Shrink wrap packaging can be made of several different kinds of plastics, and depending on the application usage, it can be of different thickness, clarities, strengths, and shrink- ratios. The shrink wrap shrinks over the product on the application of heat, conforming to the shape of the product being wrapped.
Different Compositions of Shrink Wraps
The shrink wrap compositions available are polyvinyl chloride (PVC) shrink wrap, polyolefin (POF) shrink wrap, and polyethylene (PE) shrink wrap. There are slight differences in the materials used for the different types of shrink wraps and the choice of wrap depends on what product is being packaged.
Polyvinyl Chloride (PVC) Shrink Wrap
PVC shrink wrap is a lightweight, thin, pliable, and cheapest form of packing material and is mostly used for lightweight retail packaging. It is often used to wrap CDs, books, and more. It shrinks only in one direction and is highly resistant to tearing or puncturing.
The presence of chloride in the shrink wrap does not make it an ideal packaging material for the packing of edible products. Also, as it emits toxic fumes during heating and sealing, and the generation of harmful by-products released during its creation, and decomposition, PVC has been banned in many countries. It is not able to bear extreme heat or cold thus hampering the strength of the seal and the plastic.
Polyolefin (POF) Shrink Wrap
Polyolefin has slowly started replacing PVC as a packing material and is an extremely durable and versatile material. It is used to package both edible and non-edible products. Polyolefin can be stored in a wide range of temperatures without affecting the durability of the packaging and is made up of 100 per cent recyclable materials.
Polyolefin is more expensive than PVC shrink wrap and sometimes, tiny holes need to be added to the wrap before application to allow air to escape during the shrinking process.
Polyethylene (PE) Shrink Wrap
Polyethylene is a stronger and more durable type of shrink wrap packaging. They can reach a gauge thickness of up to 1200 and are also printable. With different forms of polyethylene available like LDPE or Low-density Polyethylene, LLDPE or Linear Low-density Polyethylene, and HDPE or High-density polyethylene, they are mostly used for industrial applications. The LDPE form is most commonly used for shrink film packaging.
PE shrink wrap does not have a high shrink rate, usually around 20 per cent, and it has a lower clarity. The application process requires more prolonged heat exposure to shrink fully and is not conducive for packaging heat-sensitive products.
The shrink wrap material can be modified for specific purposes like UV protection, flame retardant, or have antimicrobial treatments that protect wrapped objects from mold and mildew. It can even have additives like volatile corrosion inhibitors (VCIs) to keep metal-based cargo from corroding due to exposure to moisture.
Application of Shrink Wrap
Shrink wrap are also available in various formats like shrink sleeves, secondary packaging, pallet shrink wraps, centrefold shrink wrap, and many more.
A shrink sleeve label consists of a heat-sensitive material that shrinks and conforms to the shape of a bottle or container when exposed to heat. It is frequently used in the FMCG industry especially in home and personal care products. These products need to be sealed with a tamper-evident label. Normally made from Polyvinyl chloride (PVC) or Polyethylene Terephthalate Glycol-modified (PETG), these sleeves not only act as a tamper-deterrent seal but also due to their printable ability, it can provide branding awareness of the product.
Secondary packaging helps to promote the products to the consumers as this level of packaging will be the first to be seen by the consumer. Secondary packaging is the exterior packaging that protects the primary packaging. Shrink wrap helps to secure multi-batch products, create easy-to-apply labels with information like barcoding, product details, and many more onto the products.
Pallet shrink wraps are used to stabilise and protect pallet loads. It helps to reduce product loss, discourage load tampering, and reduce worker injury. Shrink banding is used around the cap of many medicines and toiletry bottles to create a safety seal. Shrink tubing and shrink bags offer ways for a product to easily be sealed and shrink wrapped with minimal effort.
When deciding on the type of shrink wrap to be used for your product, the cost is a huge factor. The positive qualities of shrink wrap packaging make it the best choice for food, beverage, and consumer product packaging.