Why food safe HDPE plastic replaced glass as the go-to milk container.
Many of you, should you be older than 60, may remember the “Milk Man”. This delivery service from decades ago, was a most common way of transporting milk to the consumer. Back then, suppliers used glass bottles, delivered by this milk man, right to your front door.
HDPE is Food Safe
When looking at alternatives, the milk processing industry found a use and benefit from replacing the glass with a plastic called High Density Polyethylene (HDPE). But what is HDPE, and what are the benefits of using it?
Glass is heavy, HDPE plastic is light
One of the characteristics of this thermoplastic is the weight of the material. The reason this is so beneficial brings us back to the milk jug. Old style glass milk containers could hold 32 oz., with the empty glass weighing 1.25 lbs. An empty gallon water or milk jug (128 oz.) weighs in at only 0.25 lbs, and holds 4 times more volume. When full, the milk jug can hold more volume than the glass bottle without compromising the strength, especially when being transported. This lowers the overall transport time and significantly reduces the cost of shipping.
This drop in weight and large increase in capacity is why the industry made the switch. The attribute of high durability in plastic materials like HDPE is known as the “strength to weight ratio”. As already mentioned, this was a huge benefit from switching to HDPE containers – the impact it has on transport costs. The high impact resistance of the material allows for easy transport. The HDPE jugs can withstand the jarring and bumping that is a natural part of mass transit, with almost zero wear or breakage to the product. Compared to the glass bottle, too hard of a turn or a pothole in the road could lead to the disheartening sound of shattering glass… not an ideal result for the distributing company. The HDPE impact resistance still holds true through out the supply chain, and even when the containers enter a store or home. If a HDPE milk jug should fall, the plastic container may spill, but it won’t cause the harm or damage that glass would. Broken glass poses a hazard and a risk, whereas plastic in this case can be easily cleaned, recycled, and used again.
When discussing this topic, the argument of recycling and sustainability sets its sights on plastics. In reality, the carbon footprint of plastics is much smaller than that of glass. The amount of heat necessary to heat up plastic for recycling is dramatically lower than that of glass, making it more sustainable in the long run. Yes, both are 100% recyclable, but the amount of fuel necessary plays a big factor. The temperature needed for melting and processing HDPE is between 248 and 356°F depending on grade. Whereas glass requires a minimum temperature of 2,600°F, according to SeattlePI. As you can see, these temperatures are very different, and shows why the life cycle of plastic is more eco-friendly and a better option to preserve our environment.
Immensely versatile HDPE applications
HDPE has many more uses, like in structural tanks, FDA approved cutting boards and industrial piping systems. This material outweighs most alternatives in benefits due to it’s cost and performance, and is produced in sheet and rod by many major manufacturers in the USA. HDPE plastics are FDA and NSF approved for food applications, making HDPE a food safe product for most food processing and packing applications. For more details on HDPE and it’s benefits see Industrial Plastic Supply or call 866-832-9315
What other applications could benefit from newer and improved materials to make our world safer, cleaner and more efficient?
People in the plastics industry have known for over 50 years that Polycarbonate Sheets are tough. This clear plastic sheet material is commonly used to replace window glazing. The best known property for this polycarbonate sheet material is that it is break resistant, or in many cases, considered unbreakable. This is a great benefit for areas where window glass is broken easily.
Recently some cities have passed ordinances to change out the plywood window coverings on abandoned homes, and they are installing clear polycarbonate sheets instead. This is a very attractive replacement, and is a big step in fighting the blight of abandoned homes.
Polycarbonate is produced under several trade names, including Plaskolite Tuffak® GP, Covestro Makrolon®, SABIC Lexan®, Cyrolon®, Zelux® and many more. These materials are available in sheets, plate, slab, bar and rod.
Read more on this material below.
Excerpt from AZCentral, The Arizona Republic:
Property owners and banks in Phoenix had begun outfitting windows with sheets of polycarbonate, a thin, nearly indestructible plastic that mirrors the appearance of glass.
And last month, the city became among the first in the U.S. to make polycarbonate windows a matter of municipal law.
