Vortex Liquid Color

4445 Gateway Drive
Sheboygan, WI 53081
phone: 920.451.9925
fax: 920.451.9926
email: info@vortexcolor.com


What is Liquid Color?

Custom Formulations

Our liquid colorant is a dispersion of pigments and/or dyes in specially selected liquid vehicles, which are customized to the polymer and process of our customer. These specialize vehicles guarantee the colorant will have total compatibility with the polymer and result in less effect on physical properties. It also promotes rapid and complete distribution of the liquid color concentrate into the polymer leading to less processing problems.

We produce high-loaded pigment concentrates by mechanically breaking up the pigment agglomerations into individual particles that result in better uniformity, opacity and intensity of the color. This high concentration results in lower letdown ratios:

  • Opaque Colors: normally six to twenty parts to 1000 parts polymer
  • Transparent Colors: normally three to five parts to 1000 parts polymer

In addition to pigments, functional additives such as anti-oxidants, anti-static agents, chemical blowing agents, UV stabilizers, and absorbers may be incorporated into the colorant.

How is Liquid Color Added to a Polymer?

Extrusion Operation

A six-roll peristaltic pump along with a flexible feed tube is used to inject the liquid colorant directly into the feed throat or into an intermixer above the injection or extrusion machine. The pump compresses the outside of a flexible feed tube, forcing liquid colorant through the tube, and is capable of metering as little as one gram of material per cycle of viscosities up to 12,000 CPS. Output of the pump can be adjusted in milligram increments, permitting fine-tuning of color levels with no interruption in processing. Because the colorant is metered into the processing machine mechanically, the system requires little supervision or labor skill to obtain consistent color.

The pump is simple in design, portable and essentially maintenance-free, and generally costs between $1,600 and $2,000.

Complete color changeovers are accomplished by simply changing to a different colorant feed tube and purging the barrel of the original resin color. Purge waste and changeovers are significantly reduced. No additional operations are required to change colors; natural resin in the hopper never requires emptying or drying, and the peristaltic pump head requires no cleaning. Any accidental spills are easily cleaned since the liquid colorant washes up with soap and water.

Liquid colorants can be used even without any metering equipment but merely with manual mixing.

How Do Colorant Types Compare?

Injection Molding


Color Concentrates

Disadvantages of Color Concentrates:

  • Metering equipment is expensive
  • They are generally more expensive than liquid color
  • Long lead times are required for delivery and small quantities are either high prices or difficult to obtain
  • They may require drying before use with engineering resins
  • Specking issues may be a problem
  • Color results may vary from shot to shot

Precolored Compounds

Advantages of Precolored Compounds:

  • They are simple to use
  • They provide consistancy of color

Disadvantages of Precolored Compounds:

  • Large quantities of each color resin must be purchased to reduce cost
  • Use considerable amount of inventory space
  • Colors other than black and white incur significant premium charges
  • Long lead times are required for reorders and new colors
  • Changing colors may require long periods of downtime to empty hoppers and dry resin

Liquid Colorant

Advantages of Liquid Colorant:

  • Lower Letdowns:
    • Opaque Colors: normally three to twenty parts to 1000 parts polymer
    • Transparent Colors: normally three to five parts to 1000 parts polymer
  • Peristalic pump is 10X more accurate than dry blenders
  • Excellent uniformity, increased opacity, and intensity of the color leading to lower pigment requirements and lower cost. Since no further color development occurs during processing, reproducibility is also excellent
  • Liquid colorant never needs drying, reducing the risk of contamination in the driers (natural polymer is the only material in the drier). Fewer driers may be required
  • Additives, polymer, and pigments only see one heat history
  • Fast color changes, short color runs can be accomplished without shutting down equipment. Purging is not required
  • Lower scrap rates
  • Screws and barrels inherently much cleaner
  • Easy clean-up, just use soap and water
  • Eliminates the amount of mix inventory on hand (unused polymer and concentrate blends)
  • Supplied rapidly in small or large quantities
  • Shorter lead times, new colors can be matched and shipped quickly
  • Lower acquisition and inventory cost
  • Purchase order required to color one hundred thousand pounds of polymer:
  • Black Concentrate Black Liquid Color
    Letdown: 2.00% 0.40%
    Price per pound: $0.83 $2.08
    Purchase order: $1660.00 $832.00
  • Reduced inventory space
    • Color Concentrate: 2000 pounds will color 50,000 to 200,000 pounds of polymer
    • Liquid Colorant: 24 five-gallon containers (or 4 thirty-gallon drums) will color 75,000 to 320,000 pounds of polymer