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The History of Polyethylene

Posted by Nana Hinsley on Fri, Feb 13, 2015 @ 10:19

On March 27, 1933, two organic chemists working for the Imperial Chemical Industries Research Laboratory were testing various chemicals. To  R.O Gibson and E.W. Fawcett's surprise the white, waxy substance they were testing would become a revolutionary substance that would change the world. Polyethylene was born!

 polethylene resin for plastic sheeting

The researchers set off a reaction between ethylene and benzaldehyde, in an autoclave. It seems their testing container sprang a leak and all of the pressure escaped. There was the white, waxy substance that greatly resembled plastic. Upon carefully repeating and analyzing the experiment, the scientists discovered that the loss of pressure was only partly due to a leak; the major reason was the polymerization process that had occurred leaving behind polyethylene. The first patents for polythene were registered in 1936 by Imperial Chemical Industries.  A year later the first practical use for the material, as a film, was discovered. In 1953 Karl Ziegler of the Kaiser Wilhelm Institute and Erhard Holzkamp invented HDPE (High Density Polyethylene). From there, two years later, in 1955, HDPE was produced as pipe.  Ziegler was awarded the 1963 Nobel Prize for Chemistry.

Did you know that polyethylene played a key supporting role during World War II? It was first  used as an underwater cable coating and then as a critical insulating material for  vital military applications as radar insulation. This is because it was so light and thin that it made placing radar onto airplanes possible thus vastly reducing the weigh. The substance was a highly guarded secret.

After the war, polyethylene became a tremendous hit with consumers It became the first plastic in the United States to sell more than a billion pounds a year. It is currently the largest volume plastic in the world.

 Today, Polyethylene has the advantages of excellent moisture-vapor, chemical, and electrical resistance. It is widely used for making containers, wire cable insulation, pipe, linings, coatings, and engineered films. It is used to power transmission, consumer goods, packaging, electronics household good and more. Its principal disadvantage is poor mechanical strength, unless it has a little help from scrim reinforcement! Developments in technology continues to improve its functionality making it the most efficient use of natural resources petroleum and natural gas. We applaud these scientists for creating polyethylene that is used in a variety of plastic sheeting products today.

Polyethylene is the largest volume polymer produced globally, with over 90 million metric tons per year!


Tags: plastic sheeting, polyethylene, film, history of polyethylene

Heavy Duty Plastic Sheeting- 4 Examples of what it is

Posted by Nana Hinsley on Tue, Feb 10, 2015 @ 09:18

What do we mean when we say, "Heavy Duty Plastic Sheeting"?  The dictionary defines "heavy duty" as, "made to withstand hard use or wear" and "made to withstand great strain or use".  So when Global Plastic Sheeting refers to "heavy duty plastic sheeting", we are referring to a plastic sheeting product that is made to withstand hard use or great strain based on the application the plastic sheeting was designed for.  Therein lies the difference.  A plastic liner is not heavy duty in every application it is presented with.  A liner/ film is heavy duty when the plastic was engineered specifically for an application and the film is capable of doing the job it was designed for. It will stay strong, and protect what it was employed to protect.

Let's take surface protection films. These are films that are engineered to cover a variety of surfaces in the most expeditious way possible.  Carpet plastic is made to stick to carpeting without transferring the adhesive onto the carpet; hold up under the PSI pressure that a ladder could place on the plastic, have a tight enough cell structure that any fluids that land on the plastic won't permeate onto the carpeting; and continue to do its job protecting the surface of the carpet for the time period it was engineered for- usually 30 to 45 days. Can any type of plastic do this job? Absolutely not. Plastic known as "visqueen" that you find in big box stores won't hold up to the riggers like a virgin polyethylene will.  Some products that have adhesive come from overseas where they don't have the quality control that we have over our plastic and our adhesives.  What can happen is this foreign film can discolor you carpet due to a petroleum based adhesive. All the films that Global Plastic Sheeting offers we consider to be "heavy duty plastics" because this are rough and tough when used where directed.  glass plastic

It's tricky for consumers to really understand what goes into making these films. On the surface they look like, well- plastic.  But just like cars for the most part all looks the same, there are a great degree of differences that explain why one may be better suited to be a race car versus a family car. What is under the hood came make a huge difference.  We offer hundreds of different types of plastic sheeting that perform different duties.

What about Fire Retardant Films? Again, plastic looks like plastic.  When you feel it you might notice one is thicker than the other. One is sticky on one side, or one is black and one is white.  How is that important?  Plastic is an amazing animal.  In the lab, additives can be added to the films to make the perform double duty.  Take fire retardant plastic (flame resistant plastic).  A fire retardant additive is mixed in with the plastic so what when a flame comes in contact with the film, the plastic will not add to the fuel source. This heavy duty fire retardant film will not burn. It may melt due to the extreme heat, but it will not burn. This constitutes being heavy duty because the flame resistant plastic is doing what it was designed to do- withstand hard use- extreme conditions.

Anti-Static Flame Resistant plastic

Another liner/ film that falls into the category of "heavy duty plastic" is a liner called, HDPE.  HDPE stands for high density polyethylene.  This plastic which is also called a "geomembrane" is engineered with a specially formulated polyethylene resin.  It contains approximately 97.5% polyethylene, 2.5% carbon black and trace amounts of antioxidants and heat stabilizers; no other additives, fillers or extenders are used.  What you get is a film that has excellent chemical resistance, very low permeability- high tensile strength and more.  This liner stands up to UV radiation and can survive outside in harsh conditions.  Now that is heavy duty!