Phoenix now requires all window and door openings visible from the street to be secured with the material if the structure has been unoccupied for more than 90 days. The 90-day provision is also new, replacing the previous deadline of 180 days. The measures were the result of an abandoned buildings task force that Gallego spearheaded.
No one likes living next to abandoned buildings with boarded up doors or windows. So the city of Durham started replacing the plywood eyesores with a clear, durable plastic.
The city is working to reduce the number of abandoned houses by helping owners fix them up. But for houses that still need boarding up, the city has found that plastic not only improves the overall appearance of a neighborhood, it may reduce crime by discouraging squatters and making it easier for police to see inside vacant buildings.
“I can’t stress enough how the elimination of the boards has a tremendous positive impact on neighborhoods and communities,” said Faith Gardner, housing code administrator of the city’s department of neighborhood improvement services.
Read more here: http://www.newsobserver.com/news/local/counties/durham-county/article20778429.html#storylink=cpy
These communities have fought back against vandalism and crime, as well as enhanced the value of local homes by changing from Plywood to Clear Polycarbonate Sheets. Tuffak GP is a super tough glazing grade clear Polycarbonate Sheet material is the same kind of material that Police Officers use for face shields and banks are using for bullet resistant glazing.
The premier manufacturer of Polycarbonate Sheet in the USA is Tuffak® PG made by Plaskolite and made from Covestro® (formerly Bayer MaterialScience) resins, and they produce Tuffak® GP Polycarbonate Sheet. Polycarbonate is also available in rod and thick plate for machined parts.
Consider using Polycarbonate sheet for your next glazing material.
Plastics have been around for over a century now, and are used in almost every industry and application. The problem is that society has made the plastics industry the poster child for waste, trash and pollution. This is unfair, and factually incorrect.
Plastic materials are lighter, cost less to produce, use less electrical power to produce, and are safer for use. It is not new phenomenon that a material or product, once used, gets thrown away. This is the normal life cycle of many materials. Some inexpensive plastic materials used in consumer goods are made to throw away once the item has been purchased. Things like the indestructible packing we fight on kids toys, the cheap plastic sporks from restaurants, the prolific plastic water bottles and of course, the plastic grocery bags. All of these materials are 100% recyclable, the hitch is that it requires a little effort to recycle.
Are Plastic Materials The Cause?
On the positive side, the products that plastic currently replaces are much larger, heavier and generally cost more to produce, and use more energy to produce. This means, that the large amount of plastics that are not being properly disposed of, are replacing much larger quantities of materials that would not be recycled. I still remember times when I was a kid, and seeing tin cans in the lakes and rivers when out fishing. People polluting with their trash is not a new thing, now it is just a different group of materials.
Thermoplastic plastic materials are recyclable, and can be used over and over again. Generally, the recycled product would not be for a Food or Medical application. A common use of recycled plastic is with the collected milk jugs and detergent bottles, both HDPE, can be ground and turned into plastic lumber. The plastic lumber can be used to replace standard wood products for decks and outdoor furniture, and it will last for 15 – 20 years with no maintenance or painting. The cost savings and reduced use of natural resources for this one product can be staggering. The color doesn’t fade, it wood won’t split or crack, and it continues to look good for up to two decades.
Our recent article, “Plastic Material Bad Reputation – How did we get here?“, we discuss the factors that have lead to the ‘throw away’ society that we have become. Much of this bad reputation is for products that are designed as one use and then designed to be thrown away. So, if we are to change the bad reputation, companies need to change this design flaw, and start using materials for applications that can be reused easily.
If we can minimize the use of throw away plastics, and recycle the plastic material once we are done with it, we can help to limit plastic in land fills.
The blame for plastic pollution should be placed…on people. The plastic is not the cause of the problem, it is the litter-bug and irresponsible individuals that trash our planet. How do the plastic bottles and grocery bags end up in the ocean. They certainly don’t throw themselves in to the ocean, it is lack of responsibility and negligent behavior.
It really only takes a couple of seconds to throw something into a recycle bin. Even better would be to reuse the plastic bottles or plastic bags. Plastic materials are not the problem, empathetic people are the problem.
