A History of Polyethylene | Polyolefin Shrink Wrap

Despite not even being theorised a century ago, today, polyolefin shrink wrap is in huge demand. There has been a century of rapid innovation that has led to us being able to use the stuff today. In this article, we explore the unlikely history of polyethylene.

If you are looking for more details, kindly visit Yuanlong Packaging.

When Was Polyethylene First Created?

The concept of high molar mass macromolecules &#; an academic way to describe polymers &#; was first theorised in the s by future Nobel Prize winner Hermann Staudinger. However, the first confirmed traces of polyolefin were created in . In the small village of Winnington, two scientists &#; Fawcett and Gibson &#; left two chemicals (ethylene and benzaldehyde) overnight by accident in their laboratory, and discovered an unexpected white powder weighing about a gram left behind. When they tried to repeat the experience, without benzaldehyde &#; they did not realise they left any behind &#; the reactor exploded. It took two more years before they managed to repeat the production of the white powder &#; and yet again, it was entirely due to luck, when a leak allowed traces of oxygen to contaminate the ethylene which, at high temperatures, created polyethylene. They quickly began mass production and testing of the new substance.

In , the process was patented by Imperial Chemical Industries where the two scientists worked, and by a hundred tons a year were produced in the first factory to make LDPE, or low-density polytheylene. The LDPE was largely used in the food industry thanks to its food-friendly advantages to substitute metals, and is still used to this end today.

When Mass Production of Polyethylene Began

One important use of the polymer was as insulation for another recent invention, radar. The Battle of Britain was won in part because of radar insulators, made from LDPE. However, during the Second World War and directly afterwards, research slowed. Most companies thought they could use polyethylene for fuel for the army, which ended up being fruitless.

It took until the s before two major breakthroughs took place. Firstly, two men at Phillips Petroleum Company were doing research on a mixture of nickel oxide and chromium oxide compounds. However, unexpectedly (if not accidentally), they plugged their reactor with solid HDPE instead. After fiddling for a little while with the reactor, they found they could polymerise ethylene with their catalyst, and later on, polymerise propylene as well. They immediately filed for patents and licensing the process using their catalysts and became immensely rich as a result &#; nowadays, Philips catalysts represent 40-50% of the global production of HDPE, and their specific method is still popular around the world.

The second innovation took place under Ziegler in the Max Planck Institute in Germany, another future Nobel Prize winner for his work in polymers. In , Ziegler found a way of producing mass polyethylene using titanium tetrachloride. Because of the way the two reacted together, polymerisation led to three times as much of polyethylene as before, creating an extremely efficient way to produce the plastic. By , the first plant was set up to produce the new plastic through the German&#;s technique. Ziegler&#;s work was especially valuable because he rigorously theorised exactly how to make polyethylene, which ultimately was why he was later on awarded the Nobel Prize for his work with synthetic polymers.

Discovery of new catalysts

By the s, another &#;incident&#; led to the discovery of a new catalyst for polymerisation. The University of Hamburg were investigating the side reactions that occurred during Ziegler&#;s experiments. During their experiment, however, polyethylene unexpectedly formed ethylene outside of the experiment, tramsmitted by moisture inside the machinery. It turned out that water was reacting with one of their materials &#; trimethylaluminium &#; to form a new polyolefin which was even more catalytic than before, dubbed MAO, a cluster of methyl, aluminium, and oxygen.

This discovery led to a flurry of more catalytic substances that led to better olefin polymerisation, and so better polyolefin production. For decades after the fact, and still now, scientists are looking into how polyolefins can be created more and more effectively with new base chemicals.

From polyethylene to polyolefin shrink wrap

Contact us to discuss your requirements of shrink film rolls wholesale. Our experienced sales team can help you identify the options that best suit your needs.

Shrink wrap, as we have covered before in our history of food packaging, began impacting the food industry almost immediately. By the s, shrink wrapping became immediately successful and shrink wrap machinery was sold across the world to package fresh vegetables. However, its popularity soon spread to other industries as well. By , for example, the first shrink wrap machine was installed in a commercial laundry in the United States.

Today, the shrink wrap industry is huge and spread across a variety of different industries from marine shrink wrapping boats and and wrapping pallets for freight transportation to disaster relief like shrinkwrapping roofs and food to extend shelf life. The size of the shrink film industry has extended over the years and is still continuing to grow at a rapid rate.

The story of polyolefin is one of how an accidentally-made substance of barely a gram has became the centre of an industry producing over 700,000 tons of material a year. If you think your business might benefit from polyolefin shrink wrap, please get in touch and we will be more than happy to provide help you with anything you need.