Containment plastic must be heavy duty as well to do its job correctly. What is contaiment plastic?  It is plastic that is used to cover the object that needs covering.  Take scaffolding.  You have seen where it is covered in plastic- that is a specialty plastic called heat shrink wrap.  This engineered plastic is made to shrink when heat is applied to tightly cover the building, boat, or object it is protecting. Pictured below is the Mars Rover protected by our specialty heat shrink wrap called, GPS Anti-stiati Fire Retardant Heat Shrink Wrap.mars

Can greenhouse plastic be heavy duty? Absolutely.  Take SolaWrap greenhouse covering film.  This bubble wrap looking plastic will last 10 years in the hashest of environment.  It is made to withstand heavy snow loads, high winds, sun, heat, rain- you name it...and it won't yellow or degrade. Other greenhouse covers made from 6 mil polyethylene will only last a few year. And while they will get the job done for a time period, they are not as heavy duty as Solawrap. Here you see SolaWrap on a commercial greenhouse for Proven Winner.  SolaWrap goes the distance.

Greenhouse plastic SolaWrap

Hopefully now you have a better understanding of what we mean by, heavy duty plastic sheeting when we refer to our product line.  Products that do what they say they will do make life a little easier.

Tags: heavy duty plastic sheeting

Recovering your Greenhouse Plastic? Greenhouse Covering Considerations

Posted by Nana Hinsley on Thu, Feb 05, 2015 @ 03:00

Is it that time again to replace your  greenhouse covering? Are looking for the best greenhouse plastic you can find? This article will look at the greenhouse covers that have been on the market for years in the US and then present a proven product that has a track record of 30 years in Europe, but if fairly new in the United States.  It is like nothing else that currently exists on the market.  You will see that it outperforms all its competitors, and is more cost effective in the long run.

 What factors are you taking into consideration for your greenhouse?  You are probably considering the amount and type of light reaching your plants, the overall appearance of your greenhouse, its ease of maintenance, safety and longevity. Most of all, you want something that is cost effective.

What are your greenhouse covering choices? 

Let's start with polyethylene films.  It comes in a variety of thicknesses with 6 mil being very common. When selecting a 6 mil greenhouse plastic, you need to make sure it is not a product out of China.  The Chinese made films are not made with virgin polyethylene which degrades in the sun! Some people chose to use a double layer for better insulation. Typically a single layer of polyethylene film has an R value of approximately 0.85. A double poly cover consisting of two layers of poly has an approximate R value of 1.25.  This is a quick inexpensive fix- but is it really inexpensive when you add in the labor cost to replace it more often than other options. Greenhouse plastic will offer some UV protection, and some versions have better tensile strength than others.

Greenhouse plastic tears One thing to be aware of is the plastic ripping where the plastic touches the PVC. This seems to be reported from growers who don't use a film that offers UV protection  The PVC may absorb the heat and speed up the breakdown of the plastic.  As we all know, sun is an enemy to all sorts of plastic sheeting. Another reason for the breakdown and tearing of the plastic could be the chlorine that is in PVC.  This too is a problem for greenhouse plastic.  There is a polyethylene greenhouse film that won't give you these problems called SolaWrap!  Read on to learn more.

6 mil greenhouse plastic coverings also come in white. They are often referred to as, white opaque greenhouse films. White greenhouse films are popular when reducing heat in the greenhouse is the goal.   Being white will however reduce the light transmission by almost half per layer.

Another option is to look at the reinforced polyethylene greenhouse films.  This product comes in a 3 ply laminate where a cord grid is placed between two layers of plastic.  The goal is to offer a high strength film that is durable yet light weight.

Polycarbonate Panels:  Another route that has been popular in the past is polycarbonate panels.  This is a translucent rigid plastic.  Some compare it to glass as it is almost as transparent.  It can be installed as a corrugated single layer, or in a flat twin wall version.  By doing a twin wall you create air pockets between the two walls which act as insulators.  Due to its glass like quality, it offers good light transmission.  People like that it is a light weight material that can be cut to size and installed.

Glass:  Glass is one of the least efficient materials for retaining heat because it has very little insulating value, and it transmits heat and cold quickly. Consider thermometers are made from glass.  

Glass is much heavier than other coverings and needs substantial framing. It doesn't diffuse light so plants could get burned; glass breaking is a huge hazard.  Consider climates that have heavy snow loads and hail storms. If the foundation or the frame shifts for whatever reason, the glass can crack. Another consideration is heat loss due to gaps between the panes.  It's important to have an installer who is experienced. It's not something that most weekend gardeners can throw up.

SolaWrap Greenhouse Plastic Cover:  SolaWrap Greenhouse Plastic (Greenhouse covering) offers:

  • R-Value 1.7
  • 83% transparency
  • 10 year warranty against UV degradation (better warranty than polycarbonate)
  • up to 83% diffused light (only product on the market with both high transparency and high diffusion)
  • 120 lbs per square foot snow load rating (approx 15 feet of snow)
  • 100 mph wind rating (has survived 135 mph windstorms in Alaska)
  • Has been shown to last up to 27 years on greenhouses in Europe
  • Does not yellow or get brittle
Greenhouse Covering SolaWrap

Pictured above the greenhouse that Proven Winners built using SolaWrap. More and more commercial growers in the U.S. are becoming familiar with Solawrap, and are selecting it.  The bubble structure offers amazing benefits when compared to the other products on the market.

Greenhouse covering SolaWrap

SolaWrap has withstood many a hailstorm, snow load, and all out terrible winters. There is no need to worry about hail storms and the resulting broken glass!broken glass greenhouse

describe the imagegreenroof problems

To find out more about SolaWrap, please call us at 855 Sola USA  (855.765.2872). Happy Growing!

Tags: Solawrap, greenhouse plastic