ABS sheet for refrigerator liners is a food-contact and deep-draw specification in one. A white goods manufacturer in Turkey changed liner sheet from a high-impact grade to a standard grade to save 4 per cent on material, and lost 9 per cent of yield in the first month. The cracks appeared at the deep rear corners, where the draw ratio is highest and the sheet thins most.
ABS sheet for refrigerator liners: the grade requirement
Food contact compliance is the first gate: the liner touches packaged food and interior air, so the grade must be approved for the application and documented.
High impact at low temperature is the second. A refrigerator interior runs to minus 18 in the freezer and the liner sees that for years. Standard ABS embrittles; impact-modified grades hold.
Deep-draw behaviour is the third, and it is a property of the grade rather than the sheet thickness.
- Food-contact approval with a declaration of compliance
- Impact retention to minus 20 degrees Celsius
- Draw ratio capability of 3:1 at the specified thickness
- Consistent white colour, since liners are visible in every unit
Draw ratio and thickness
A typical upright liner is 600 mm wide and 500 mm deep, a draw ratio close to 1:1 on the depth-to-width measure but far more demanding at the corner where material must flow in two directions.
In practice liners start at 2.5 to 4 mm and finish with a minimum wall of 1.2 to 1.5 mm after forming. Starting thinner than 2.5 mm gives a wall that dents in service.
Forming the liner
Sheet at 165 to 175 degrees Celsius, female mould at 70 to 80 degrees Celsius, vacuum held until the part is below 80. The cycle is longer than a shallow enclosure because the draw is deeper and the sheet thicker.
Trimming happens after full cooling. A liner trimmed warm will creep and the door will not sit square.
Bonding, trim and the details that affect yield
Liners are often bonded to a shell or fitted with a door gasket frame. The adhesive must be compatible with ABS and survive low temperature; a standard contact adhesive will fail in a freezer.
Trim lines should be straight and generous: a 3 mm trim allowance absorbs forming tolerance and prevents the thin white edge that appears when a liner is trimmed exactly to size.
Why colour consistency matters more here than elsewhere
A liner is the interior of a product that customers open every day. A batch that is 2 Delta-E units warmer than the previous one is not a defect by specification, and it is a visible mismatch on a production line.
Approve a chip, keep the pigment batch on record, and quote the chip number on repeat orders. That is the whole colour control system, and it costs nothing to run.
Weight checks catch thickness drift before forming; the ABS weight table gives the expected figures. For costing the liner against alternatives, the ABS price per sheet note breaks the invoice into its lines.
For a first production run, ask for ten formed samples from the specified grade before the container ships. Ten parts answer the draw, the trim and the colour questions at once.
Send liner drawings, draw depth and volume to oversales@rpplexiglass.com for a grade recommendation and a first-run quotation.
Frequently Asked Questions
Which ABS grade is used for refrigerator liners?
A food-contact approved, high-impact grade with good deep-draw behaviour, usually 2.5 to 4 mm starting thickness. Standard grades crack at the deep corners.
What draw ratio do liners need?
Three to one or more for a typical upright liner. That requires a high-impact grade and a thicker starting sheet than a shallow enclosure would use.
Will ABS crack in a freezer compartment?
Not if the grade is impact modified for low temperature. Standard ABS embrittles below about minus 20 degrees Celsius, which is why the grade choice matters more than the thickness.