1. Check Raw Materials: Distinguish Virgin Resin from Recycled Resin

Prioritize brand-new virgin LDPE/LLDPE pellets, which feature high clarity and no black specks or impurities.

General warehouse lining: Standard virgin resin is sufficient.
Feeding for chemical and rubber/plastic processing: Opt for high-purity virgin resin with zero extractables.
Avoid recycled resin bags: They have poor transparency, tear easily and contain contaminants, making them unfit for production feeding.
Special requirement for internal mixer feeding: Select low-melting-point modified PE formulations directly.

2. Select Gauge Based on Loading Weight

Thickness directly determines load-bearing capacity and puncture resistance. Thicker films offer better tensile strength but come at a higher cost.

Materials weighing 5–15 kg: 0.05–0.08 mm
Materials weighing 15–30 kg: 0.08–0.12 mm
Heavy loads (30–50 kg) or sharp granules: Heavy-duty 0.12–0.20 mm
For bulk bag liners: Minimum 0.10 mm to prevent tearing during filling and pulling.

As liners for bulk bags/cartons: Add 10–15 cm to both width and height of the outer container for easy unfolding and fitting, and reserve ample flange space at the bag opening.
Standalone direct packaging: Bags expand once filled. Oversize both length and width by 15–20% relative to the actual material dimensions to avoid seal rupture during filling.

Never order bags cut exactly to material dimensions; insufficient clearance leads to difficult filling and bag bursting.

Heat sealing: Choose LDPE with superior heat-seal performance if thermal heat seaming is required post-filling.
Tied with rope/cable ties: Request tear notches for effortless opening.
Bulk bag liners: Vent holes may be specified to release trapped air for full, compact filling.
Production feeding: No perforations allowed to keep the bag intact for whole-bag feeding into internal mixers.
Material identification marking: Custom printing of logos and batch numbers is available.

Liners for bulk bags of plastic pellets/compounds: Virgin resin, 0.10–0.14 mm gauge, oversize for fitting allowance, optional micro vents.
Standalone packaging for chemical powder additives: Heavy-gauge puncture-resistant film with strong heat seals and high clarity for visual batch differentiation.
Feeding bags for rubber/plastic internal mixers: Custom low-melting-point PE, zero extractables and impurities, no perforations permitted.
Protective packaging for hardware parts: Medium gauge, prioritizing scratch and abrasion resistance.

Visual check: Clear, transparent film free of crystal spots and black specks.
Tensile test: Moderate pulling with both hands with no easy tearing.
Seal inspection: Fully formed heat seals with no incomplete sealing, no powder or air leakage.