- multitude of design and visual appearance options
- basically the same properties as solid sheet and the possibility to use optimized PVC formulations for the rigid and foamed layers
- considerable cost savings in raw material because of:
- only the thin outer layers need to be pigmented (color, UV stabilizing, etc.)
- up to 20% regrind can be used for the middle layer
- sheet densities and thicknesses for difficult applications
- furniture, construction and advertising industries
- extrusion line with co-extruder for the second material and feedblock with sheet die - similar to lines for free foamed or low density free foamed sheet - are used
- important downstream equipment are pre-cooling rolls (similar to those used for low density free foamed sheet production) and polishing stacks
Feedblock designs dominate the PVC foam core sheet production because of their minimal pressure build-up and a constant layer thickness distribution.
The feedblock consists of two major parts:
- an inner core to divert the co-ex layer to the top and bottom layer and to guide the melt flow to generally ensure an equal wall thickness distribution
- an outer core
The middle foam core layer flows through the center of the feedblock.
