An apparatus for starting an extrusion process, including at least a drawing device having a main frame, a platform arranged on the main frame, a cable winch arranged on the platform and having a drum, and a wire cable that can be wound up on the drum of the cable winch and pulls an extruded plastics pipe in an extrusion line by way of deflection rolls until the pipe is taken over by a take-off device, wherein the platform is movable transversely to an extrusion direction.

The invention relates to a process for the production of articles, exemplarily a plastic article, by means of an extruder (1) to which a first plastic composition of a first main component and at least one associated minor component is supplied from a first group of dosing stations (21, 24). According to the invention, during the production time of a first production order there is prepared a second group of dosing stations (31, 33) at the extruder for a second production order for which a second plastic composition of a second main component and at least one associated minor component that is different from the first plastic composition has to be supplied to the extruder. After completion of the first production order it is reset to the second production order by terminating the supply of the first plastic composition by closing a first shut-off device (8) and starting the supply of the second plastic composition by opening a second shut-off device (8′).

A system for adjusting a gap in a slot die for producing a polymeric web. The system includes a slot die that has a polymer reservoir that extends between a polymer inlet and a melt outlet. The melt outlet has a first edge and a second edge that each extend longitudinally along the melt outlet. The second edge is opposite the first edge. A plurality of actuators move the second edge along a plurality of positions along a length of the second edge. The first edge is spaced apart from the second edge by a gap that has an adjustable profile. A pressure sensor communicates with the reservoir and measures the pressure of the polymer in the reservoir. A control unit with an algorithm correlates the profile of the gap to the pressure in the reservoir. The algorithm is configured to generate control signals to cause the profile of the gap to be uniform.

A system for adjusting a gap in a slot die for producing a polymeric web. The system includes a slot die that has a polymer reservoir that extends between a polymer inlet and a melt outlet. The melt outlet has a first edge and a second edge that each extend longitudinally along the melt outlet. The second edge is opposite the first edge. A plurality of actuators move the second edge along a plurality of positions along a length of the second edge. The first edge is spaced apart from the second edge by a gap that has an adjustable profile. A pressure sensor communicates with the reservoir and measures the pressure of the polymer in the reservoir. A control unit with an algorithm correlates the profile of the gap to the pressure in the reservoir. The algorithm is configured to generate control signals to cause the profile of the gap to be uniform.

The invention relates to a process for the production of articles, exemplarily a plastic article, by means of an extruder (1) to which a first plastic composition of a first main component and at least one associated minor component is supplied from a first group of dosing stations (21, 24). According to the invention, during the production time of a first production order there is prepared a second group of dosing stations (31, 33) at the extruder for a second production order for which a second plastic composition of a second main component and at least one associated minor component that is different from the first plastic composition has to be supplied to the extruder. After completion of the first production order it is reset to the second production order by terminating the supply of the first plastic composition by closing a first shut-off device (8) and starting the supply of the second plastic composition by opening a second shut-off device (8′).

The invention relates to a process for removal of volatile components from an olefin polymer, the process carried out in an extruder comprising at least one vacuum degassing zone, said process comprising the steps of: (a) introducing a stream of an olefin polymer into the extruder; (b) extruding the olefin polymer in the extruder at a temperature which is higher than the melting temperature of the olefin polymer but lower than the decomposition temperature of the olefin polymer, thereby producing an olefin polymer melt having reduced amount of volatile components, wherein the process in the extruder has a residence time distribution broadness (σ2) in the range of 800 to 4000 as define by equation (1) wherein: σ2 is the residence time distribution broadness, T is the mean residence time, t is the interval of residence time a fluid element of the olefin polymer spends in the extruder, E(t) is the residence time distribution function, and wherein the process optionally comprises a step (c) where the melt of the olefin polymer is passed through a die zone to a pelletizer for pelletizing the obtained olefin polymer.
σ.sup.2=∫.sub.0.sup.∞(t−τ).sup.2E(t)dt  equation (1)

An apparatus for starting an extrusion process, including at least a drawing device having a main frame, a platform arranged on the main frame, a cable winch arranged on the platform and having a drum, and a wire cable that can be wound up on the drum of the cable winch and pulls an extruded plastics pipe in an extrusion line by way of deflection rolls until the pipe is taken over by a take-off device, wherein the platform is movable transversely to an extrusion direction.

The invention relates to a method for automatically regulating the size of a nozzle discharge slot of a nozzle assembly, wherein the nozzle assembly comprises a first and a second nozzle lip and a nozzle discharge slot arranged between the nozzle lips for setting in a controlled manner a thickness profile of a conveyable melt. A plurality of adjusting elements, in particular a plurality of adjusting pins, coupled to a respective thermoelement, is arranged on the first nozzle lip, the thermoelements being controllable by the regulation in such a way that the slot can be adjusted by the action of a mechanical force from the respective adjusting element on the first nozzle lip, as a result of the expansion or contraction of the thermoelements. At an initial operation of the nozzle assembly for conveying the melt, the adjusting elements for subsequent regulation of the slot size are set uniquely free from play as the initial setting. The invention further relates to a control and/or regulation system.

A monitor system for monitoring a status of a material in an extruder device is provided. The monitor system includes: a heater, a thermal sensor, a hardness measuring module and a material status monitor. The heater is for heating the material in a material delivering part of the extruder device; the thermal sensor is for measuring a thermal variation of the material; the hardness measuring module is for measuring a first hardness value of the material; and the material status monitor is for determining the status of the material according to the thermal variation and the first hardness value.

The invention relates to a process for removal of volatile components from an olefin polymer, the process carried out in an extruder comprising at least one vacuum degassing zone, said process comprising the steps of: (a) introducing a stream of an olefin polymer into the extruder; (b) extruding the olefin polymer in the extruder at a temperature which is higher than the melting temperature of the olefin polymer but lower than the decomposition temperature of the olefin polymer, thereby producing an olefin polymer melt having reduced amount of volatile components, wherein the process in the extruder has a residence time distribution broadness (σ2) in the range of 800 to 4000 as define by equation (1) wherein: σ2 is the residence time distribution broadness, T is the mean residence time, t is the interval of residence time a fluid element of the olefin polymer spends in the extruder, E(t) is the residence time distribution function, and wherein the process optionally comprises a step (c) where the melt of the olefin polymer is passed through a die zone to a pelletizer for pelletizing the obtained olefin polymer.

σ.sup.2=∫.sub.0.sup.∞(t−τ).sup.2E(t)dt   equation (1)