What is shrink film and how does it work?

How does it work?

Shrinkwrap (also referred to as shrink film or shrink wrap) is a versatile polymer material used for the packaging of finished goods. Heat is applied to the film – by either a conveyor heat tunnel or an electric or gas heat gun – which catalyzes the film to shrink tightly around the item placed within. This process results in a clear, durable barrier of protection around the product.

So, how exactly does this happen? The science of shrink wrap can be explained in terms of molecular behavior. The molecules of a shrink film sheet or tube are randomly intertwined, meaning they are coiled and twisted with no particular alignment. When the film is warmed, the structureless regions of the chains are straightened and aligned to the direction of orientation. More simply, the molecules reorient from their initial random pattern to ultimately fit the mold of their contents. When cooled properly, the film’s molecular characteristics are set, so it remains in this stretched state until sufficient heat energy is applied for the molecule chains to shrink back to their original form.

Characteristics of shrink film for product packaging

Below are 5 characteristics that detail some functions of shrink film. These are important to consider when using them for your product packaging.

Shrink force 

This is typically measured in PSI and tells you the amount of force that the shrink film will exert on your product. If you’re packaging a multi-pack that needs to be tightly contained without damaging, understanding your shrink force is very helpful, especially for adjusting your shrink machinery accordingly. If the shrink force is high and you’re packaging wood, this won’t matter.

Resistance to puncture / tear

This measures how hard it is to actually break the film, and how hard it is to tear the film once it has been punctured.

Often, films with high resistance to puncture have lower resistance to tear and vice versa. If you need to make this trade-off, select the character that is more important (e.g., if you have a window box, puncture resistance is very important). Choose a shrink film that balances the security of your product with ease of access to the actual product. Be sure to keep your shrink wrap stored in a cool (but not too cool) storage area to prevent any weakening of the film prior to use.

Read more: Protects fruit bunches of bananas

Moisture vapor transmission rate

This characteristic is a measure of how much moisture will or will not travel through the film.

If low moisture transmission into or out of your package is important, you should pay attention to this characteristic for improved shelf life. Something you will want to consider for this and to reduce or eliminate fog is modified atmosphere packaging.

Antifog

Antifog films are used on food (fresh and frozen) to mitigate moisture build-up on the film.

The moisture can cause a fog that affects the viewing of the product through the film. (If I’m buying something, you bet that I’m skipping over the fogged-up package for the one with the product I can actually see).

Odor barrier

Odor barrier films are used to prevent unacceptable odors from either traveling into or out of your package. Don’t disappoint your customers after they’ve purchased your product with a foul smell.

Why choose us?

Bao Ma Production & Trading Co Ltd is complying with the ISO 9001-2015 which ensures the quality control system and the ability to produce different materials and sizes of poly bags and rolls, including:

• Packing products for agricultural, aquatic, food consumption, industrial purposes.
• Zip-lock bag, shopping bag, garbage bag, plastic carriers.
• Plastic sheeting
• Perforated plastic roll
• Poly roll of 2m – 4m measurement for the use of lining prawn-raising ponds, for construction sites and sewage system usage, and as cover sheets for agricultural and industrial purposes.
• Printing services on packages of up to 6 colors with customization
• Trading various plastic raw materials such as PP, HDPE, LDPE, LLDPE…

So, please contact us via hotline: (028) 37540 999 – 096 314 5959 and let us be honored to serve you in the best way possible.

BAO MA PRODUCTION & TRADING COMPANY LIMITED

Address: No. 21 Tan Tao Industrial Park, Road No. 3, Tan Tao A Ward, Binh Tan District, HCMC

 Tel: (028) 37540 999 – 096 314 5959

 Email: info@poma.com.vn

 Website: www.poma.com.vn