13 Reference Standards for Polyethylene Plastic Packaging Film

PE plastic packaging film is made from film-grade polyethylene pellets, processed into a fixed film form with a thickness of 0.002-0.3 mm by blown film or cast film extrusion. With the growing popularity of plastic packaging products, PE plastic packaging film occupies an increasingly large market share and is widely used in hardware and machinery, auto parts, logistics and express delivery, furniture and home appliances, food and pharmaceuticals, clothing and chemicals, and many other industries, bringing great convenience to people's lives.

Different types of plastic packaging film have different properties. When selecting, we need to consider several basic functions of plastic packaging film, mainly the protective function for goods, the promotional function, adaptability to packaging machinery, and other special application requirements, which are divided into the following 13 items, referred to as the 13 reference standards:

1. Protective function

As a packaging material, the protective function of plastic film for goods is the most important and most basic function. If plastic film does not reliably protect the packaged goods and causes damage or depreciation of the goods, it loses its value as a packaging material. The protective function of plastic film for goods is multifaceted; different goods and different packaging forms place different emphases on the protective function requirements of plastic packaging film.

1. Mechanical protection

Prevent leakage of the goods inside the package or the entry of external substances that may damage and contaminate the goods. The performance indicators that directly reflect the mechanical protection function of plastic film are mainly the mechanical strength of the film, such as tensile strength, tear strength, falling-dart impact strength (falling-dart impact), and puncture resistance.

1. Good heat-seal strength

Heat-seal strength is also a necessary condition for plastic film bags to reliably protect goods. If the seal strength is insufficient, the seal seam will become the fatal weakness of the plastic film bag, and the rupture of the seal seam will cause the plastic bag to lose its protective function for goods.

1. Barrier performance

Barrier performance refers to the ability of plastic film to prevent the permeation of gases such as oxygen, carbon dioxide, and nitrogen, as well as aroma, water vapor, and other substances. When the scope is not specified, it generally refers to the barrier against non-polar gases such as oxygen, carbon dioxide, and nitrogen. The quality of the display effect of plastic film on goods is closely related to the film's light transmittance, haze, gloss, anti-static property, printability, etc., and sufficient attention needs to be paid to light transmittance and haze.

1. Light transmittance and haze

Light transmittance and haze are important indicators that determine the visibility and clarity of packaged goods, and have a particularly large impact on the display effect of goods. Both light transmittance and haze are expressed as percentages. The larger the light transmittance value, the better the transparency of the film; the larger the haze, the greater the turbidity when observing objects through the film, that is, the worse the clarity.

1. Gloss

Gloss indicates the ability of plastic film to reflect light when exposed to light, expressed as the percentage of the reflected light intensity in the specular reflection direction relative to that of a standard surface.

1. Anti-static property

With the rapid development of the electronics industry, the integration level of electronic circuit boards is becoming higher and higher. Packaging products with anti-static film can avoid damage to integrated circuits from static electricity.

1. Good slip property

Good slip property facilitates the smooth movement of film on the packaging production line during packaging, avoiding damage due to excessive resistance during movement. The slip property of film can be described by its coefficient of friction. The smaller the coefficient of friction, the better the slip property.

1. High-temperature resistance

What often needs to be considered is the high- and low-temperature resistance of the film. For example, plastic packaging film used for refrigerated and especially frozen foods needs to have good low-temperature resistance; plastic packaging film used for retort foods needs to have good high-temperature resistance, and so on.

1. Hygiene performance

When packaging food or pharmaceuticals, the selected plastic packaging film must have good hygiene performance and meet the requirements of relevant national hygiene standards, so as to ensure that the plastic film will not contaminate the packaged goods.

1. Airtightness

Good airtightness can effectively block the exchange of gases inside and outside the packaging container, which is necessary for most products.

1. Moisture resistance

Good moisture resistance is a means of effectively protecting goods. Generally, the moisture resistance of plastic film increases with increasing thickness and decreases with decreasing temperature.

1. Oil resistance

For oily foods such as sausages and cured meat, the packaging film must be oil-resistant; otherwise, product quality will be affected.