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Vacuum zones for mixed sheets

Vacuum zoning prevents small or mixed parts from lifting during CNC sheet cutting. This guide covers what to expect, who benefits, and the steps we use in South African workshops.

Mr James Naidoo · Field engineering

Checking seals before each run

Before starting a mixed-sheet job, always check the gasket seals on your CNC bed. In South African shops, dust and offcut debris can settle quickly, especially in Gauteng’s dry winters or coastal humidity. A small gap or worn section along a zone divider will leak air, dropping the hold and letting small parts shift. Run your hand along every gasket and press lightly to feel for soft spots or cracks. Replace any section that feels loose or brittle before you load material. We have seen batches ruined just from a single missed leak near the edge.

If you are switching between different sheet types, keep a soft brush and vacuum handy to clear the bed between each run. Even a few stray MDF fibres can break the seal with acrylic or aluminium. These quick checks take a minute but save hours of rework and wasted stock, keeping your vacuum zones working at their best.

Workshop context

Zoning beds so small parts do not lift.

What we recommend

For best results, use vacuum zoning together with a VacuumHold Fixture. If you want to see how it handles your own material mix, bring your sheet in for a demo at Sunnyrock or your nearest showroom. We will show you real hold-down on your actual job layout.

What vacuum zones do for mixed sheet cutting

Vacuum zones split a CNC bed into separate hold-down areas. This keeps small parts and offcuts in place during the cut, especially when working with mixed materials or jobs with many individual pieces. If you are running both larger and tiny shapes on one sheet, zoning keeps the smallest pieces secure so they do not shift or lift on the toolpath. We see requests for this from Gauteng through to the Cape, especially where jobs involve nested production or several different materials on one run.

Who should use vacuum zones - and who should not

Vacuum zoned beds are suited to workshops or manufacturers who regularly cut mixed-size batches, small repeat items, or jobs that need precise part placement without secondary taping, tabs, or hand clamping. If your work is mostly large, simple shapes or one material per sheet, the benefit is lower, and the extra setup may slow you down. Zoning is most valuable in shopfitting, display production, signwriting, and any short-run pack where minimising manual handling is a real cost.

How zoning works in practice on SA floors

On a typical South African CNC table, vacuum zoning divides the bed into sections controlled by mechanical slides or valves. The operator activates only the area under the parts being cut, which concentrates suction and keeps even small, light parts stable. This is especially handy when you need to mix aluminium, MDF and acrylic on the same job, or when working in Highveld shops where dust can break seal if zones are too broad. Most weeks, our crew in Isando sets up beds like this for mixed runs. It is simple enough for any foreman to brief out after one run-through.

What to sort out before you email us

Before you get in touch, you will save time by lining up a few details. We get the most workable results when your brief includes the following:

Emailing these points through our contact form lets us give a clear answer without a second round of calls. If you are not sure about a detail, just mark it as a question. For longer jobs or repeat runs, it pays to link your query to the relevant industries or machines pages for faster referencing.

A single-page summary of what you need to cut (including material, sheet size, and thickness)

Drawings or sketches showing part placement and count per sheet

Any power constraints (such as outages, municipal faults, or three-phase requirements)

Who will sign off onsite

Preferred finish, nesting, or handoff instructions

A real example from the Cut2Shape floor

A sign shop in Durban needed to nest 60 acrylic badges and 4 large backplates on one bed. Without zoning, smaller badges warped upward after the first pass, chewing time with tape and re-cuts. We set up three vacuum zones so suction only ran where badges lay. The foreman briefed the install with a one-page sketch, we walked through the plan together, and the operator closed out the run with notes for the next shift. The job finished in one session, with every badge flat and ready for finishes without bench cleaning.

In contrast, an office furniture line in Bloemfontein with all large panels found no gain from zoning, as every part spanned the full width of the sheet, and the single vacuum path was already strong enough. It is not a one-size-fits-all.

Pitfalls and how we keep them off your job

Typical problems include missing key constraints during planning, splitting beds into too many zones for their size, or relying on old gaskets that do not seal properly. If your crew simply repeats an old setup without checking current power supply, sheet sizes, or any local power reduction, you risk losing suction partway through and wasting both material and machine time. We always confirm constraints first: access, timing, available power, and who will sign off. That is how we avoid most of the issues seen on the shop floor.

If you want to see how zoning matches your next run, or just want a short walkthrough, send a message through our contact form and mention Vacuum zones for mixed sheets. You can also browse our notes on nesting before you cut or soft hold-down for clear faces for related tips.