You have heard of 12 mil polyethylene sheeting, but what are its uses? It depends if you are looking at a scrim (string) reinforced liner, or plain Construction and Agricultural grade plastic.
For the purposes of this article, let us look at a heavy-duty scrim reinforced, tear resistant, high strength virgin polyethylene film. As you may have read from our prior article (Is your resin a virgin- should you care?), virgin resin is what you want to do the following jobs well. If you are going to use this 12 mil liner as a vapor retarder, then you want a liner that meets or exceeds ASTM E-1745 Class “C” standard. This standard is for water vapor retarders that are used in contact with soil or granular fill under concrete slabs. In some of the jobs mentioned below, this 12 mil plastic sheeting will be exposed to outdoor elements. For that reason you will want a liner that contains UV additives and thermal stabilizers.
Great uses for a 12 mil Scrim Reinforced Polyethylene are:
Crawlspace and Basement liners: Protects the interior or your home from moisture migration
Cargo Coverings: For covering cargo on a truck, on a train or on Ships.
Pond and Pit Liners: Our 12 mil liners are guaranteed fish and plant safe, and available in very large sheets, with factory certified seams.
Temporary Earthen Liners : Excellent for most short-term lining applications
Temporary Rainshed Covers: special long-term version can be used for terms as long as 4+ years
Landfill Covers: Both daily and interim lands fill covers will benefit from the strength of the scrim reinforcement. Long-term special version lasts 4+ years in fully exposed conditions.
Temporary Erosion Control- Control watershed with this heavy duty reinforced film. Holds up well in the elements, because of UV inhibitors and thermal stabilizers
Remediation Liners or Covers: Depending on contaminants and levels of contamination, this can be a very cost effective liner and covering material for soil remediation.
Divider Curtains: Available in many widths and lengths, this film makes for an excellent divider curtain. Also see Dura Skrim 2FR, 10FR, Poly Scrim 6FR, 8FR, 10FR, and 14FR if fire retardant curtains are needed.
Vapor Retarders for under slabs and in walls: often used as a vapor/moisture retarder underslab and within wall structures, both, commercially and residentially.
What is meant when someone mentions “flexible plastic sheeting” ? What kinds of “flexible plastic sheeting” is there? Are there different types? In its simplest terms, the main difference between the different types of plastic is the way their cellular structure, or molecules bond with each other, and how tightly they are formed.
Which is the most flexible of them all?
Linear Low Density Polyethylene (LLDPE) is the most flexible of the plastic sheeting films. LLDPE is blended form of LDPE where the film has much more flexibility, tensile strength, and more conformability. It is more pliable and softer. LLDPE is used for pond liners or blended into other films to give them more flexibility and extra strength. LLDPE is used for films that need a tremendous amount of strength to absorb impacts while not tearing or puncturing. An example of this is a carpet plastic film that adheres to the carpet. It is strong enough to withstand foot traffic, even from stiletto high heels! The molecules all line up and strongly hold together as the film is stretched. The most common thickness range is from 0.5 mil to 40 mil in flexible plastic sheeting.
Which is the most common of them all?
Low Density Polyethylene (LDPE) is the most common type of plastic sheeting. It is very flexible, most often from 0.5 mil thick to about 40 mil in flexible sheeting forms. Due to its flexibility is conforms well to a variety of surfaces. The downside is that this LDPE is not as strong or dense as some other types of plastic sheeting. It is not nearly as puncture resistant either. LDPE is used quite widely in construction, agriculture, surface protection applications, covers of all sorts, tarps and much more.
Which is least commonly used of them all?
Medium Density Polyethylene (MDPE) is the least commonly used form of polyethylene for flexible plastic sheeting. Its positive attributes is that it is stronger than LDPE and has a little more chemical resistant. It has a tighter cell structure making it more tear and puncture resistant. When pond liners are manufactured they are often made with MDPE and blended with LDPE or LLDPE to achieve a strong yet flexible pond liner.
Which is the toughest of them all?
High Density Polyethylene (HDPE, aka HD), has the distinction of being the strongest, toughest, most chemical resistant and least flexible of the four types of flexible plastic sheeting referenced in this article. HDPE is also the most UV resistant- holding up to the harsh rays of the sun without needing UV additive packages. HDPE’s strength comes from its tight cell structure that makes it very difficult for other molecules to pass through its structure on a microscopic level. When applications call for very large liners such as pond liners, HDPE is the most easily seamed or “sewn” together. Used industrially, the thickness range from 12 mils to100 mil thick. HDPE is used as secondary containment liners for oil tanks, and most industrial ponds and canal liners where chemical resistance is needed.