Heat shrink plastic tubing is expanded, extruded plastic sleeving that is designed to contract when heated. It is commonly used to provide sealing, termination, identification, insulation and strain relief for cables. It has many uses in electrical, electronic, telecommunications, cable management and virtually all other industries. There are many variations to meet different needs: economical options for light, unexposed use; general purpose and high temperature versions for automotive, aerospace and military applications; and adhesive lined heat tubing for tight seals that keep out dust and moisture.

The most common method for contracting heat shrink is the heat gun. Heat guns range from moderate heat fixed temperature versions for general use, to variable temperature models with digital readouts. The heat shrink oven is a costlier and less portable option but is more energy efficient.

In addition to heat shrink tubing and heat gun/hot air tools, this section also features heat shrink connectors you need to take your heat shrink project from start to finish, including heat shrink labels and high temperature specialized heat tubing.

Heat Shrink Tubing: How It Was Invented, and Why We Use It

Sure, heat shrink tubing is cool and fun to use, but have you ever wondered how it came about, what makes it work, or how many uses it actually has? If so, CableOrganizer® can help &#; just have a quick read through our FAQs and you'll be an expert on heat shrink tubing in no time.

WHO INVENTED HEAT SHRINK? WHAT'S THE HISTORY BEHIND IT?

Heat shrink tubing was originally developed by Raychem Corporation in the late s, when Raychem's chemical engineer founder Paul Cook, along with inventor Judson Douglas Wetmore, made use of radiation chemistry (from which his company's name is derived) to develop the two main products that Raychem was originally known for: lightweight aircraft cable, and heat-shrinkable tubing. While Raychem pioneered heat shrink polymers, today they're produced by many different manufacturers including 3M®, NTE®, Techflex® and Zippertubing®.

WHAT IS HEAT SHRINK TUBING MADE OF?

Heat shrink tubing can be made of any one of a range of thermoplastics, including polyolefin, polyvinyl chloride (PVC), Viton® (for high-temp and corrosive environments), Neoprene® (polytetrafluoroethylene (PTFE)), fluorinated ethylene propylene (FEP) and Kynar®. In addition to these polymers, some types of special-application heat shrink can also include an adhesive lining that helps to bond the tubing to underlying cables and connectors, forming strong seals that can often be waterproof. Another material that is sometimes added to heat shrink tubing is conductive polymer thick film, which provides an electrical connection between the two or more conductive objects that are being joined by the tubing &#; without the need to solder them first.

WHAT MAKES HEAT SHRINK TUBING SHRINKABLE?

You've probably noticed that most plastics you encounter won't just shrink down if they're heated &#; so what makes heat shrink tubing different? The answer is cross-linking, the process of exposing a polymer to radiation in order to create covalent bonds between that polymer's atoms. Following World War II, it was discovered that radiation could alter the molecular structure of certain plastics so that they wouldn't melt or develop a flowing consistency, no matter what temperatures they were exposed to. Covalent bonds also give polymers plastic memory, which means that once a polymer has been cross-linked and stretched into an expanded shape, it will automatically shrink back to its original dimensions when a certain amount of heat is applied.

DOES ALL HEAT SHRINK TUBING SHRINK THE SAME AMOUNT?

Each type of heat shrink on the market is labeled with a shrink ratio, or the measurement of how small the tubing becomes when shrunken in comparison to its original expanded size. For example, heat shrink tubing with a 2:1 shrink ratio has an expanded diameter that is twice the size of its shrunken diameter. Likewise, a 6:1 ratio indicates that a piece of heat shrink is capable of shrinking to 1/6th of its expanded size. These, of course, aren't the only shrink ratios out there; a wide variety is available on the market, but their ratios can all be interpreted as easily as the two examples just given.

WHAT IS HEAT SHRINK TUBING USED FOR?

Likely to be found just about anywhere there are cables and wires, heat shrink is extremely useful, both for protection and cosmetic enhancement. It can be used to:

For more information, please visit plastic film wholesale.

• &#; Seal water and dust out of cable splices
• &#; Insulate cables and wires against extreme heat in aircraft, boats, and military vehicles
• &#; Provide a barrier between cables and corrosive chemicals
• &#; Color code cables for easy identification
• &#; Harness multiple wires together
• &#; Make long-lasting labels for network patch cords
• &#; Neatly terminate the ends of braided sleeving
• &#; Improve the look of cables in computer case mods or custom cars and motorcycles