When a customer tells me their film keeps splitting, the first thing I ask is not about the resin. It's where the split happens and when. That tells me almost everything.
Splits at the seal
If the film consistently splits right at or next to the seal bar, the seal is usually too hot, too cold, or held too long. An overheated seal can scorch and embrittle the film right at the edge of the bond, creating a weak point that fails under the lightest stress. Walk the seal temperature down in small steps before changing anything else.
Splits across the width
If the split runs across the film rather than along an edge, look at gauge variation first. A thin band running down the roll, even a fraction of a mil thinner than the surrounding film, becomes the failure point under tension. Check your gauge profile across the full width, not just at the center.
Splits in cold storage
If the failures only show up after the product sits in a freezer or a cold warehouse, the resin blend is probably too brittle at low temperature for the application. Standard LDPE and many LLDPE blends lose impact strength as temperature drops. A cold-resistant blend, or a higher percentage of metallocene LLDPE, usually solves this without changing gauge at all.
The short version
Seal location points to seal settings. A cross-web split points to gauge control. A cold-only failure points to resin selection. Most splitting complaints we get fall into one of those three buckets, and most get solved without re-engineering the whole structure.