Guide
Membrane door drawing in Alphacam: pattern, cutters, depth and holes
How a membrane (vinyl-wrapped) door is drawn and machined in Alphacam: MDF choice, pattern grooves, V/profile cutters, depth and corner radius the membrane press can wrap, handle and hinge holes, operation order and a parametric macro for series production.
Published: 8 min read
A membrane door is an MDF blank with a CNC-routed pattern, wrapped with PVC foil under heat and vacuum; it is the most common kitchen and bathroom door in Turkey. Visible quality is decided in two places: at the press (foil, adhesive, temperature) and on the CNC (pattern geometry, cutter choice, depth, corners). This article covers only the CNC side, through Alphacam. For door types in general: Cabinet door drawing in Alphacam: membrane, panel, American, framed, glazed and louvred doors
Material: which MDF, which thickness
Membrane doors use raw (unfaced) MDF; 18 mm is standard, 16 mm for shallow patterns, 22 mm for deep profiles. Density matters: low-density MDF leaves fuzzy routed edges that show through the foil. The back face usually comes pre-faced with white melamine or PVC (single-sided board), so the pattern is routed only on the front and the through cut is made with a compression cutter so the back facing does not chip.
Pattern geometry: groove, profile and surface
A membrane pattern consists of three geometry types:
- Groove (line pattern): a frame line at a fixed distance from the edge, or parallel lines. V or ball-nose cutter at fixed depth. KANAL/DESEN layer.
- Profile (sloped edge): an angled or curved transition between frame and panel; profile cutter in one pass. Separate layer — different cutter.
- Surface (balloon/dome): the whole door or its panel is routed with a curve; surfacing with a ball-nose cutter in passes. The slowest type; balloon doors in Cabinet door drawing in Alphacam: membrane, panel, American, framed, glazed and louvred doors.
In Alphacam the pattern is drawn as closed or open geometry like the outer contour; which cutter and depth machine it comes from the layer (Auto Style) or is assigned by hand. The pattern line is derived from the door size: fixed edge allowance (e.g. 60 mm), fixed corner style (square/rounded), variable door size. This "fixed + variable" structure is the exact definition of a parametric macro — see How Alphacam-based parametric door and cabinet door macros work
Depth and corners: what the foil can wrap
A membrane press cannot wrap a sharp inner corner or a deep narrow groove: the foil stretches, thins and lifts over time. Typical shop limits (they depend on foil thickness and the press; test with your own):
| Item | Safe range | Why |
|---|---|---|
| Groove depth | 2–4 mm (V), 3–6 mm (profile) | Deeper: foil does not reach the bottom, air stays |
| Groove width | ≥ 6 mm at the bottom | Foil bridges a narrow groove |
| Inner corner radius | ≥ 3 mm (cutter radius gives it) | Foil tears at a sharp corner |
| Pattern–edge distance | ≥ 30 mm | Pattern near the edge lifts at pressing/banding |
| Edge profile | R2–R3 round-over | A sharp edge cuts the foil |
Cutter selection
- Through cut: Ø8–12 mm compression cutter; no chipping of the back facing, no fuzz on top.
- Line pattern: 90° or 60° V cutter — depth sets width (at 90°, depth = half the width).
- Soft groove: ball-nose cutter; the foil wraps more easily.
- Profile: pattern-specific profile cutter (Roman ogee, classic, quarter round); one pass.
- Holes: Forstner-type or helical boring for the Ø35 hinge cup; Ø5 drill for handles.
Holes: hinge, handle, push-to-open
Holes are drilled from the back (hinge cup, handle screws) and do not affect the membrane front; most shops therefore route the pattern from the front and drill in a separate operation from the back, or drill after pressing on a horizontal boring machine. Two approaches in Alphacam: (a) holes in the same drawing on DELIK, separate NC for flipped machining; (b) holes in a separate drawing. Either way the macro computes the hole from the door size: hinge 21–23 mm from the edge, 80–100 mm top/bottom, 2–5 evenly spaced; handle holes at multiples of 32 mm, left/right by opening side.
Operation order
- Board held by vacuum; 10–12 mm between doors in the nest (cutter diameter + allowance).
- Pattern first (groove/profile/surface) — the part is still fully attached, no vibration.
- Then holes (if drilled from the same face).
- Through cut last; on small doors leave tabs or an onion skin and separate by hand — vacuum cannot hold a small part.
In Auto Style this order is fixed by layer priority: DESEN → DELIK → KESIM. Setup: Alphacam Auto Style setup: automatic machining by layer name
Series production: 40 doors from a dimension list
A kitchen is 25–45 membrane doors, all the same pattern, different sizes. By hand each door (pattern + holes + contour) is 3–5 minutes and edge allowance / hinge distance is subtracted manually every time. The Framed Door (pattern), Hinge (Ø35), Handle Holes and Edgeband / Size Calculation tools in GMacros Cabinet Door draw the series from the list onto the right layers; Panel Door Design (GMacros Tools) produces multi-step inner offset patterns. Details: GMacros Cabinet Door · GMacros Tools
Frequently asked
How deep should a membrane door pattern be?
2–4 mm for line patterns, 3–6 mm for profiled edges is common; it depends on foil thickness and press vacuum. Verify with a test door on your own press, then write it into the macro default.
Can a membrane door be made from 16 mm MDF?
For shallow patterns, yes; if the profile depth exceeds 4 mm, 18 mm is preferred, otherwise the blank weakens and the door warps.
Should I drill the holes after pressing?
Back-face holes (hinge, handle) can be drilled on the CNC before pressing; the foil covers the front and the overhang is trimmed like edgeband. Many shops drill after pressing to avoid vacuum loss; the macro draws both flows.
Related products
Tools that do the work described here with one click inside Alphacam: the GMacros Alphacam Package. Purchasing and licensing are explained on How it works.
Written by the GMacros team. Alphacam is a registered trademark of Hexagon AB; this guide is independent.