Abstract: An improved process can be used for the acid hydrolysis of polylaurolactam with sulfuric acid. An especially suitable starting material is polylaurolactam which is intended for recycling and which is characterized by a low laurolactam content.

Abstract: A device for producing a dyed plastic melt and an undyed plastic melt includes a multi-shaft screw extruder, a first metering installation, a second metering installation, and a control installation for selecting between a first operating mode for producing the dyed plastic melt and a second operating mode for producing the undyed plastic melt. The first metering installation serves for feeding an undyed plastic material through a first infeed opening into a housing of the multi-shaft screw extruder, and the second metering installation serves for feeding at least one color granulate through a second infeed opening into the housing. The plastic material is fed exclusively by way of the first infeed opening such that residual color granulate or dyeing agent contained therein, respectively, which is still located in the second metering installation or in the region of the second infeed opening does not contaminate the undyed plastic melt.

Abstract: A device for producing dyed plastic granulate and undyed plastic granulate includes a multi-shaft screw extruder and an underwater pelletizing installation. A granulate changeover unit which separates the dyed plastic granulate from the undyed plastic granulate is disposed in a conveying direction downstream of the underwater pelletizing installation. The dyed plastic granulate is separated from the pelletizing water via a first separator installation, and the undyed plastic granulate is separated from the pelletizing water via a second separator installation. The separator installations are disposed so as to be mutually parallel. The device enables a simple, flexible and economical selective production of the dyed plastic granulate and the undyed plastic granulate.

Abstract: A stirrer mill for the treatment of flowable grinding stock. The stirrer mill includes a milling container, a milling chamber delimited by the container wall, and a stirring mechanism having a rotor which rotates about a central longitudinal axis and has an inside diameter (d351). Tools, which extend toward the container wall, are attached to the rotor. The stirrer mill also includes an internal stator arranged inside the rotor. A grinding stock discharge channel is formed, between the rotor and the internal stator, through which the grinding stock passes to a separating device and, thereafter, to a discharge line. The milling chamber is at least partially filled with grinding bodies having a diameter (c). Above the internal stator is arranged a separating device with a diameter (d30). The distance (s) between the rotor and the grinding body separating device is given by the relationship: s=0.5·(d351?d30)?5·c.

Abstract: A device for producing a dyed plastic melt and an undyed plastic melt includes a multi-shaft screw extruder, a first metering installation, a second metering installation, and a control installation for selecting between a first operating mode for producing the dyed plastic melt and a second operating mode for producing the undyed plastic melt. The first metering installation serves for feeding an undyed plastic material through a first infeed opening into a housing of the multi-shaft screw extruder, and the second metering installation serves for feeding at least one dyeing agent through a second infeed opening into the housing. In order for the undyed plastic melt to be produced, the plastic material is fed exclusively via the first infeed opening such that residual dyeing agent which is still located in the second metering installation or in the region of the second infeed opening does not contaminate the undyed plastic melt.

Abstract: A device for producing dyed plastic granulate and undyed plastic granulate includes a multi-shaft screw extruder and an underwater pelletizing installation. A granulate changeover unit which separates the dyed plastic granulate from the undyed plastic granulate is disposed in a conveying direction downstream of the underwater pelletizing installation. The dyed plastic granulate is separated from the pelletizing water via a first separator installation, and the undyed plastic granulate is separated from the pelletizing water via a second separator installation. The separator installations are disposed so as to be mutually parallel. The device enables a simple, flexible and economical selective production of the dyed plastic granulate and the undyed plastic granulate.

Abstract: A device for producing a dyed plastic melt and an undyed plastic melt includes a multi-shaft screw extruder, a first metering installation, a second metering installation, and a control installation for selecting between a first operating mode for producing the dyed plastic melt and a second operating mode for producing the undyed plastic melt. The first metering installation serves for feeding an undyed plastic material through a first infeed opening into a housing of the multi-shaft screw extruder, and the second metering installation serves for feeding at least one color granulate through a second infeed opening into the housing. The plastic material is fed exclusively by way of the first infeed opening such that residual color granulate or dyeing agent contained therein, respectively, which is still located in the second metering installation or in the region of the second infeed opening does not contaminate the undyed plastic melt.

Abstract: Disclosed is a wallcovering assembly consisting of a base material and at least one ceramic coating/topcoat with or without an optional ceramic interlayer.

Abstract: Disclosed is a wallcovering assembly consisting of a base material and at least one ceramic coating/topcoat with or without an optional ceramic interlayer.

Abstract: The present invention relates to a sealed natural cut stone, the pores of which are permeable to water vapor but are impermeable to aqueous liquids, and a method for the production thereof and the use of such natural cut stones.

Abstract: Disclosed is a wallcovering assembly consisting of a base material and at least one ceramic coating/topcoat with or without an optional ceramic interlayer.

Abstract: An electric heater for gaseous media with at least one support plate and at least one helix of corrugated, electric resistance heating wire wound continuously around the support plate and whose turns are held by means of heating wire bend-offs on the longitudinal edges of the support plate is characterized in that the heating wire is positioned in such a way that it only contacts longitudinal narrow sides and/or edges of the longitudinal narrow sides of the support plate, the bending angle being much larger than 40°. This significantly reduces the risk of thermal damage to the heating wire, particularly in the vicinity of the plate edges. As a result of the largely naturally stable design of the heating wire, the heater according to the invention requires no spacers between the support plates and is therefore particularly simple and inexpensive to manufacture.

Abstract: An electric heater for gaseous media with at least one support plate and at least one helix of corrugated, electric resistance heating wire wound continuously around the support plate and whose turns are held by means of heating wire bend-offs on the longitudinal edges of the support plate is characterized in that the heating wire is positioned in such a way that it only contacts longitudinal narrow sides and/or edges of the longitudinal narrow sides of the support plate, the bending angle being much larger than 40ø. This significantly reduces the risk of thermal damage to the heating wire, particularly in the vicinity of the plate edges. As a result of the largely naturally stable design of the heating wire, the heater according to the invention requires no spacers between the support plates and is therefore particularly simple and inexpensive to manufacture.

Abstract: The invention relates to a method for producing 1-methyl-3-nitroguanidine. According to said method, nitroguanidine is reacted with methylamine and/or a methylammonium salt in an aqueous solution, at temperatures of 30 to 60° C. and at a pH value of 95 to 12.3. In this way, yields of 1-methyl-3-nitroguanidine of at least 80% and degrees of purity>99% can be obtained in a particularly environmentally friendly and technically simple way.

Abstract: The invention relates to a method for producing 1-methyl-3-nitroguanidine. According to said method, nitroguanidine is reacted with methylamine and/or a methylammonium salt in an aqueous solution, at temperatures of 30 to 60° C. and at a pH value of 9.5 to 12.3. In this way, yields of 1-methyl-3-nitroguanidine of at least 80% and degrees of purity >99% can be obtained in a particularly environmentally friendly and technically simple way.