Zhejiang Zhongcheng Packaging Material Co., Ltd

Stock code

002522

Language : EN
中文
What products and services do you need to know?

Why Do Packaging Films Frequently Tear & Shrink Unevenly?

2026-07-27 09:43:11 Zhejiang Zhongcheng Packaging Material Co., Ltd Viewd 17

Many manufacturers operating fully automatic heat shrink packaging lines encounter two prevalent issues: the film ruptures unexpectedly during high-speed sealing and cutting, and sharp edges puncture packaged goods. Finished products also suffer from partial wrinkles, uneven tightness across packages, blistering and whitening after heating. Many procurement teams assume these problems stem from improperly adjusted equipment temperature or conveyor speed, yet material waste remains high even after repeated parameter tweaks. In reality, these defects largely originate from differences in the material composition and structure of the film—specifically the two mainstream options on the market: regular POF heat shrink film and cross-linked POF heat shrink film.

Regular POF Heat Shrink Film

Standard Multi-Layer Co-Extrusion

Linear chains — no cross-links, basic intermolecular forces only

Regular POF film is manufactured via standard multi-layer co-extrusion. Its internal molecules are arranged in separate linear chains bonded only by basic intermolecular forces, lacking a stable network structure. This results in weak high-temperature resistance, tear resistance and puncture resistance, alongside a narrow temperature tolerance range. During high-speed automated sealing, uneven heating, or wrapping products with sharp edges, local tearing and bag breakage frequently occur in mass production. It also commonly causes uneven shrinkage, foggy film surfaces and loose wrinkling.

Cross-Linked POF Heat Shrink Film

Electron Beam Irradiation Cross-Linking

3-D network — stable cross-linked bonds between molecular chains

structure of cross-linked POF films

Cross-linked POF film's core differentiator is an additional electron beam irradiation cross-linking process, which restructures linear molecular chains into a three-dimensional network and boosts structural stability at the molecular level. Thanks to this unique cross-linked structure, cross-linked POF film features a far wider high-temperature tolerance range, delivering more consistent and stable heat shrinkage ideal for high-speed automated lines and high-temperature packaging workflows. Meanwhile, its tear, puncture and stretch resistance are drastically enhanced. It resists damage even when wrapping hard, angular goods or enduring friction during long-distance transportation, drastically cutting production waste.

Neither regular POF film nor cross-linked POF film is universally superior; their core gaps arise from structural upgrades enabled by cross-linking technology. Zhejiang Zhongda boasts a complete R&D and mass production system for both regular and cross-linked POF films, continuously refining formula and process standards for both film types backed by long-term material test data. Industry practitioners can select the appropriate film type based on their line speed, product shape and storage & distribution conditions to reduce packaging waste from the raw material stage and improve overall packaging stability and aesthetics.

Zhejiang Zhongda — complete R&D and production for both regular and cross-linked POF film, with long-term material test data to back every recommendation.

Contact us
  • captcha
×