REPI develops and manufactures a range of dosing units and analysis instruments support users in the use of REPI’s colours and additives.

The dosing units are suitable for both injection moulding and extrusion processes.
These instruments ensure maximum precision and constant control of the dosing process. Gear pumps of different flow rates can be easily and quickly installed and removed and allow for easy cleaning.

REPI dosing units are also part of complex and customized control systems customized on customers’ needs, such as the Colour Management System: an in-line colour control system for extrusion processes.

REPI offers as well the Light Meter, an analysis instrument to check colour and additive consistency in PET preforms quickly and reliably.



REPI develops and produces dosing units able to dose liquid colours and additives.
The range of U2011 Dosing Units represents the last generation of electronically controlled dosing systems developed by REPI. Suitable for injection moulding as well as extrusion processes, they are normally fitted with gear pumps of different sizes, that ensure high precision and constant dosage of colours or additives.
The unit gets the input signal from the machine, it adapts to the output possible fluctuations, in order to maintain the same dosage throughout the production. The metered quantity can be checked in real time and adjusted if required, while the machine is working. The amount of colour in the service drum is constantly checked to allow the operator to refill the drum before it is empty. Pumps are quickly installed and removed, and easily cleaned by the operator for colour change.
U2011 are designed to be user- friendly instruments. Calibration of the specific colour or additive is required only once and is a simple and quick operation.
The parameters are stored in the unit memory and can be recalled when needed, by simply pressing the specific program name. A vast amount of data is available, including a historical log going back for months and colour consumption data related to the pump turns.
U2011 have a digital touchscreen and an intuitive software. A limitless number of programs can be stored.

Once the colour/additive calibration has been performed, the relative data are saved in the memory of the control unit and can be recalled simply by pressing a button or can be transferred to a computer in the form of an Excel file (using a USB port); all this offers the opportunity to analyse and compare the consumption levels of the product and, consequently, correct any possible inefficiency in order to obtain a more accurate and precise dosage. The saved programs can be transferred to other dosing units in order to speed up the machine configuration phase.
  • Touch-screen display
  • Manual and automatic operational modes
  • Dedicated software with LOG, large memory capacity
  • Digital input: open close powerless contact
  • Analogical input: 4-20 mA and 0-10 VDC
  • Interfaces: I/O, PC, LAN, USB, SD
  • Acoustic and visual alarm interfaces
  • Pump feedback and external alarm connections
  • Type of connection: 230v –50hz (110v also available)
  • Colour level control by load cell; +/- 1 gram tolerance and max 50Kg load
  • Gravimetric control during production
  • Auto refilling system
  • Colour management System
  • Low tension motor: 48 VDC (220VDC with inverter for 10cc pump)
  • Encoder control
  • Power: 190W standard (750-1500 W for 220VDC)
  • Maximum speed: 3.000 rpm
  • Motor reduction: standard 1:20
  • Gear pump output: 0,06- 0,2-1,0-2,0-5,0-10,0 cc/ revolution
  • Screw pump output: 1,1 and 3,0 cc/revolution
  • Pump speed (min/max): 1-150 rpm
  • Digital pressure switch for colour pressure control: 0-25 or 0-100 Bar
  • Colour drum with quick connection


The dosing unit range U2011 is the basis of “closed-loop” dosing systems, in which the colour/additive never comes into contact with the surrounding environment, therefore ensuring non-contamination.

The CLOSED LOOP - DOUBLE DRUM system consists of two drums, in which the one on the right is the service drum, fed by the left drum. The product is pumped via a diaphragm pump to the service drum and then injected into the machine through a gear pump.
A load cell controls the colour/additive level in the service drum with a tolerance of +/- 1 Gram.
The system is suitable for packaging such as iron or plastic drums, as well as bag in box - REPI Cubi.