UHMW (Ultra High Molecular Weight Polyethylene) and PTFE Sheet(PolyTetraFlouroEthylene) are very similar materials, and yet very different at the same time. They both possess certain characteristics that make them similar to each other. For instance, they both have a very low co-efficient of friction, which means they are great for sliding applications and are easy to machine.
Both of these materials are very resistant to chemicals such as chlorine and some acids and have great wear resistance. They have low to no water absorption. They also are FDA approved for handling food. PTFE and UHMW Polyethylene are both nearly impossible to bond (without treatment) and are susceptible to sagging under tensile load which is called ‘creep’. These both have very low coefficient of friction and work well for wear strips, slide pads and truck liners to make it easy to empty. These two materials are different in many ways also, and choosing between the two materials for a specific job is critical.
Below are a few examples of how these two materials are different.
1. UHMW is a polyolefin and PTFE is a fluoropolymer. Polyolefins are double bonded carbon while Fluoropolymers are carbon and fluorine bonded. UHMW is a monomer which is consisted of one atom that will bond with another to form a polymer. PTFE is a polymer which is made up of a repeating chain of monomers.
2. PTFE has a higher temperature range than UHMW. The PTFE has a continuous use temperature of 500 degrees F. UHMW is much lower with a continuous use temperature of 200 degrees F and a melting point of 271 degrees F. The UHMW starts to become become soft at higher temperatures while the PTFE is much more resistant and with a melting point of 621 degrees F.
3. UHMW has higher abrasion resistance than PTFE. Both have great impact and wear resistance but because of UHMW having a molecular weight between 2-6 million making it the best wear resistance material in the plastic family, it makes it ideal to take wear and impact over a wider range and longer period of time without losing its properties.
4. UHMW has a much lower density than PTFE. This makes UHMW able to float in water while Fluoropolymers are significantly heavier (almost twice the density of UHMW) and would sink.
5. PTFE has excellent electrical and thermal properties. The virgin grade of PTFE is a better insulator and exhibits better electrical properties which can be used in radio frequencies, cables and circuit boards while UHMW cannot.
6. UHMW is much less expensive than the Fluoropolymers. Especially recently, PTFE has become harder to come by, and during the last 18 months there has been a global shortage of a key raw material called fluorspar that is used to make all Fluoropolymer materials. The ability to take lots of wear and tear and requiring low long term maintenance makes UHMW more cost effective.
7. The standard color of PTFE is Natural, which is a dense white. The UHMW comes in Natural (a deep milky white) or Black. The UHMW can be produced in many colors, and minimums are rather low. To obtain PTFE in colors is much more difficult, and would also have large minimum orders.
Click here for data sheet comparisons for each material…
Both the UHMW and the PTFE are available as sheet, sheets, sheeting, slab, bar, strip, panels, film, round rod, rods and block. Contact us for assistance with these or other shapes.
PTFE Sheeting Properties
Specific Gravity D792 2.14 – 2.24
Tensile Strength Yield D638 2,500 – 6,000
Tensile Modulus D638 80,000
Izod Impact – Notched D256 3.0
Hardness – Rockwell D785 D50 – D65
Deflection Temp @ 264psi D648 150
Deflection Temp @ 66 psi D648 250
Co. Thermal Expansion D696 5.5X10-5
UHMW Sheeting Properties
Specific Gravity D792 .93 – .94
Tensile Strength Yield D638 6,800
Coefficient of Friction – Static D1894 .25
Izod Impact – Notched D256 No Break
Hardness – Rockwell D785 R64
Vicat Softening Temp D1525 260
Deflection Temp @ 66 psi D648 174
Co. Thermal Expansion D696 11.0X10-5
These are just some examples of plastic materials being similar, and yet having very different properties. The PTFE Sheet and UHMW Sheet may appear very similar in color and can be used for some of the same applications, but when needed for a specific use or property needed, one might be dramatically better than the other. As the old saying goes, “You should never judge a book by its cover” and the same is true with plastic. Review the properties and test prior to choosing a final material for your application.
When choosing a plastic raw material, the first step should be to look for the material with the proper physical properties. PVC (Polyvinyl-chloride or Rigid Vinyl) is an amazingly strong and versatile material that has proven itself a champion in the ever growing demand for mechanical grades of plastic. We can see its wide versatility in the way it is used and how it can keep up with the rough conditions it’s put under. PVC Pipe has been shown to take a beating in construction sites and it serves its purpose underneath our front lawns for our sprinkling systems. There are many more ways this strong industrial grade PVC can be used.
