- Polyolefin Vs Polyethylene Vs PVC
Each type of shrink film mentioned above has been co-extruded.
Co-extrusion is a manufacturing process used to create multi-layered films by extruding multiple layers of materials together.
The principle behind co-extrusion is that it allows for the combination of different materials, each with its unique properties, to create a film that combines these properties.
The process involves feeding multiple extruders with different types of plastic and then combining the molten materials into a single, multi-layered film.
In recent years, for instance, certain metallocene polyethylenes and linear low-density polyethylenes(LLDPE) have been shown to exhibit good lateral shrinkage qualities in addition to great mechanical capabilities.
As a result, many new high-strength PE shrink films with high levels of transparency have recently entered the market.
Top tier manufacturers will give custom shrink wrapping solutions based on the actual needs of end users.
- The summary of each shrinkable film：
Polyolefin Shrink Wrap:
1. Environmentally friendly and non-toxic, polyolefin shrink wrap conforms to FDA and USDA requirements and can be used to package food.
2. The shrinkage rate is high, typically 60% or more (with the cross-linked film reaching 80%), and the flexibility is greater.
3. Superb Clarity, nice gloss, can clearly depict the product’s appearance.
4. Perfect for grouping together various things, such as tissue boxes.
5. Strong Resistant to Punctures.
6. Despite exposure to temperatures as low as -50 degrees Fahrenheit, the material retains its pliability and shows no signs of fragile.
PE Shrink Wrap:
1. Good for lower-end applications and unitization (24-pack of waters).
2. Uses include huge, heavy goods such as the bundling of multiple water bottles.
3. It’s easy to print and the images look amazing.
PVC Shrink Wrap:
1. The Chloride in PVC shrink film generates a distinct stench when heated and cooled. Since it is not eco-friendly, the market has gradually phased it out.
2. Due of its increased brittleness after shrinking, this material is unsuitable for grouping many components.
- Various performance comparisons:
1. Comparison of physical properties
POF has excellent moisture resistance, a uniform thickness, a soft texture, a strong tensile strength and a resistance to tearing, a shrinkage range that can be adjusted, and strong friction resistance.
PE has consistent thickness, is moisture-resistant, feels soft to the touch, has a lower tear strength than polyolefin (POF), but a lot greater tear strength than polyvinyl chloride (PVC), and has a significantly lower friction resistance than POF.
PVC is thick, irregular in thickness, hard and brittle in texture, low in strength, low in shrinkage, and poor in friction resistance.
2. Comparison of cold resistance
Since POF shrinkable film is not hard or brittle at -50 degrees Celsius and is not easily broken, it is suitable for the packaging of frozen foods. Long-term storage at -50 to -95 degrees Celsius will not affect the integrity of the shrunken packaging. It is difficult to contaminate the dust and maintain products freshness with static electricity anti-fog treatment.
The PE shrinkable wrap performs well in the cold. It retains its integrity after being frozen and can be transported without fear of cracking. Static electricity elimination treatment helps prevent the accumulation of dust and dirt, allowing the product to remain pristine.
It is difficult to transport PVC shrink film without it breaking due to its brittleness in the cold or when it has been frozen. It’s not compatible with static removal treatment, and it’s easy to get dust on it, which can mess with how your products seem on display.
3.Comparing processing performance
POF processing produces no gas, does not adhere to seals, and is simple to maintain and run. Ideal for automatic packing on high-speed production lines because to its excellent tenacity, smoothness, and friction resistance.
PE processing does not generate gas, does not adhere to seals, and is simple to operate and maintain. Superior tensile strength, appropriate for automatic packaging on high-speed production lines;
The processing of PVC will produce toxic gas that does not satisfy environmental protection standards and is likely to cause mechanical damage, it is easy build up on sealing components during shrink wrapping, and challenging to maintain.
4. Security evaluation
After POF shrink wrapping, the seal’s four corners are soft, won’t hurt hands, and are resistant to friction.
After PE shrink wrapping, the seal’s four corners are soft and will not harm the hands.
After shrink wrapping with PVC, the four corners of the seal are hard, making it easy for hands to be injured.
5. Environmental safeguards and hygiene
POF is non-toxic, does not emit a toxic odor during processing, and conforms to FDA and USDA regulations.
PE is non-toxic, produces no toxic gases during processing, and conforms to FDA and USDA standards.
PVC is toxic and will produce a peculiar odor during processing, so its use is being phased out gradually.