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What year did shrink wrap come out?

Author: Daisy

May. 13, 2024

Machinery

How Does Shrink Wrap Work? | RAJA UK

Shrink wrap is one of the quickest and easiest ways to package and protect goods. What shrink wrap is used for typically is wrapping especially awkwardly shaped items – from individual packages to boxes on a pallet. It can even be used to wrap up helicopters. It is weather proof and dust proof, while the transparent option easily allows the goods underneath to be identified.Shrink wrap is so versatile it is even used to wrap up US Navy helicopters for transport (Image: Wikipedia)

The company is the world’s best shrink wrap packaging machine supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.

But what is shrink wrap made of, how does shrink wrap work and is shrink wrap recyclable? Here we answer these questions and find out how to use it on a practical level in the warehouse, using the right shrink wrap and shrink wrapping equipment to get the job done.

How does shrink wrap work?

Shrink wrap and what shrink wrap is used for covers everything from simple packaging, to holding items together, to protecting them.

How shrink wrap works is something that requires a look at the very molecules that the shrink wrap is made from. To make the plastic film that is used to shrink and wrap items, plastic polymer molecules  – long chains of carbon and hydrogen atoms, essentially  – that usually all tangle round each other are heated and stretched so that they all form into straight rows. Once cooled they maintain this aligned structure.

Heating the film again, once wrapped around the goods being packaged, the molecules move about (thanks to all that lovely heat energy being pumped in) and they get all tangled again: making the film as much as 50% smaller.

The shrinking can take place in one direction (uni or monodirectional) or in both length and width (bidirectional) and requires the film to be applied over the goods using a special frame – called a tenter frame – and applying heat correctly. To do it correctly requires the right shrink wrap equipment.

What is shrink wrap?

Shrink wrap is a plastic film that can be stretched over awkwardly shaped items and heated to shrink to tightly fit its contours and crevices as if stuck to it – all without any kind of adhesive.

This protective packaging comes in sheets and on rolls

So, when was shrink wrap invented? The process of heating and stretching polythene sheets and cooling them and then reversing the process was first trialled in the US as a potential packaging process in the 1960s. It was then refined and had its first commercial use in 1981 in the US.

As to who invented shrink wrap, its provenance is murky. It is claimed that the process was actually invented in the 1960’s at WR Grace and company, by Robert D. Lowry, John Dreyfuss and John W. Harrison of Winchester Massachusetts in the US. The process was then refined and rolled out for industrial use by Global Wrap LLC in the US in 1981.

What is shrink wrap made of?

Shrink wrap is made of plastic. What type of plastic is shrink wrap made from depends on how it is to be used, but typically it is made from plastic polymer – usually low density polythene or, sometimes, PVC. It can also be made from biaxially orientated polypropylene, a more complex version of polythene. What they all have in common is that they are made of long chain molecules that, in their natural state, tangle round each other like spaghetti.

How to use shrink wrap

Shrink wrap can be used to cover all sorts of things. To use shrink wrap, you need the right plastic shrink wrap film and the right equipment: usually at the very least a heat gun. You may also need a frame to hold the film.

When shrink wrapping pallets of goods, individual shrink wrap pallet covers are available if you want to cover standard sized pallets of goods – available as sheets and on rolls. For more awkward shapes, this protective packaging comes in rolls and sheets, which can then be wrapped or put over the goods and then heated, often with a hand-held heat gun.

How to heat shrink wrap

So, how does heat shrink wrap work? As we have seen, heating pre-stretched polymer sheets allows the ordered molecules to move about and re-order themselves as a tangle of molecules, occupying a much smaller volume and causing the sheet to shrink.

In practice, this means that putting, say, a shrink wrap pallet cover over a pallet, and heating it the cover will start to contract and pull tight over the goods.

How to use heat shrink wrap involves the following steps:

  • place goods on the pallet and loosely cover with a shrink wrap pallet cover
  • make sure it covers everything
  • gently heat with a heat gun evenly, moving round and round the pallet to ensure even shrinkage
  • when tight, stop and allow to cool.

How to use a heat gun for shrink wrap is perhaps the hardest part of the process. It needs a specialist gun, which burns propane or butane to create a hot flame.

However, it is crucial that the flame doesn’t contact the film nor the goods being wrapped. For this reason, the flame heats a plate at the business end of the heat gun which radiates heat onto the plastic.

How to recycle shrink wrap

With more attention than ever on the impact of plastic on the environment, many ask can shrink wrap be recycled? So is shrink wrap recyclable: in short it is. Being made of low density polyethylene – or polythene – means that the answer to is plastic shrink wrap recyclable is yes. Polythene is widely recycled and can be put into the recycling waste and reused.

To recycle it, simply keep it once you have removed it and either put it in the standard recycling or, if you find you have a lot of it, there are companies that will come and collect it and take it away to recycle. They will shred it and melt it down to make polythene beads which may very well end up being used to make new shrink wrap.

Want to know more about shrink wrap and shrink wrapping equipment?

For all your packaging advice, our Packaging Experts are here to help you find the right solutions. Simply call us on 0800 542 44 28 or visit www.rajapack.co.uk.

When Was Shrink Wrap Invented and Who Was the Inventor

There are many different plastics in use today, and the polymer used in shrink wrap is one of the most popular. It's easy to understand why shrink-wrapping is so commonplace these days. After all, it keeps products stacked together, foods fresher for more extended periods, and reduces transportation and storage loss. If you've ever been curious and wondered, "When was shrink wrap invented?" it all started in 1933 when an employee at Dow Chemical in Midland, Michigan, was asked to develop a new product from two existing ones - hydrocarbon and chlorine.


