Picking the wrong stretch film costs more than the roll — it shows up as film breaks at the pallet corner, load shift in transit, and a 2-4% scrap rate that nobody budgeted. Five spec gates separate a working pallet wrap from a 2026 spec-grade one: resin type, gauge, pre-stretch ratio, cling configuration, and roll geometry [S1].
The category covers hand rolls (typically 17-23 µm, 400-500 mm width, 250-300 m length) and machine rolls (typically 20-35 µm, 500-1000 mm width, 1500-3000 m length). Current 2026 offerings from European packagers and Chinese OEM lines (1/2/3/5/7-layer coextrusion) cover the full spread [S1][S3].
Resin and Layer Count: LLDPE on a 5-7 Layer Coex Line
Linear low-density polyethylene (LLDPE) from C4/C6/C8 catalysts is the dominant resin for pallet stretch film, with melt index typically 1.0-3.0 g/10 min and density 0.918-0.922 g/cm³ [S1]. The 5-layer and 7-layer coextrusion lines now common at Chinese OEM shops allow positioning of different LLDPE grades (or mPE metallocene skins) at the core, cling, and outer slip layers independently [S1].
2- and 3-layer lines still produce economy-grade hand film; 5- and 7-layer configurations are the new default for machine-grade film where puncture and tear resistance in the cross-direction (TD) matter, because alternating stiff/ductile layers suppress zippering under pre-stretch [S1]. Buyers specifying 17 µm machine film with 250% pre-stretch should confirm the line is at least 5-layer, otherwise TD tear will dominate the failure mode.
Gauge, Pre-Stretch, and the Hand vs Machine Cut
Hand-grade stretch film typically runs 17-23 µm (about 60-80 gauge), with hand-roll stretch capacity of 75-150% before necking; machine-grade film runs 20-35 µm with pre-stretch capability of 200-300% on a powered prestretch carriage [S1][S2].
That ratio is why European distributors like Cierpronti position machine-grade film as the high-performance line and reserve hand rolls for low-volume or odd-shape skids [S2].
Cling Configuration: Single-Side vs Double-Side, and Noise
Stretch film is produced as single-side cling (cling on the inside of the roll only, slip on the outside for pallet-to-pallet stacking without blocking) or double-side cling (cling on both faces, used where the film contacts itself repeatedly on irregular loads) [S3]. The cling additive is typically a polyisobutylene (PIB) or a metallocene-based tackifier dosed at 1-5% in the skin layer; higher PIB loads boost cling but raise the unwind noise and can transfer to adjacent surfaces.
For cold-chain or refrigerated loads (2-8 °C), specify a low-temperature cling variant — standard PIB cling drops off sharply below 5 °C and the film starts to telescoping on the roll.
Roll Geometry: Core ID, Width, and Pallet-Stack Fit
Core inner diameter is 50 mm (European hand-roll standard) or 76 mm (machine-roll and US hand-roll standard); a mismatched core ID is the most common reason a hand roll won't fit a wrapper's carriage [S1][S4]. Roll width runs 400-500 mm for hand and 500-1000 mm for machine; Chinese OEM lines offer 1000/1500/2000 mm wide machine film as catalog standard widths [S1].
Outer roll diameter is typically 250-300 mm for hand rolls and 350-450 mm for machine rolls, capped by the wrapper's carriage geometry. Buyers should match the roll OD to the carriage's max OD spec — exceeding it causes film tension spikes at the core and breaks at the clamp [S1]. For unitization of 1200×800 mm Euro pallets, a 500 mm film width with 2-3 wrap revolutions at the corners is the typical cycle.
Use-Case Fit: Load Profile, Machine Type, and Cost Levers
Hand film fits operations below 30 pallets/day with mixed load sizes, where wrapper capex is unjustified; machine film pays back above 50 pallets/day on a turntable or ring wrapper [S2][S3]. Specialized variants include silage film (wider, 750-1500 mm, UV-stabilized for forage bale wrapping) and PE cast film for non-pallet applications — both appear as separate machine lines at OEM catalogs [S1].
Cost levers, in order of impact: pre-stretch ratio > gauge > layer count > cling configuration. For 2026 spec work, the stretch film encyclopedia reference gives the full resin-and-process breakdown behind these ratios. Buyers also cross-reference this against palletizer and wrapper controls — see the solenoid coils vs electric ball valves spec cut for the pneumatic side of automated wrapper carriages, which is where film-tension regulation actually lives.
Failure Modes and What Spec Gate Catches Them
Film breaks at the corner usually point to insufficient TD tear (spec gate: 5-layer coex with mPE skin) or wrong pre-stretch setting (spec gate: carriage calibration, not the film). Load shift in transit usually points to low holding force, traced to either gauge under-spec or insufficient cling transfer — double-side cling at 3-5% PIB fixes the second; the first is a resin upgrade [S3].
Telescoping rolls on storage point to a 50/76 mm core mismatch or a low unwind tension spec; blocking (film fused to itself) points to a slip-side formulation issue, typically an overloaded cling additive or wrong anti-block loading in the outer layer [S1][S2]. A spec gate on the datasheet should call out core ID, cling side, and slip coefficient (static COF 0.2-0.4 is the typical target for pallet-to-pallet stacking without sliding). For teams also specifying other 2026 capex lines, the gantry crane spec gate primer is a useful cross-reference on how a 4-5 gate spec sheet is structured across categories.
Both will reshape the spec gates above by mid-2027.
For component-level specifications, see pressure transmitter, and flow meter.