Solid colorant dispensing unit and tinting machine comprising the same

Abstract

A solid colorant dispensing unit for dispensing charges of solid spherical colorant particles in a time-controlled way, the dispensing unit having a supply container having a nozzle for dispensing the particles having a number average particle size and a number particle size distribution, wherein a ratio of the standard deviation of the number particle size distribution to the number average particle size of the particles is less than 25%. The nozzle having a dispensing outlet having a diameter taking into account the number average particle size of the particles. The dispensing unit having a control assembly for controlling the dispensing of the charges of the particles by taking into account the properties of the particles and the diameter of the outlet of the nozzle. A tinting machine having the solid colorant dispensing unit.

What is claimed is: 
     
         1 . A solid colorant dispensing unit configured to dispense at least one charge of solid spherical colorant particles in a time-controlled way, the solid colorant dispensing unit comprising:
 a supply container comprising a free end portion that is provided with a nozzle that is configured and arranged to dispense said at least one charge of solid spherical colorant particles during operation of the solid colorant dispensing unit, said solid spherical colorant particles having the following properties:
 a number average particle size; and 
 a number particle size distribution, wherein a ratio of the standard deviation of the number particle size distribution to the number average particle size of the solid spherical colorant particles is less than 25%, wherein the number particle size distribution is determined with light scattering with fully automated image analysis according to ISO 13322-1:2004, Particle size analysis—Image analysis methods—Part 1: Static image analysis methods by the use of an OCCHIO ZEPHYR ESR analyzer; 
   the nozzle comprising a dispensing outlet having a diameter taking into account the number average particle size of the solid spherical colorant particles; and   wherein the solid colorant dispensing unit comprises a plunger arranged such that its longitudinal center line is directed transverse to a longitudinal center line of the nozzle.   
     
     
         2 . The solid colorant dispensing unit according to  claim 1 , wherein a detector is provided on an inner surface of the supply container that determines a current height of solid spherical colorant particles in the supply container. 
     
     
         3 . The solid colorant dispensing unit according to  claim 1 , wherein the supply container comprises a first part having the free end portion that is provided with the nozzle and a second part having an end portion that is connected in open communication with an end portion of the first part that is arranged opposite the nozzle thereby providing a transition between the second part and the first part, the first part having a cone-shaped inner wall that with respect to its longitudinal centerline is arranged at an angle (α) in a range of 15-55 degree. 
     
     
         4 . The solid colorant dispensing unit according to  claim 1 , wherein an overflow compartment is provided adjacent the dispensing outlet of the nozzle so as to receive solid spherical colorant particles dispensed by the nozzle as a result of a displacement of the plunger. 
     
     
         5 . The solid colorant dispensing unit according to  claim 1 , wherein a vibratory unit is provided that is configured and arranged to allow the supply container to vibrate at a frequency in a range of 0-55 Hz during operation of the solid colorant dispensing unit. 
     
     
         6 . The solid colorant dispensing unit according to  claim 1 , wherein an exchangeable cartridge is provided comprising solid spherical colorant particles, the exchangeable cartridge being associated with the supply container so as to provide the supply container with a stock of solid spherical colorant particles and to allow automatic replenishment of said stock in the supply container with solid spherical colorant particles from the exchangeable cartridge, until the exchangeable cartridge is empty, in response to dispensing at least one charge of solid spherical colorant particles via the nozzle. 
     
     
         7 . The solid colorant dispensing unit according to  claim 1 , wherein the plunger is spring-loaded and has a free end part that is arrangeable with respect to the dispensing outlet of the nozzle so as to control dispensing of the solid spherical colorant particles, wherein said free end part has an outer circumference having a shape that is configured to ensure a uniform flow of dispensed solid spherical colorant particles when the free end part partially blocks the dispensing outlet. 
     
     
         8 . The solid colorant dispensing unit according to  claim 2 , wherein the supply container comprises a first part having the free end portion that is provided with the nozzle and a second part having an end portion that is connected in open communication with an end portion of the first part that is arranged opposite the nozzle thereby providing a transition between the second part and the first part, the first part having a cone-shaped inner wall that with respect to its longitudinal centerline is arranged at an angle (α) in a range of 15-55 degree. 
     