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In the Beginning…

Ralph Wiley, a 1930s Dow Chemical employee, is credited with creating polyvinylidene chloride (PVDC) while working with two byproducts of a manufacturing dry-cleaning agent known as perchloroethylene. At first, called his invention eonite because it reminded him of an indestructible agent he read about in the Little Orphan Annie series. He discovered that the molecules in his invention would bind tightly and therefore weren't penetrable by water or oxygen molecules. In addition to helping with the war effort, this invention also led to the creation of Saran Wrap in the 1950s, although today's Saran Wrap is made differently.

While PVDC was an accidental discovery, it instantly became desirable as a food wrap, mainly because it could hold in odors, cling to itself, and survive in the microwave. But perhaps the main advantage of this discovery was that it led to the development of shrink wrap. Even though shrink wrap has some environmentalists concerned, its use doesn't seem like it will be diminishing anytime soon. To learn how we got from PVDC to shrink wrap, let's look at the process.

First of all, knowing that plastic and heat have a close relationship helps you understand how shrink wrap got started. When plastic is exposed to high temperatures, the molecules get configured into a new shape. This results in a tighter and firmer plastic than it was in the beginning. The plastic even reshapes itself around an item because it creates a close fit.

Raychem and Its Contribution to Shrink Wrap

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In 1957, Raychem was founded and specialized in creating a type of heat-shrink tubing used for electrical wiring. A kind of radiation treatment was applied to the plastic to do this. The tubing used a little heat so that handmade wiring work was a little more secure, and it also prevented the wires from being exposed. Simply put, the small amount of heat they used meant it was easier to repair wires because the changes were kept in place because of the heat. Paul Cook, was the inventor of this process at Raychem.

Now let's back up a few years. In the late 1930s/early 1940s, companies such as Butterball used a process called cry-o-vac to vacuum-seal chickens and turkeys inside of bags. They wrapped a plastic film around the entire bird and it was dipped in a hot water bath for the packaging to shrink and conform to the bird. Afterward, the bird was frozen and put through several heat and cooling cycles. This, in turn, firmed up the packaging and allowed the birds to be preserved longer.

In 1946, Cryovac, Inc. was formed, and it became the leading company to offer this technique to poultry manufacturers. The method is essentially a precursor to the shrink-wrap process.

This heating-chilling process for plastic was a super-advanced innovation, but companies still wanted to improve upon it. When Bill Baird at Cryovac and Paul Cook, the inventor of heat shrink, met, they compared notes and worked to improve the process. This was when they decided that if you applied the concepts that involved irradiated polyethylene to turkey bags, the process came much closer to what we call shrink wrap today. Nevertheless, the freeze-heat-chill technique needed some improvements, which eventually resolved themselves and became what we now call the shrink-wrapping process.

The Biggest Advantages of the Shrink-Wrapping Process

If you're not convinced that shrink-wrapping is a widespread technique, consider what we use it for today:

● In the packaging of perishable foods: Shrink-wrapping can be used to preserve raw meat, fruits and vegetables, and so much more. The process may have started with whole turkeys, but it didn't end there.

● To help ship larger and bulkier items: Sometimes, larger objects need to be shrink-wrapped together to remain intact during shipping. One of the most common products to involve shrink-wrapping is furniture that comes in the pre-assembled form.

● To protect products from exterior elements: valuable items in storage or on shelves should be protected to preserve the new look of a product.

● Tamper Evident Packaging: Everyone wants to be sure consumable products have not been tampered with. Shrink wrapping is a way to ensure products arrive the same as when leaving the production facility.

● Branding and Readily Available Packaging: Most heat shrink wrap is available in clear. The clear packaging allows many options for branding. Printed boxes and labels are the easiest way to quickly brand products being shrink wrapped. Some companies have enough volume to justify a printed shrink wrap for branding. Shrink sleeves are really popular printed shrink wrap materials. They can change the color of the bottle and feature vibrant and eye-catching graphics.

More Recent Developments

Many products for Amazon fulfillment and other companies are required to be double sealed. The seal for a bottle would be something around the bottle cap and then the bottle placed in a sealed package. Poly bags are common but can lead to excess packaging unless companies keep multiple bag sizes on hand. Centerfold polyolefin shrink wrap has become a favorite for many online sellers to provide the extra seal in case of product breakage. We recommend a 100 ga crosslinked polyolefin shrink film for double seals to ensure extra protection.

Several companies are working on ways to make shrink wrapping more environmentally friendly. One popular option was biolefin shrink film. It was supposed to decompose within months of disposal. It also overcame the obstacle of storage without degrading. Over time, problems arose with the dependability of the film by some producers. Since then, many shrink film producers have tried to find biodegradable shrink wrap options that do not have storage obstacles to overcome but can decompose within an adequate time.

Conclusion

Plastic polymers have come a long way in the past few decades, and the growth process has resulted in a fantastic technique known as shrink-wrapping. The polymers used in shrink-wrapping today are versatile and very strong, so when something is wrapped, you can count on that product being very tight until the customer decides to open it. Shrink-wrapping is a cost-effective method of protecting items and keeping them intact until they reach their final destination. When it comes to packaging various food items, it provides numerous other benefits, not the least of which is its ability to preserve and protect.

If you're interested in learning more about the shrink-wrapping process and the items that can accommodate the process, the right company can help you get started. We have everything for shrink wrapping from starter to fully automatic machines and everything in between. It is easy to learn more about the shrink-wrap process because it's straightforward. We can help you whether you've never had a shrink-wrap machine or if you want a newer and more updated one, and we'll make the entire process easy.

 

Want more information on Shrink Wrapping Machines for Sale? Feel free to contact us.

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