.
摘要:
A thermoplastic molding composition comprising a thermoplastic polyurethane and a wax mixture is disclosed. The polyurethane is a product of an organic diisocyanate, a linear, hydroxyl-terminated polyol and a diol or diamine chain extender. The wax mixture contains a first mixture of an ester of a C.sub.10-45 aliphatic carboxylic acid and a diol, and an alkali metal or alkaline earth metal salt of a C.sub.10-45 aliphatic carboxylic acids, and at least one member selected from the group consisting of fatty acid ester, fatty acid amide, fatty acid ester amide and polyethylene wax.
摘要:
A thermoplastsic molding composition comprising thermoplastic polyurethane resin and about 0.05 to 2 percent of a wax is disclosed. The composition which offers processing advantages, including release and cosmetic properties, is characterized in that the wax contains acylation products of hydroxy groups and of amino groups of amino alcohols.
摘要:
The present invention relates to a process for the continuous production of thermoplastically processable polyurethanes having improved processing behaviour, wherein in a multistep reactionA) one or more linear hydroxyl-terminated polyols a) having a molecular weight of from 500 to 5000 are mixed continuously with a proportion of an organic diisocyanate b) in an NCO:OH ratio of from 2.0:1 to 5.0:1, in a mixing unit at high shear energy,B) the mixture prepared in step A) is reacted continuously to form an isocyanate-terminated prepolymer in a reactor at temperatures of >120.degree. C., until a conversion of >90%, referred to component a), is achieved,C) the prepolymer prepared in step B) is mixed with the remainder of component b), an NCO:OH ratio of from 2.05:1 to 6:1 being established overall in steps A) to C) and an NCO:OH ratio of 0.9 to 1.1 being established when all the components of steps A) to F) are included,D) the mixture prepared in step C) is cooled to a temperature of
摘要:
A process for the continuous production of a thermoplastic molding composition containing a mixture of TPU and a (co)polymer is disclosed. The process comprises (a) introducing into an extruder under time and temperature conditions sufficient to bring about the formation of thermoplastic polyurethane a (co)polymer, and polyurethane-forming components comprising A) an organic diisocyanate, B) a linear polyol having terminal hydroxyl groups and a molecular weight of 500 to 5000, and C) a chain extender having a molecular weight of 60 to 500, and upon completing the formation of said polyurethane (b) discharging the resulting TPU/(co)polymer mixture from the extruder. Importantly, the (co)polymer contains a flow enhancer and the molar ratio of the NCO groups in A) to the groups which react with NCO in B) and C) is 0.9 to 1.2.
摘要:
This invention relates to novel, thermoplastically processible, branched polyurethanes based on naphthylene-1,5-diisocyanate which have good heat stability and are obtained by the claimed process. In the first stage of the process long-chain polyols are reacted with a first diisocyanate which is any diisocyanate other than naphthylene-1,5-diisocyanate in substoichiometric NCO quantities to produce an OH prepolymer which is then lengthened with excess napthylene-1,5-diisocyanate and with a chain lengthening mixture of short-chain diols and triols and/or polyols in specific ratios. The resulting semi-rigid, thermoplastic polyurethane elastomers are characterized by their good dimensional stability under heat, a good rebound elasticity (even at relatively high temperatures), acceptable low temperature flexibility and an outstanding resistance to wear which properties render them useful for the production of hydraulic seals, seals, rollers, buffers, tubes, bellows, plugs, cylinders, couplings and similar moldings.
摘要:
The invention relates to a process for preparing polyether alcohols by catalytic addition of alkylene oxides onto a starter substance mixture comprising water-soluble H-functional starter substances which are solid at room temperature, alcohols which are liquid at the reaction temperature and water using alkali metal hydroxides and/or alkaline earth metal hydroxides as catalysts, wherein the amount of water is from 1.0 to 6.0% by weight, based on the weight of the starter substance mixture, and the starter substance mixture comprises no amine constituents.
摘要:
A method of crushing material between cooperating jaws of a crushing jaw assembly of a demolition tool includes the steps of applying a closing force to at least one of the jaws for urging the jaws toward one another; and imparting a vibratory motion to at least one of the jaws while the closing force is applied.