Applications

PVC Door and Door Frame Extrusion Line

A PVC door and door frame extrusion line produces the two halves of a finished door set: the wide foamed slab that becomes the door panel, and the multi-chamber frame profile it hangs in. Both run on the same line with different dies, and door work uses the largest extruder we build for profiles, up to 90 mm.

Door sections are where profile extrusion stops being about output and starts being about wall integrity. A frame that will not hold a hinge screw, or a panel whose foam core is denser on one edge than the other, passes every dimensional check and still comes back from the customer.

Send us the panel and frame sections, the foam density you are targeting, and the hardware the frame has to accept. We size the extruder, the die head and the calibration length around those before quoting a layout.

What a PVC Door Line Produces

A door set is not one profile, it is a family of them, and a line is specified around the whole family rather than around the widest piece:

Door panels and slabs. Wide foamed PVC sections, usually the largest cross-section on the line and the reason door work runs a 90 mm extruder.
Door frames and jambs. Multi-chamber closed profiles that carry the hinges, the strike plate and the seal groove.
Architraves, beading and glazing bead. Small sections that finish the set and are usually run on the same tooling family.
Louver and panel inserts. Narrow repeated sections for ventilated and paneled door designs.

Doors are bought on appearance, so the decorative face is added in line: our PVC wood-grained printing and ultraviolet (UV) curing equipment prints and cures the panel face after cutting, which is how one extrusion line supports a full wood-finish range.

How PVC Doors and Door Frames Are Made

A complete PVC door production line runs six stations, each sized against your sections rather than picked off a catalog:

Dry blend preparation. A high-speed mixer brings PVC resin, stabilizer, filler and foaming agent to an even blend. On foamed door panel the blowing agent has to be distributed evenly, because density variation across the blend becomes density variation across the slab.
Main extruder. Door work runs on our parallel counter-rotating twin screw extruder, sized up to 90 mm for large sections. Counter-rotating screws convey rigid dry blend positively and hold residence time short, which is what keeps a foamed core consistent at high throughput.
Extrusion tool. Segment-type die heads machined from stainless steel alloy, with independently heated zones. A door panel die is the widest tool on any profile line, so zone control across its width is what stops one edge running hotter and foaming differently from the other.
Vacuum calibrating system. Sectional calibration on a common base plate, each section with its own vacuum and cooling water connection. Foamed sections need the skin to set before the core finishes expanding, which is a cooling sequence question rather than a cooling capacity question.
Profile caterpillar haul-off. Pulls the section at a speed matched to extruder output. On a foamed slab, haul-off speed also sets the degree of stretch in the skin, so it is a product parameter here rather than only a transport one.
Saw. Cuts to length in line, synchronized with the haul-off.

The Die Head Is the Part You Are Really Buying

On a door line, the extruder is a commodity decision and the die head is not. Three things follow from that:

Single cavity, high speed. Door panels are wide enough that one cavity per die is normal. Output comes from line speed and from melt delivery across the width, not from running two cavities.
Segment construction. Our dies are built in segments, so a worn or damaged land can be replaced without recutting the whole tool. On a door panel die, that is the difference between a repair and a new tool.
One tool family, several sections. Panel, frame and architrave are dimensioned together so they mate, which means specifying them as a set rather than ordering dies one at a time as the range grows.

FAQ

What is a PVC door extrusion line?

A PVC door extrusion line melts rigid PVC dry blend and forms it through a die head into door panels, frames and trim, then sets the section under vacuum while it cools. A complete line runs six stations: dry blend preparation, extruder, die head, calibrator, haul-off and saw.

What size extruder does a door profile need?

Door work uses the largest extruder on a profile line, up to 90 mm, because the panel section is wide and the volume per meter is high. Frames and trim run on the same machine with different dies.

Can one line make both door panels and door frames?

Yes, by changing the die head and the matching calibrator. We dimension panel, frame and architrave as one tool family so the parts mate, rather than tooling them separately as the range grows.

What makes a foamed door panel fail quality control?

Uneven core density, usually traced to blowing agent distribution in the dry blend or to temperature variation across the width of the die. The panel measures correctly and still fails, because density decides whether the frame holds a hinge screw and whether the panel warps in service.

How is the wood finish applied?

In line, after the saw. Our PVC wood-grained printing and UV curing equipment prints and cures the panel face, so a full wood-finish range runs off one extrusion line.

What do you need to quote a door line?

Four things: the panel and frame sections, the wall thickness, the target foam density, and the output in kilograms per hour. Tell us which hardware the frame has to accept and we will check the section against it.