Single Valve X-flow System 4/6

Description

Our patented Single Valve X-flow System 4/6 is an instant color change system which allows very fast skin or striping color changes.

Substantial raw material cost saving can be achieved with this system through color change scrap reduction. The possible production flexibility and no color change downtime assure high productivity with an X-flow system.

An extrusion group with a single X-flow valve is composed of one main and two auxiliary extruders, an X-flow valve and a triple layer crosshead. The X-flow valve is one of the key components of this color change system. It is located between the auxiliary extruders and the crosshead. The main extruder is used for the uncolored middle layer of the insulation of products without striping. The material flow from this extruder goes directly to the crosshead through a passage in the valve. One of the auxiliary extruders makes a colored outer skin while the other auxiliary extruder supplies its material to the inner layer. Raw material containing the next skin color is fed to the inner layer extruder a certain time before the next color change. This colored inner layer will be not visible since the main insulation and the outer skin hides it.

The function of the X-flow valve is to cross the flow between the two auxiliary extruders. The X-flow valve is activated when the production length of the current color is reached and the inner layer extruder with the next color becomes outer layer extruder. The extruder used previously for the outer layer will now make the hidden inner layer. The skin insulation will start changing color almost instantly and will have the full new color after 5 to 30 seconds depending on the used colors and insulation thickness. Coloring of the inner layer is only needed just before a color change.

The two auxiliary extruders are independent, which means that the thickness of inner and outer layer can be adjusted separately.