PVC Sheet and Rod for a wide variety of industrial and mechanical applications
A standard industrial plastics, it is available as PVC Sheet or PVC Rod. The PVC, unlike other materials, is very easy to work with. It’s not necessary to buy expensive tools to get the job done. You can use the most of the same tools you would use on wood and steel. Unlike other materials, PVC can be kept cool easily using cold water or you can use an air compressor. Standard CNC equipment, punch machines, routers, drills and saws can all be used to shape PVC. If you wanted to seal and bond this material, that’s not a problem because like the PVC Pipe, the sheets and rods can be bonded with cements or heat welded. The cost of PVC is also lower than most other plastic materials that are harder to work with. So you can see why PVC should be on your short list of plastic materials.
Standard PVC sheet sizes and thicknesses for PVC Sheet
The standard sheet size for PVC is 48” x 96”. Some of you may know those measurements because that is also the standard size of drywall and plywood. Because PVC comes in the same sizes as other common materials it would be fairly easy to store. As for the thickness .062” – 3” are the most standard thicknesses, but it can be made thicker if needed. The material cuts and fabricates well, and we do offer cutting to your blank or precision sizes. We also cut the rest of the industrial and engineering plastics, including: Acetal/Delrin, Nylon, PEEK, Ultem, and dozens more; call for details.
PVC Sheets take a beating
PVC has many excellent properties, including the unbelievable UL 94 V-0 flame rating. This certification means that the Rigid Vinyl material is fire retardant, and is considered ‘self extinguishing. By now you are probably were thinking “PVC sounds great so far, but I wanted to paint and screen print on a material”, then have no fear because PVC Sheet and Sheeting is here! PVC is also known for its ability to hold paint and a screen print. It is heat bendable, vacuum formable in thinner gauges, and bondable to materials such as wood, paper and other plastics. Because of PVC’s many usages and qualities we even see it being use to create house hold items.
The material can be sanded, routed and you can eliminate scratches and scrapes by simply buffing or sanding them away. With PVC being so versatile and also low in cost, it’s no wonder why it is a top choice for manufacturing and engineering companies. Click here for
A common standard item in the metals industry is ‘strip’. Strip is normally a piece of material that is 1/16″ – 3/8″ thick and 1.0″ – 4.0″ wide, although thicker and wider materials can also be referred to as strip. The metals industry produces various metals in these sizes of strip. In the plastics industry, strip is something we cut from larger sheets. The sizes are the same as listed above, but are cut from 48″ X 96″ or 48″ X 120″ sheets.
The a few of the most common plastics materials we cut to plastic strips are:
Most plastics can be cut to these strip sizes, with various lengths available depending on type of material. In some materials and in some sizes, depending on quantity, special run to size plastic strip is available. These special run plastic strips can be run to almost any length. Specifically, in the UHMW and PTFE materials, much longer lengths are available in rolls of material. The UHMW can be purchased in standard and adhesive back varieties. This UHMW with adhesive is a commonly used item in the wear strip applications because of its ease of installation. A large market for this kind of strip is in the food processing industry for all wear points and to reduce noise in the plant. Some of these same sizes with adhesive on the back are available in the PTFE, and are available in long tape style rolls. In some cases, colors other than natural are available, contact us for details.
Plastic Strip and Strips are available in special sizes
With the massive range of plastics available, and most of these materials available to be cut to strips, the nearly unlimited amount of choices in plastic strip availability make this post difficult to be all inclusive. Great material for the industrial, food processing, material handling, automotive and recreational industries.
Most plastics are available in large sheets, and we can cut these sheets to strip for you. Also, depending on the material, size and quantity, we can custom extrude your strip in longer lengths and to your requirements. Decide on a type of plastic, determine the size and quantity, and give us a call. Use your imagination, we can help.
If you have a project where strips would be ideal, please contact us to see if the type of material you need is available in the strip configuration that would be beneficial. Call us at: 866-832-9315 or drop us an email and we will be happy to go to work on your requirement.