Presentation and retail bags are better moisture barrier, clearer and stronger. It is one the best choices for product presentation and preserving product freshness when used for a food service application.
How presentation / retail bags are made
Presentation and retail bags are mainly made from high clarity polypropylene or cellophane. However, polypropylene have the advantage of being less expensive than cellophane (cello) bags.
Polypropylene film is either made under BOPP (biaxially oriented PP) or Cast film extrusion process. The major portion of this is Biaxially Oriented PP (BOPP) film, however cast films are an important segment as well.
Bi-Oriented Polypropylene (BOPP) refers to the manufacture of polypropylene films using an orienting system. BOPP films are manufactured using a tenter frame sequential process or the double bubble process, in which a polypropylene (PP) film is oriented in two directions (machine and transverse directions). BOPP films are typically used for packaging snacks, pasta, and confectionery goods, and as collation wrap for multi-packs.
The main features of BOPP films are improved stiffness, high tensile strength, excellent optics and good water vapour barrier properties. BOPP films range from 15 to 50 microns and are most commonly 15 to 30 microns. BOPP films can be monolayer or co-extruded structures, and transparent, opaque, or metallized. The films use mainly homopolymer PP and random copolymer PP.
The cast film process involves the extrusion of polymers melted through a slot or flat die to form a thin, molten sheet or film. This film is "pinned" to the surface of a chill roll (typically water-cooled and chrome-plated) by a blast of air from an air knife or vacuum box. The film quenches immediately and then has its edges slit prior to winding.
Cast film extrusion offers better gauge control and gauge consistency, which are critical for thin films below 1 mil (25 microns). Lastly, optical properties such as gloss and haze percentage are typically better for any given material when produced on cast film However, it has the disadvantage of higher scrap due to edge-trim, and very little film orientation in the cross-direction.
Cast films are used in a variety of markets and applications, including stretch/cling films, personal care films, bakery films, and high clarity films.
Options for presentation & retail display bags
- Clear or Coloured Polypropylene bag/film - Standard polypropylene bag either clear or coloured (tint, opaque)
- Plain or Printed Polypropylene bag/film - Standard polypropylene bag either plain or printed (1, 2 or multicoloured)
- Flat polypropylene bags - Standard plastic bag with seal on the bottom and opening at top, often called as flat bags
- Gusseted polypropylene bags - Polypropylene bags with fitted bottom and expandable sides (gusset) form to the shape of your product called as 'Side gusseted bag'. Also bag with fixed sides with expanded bottom referred to as 'Bottom gusseted bag'.
- Reclosable polypropylene bags - Reclosable bags have a simple plastic ridge that clicks shut and pulls open for continual re-use.
- Peel n' seal polypropylene bags - Polypropylene bags with a resealable adhesive strip already attached for convenience - just peel and seal! Peel back release strip and fold to seal on short side of the bag.
- Bags on roll - Bags attached by perforation and rolled up on a core
- Polypropylene Film on a roll - Polypropylene film wounded on a standard core
Major UK suppliers:
Advantages of Polypropylene bags/film
- Cheaper than cellophane - Polypropylene bags are great value for money! And a better alternative to Cellophane bags
- Excellent clarity - Polypropylene is typically used in applications where maximum clarity is desired, such as candy pack aging, greeting cards, art prints, etc.
- Moisture and grease resistant
- Preserves freshness and taste of the content
- Available as food-use approved
- Best in high temperature resistance
- Stiffer and stronger - Polypropylene bags feel stronger and stiffer in a same thickness comparison
- Also offers high temperature resistance - does not start to soften until about 270 degree Fahrenheit
Standards for polypropylene bags to use for food contact and medical application
Food Contact - To use Polypropylene bags inside European Union, in contact with food should comply with the relevant legislation on food contact including Great Britain.
- Great Britain: Statutory Instrument, 1998 No. 1376 and BPF-BIBRA (1995), Polymer Specification 4, Polyethylene
- EU: Commission Directive 90/128/EEC, 92/39/EEC, 93/9/EEC, 95/3/EEC and 96/11/EC, Section A.
- Example of a company comply with food contact: Polybags Limited
Medical use - Similarly, to use Polypropylene bags inside European Union, to produce containers for preparations for medico-pharmaceutical purposes should comply with the following regulation:
- European Pharmacopoeia - Monograph 3.1.3 "Polyolefin's" for medico-pharmaceutical purposes.
- The final responsibility for the decision of whether a material is fit for a particular application lies with the pharmaceutical firm.
- Example of a company comply with medical use: Polybags Limited
80 Gauge (20microns) to 1000 Gauge (250microns)
Common materials used for presentation / retail bags:
- Plastics - Polypropylene and Cellophane
- Recycled polypropylene bags
Normally, Polypropylene bags in Great Britain should follow widely accepted industrial standards according to British Standard - see BS7344, 1990
- Width: Plus or minus 3mm (0.125") or 2% whichever is greater
- Length: Plus or minus 6mm (0.25") or 2% whichever is greater
- Gauge: Plus or minus 10%
Polypropylene bags must be heat sealed, taped or tied for closure to protect the content within.
Common uses of presentation and retail bags
- Floral/basket wrap
- Magazine overwrapping
- Media packaging (CD, DVD)
- Greeting card bags
- Flower sleeves
- Candy sweet bags
- Display bags(cookies, portraits, t-shirts, artwork, dress, shirts, calendar)
- Clear wrapping film