Method for the selective on-line measuring and controlling of a geometrical parameter of elongated articles

Claim 1

A method of controlling a geometrical dimension related to coating thickness of each of a plurality of continuously advancing elongated articles, comprising the steps of: coating said aarticles with a layer of coating material having a thickness that is responsively controlled by at least one adjustable operating parameter; measuring said geometrical dimension of at least certain ones of said plurality of coated articles fluidically by respectively passing them through different substantially confined and pressurized areas that each establishes a detectable back-pressure in the presence of an article, the magnitude of which back-pressure is correlated with said geometrical dimension of the article passed therethrough; determining fluidically whether said measured geometrical dimension of each coated article is within a predetermined acceptable tolerance range, and producing a separate process signal having a magnitude correlated with and for every measurement, and whenever any process signal indicative of any measurement is outside said tolerance range, at least momentarily substituting a reference signal representative of a nominal geometrical dimension for any such process signal; averaging all of said process signals and any reference signals fluidically so as to form a composite control signal representative of the average of at least all of the measured geometrical dimensions that have been found to be within said tolerance range; utilizing said composite control signal to change at least said one adjustable operating parameter, as required, to maintain said measured geometrical dimension and, thereby, the coating thickness of at least the majority of said articles within said acceptable tolerance range during said coating operation, and sensing each advancing coated article upstream from the point at which it is being measured for any region therealong having an abnormally large cross-sectional area, and in response to such a sensed abnormally large condition, enlarging said confined pressurized area downstream so as to allow said article region having an abnormally large cross-sectional area to freely pass therethrough, and after a pedetermined time delay re-establishing said confined area.

Claim 2

A method of controlling a geometrical dimension related to coating thickness of each of a plurality of continuously advancing elongated articles, comprising the steps of: coating said aarticles with a layer of coating material having a thickness that is responsively controlled by at least one adjustable operating parameter; measuring said geometrical dimension of at least certain ones of said plurality of coated articles fluidically by respectively passing them through different substantially confined and pressurized areas that each establishes a detectable back-pressure in the presence of an article, the magnitude of which back-pressure is correlated with said geometrical dimension of the article passed therethrough; determining fluidically whether said measured geometrical dimension of each coated article is within a predetermined acceptable tolerance range, and producing a separate process signal having a magnitude correlated with and for every measurement, and whenever any process signal indicative of any measurement is outside said tolerance range, at least momentarily substituting a reference signal representative of a nominal geometrical dimension for any such process signal; averaging all of said process signals and any reference signals fluidically so as to form a composite control signal representative of the average of at least all of the measured geometrical dimensions that have been found to be within said tolerance range; utilizing said composite control signal to change at least said one adjustable operating parameter, as required, to maintain said measured geometrical dimension and, thereby, the coating thickness of at least the majority of said articles within said acceptable tolerance range during said coating operation, and sensing each advancing coated article upstream from the point at which it is being measured for any region therealong having an abnormally large cross-sectional area, and in response to such a sensed abnormally large condition, enlarging said confined pressurized area downstream so as to allow said article region having an abnormally large cross-sectional area to freely pass therethrough, and after a pedetermined time delay re-establishing said confined area.

Claim 3

A method of controlling the thickness of a coating applied to each of a plurality of continuously advancing elongated articles, comprising the steps of: passing said elongated articles through a coating station whereat a layer of coating material is applied thereto having a thickness responsively controlled by any one of a plurality of adjustable operating parameters including the percentage concentrations of the various constituents forming the coating composition; measuring a geometrical dimension related to the coating thickness of at least certain ones of said articles by respectively passing them through different pressurized passageways that each establishes a back-pressure process signal in the presence of an article, the magnitude of which process signal is correlated with said measured geometrical dimension of the coated article passed therethrough; removing any process signal representative of a measured article geometrical dimension that is outside a predetermined tolerance range, and substituting therefor, at least momentarily, a reference signal having a magnitude representative of a nominal article geometrical dimension for use in establishing an averaged composite control signal; averaging all of said back-pressure process signals and any reference signals so as to form a composite control signal representative of the average of all of the coated article geometrical dimensions that have been measured; utilizing said composite control signal to control the flow rate of at least one constituent of the coating composition so as to vary the consistency thereof, as required, to maintain the thickness of the coating on said articles within limits defined by the tolerance range or said measured and related geometrical dimension, and sensing each of said advancing articles upstream from the point at which it is being measured for any region therealong of abnormally large cross-sectional area, and in response to such a sensed abnormally large condition, enlarging said pressurized passageway associated with said article having an abnormally large cross-sectional area so as to allow said article having the abnormally large cross-sectional area to pass therethrough, and after a predetermined time delay, reducing said passageway to its previous measuring size.

Claim 4

A method of controlling the thickness of a coating applied to each of a plurality of continuously advancing elongated articles, comprising the steps of: passing said elongated articles through a coating station whereat a layer of coating material is applied thereto having a thickness responsively controlled by any one of a plurality of adjustable operating parameters including the percentage concentrations of the various constituents forming the coating composition; measuring a geometrical dimension related to the coating thickness of at least certain ones of said articles by respectively passing them through different pressurized passageways that each establishes a back-pressure process signal in the presence of an article, the magnitude of which process signal is correlated with said measured geometrical dimension of the coated article passed therethrough; removing any process signal representative of a measured article geometrical dimension that is outside a predetermined tolerance range, and substituting therefor, at least momentarily, a reference signal having a magnitude representative of a nominal article geometrical dimension for use in establishing an averaged composite control signal; averaging all of said back-pressure process signals and any reference signals so as to form a composite control signal representative of the average of all of the coated article geometrical dimensions that have been measured; utilizing said composite control signal to control the flow rate of at least one constituent of the coating composition so as to vary the consistency thereof, as required, to maintain the thickness of the coating on said articles within limits defined by the tolerance range or said measured and related geometrical dimension, and sensing each of said advancing articles upstream from the point at which it is being measured for any region therealong of abnormally large cross-sectional area, and in response to such a sensed abnormally large condition, enlarging said pressurized passageway associated with said article having an abnormally large cross-sectional area so as to allow said article having the abnormally large cross-sectional area to pass therethrough, and after a predetermined time delay, reducing said passageway to its previous measuring size.

