Thermoforming for Appliances & White Goods: Fridge Liners, Trays & Panels

The refrigerator inner liner is one of the classic thermoformed parts — and a good lens on why thermoforming dominates white goods. Appliance parts are large, thin-walled, cosmetic on one side, and made in the tens of thousands rather than the millions. That is precisely the window where thermoforming for appliances and white goods beats injection moulding on tooling cost, lead time and large-format capability. Here is how we approach it.

The refrigerator inner liner: a material problem first

A fridge liner looks simple. It is not. The liner has to survive years of contact with blown-in polyurethane foam insulation, whose blowing agents and the oils/fats from stored food attack many plastics — leading to environmental stress cracking (ESC), the slow crazing and splitting of a stressed part exposed to an aggressive chemical.

That is why we specify HIPS Cool, a high-impact polystyrene grade formulated for exactly this duty:

• High ESCR — resistance to the foam blowing agents and food oils that crack ordinary HIPS.
• FDA-compliant — cleared for repeated food contact inside the cabinet.
• Good thermoformability — deep draws, sharp shelf ribs and door-liner detail without excessive thinning.
• Low-temperature toughness — it stays impact-resistant at refrigeration and freezer temperatures.

Because we extrude sheet in-house (0.1–12 mm, wide-web), we can supply the liner in the gauge and width the cabinet needs, and hold the surface and thickness profile that deep-draw liners demand.

Beyond the liner

The same logic applies across the appliance:

• Crisper and vegetable trays, egg trays, door bins — food-safe, transparent or tinted, formed to nest and slide reliably.
• Washing-machine parts — detergent dispensers, top-panel covers, tub surrounds and service covers.
• Air-conditioner panels — indoor-unit front panels and louvres, where finish and dimensional stability drive fit.
• Microwave and dishwasher interior components — where thermal and food-contact behaviour matters.

Dimensional stability drives assembly yield

An appliance is an assembly of many parts that must snap, slide and seal together. A liner that bows, or a panel that warps after demoulding, costs you on the line. We control this through sheet consistency, tool temperature management and post-form CNC trimming — our 5-axis trimming holds cut-outs, mounting holes and edge profiles across large panels so parts drop into the jig without hand-fitting.

Cost vs injection moulding

For a large liner or panel, an injection mould is a large steel investment with a long lead time, justified only at very high annual volume. A thermoforming tool for the same part — single-surface aluminium — is a fraction of that cost and can be cut in weeks. The break-even maths favours thermoforming across most appliance volumes, and decisively so for large parts, new model introductions and shorter production runs. It also de-risks a launch: an engineering change to a thermoform tool is cheap and fast next to re-cutting a steel cavity.

Where it makes sense to switch

If a part is large (say over 300–400 mm), thin-walled, cosmetic on one face, and made in volumes up to the low hundreds of thousands a year, it is worth costing as a thermoformed part. Deep boxy geometries like liners and trays are the sweet spot; very thick solid sections or parts needing detail on both faces are better left to injection.

Let’s cost your appliance part

If you build refrigerators, washing machines, air-conditioners or other white goods and want to compare a thermoformed liner, tray or panel against your current process, share the part and annual volume. Explore our materials including HIPS Cool, or contact us for a tooling and part estimate.