Method and an apparatus for the continuous crimping of thermoplastic threads

An apparatus for the continuous crimping of a thermoplastic thread comprising

• a texturing nozzle having a delivery channel for conveying travelling length of thermoplastic thread at a predetermined thread speed therethrough, an inlet into said channel for a flowable delivery medium, and an orifice at one end of said channel;
• a stuffer box for receiving a thread from said orifice and forming a thread plug therein, said stuffer box having stationary walls for braking the yarn plug therealong;
• and
• sensory means for monitoring at least one pressure characteristic of plug formation in the vicinity of the orifice of the delivery channel to emit a signal corresponding to a measured value of said characteristic of plug formation.

An apparatus for the continuous crimping of a thermoplastic thread comprising

• a texturing nozzle having a delivery channel for conveying a travelling length of thermoplastic thread at a predetermined thread speed therethrough, an inlet into said channel for a flowable delivery medium, and an orifice at one end of said channel;
• a stuffer box for receiving a thread from said orifice and forming a thread plug therein, said stuffer box having stationary walls for braking the yarn plug therealong;
• a pressure measuring element for measuring the pressure in said channel adjacent said orifice and emitting a corresponding signal in response thereto;
• and
• a proportional/integral controller for receiving said signal from said pressure measuring element and for emitting a corresponding control signal in response thereto to maintain a constant plug formation.

A method for continuous crimping of a thermoplastic thread comprising the steps of

• conveying a travelling length of thermoplastic thread at a predetermined thread speed through a delivery channel having an orifice at one end thereof into a stuffer box;
• passing a flow of heated delivery medium into the channel for passage out of said orifice with the thread;
• braking the speed of the thread in the stuffer box to form a thread plug;
• conveying the thread plug from the stuffer box at a plug speed less than said thread speed;
• monitoring the optical appearance of the thread plug at a predetermined location in the stuffer box in close proximity to said orifice as a measure of plug formation and emitting a signal corresponding thereto, and
• thereafter processing said signal to selectively maintain plug formation constant or to activate an alarm indicative of said characteristic of plug formation deviating from a preset value.

A method for continuous crimping of a thermoplastic thread comprising the steps of

• conveying a travelling length of thermoplastic thread at a predetermined thread speed through a delivery channel having an orifice at one end thereof into a stuffer box;
• passing a flow of heated delivery medium into the channel for passage out of said orifice with the thread;
• braking the speed of the thread in the stuffer box to form a thread plug;
• conveying the thread plug from the stuffer box at a plug speed less than said thread speed;
• monitoring at least one pressure characteristic of plug formation in the vicinity of the orifice of the delivery channel to emit a signal corresponding a measured value of said characteristic of plug formation;
• thereafter processing said signal to selectively maintain plug formation constant or to activate an alarm indicative of said characteristic of plug formation deviating from a preset value;
• feeding a predetermined quantity of flowable medium into the stuffer box to brake the thread therein;
• and
• varying said quantity of flowable medium in dependence on said processed signal to maintain plug formation constant.

An apparatus for the continuous crimping of a thermoplastic thread comprising

• a texturing nozzle having a delivery channel for conveying a travelling length of thermoplastic thread at a predetermined thread speed therethrough, an inlet into said channel for a flowable delivery medium, and an orifice at one end of said channel;
• a stuffer box for receiving a thread from said orifice and forming a thread plug therein;
• and
• an optical sensor in said stuffer box and in close proximity to said orifice for monitoring the formation of a thread plug thereat and emitting a signal corresponding thereto.

An apparatus for the continuous crimping of a thermoplastic thread comprising

• a texturing nozzle having a delivery channel for conveying a travelling length of thermoplastic thread at a predetermined thread speed therethrough, an inlet into said channel for a flowable delivery medium, and an orifice at one end of said channel;
• a stuffer box for receiving a thread from said orifice and forming a thread plug therein;
• a pressure measuring element for measuring the pressure in said channel adjacent said orifice and emitting a corresponding signal in response thereto;
• means for feeding a predetermined quantity of a flowable medium into said stuffer box to brake the thread plug;
• and
• a proportional/integral controller for receiving said signal from said pressure measuring element and for emitting a corresponding control signal in response thereto to said means to vary the braking of the thread plug in said stuffer box to maintain a constant plug formation.