Claim 6

A method of controlling a geometrical dimension of a plurality of continuously fabricated wood-based pulp coated articles wherein the articles are passed through a pulp slurry so that ribbons of pulp are positioned on and thereafter formed about said articles in the form of coatings thereon, and wherein the pulp slurry is replenished and the consistency thereof adjustably controlled by flowing a pulp solution of a predetermined consistency and at a controllable rate into the slurry, characterized by the steps of: measuring said geometrical dimension of at least certain pre-selected ones of said coated articles by respectively passing them through different substantially confined and pressurized areas that each establishes a detectable back-pressure in the presence of an article, the magnitude of which back-pressure is correlated with said measured geometrical dimension of the pulp-coated article passed therethrough, and producing a process signal for each measurement, the magnitude of which signal is correlated with said geometrical dimension of each measured article; averaging all of said process signals so as to form a composite process control signal representative of the average of all of the geometrical dimensions that have been measured, and removing any process signal representative of a measured geometrical dimension of an article that is outside a predetermined tolerance range, and substituting therefor, at least momentarily, a reference signal having a magnitude representative of a desired geometrical dimension for use in establishing said averaged process control signal; utilizing the process control signal to control the flow rate of the pulp solution supplied to the pulp slurry so as to vary the consistency thereof, as required, and thereby control the ultimate geometrical dimensions of the coated articles, and sensing each advancing pulp insulated article upstream from the point at which it is being measured for any region therealong having an abnormally large cross-sectional area, and in response to such a sensed abnormally large condition, opening said confined pressurized area so as to allow said article region having an abnormally large cross-sectional area to freely pass therethrough.

Claim 7

A method of controlling a geometrical dimension of a plurality of continuously fabricated wood-based pulp coated articles wherein the articles are passed through a pulp slurry so that ribbons of pulp are positioned on and thereafter formed about said articles in the form of coatings thereon, and wherein the pulp slurry is replenished and the consistency thereof adjustably controlled by flowing a pulp solution of a predetermined consistency and at a controllable rate into the slurry, characterized by the steps of: measuring said geometrical dimension of at least certain pre-selected ones of said coated articles by respectively passing them through different substantially confined and pressurized areas that each establishes a detectable back-pressure in the presence of an article, the magnitude of which back-pressure is correlated with said measured geometrical dimension of the pulp-coated article passed therethrough, and producing a process signal for each measurement, the magnitude of which signal is correlated with said geometrical dimension of each measured article; averaging all of said process signals so as to form a composite process control signal representative of the average of all of the geometrical dimensions that have been measured, and removing any process signal representative of a measured geometrical dimension of an article that is outside a predetermined tolerance range, and substituting therefor, at least momentarily, a reference signal having a magnitude representative of a desired geometrical dimension for use in establishing said averaged process control signal; utilizing the process control signal to control the flow rate of the pulp solution supplied to the pulp slurry so as to vary the consistency thereof, as required, and thereby control the ultimate geometrical dimensions of the coated articles, and sensing each advancing pulp insulated article upstream from the point at which it is being measured for any region therealong having an abnormally large cross-sectional area, and in response to such a sensed abnormally large condition, opening said confined pressurized area so as to allow said article region having an abnormally large cross-sectional area to freely pass therethrough.

Claim 12

A method of monitoring the geometrical dimension of an elongated, continuously advancing article, comprising the steps of: passing the article through a substantially confined and pressurized area that establishes a detectable back-pressure signal in the presence of an article, the magnitude of which signal is correlated with said geometrical dimension; determining whether the geometrical dimension of said article, as determined by the magnitude of the back-pressure signal, is within a predetermined acceptable tolerance range, and producing an alarm signal indicative of an article having an abnormally large cross-sectional area, and sensing upstream of the confined area for any region along the article of abnormally large cross-sectional area, and in response to such a condition, enlarging said confined area, at least momentarily, so as to allow said article having an abnormally large cross-sectional area to pass therethrough, and with an alarm signal being produced as a result of said sensed abnormally large cross-sectional area.

Claim 13

A method of monitoring the geometrical dimension of an elongated, continuously advancing article, comprising the steps of: passing the article through a substantially confined and pressurized area that establishes a detectable back-pressure signal in the presence of an article, the magnitude of which signal is correlated with said geometrical dimension; determining whether the geometrical dimension of said article, as determined by the magnitude of the back-pressure signal, is within a predetermined acceptable tolerance range, and producing an alarm signal indicative of an article having an abnormally large cross-sectional area, and sensing upstream of the confined area for any region along the article of abnormally large cross-sectional area, and in response to such a condition, enlarging said confined area, at least momentarily, so as to allow said article having an abnormally large cross-sectional area to pass therethrough, and with an alarm signal being produced as a result of said sensed abnormally large cross-sectional area.