Introduction: Double-sided PE film is the standard barrier on a frozen seafood block liner, while waxing is an optional upgrade for condensation-heavy handling.
A pallet of 7.5 kg fish blocks leaves a cold store, crosses a wet loading dock, and sits in a container for weeks. The liner box has to hold the block shape, block moisture from both sides, and stay stiff enough to stack while it does it. Wholesalers comparing samples often see boxes that look almost identical in print and board thickness, yet one is quoted lower because it carries thinner film or no wax at all. That difference is hard to see in a photo, which is why material configuration deserves its own conversation before you compare price per piece.
Frozen seafood blocks are wet on the surface even when they look dry. In storage, small temperature swings move water from the product toward the coldest surface, and paperboard is hygroscopic, meaning it pulls that moisture into its fibers instead of shedding it. Fibers that take on water swell, the board softens, and the compressive strength that keeps a pallet standing drops. Industry guidance on frozen fish handling has long tied product protection to preventing dehydration and cold damage, and the box is the first line of that protection. Once a liner goes soft, nothing further down the chain recovers it. The block liner also works as a forming mold, not just a container. A 481 x 253 x 60 mm liner holds a 7.5 kg block at a flat, even height, which is what lets a master carton carry several units and a pallet carry a full load without leaning. The box at the bottom of that stack carries the weight of everything above it, and it does so at cold-store temperatures for weeks. Production controls matter here, including keeping board moisture content under 14% at the factory, so the paper starts dry and has room to absorb before it loses stiffness. Failures from excess moisture usually show up mid-shipment, not at packing.
The base configuration on a BEF GROUP block liner is food-grade PE film bonded to both the inside and the outside of 337G kraft or white coated paper. Waxing sits on top of that as an option, not as the default. These are two different barriers doing two different jobs, and keeping them separate in a quote is what lets a wholesaler offer a standard liner and a condensation-resistant liner to different customers without confusing either one. The film handles moisture migration. The wax handles water that lands on the surface.
PE film is a continuous plastic layer, so it blocks vapor instead of absorbing it. Paperboard barrier research describes exactly this mechanism: a laminate or coating on the board surface reduces how much moisture the fibers underneath can take up. On a block liner, the inner film faces the wet block and stops moisture from migrating into the board, while the outer film faces humid air and rubs against neighboring boxes during handling. The film is bonded with low-temperature glue rated for nominal -40 C conditions, so the layers hold together at freezer temperatures. The film itself is thin and adds no real stiffness; the 337G board behind it carries the load.
Wax changes the surface of the board so water beads and runs off rather than soaking in. That matters most in specific spots, not everywhere: repeated cold-store and dock transitions where the box sweats, humid processing rooms, wet gloves and wet pallet boards, boxes handled several times before loading, and boxes shipped as the outer pack rather than hidden inside a master carton. Where it earns less of its cost is a dry packing room, where a PE-lined liner goes straight into a master carton and never sees surface water. Wax is a surface treatment on top of the film, and it is an upgrade rather than a full saturation of the board.
The cleanest way to quote a wholesale waxed block liner is to build the sheet in two layers. The first layer is the standard box: double-sided food-grade PE film, 337G kraft or white coated paper, 481 x 253 x 60 mm for a 7.5 kg block, moisture content under 14%, low-temperature glue rated to nominal -40 C, and a choice of euro lid-and-bottom or fold type. The second layer is the optional wax, priced and listed as its own line. A waxed block liner manufacturer who keeps those lines separate makes it easy for a wholesaler to show two configurations to two different accounts without re-quoting from scratch. The decision points that actually change the answer are practical. How long does the box sit in the cold store before it ships, and does it ever leave the freezer? Is the packing room dry or humid? Is the box loaded by hand or by machine, and how many times is it touched after filling? Does the customer ship the liner inside a master carton, or does the liner travel as the outer pack? The 337G board handles a 7.5 kg block either way, and standard orders run at 1000 pcs per design for both the plain and waxed versions. Unbranded boxes run 5 to 7 working days, custom printed boxes 7 to 10, with delivery usually inside 7 to 15 working days after files and payment are set. Samples settle most of these questions faster than a specification sheet. Put a liner in a freezer overnight, move it to a humid room, and watch the surface. Look at how the film edges behave, whether the glue lines stay clean at the corners, and whether the board still feels rigid after a few hours. For a wholesaler holding stock for several export accounts, the useful quote format lists base PE film pricing and the waxed option side by side, along with box type, print, quantity and lead time. Send the block weight, target temperature, storage pattern and design file, and the configuration can be costed as a single line.
PE film and wax are not competing choices. Double-sided food-grade PE film is what every BEF GROUP block liner starts with, and wax is an add-on you buy when condensation and wet handling are real parts of the customer's route. Wholesalers who treat them as one bundle usually over-spec the dry accounts and under-spec the wet ones. Build the quote in two layers, test a sample in the conditions that matter, and confirm box type, print, MOQ and lead time before the order goes to production. Send the block weight, temperature range and design file to get a configuration priced for your batch.
A：A PE coated block liner has food-grade polyethylene film bonded to both the inside and outside of the board, and that film is the primary moisture barrier. A waxed liner box keeps the same double-sided PE film and adds a wax surface treatment on top, which helps water bead and run off during condensation and wet handling. The liner box is the same box; the second one simply carries an extra surface layer.
A：No. Double-sided food-grade PE film is the base configuration, and waxing is an optional upgrade ordered for specific conditions such as humid packing rooms or repeated freezer-to-dock movement. Both versions are quoted at 1000 pcs per design, so the price difference stays clear. If wax matters for your customer, it should appear as its own line on the order confirmation.
A：The 337G paper weight gives the liner its body behind the film. It is what holds the 481 x 253 x 60 mm shape around a 7.5 kg block and what carries stacked weight in a cold store. Because film adds almost no rigidity on its own, board weight and moisture content together decide how long the box stays firm, which is why it leaves production under 14% moisture.
TORRY ADVISORY NOTE No. 38 The composition of fish
BEF GROUP 7.5KG waxed block liner product data