The CLOSED LOOP COLOR KART system is the ideal portable dosing unit when many colours are used. It consists of a control unit and dedicated carts based on the number of colours/additives in use.
The control unit is equipped with a monitor, CPU, alarm, motor and flange, solenoid valve, pressure gauge (optional).
The Kart is equipped with support for service drum, support for specific packaging (drum or REPI Cubi), gear pump, diaphragm pump and load cell.


Most beverages need special protection from visible light, in order to maintain their sensorial and nutritional characteristics. in food packaging applications, such protection is often obtained by using colours, which are dosed at different addition rates. One of the best ways to ensure that the final container will have the necessary light protection is to measure light transmission directly on the PET preform, before it passes to the blowing stage.
The colour amount level in the preform is tested by spectrophotometer techniques or, very often, just by visual control. The first approach is expensive, requires lab skills and often yields more data than needed. Moreover, it is difficult to apply to opaque preforms.
Visual checking is a standard practice for checking preforms on the shop floor, but there is a limitation with opaque preforms and the reliability of the result depends a lot on the operators’ experience.
Light MeterPlus measures all opaque, semi-transparent and transparent preforms, offering a more scientific alternative to visual control for all coloured preform ranges.
Depending on preform opacity and on the purpose of the control, different options are available:
• Flash
  • A light source is positioned inside the black test cell, which is completely isolated, allowing no light to enter. The preform is placed on the fixed light source emitter in the middle of the test cell area. This is surrounded by several sensors able to catch, at different levels of sensitivity, the light passing through the preform wall to the test cell. The sensor systems give an electrical signal which is proportional to the amount of light passing through the preform. Depending on the preform light barrier properties, different values are registered.
  • Fit the preform into the support.
  • Automatically load all the preform data requested for the test.
  • Press “MEASURE”, and the following occurs automatically
  • light discharge
  • capture of the light (volt/time)
  • peak integration
  • signal elaboration
  • An “ok” or “fail” message appears on the test report
  • The analyzer reports the following results:
    1- PEAK Area: areas of peaks relating to the intensity of the transmitted light.
    2- Light Transmittance (TR%): percentage of transmitted light calculated with respect to 100% of the measured emission without preform (calibration).
    3- If the measurement is performed by recalling a reference value in the database, these values (TR%) will be shown in black when within tolerance, while they will be in red if out of tolerance. In the latter case, a positive (overdosed preform) or negative (underdosed preform) sign will appear after the value.

    The results of all the analyzes performed and the information relating to the measurement are saved in a .csv file that is automatically generated at the end of the first daily analysis.
  • Control on CIELab and DeltaE
  • No preform database limits
  • Direct loading and consultation of historical data on the instrument
  • Wi-fi connection
  • Touchscreen
  • The user-friendly software allow also unskilled people to use the instrument properly.
  • Languages available are: Italian and English.
  • The use of different light sources allows the definition of the best compromise, colour by colour. Depending on the model, different measurements can be carried out
  • Analysis on transparent, semi-transparent and opaque preforms
  • Analysis of the UV content
  • Analysis of IR absorption
  • Analysis of preforms with very high levels of opacity



A customized spectrophotometer interacts with the REPI U2011CL dosing unit in order to automatically increase or decrease the dosage of colour or additive based on the colorimetric readings and the reference during the sheet extrusion process.
  • Recognition of the standard at the start of a new production simply by placing the reference in front of the spectrophotometer.
  • Quick start of industrial production: it is not necessary to cut pieces of sheet, analyse them in the laboratory and then adjust the dosage manually.
  • Automatic correction of colour intensity and shade even when using uneven input material (recycled material - coloured scraps - etc.). The quantity of colour dosed is always correct and precise, without the risk of overdosing.
  • The system can read and be set in transmission or reflection mode
  • It is possible to correct the dosing time by connecting it to the extruder output.
  • The dosage corrections and its automatic calculation are possible starting from a minimum of 0.005%.
  • Stable sheet colouring is ensured throughout the entire production.
  • Quality control is carried out remotely. The data obtained can be used as a quality certification to the final customer.
  • The system is easy to install, without the need to modify the extrusion line and without any impact on the production set-up.

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