     
         9 . The solid colorant dispensing unit according to  claim 8 , wherein an overflow compartment is provided adjacent the dispensing outlet of the nozzle so as to receive solid spherical colorant particles dispensed by the nozzle as a result of a displacement of the plunger. 
     
     
         10 . The solid colorant dispensing unit according to  claim 9 , wherein a vibratory unit is provided that is configured and arranged to allow the supply container to vibrate at a frequency in a range of 0-55 Hz during operation of the solid colorant dispensing unit. 
     
     
         11 . The solid colorant dispensing unit according to  claim 10 , wherein an exchangeable cartridge is provided comprising solid spherical colorant particles, the exchangeable cartridge being associated with the supply container so as to provide the supply container with a stock of solid spherical colorant particles and to allow automatic replenishment of said stock in the supply container with solid spherical colorant particles from the exchangeable cartridge, until the exchangeable cartridge is empty, in response to dispensing at least one charge of solid spherical colorant particles via the nozzle. 
     
     
         12 . The solid colorant dispensing unit according to  claim 11 , wherein the plunger is spring-loaded and has a free end part that is arrangeable with respect to the dispensing outlet of the nozzle so as to control dispensing of the solid spherical colorant particles, wherein said free end part has an outer circumference having a shape that is configured to ensure a uniform flow of dispensed solid spherical colorant particles when the free end part partially blocks the dispensing outlet. 
     
     
         13 . The solid colorant dispensing unit according to  claim 2 , wherein an overflow compartment is provided adjacent the dispensing outlet of the nozzle so as to receive solid spherical colorant particles dispensed by the nozzle as a result of a displacement of the plunger. 
     
     
         14 . The solid colorant dispensing unit according to  claim 2 , wherein a vibratory unit is provided that is configured and arranged to allow the supply container to vibrate at a frequency in a range of 0-55 Hz during operation of the solid colorant dispensing unit. 
     
     
         15 . The solid colorant dispensing unit according to  claim 2 , wherein an exchangeable cartridge is provided comprising solid spherical colorant particles, the exchangeable cartridge being associated with the supply container so as to provide the supply container with a stock of solid spherical colorant particles and to allow automatic replenishment of said stock in the supply container with solid spherical colorant particles from the exchangeable cartridge, until the exchangeable cartridge is empty, in response to dispensing at least one charge of solid spherical colorant particles via the nozzle. 
     
     
         16 . The solid colorant dispensing unit according to  claim 2 , wherein the plunger is spring-loaded and has a free end part that is arrangeable with respect to the dispensing outlet of the nozzle so as to control dispensing of the solid spherical colorant particles, wherein said free end part has an outer circumference having a shape that is configured to ensure a uniform flow of dispensed solid spherical colorant particles when the free end part partially blocks the dispensing outlet. 
     
     
         17 . The solid colorant dispensing unit according to  claim 3 , wherein an overflow compartment is provided adjacent the dispensing outlet of the nozzle so as to receive solid spherical colorant particles dispensed by the nozzle as a result of a displacement of the plunger. 
     
     
         18 . The solid colorant dispensing unit according to  claim 3 , wherein a vibratory unit is provided that is configured and arranged to allow the supply container to vibrate at a frequency in a range of 0-55 Hz during operation of the solid colorant dispensing unit. 
     
     
         19 . The solid colorant dispensing unit according to  claim 3 , wherein an exchangeable cartridge is provided comprising solid spherical colorant particles, the exchangeable cartridge being associated with the supply container so as to provide the supply container with a stock of solid spherical colorant particles and to allow automatic replenishment of said stock in the supply container with solid spherical colorant particles from the exchangeable cartridge, until the exchangeable cartridge is empty, in response to dispensing at least one charge of solid spherical colorant particles via the nozzle. 
     
     
         20 . The solid colorant dispensing unit according to  claim 3 , wherein the plunger is spring-loaded and has a free end part that is arrangeable with respect to the dispensing outlet of the nozzle so as to control dispensing of the solid spherical colorant particles, wherein said free end part has an outer circumference having a shape that is configured to ensure a uniform flow of dispensed solid spherical colorant particles when the free end part partially blocks the dispensing outlet.