Automatic packaging machine experiencing film jamming or uneven shrinkage? Choose the right heat shrink film by considering these three key parameters.
In automated packaging production, the selection of heat shrink film directly impacts production efficiency and packaging quality. Many companies have encountered similar problems: frequent film jamming in the packaging machine, uneven surface after shrinking, or even film breakage—which not only slows down production but can also affect the product's appearance and protective performance. In fact, these problems are often not due to equipment malfunction, but rather because the key parameters of the heat shrink film do not match the equipment or the product.
Today, we'll help you choose the perfect film by focusing on three key parameters, ensuring a smooth packaging process and flawless results.
I. Thickness: Balancing protection and machine compatibility
The thickness of heat shrink film directly affects its mechanical strength and smooth running through the machine. If the film is too thin, it is easily torn or punctured during the conveying or shrinking process, leading to film jamming or package leakage; if the film is too thick, its excessive rigidity and difficulty in flattening can cause jamming during pre-sealing or conveying, while also increasing material costs.
Suggestion:
• For lightweight products (such as cardboard boxes and small household goods), 15–19μm film is recommended;
• For heavier or products with sharp edges (such as hardware and full cases of beverages), 23–30μm film is recommended, and ensure even film tension to reduce stretching and deformation.
II. Heat sealing performance: Determines the strength of the seal and the ease of opening.
The formulation and processing of the heat-seal layer material directly affect the sealing and cutting performance of the film on automatic packaging machines. If the heat-sealing temperature range is too narrow or the sealing strength is insufficient, it can easily lead to poor transverse sealing, improper opening, and subsequent film jamming or tearing after shrinkage.
Key indicators:
• Heat seal strength: Ensures sufficient tensile strength immediately after heat sealing to prevent tearing during transfer between workstations;
• Opening force: Requires a balance between "easy opening" and "no cracking during transport," preventing difficulties in film feeding due to static electricity or adhesion.
III. Shrinkage Rate and Heat Shrink Temperature: Key Factors for a Uniform and Snug Fit
Uneven shrinkage, wrinkles, or "fish-eye" patterns are often caused by a mismatch in the transverse and longitudinal shrinkage rates of the film, or by an excessively wide heat shrinkage temperature window. If the film cannot shrink uniformly at the set temperature, localized overheating or undercooling will affect the flatness of the surface.
How to match:
• Choosing a film with balanced bidirectional shrinkage (such as an aspect ratio close to 1:1) can significantly reduce localized wrinkling;
• Prioritizing films with low-temperature, high-shrinkage properties (such as POF) allows for rapid and uniform shrinkage at lower temperatures (typically 130℃), reducing uneven shrinkage caused by temperature differences, while also saving energy and reducing costs.
Whether automatic packaging is smooth and the shrink wrap is even is never solely dependent on the equipment. Thickness, heat sealing performance, and shrinkage rate—these three parameters are like the "identity card" of the heat shrink film, determining whether it can work perfectly with your equipment and products.
As a domestic enterprise specializing in the research and production of high-performance heat shrink film, Mingca Packing deeply understands the pain points in production lines. We not only provide multi-material shrink films such as POF, PEF, and PCR POF that meet international standards, but we can also customize the appropriate thickness, shrinkage rate, and heat sealing formula according to your equipment model, product shape, and speed requirements. This helps you reduce film jamming, improve shrinkage uniformity, and enhance overall packaging performance from the source.
If you are struggling with packaging efficiency or product presentation, please contact the Mingca team for free samples and professional technical solutions – let packaging truly become a seamless part of your efficient production process.