Resin and resin combinations used for a specific food and pharmaceutical packaging is subject to government regulation in Canada and the US (Canadian Food Inspection Agency in Canada, Food and Drug Administration in the US).

Once we understand the specification of your packaging project, we ensure that your packaging complies with the applicable government regulations.

Bottom gusset poly bags are created by pushing the bottom, closed end of a flat plastic bag up, into the bag interior making a pleat at the bottom of the bag.

Bottom gusset bags are side-welded by default. The size of the bottom gusset is measured across the open or unfolded dimension.

Bottom-seal Poly Bags have a heat seal across the width at the bottom. This product is manufactured by making a seal about 1/4" up from the bottom.

Cellophane (Cello) is a high clarity film with the density and thickness of paper. It is made out of cellulose, a wood product, so its properties are very similar to paper.

It looks like Polypropelyne and the way to tell them apart is if you twist the cello film, it will not bounce back. It will stay twist just like paper does. Cello is very expensive to produce so we are slowly phasing out this product.

EVA Freezer Film is made by using Low Density Polyethylene (LDPE) that typically contains EVA (Ethyl Vinyl Acetate) which maintains pliability at low temperatures.

The flat poly bag is the most basic of the different poly bag types. No gussets (folds or pleats), therefore they can be either side-welded or bottom-sealed.

Flat plastic bags have a width and a length dimension and one open end measured across the width. Sleeves are as side-welded flat bags, but they have two openings.

Film for frozen food applications requires the highest quality and tight specifications regarding a heat seal initiation temperature (lowest temp required to make a good seal, the lower the better.)

Slip level (proper slip level so the film will travel freely on the vertical form $& fill machines – VFF) and film Gauge variance to be under 10% (for printing high end process jobs). Very important is the opaqueness when making white film and high clarity when making clear film. All frozen food film are made in a co-extruder in a 3 layer structure.

Outside and inside layers will have mLLD/LDPE blend for sealing. Middle layer can be the same or use some reclaim material.

The term "mil" is used in reference to the thickness of the plastic film. It expresses thousandths of an inch as a whole number. Thus, 2.5 mil is one and one half thousandths of an inch or .0025".

When this measurement is given in a bag dimension, it refers to the thickness of the film for one side of the poly bag.

All our normal resin has slip and anti block added so that the plastic bags we manufacture can be opened easily. Some applications need to use non-slip resin. For example, coin bags and soil bags. Customers who require no-slip bags so that they will not slide out too easily.

There is an overwhelmingly wide range of plastic resin options and combinations available for your plastic film or poly bag. To ensure optimal outcome for your poly bag project, please contact a Polynova sales engineer to discuss the ideal configuration of your resin.

Film Clarity or "Gloss" can be achieved with additives like EVA or Metallocene blended into the base polyethylene resin. Shiny / glossy film has better optics for retail packaging with either clear or colored films or in any application where appearance is important. Depending on the purpose of your packaging, it may be essential to choose between either clarity or strength.

Most polyethylene films that are tough, strong and resist punctures or tearing are not very clear or glossy. This packaging has a more or less milky appearance. However, there are resin combinations that can improve the shine / gloss / clarity, but typically, if a bag is very tough strong it is also more translucent than transparent.

Low Density Polyethylene (LDPE) can normally be identified by its softer feel, shinier appearance and more muffled sound when it is handled while High Density Polyethylene (HDPE) typically has a matte finish, and feels and sounds more like slippery tissue paper. This is a very general comparison since both HDPE and LDPE can each be modified to have characteristics of the other.

Plastic freezer bags, most of the time, are made of a blend of Metallocene Linear Low Density Polyethylene (mLLD) and Low Density Polyethylene film. The mLLD will improve film toughness and not crack easily during freezing.

LDPE – Low Density Polyethylene: In 95% of our production, we are using a resin combination that contains LDPE. It has a soft feel to it and is very stretchy and pliable.

LLD-Linear Low Density: It is a different version of the LD resin. We normally blend this in with LDPE to increase toughness stong and improve seals.

mLLD – Metallocene Linear Low Density Polyethylene: Resin this is the newest high performance LLD resin. It will drastically improve toughness of the film; it can be sealed at a lower temperature and not easily burned through. We are using mLLD now to replace LLD.

HDPE – High Density Polyethylene: Crinkly when touched. Most of the supermarket t-shirt handle bags are made of HDPE. They are stronger and can be produced very thin (less than 1 mil) Unit for measurement for HD usually in microns (25micron = 1mil) With the installation of the new extrusion line, we will make more HD film. A natural color of the HD film is called frosty because it is not high clarity like the LD film.

Polypropylene (PP) film is a very high clarity, stiff and crinkly film mainly used for food packaging because it has a higher clarity than LDPE.

We cannot make PP film but we stock different size PP tubing (3” to 9”) and convert bags to size. (Bottom seal only) We can also purchase PP sheeting locally for roll stock orders. Most of the PP orders are imports.

Side-gusseted poly bags are created by pushing the side edges of a flat poly bag into the bag interior, making a pleat along both sides of the bag. Side gusset bags are bottom-sealed by default. The size of the side-gusset is measured across its open or unfolded length.

Plastic bags that have a heat sealed edge along the length of each side. They are manufactured by sealing the sides of the bags.