English 
Zhengfeng Road, Licheng District, Jinan City, Shandong Province,China
Author: Alex Song Publish Time: 2026-10-25 Origin: Site
Almost every week a buyer asks us some version of the same question: is a thermoforming machine better than a vacuum forming machine? The honest answer is that the question contains a category error. Thermoforming is the family name for shaping a softened sheet or film against a mould. Vacuum forming is one of the methods inside that family — the one that uses air pressure difference to pull the material onto the mould. You cannot choose between them any more than you can choose between “cooking” and “boiling”.
That sounds like pedantry until it turns into a wasted purchase. Buyers who search for one term and land on a page about the other routinely end up quoting the wrong class of machine. This article separates the two, explains the process, and then narrows to the only question that matters: which machine does the job in your plant.
Thermoforming is the general process: heat a thermoplastic sheet or film until it softens, then form it against a mould and let it cool in shape. Vacuum forming is one way to make that form happen, by evacuating the air between the sheet and the mould so atmospheric pressure pushes the sheet into contact. Pressure forming and mechanical (plug) forming are the other two common methods. All three are thermoforming; only one is vacuum forming.
So the correct phrasing is that vacuum forming is a subset of thermoforming — a technique, not a rival technology.
Two different industries use the same vocabulary for different products, and search engines do not separate them.
The plastics industry thermoforms sheet into packaging components — trays, clamshells, blister packs, cups. The output is an empty container sold on to a packer. The buyer is a converter, and the machines are judged on sheet utilisation and cycle time.
The food industry thermoforns film directly around a product, inside the packaging machine. The output is a finished, sealed pack. The buyer is a food processor, and the machine is judged on vacuum level, seal integrity and cleanability.
Both are legitimately called thermoforming. Only the second one is what a food plant needs. If you are shopping for a machine to produce empty plastic trays for resale, you want the first. If you want film and product to go in one end and a sealed pack to come out the other, you want the second — and that is the only kind we build.
In a food packaging line the vacuum thermoforming process runs continuously, in six stages:
Heat. The bottom film is brought to forming temperature by contact or radiant heaters. Too cold and the draw tears; too hot and the walls thin out.
Form. Vacuum is drawn through the mould so the softened film collapses into the cavity and takes its shape. Depth of draw is the limiting factor here, not film width.
Load. The product drops or is placed into the formed cavity. At this point the tray exists but is not yet closed.
Seal. The top film is laid over and sealed to the bottom film’s rim under vacuum — and, where the product needs it, with a gas flush.
Cut. Packs are separated from the web, either in-line or at a separate station.
Trim. Edge trim and skeleton waste are removed and wound off.
Every stage runs in one pass, which is what makes the throughput high and the labour content low. It is also why a film-width change is a real changeover and not a parameter tweak.
A tray sealer performs stages four to six only. It takes a pre-formed tray — bought in, or made elsewhere — fills it, and seals a lid on. No forming happens, so there is no vacuum forming stage and no film-width constraint tied to a mould.
That makes the trade-off simple. A thermoformer buys film and makes its own tray: lower consumable spend per pack, full control of tray shape, but a larger upfront investment and a changeover when the tray changes. A tray sealer buys finished trays and only owns the seal: less upfront investment, faster to change product, but you pay a tray supplier for every pack you ship.
Neither is better. They answer different questions, and a plant that already has a tray supply relationship is usually better served by the sealer.
Once the terminology is straight, the selection narrows to four numbers. Fix these before you ask anyone for a proposal:
Pack footprint — length and width of the finished pack. This sets film width and eliminates most models immediately.
Draw depth — how deep the tray has to be. This is the real constraint on a former, and it is the number buyers most often leave out.
Vacuum level — 200 Pa covers most fresh meat; longer shelf life or hot fill usually needs better.
Packs per minute at that footprint — not the headline cycle rate, which is always measured on the smallest tray.
Answer those and the choice usually collapses to one configuration. Answer only “packs per hour” and every supplier will quote their smallest machine against your largest requirement.
Roll-fed thermoformer — forms, fills and seals in one pass. Our LS420 thermoforming vacuum packing machine runs bag widths from 60 to 600 mm on 18–20 kW and pulls vacuum to 200 Pa or better. Right for plants that want the tray made on site.
Tray sealer — seal only, for plants with a tray supply already in place. The MAP and VSP tray sealer covers modified-atmosphere and skin packs.
Rotary tray packer — a carousel sealing one tray at a time at 3–4 cycles per minute. The rotary MAP tray packing machine suits small-to-medium output where an in-line former would sit idle.
All three sit under the same thermoforming vacuum packaging machine family page, which is the fastest way to compare them side by side.
Thermoforming is the process family; vacuum forming is the method most food packaging machines use to execute it. If your question was “which one should I buy”, the useful version of that question is: do I want to make the tray from film, or do I want to seal a tray someone else made? Answer that, and the thermoforming vs vacuum forming distinction stops being academic and starts being a purchasing decision.
