what is pvc celuka board?

Yocret PVC foam board

                                                     -what is pvc celuka foam board?

However there is more to this simple phenomenon than meets the eye. Celuka is primarily a process. PVC, and more specifically uPVC, can be made to reduce it’s density by many methods.

Firstly there are mechanical systems for the introduction of high pressure, inert gasses directly into the PVC melt stream before the exit from the die. Super low densities can be achieved by this method, but the costs of machinery and process control necessary usually prohibit this method on an industrial scale. Even so, this method is used widely with other polymer families.

Secondly, and more common, is to employ chemical blowing agents to provide the expansive force necessary to produce the desired cell structure and weight saving. Within this method, there are two ways of achieving the blown nature of PVC foam.

If you allow the melt containing the dissolved blowing agents to exit the die and then expand outwards in all directions this is known as freefoam or outward foaming process.

In the freefoaming process the melt expands freely upon exit of the die. The gasses evolve slowly to increase the volume of the extrudate, both in length and in cross section. The calibrator (or cooler) is generally larger than the die exit and the material expands to fill the profile shape. The draw down rate (or haul off speed) is used to control thickness of the final product. The freefoaming method is preferred to manufacture thin, geometrically simple profiles.

In the Celuka or inward foaming process the surface of the extrudate is cooled immediately upon exiting the die.

This is to suppress cell formation at the surface creating a hard, high quality finish, while allowing the hot melt to expand inwards. The melt rejoins, fusing, to fill the profile. The gasses are evolved rapidly, so this method calls for simultaneous calibration of the final shape.

The Celuka process is preferred for profiles thicker than 6mm, geometrically more complex products and products where a high quality hard surface is required.

A third hybrid type, which is the most common these days, is to co-extrude a weatherable skin or cap material onto a non-weatherable Celuka core. This reduces meterage costs due to lower formulation cost in the bulkiest part of the profile and inventory when several colours are in the marketing range.

Profiles extruded using the Celuka method are aesthetically the more pleasing of the two systems and structurally provide a stronger product, due to the integration of the solid skin.

Celuka products can be manufactured in densities all the way down from near rigid PVC of 1.4 gms/cc to as low as 0.4 gms/cc. Within this range the products can, and are, used as an excellent replacement material for wood based products and as a cheaper but more aesthetic replacement for other polymer thin wall extrusions.

Even at the lowest density, Celuka has the same screw pull rating as pine. Yet none of the profiles produced with Celuka will ever be troubled by rot, mould, chemical attack or insect infestation.

Foamed PVC products offer a much higher insulation factor over other profile types due to the trapped gasses inside them. What’s more, when the lifecycle of the product is over, the profile can be ground and pulverised for inclusion back into fresh profiles at high percentages.

It is for these reasons coupled with the low polymer and energy usage, due to it’s low extruded density, that Celuka has an excellent L.C.A. rating.

Celuka products have been used in wide ranging applications such as advertising materials, building products, furniture design, decorative moldings and many more.

Fresh uses for this versatile and cost effective process are being thought of every day and its use is growing all over the world, where it is bringing down the cost of manufacture and enhancing the product aesthetics and usability of many established and new profile shapes.