HDPE v LDPE Tubing Custom Applications

High-density polyethylene [HDPE] and low-density polyethylene [LDPE] derive from the polymerization of ethylene. Polyethylene is the world’s most utilized plastic.  Manufacturers of HDPE and LDPE polymers generally take polyethylene pellets and, using heat and pressure, extrude a resin into the shape of tubing or various custom profiles, depending on usage.

The different chemical composition between HDPE and LDPE is determined through the polymerization method. The main difference between the two – dense and rigid versus flexible – determines the uses for each.  The demand for both HDPE and LDPE tubing and custom shapes is enormous and covers a vast array of products that impact every aspect of our lives.

Let’s look at applications for both products:

HDPE Tubing and Custom Shapes Applications

 Aside from being rigid, HDPE has high impact, chemical and abrasion resistance; has a low co-efficient of friction and excellent wear properties.

Among the applications for HDPE tubing and custom shapes are:

  • Automotive
  • Conveyor
  • Geophysical
  • Industrial
  • Material Handling
  • Military and defense
  • Wire and cable

LDPE Tubing and Custom Shapes Applications

The beauty of LDPE is it has most of the benefits of HDPE but is flexible.

Among the applications for LDPE tubing and custom shapes are:

  • Automotive
  • Conveyor
  • Geophysical
  • Industrial
  • Material Handling
  • Military and defense
  • Wire and cable

What to Look for When Buying HDPE and LDPE Tubing and Custom Shapes

There are numerous manufacturers of HDPE and LDPE tubing and custom shapes. If you are looking for a company to partner with you should consider the following:

  • Years of experience
  • The sophistication of their extrusion process
  • Their ability to meet your specs in terms of size, etc.
  • Their track record on completing projects on time
  • Cost
  • Who their customers are

Ideally, if you choose the right company you will build a long-term relationship which will alleviate supply and quality issues and allow you to focus on other things.

Flexible Vs. Rigid Plastic Extrusion

Many custom plastic extrusion companies offer flexible and rigid plastic extrusion parts. Which one is right for you is always an interesting question that requires some research and thought.

Let’s look at each part – flexible and rigid – and see how they are commonly used.

Flexible Plastic Tubing

 Generally, flexible plastic tubes are used where the plastic needs to bend to fit a particular use.

When speaking of flexible plastic tubing, there are two common materials:  Polyvinyl Chloride [PVC] or Polyurethane [TPU].  PVC is widely used in the industry and typically is the lowest cost material.  Polyurethane is better suited for certain applications, typically involving wear, than Flexible PVC.

PVC vs Polyurethane

 Let’s examine the differences between the two in more detail.

PVC [or in this case FPVC] is the most popular flexible plastic extrusion tubing material for a reason. It has rubber-like flexibility [although it can be made to be rigid.]  It allows for outstanding liquid flow. And it offers a broad range of chemical and corrosion resistance as well as solid abrasion and wear resistance.

Additionally, PVC plastic has numerous construction options such as spiral, wire or cord reinforcement or unreinforced tubing.

Industries that use PVC tubing:

  • Medical
  • Industrial
  • Laboratory
  • Chemical
  • Food and beverage
  • Dairy
  • Appliance
  • Cleaning apparatus
  • Pool and spa
  • Energy

A PVC plastic tubing downside is that it can harden and crack when used to move certain liquids, such as concentrated acids and alkalis. Also, flexible PVC is made with an additive plasticizer, which over time gets sticky and gummy.

Unlike PVC, Polyurethane has no plasticizers added to its composition. It combines the best characteristics of plastic and rubber, which allows for tremendous natural flexibility and is abrasion resistant.

Like PVC, Polyurethane has its issues. Depending on its composition properties, which can vary, certain polyurethane plastics do better – or worse – than others depending on its usage.  Ether based TPU’s are preferred if the product is to be submerged or used in a very humid environment.  Ester based TPU’s work best if the product comes in contact with oils, fuels, or solvents.

Most common applications for polyurethane plastic tubing include:

  • Cable jacketing
  • Pneumatic control systems
  • Air lines
  • Powder and granular material transfer
  • Fluid line
  • Sleeving
  • Low pressure hydraulics
  • Robotics
  • Industrial
  • Food and beverage

Rigid Plastic Tubing

Rigid plastics are as advertised hard and inflexible and mostly used in external environments. They are often used as a cheaper alternative to metal, or more expensive materials.

Rigid plastics can be made with a variety of materials. They include:

  • Acetal
  • Acrylic
  • ABS
  • Polycarbonate
  • Polystyrene
  • PVC
  • Nylon
  • UHMW

Rigid PVC [or RPVC] can be easily extruded into weather resistant, high tensile and impact resistant plastic that makes it ideal in a number of industries. They include:

  • Electrical equipment
  • Construction products
  • Automotive
  • Horticulture
  • Engineering

Where Should You Buy Your Flexible or Rigid Plastics?

 The best thing to do when you are undecided in what type of plastic you need for your project is to find an experienced and reputable manufacturer.

In addition to helping you decide which type of plastic is best for you, you’ll want a manufacturer that offers a variety of options and choices.

For instance, what materials do they offer that can work in your application?  Can they provide long lengths of plastic?   Can it be spooled or wound on a reel?  Since flexible plastics can range from very flexible – 60a – to almost but not quite rigid – 95a –  you’ll want a manufacturer that has the capability to machine exactly the type and consistency of plastic that will work best for you.

Once you find the right company you can then develop a long-lasting relationship which will make your future plastics tubing buying an easier and less stressful process.

Spiratex UHMW Applications

Ultra High Molecular Weight Polyethylene, or UHMW/PE, is one of the most versatile and efficient polyethylene plastics manufactured in today’s industrial marketplace. Unlike most common thermoplastics, UHMW/PE can’t be injection molded. Rather, it’s extruded using significant heat and pressure, allowing UHMW/PE parts manufacturers to mold it into various shapes and sizes that make it ideal for numerous applications.

Qualities that make UHMW/PE a popular thermoplastic choice

UHMW/PE has a number of qualities that make it a desirable part component. They include:

• high impact strength, while remaining flexible
• high abrasion resistance
• low friction
• chemical resistance
• water repellent
• excellent dielectric and insulating properties
• stress-crack resistant
• biologically inert
• FDA-certified food safe capable

UHMW/PE applications

The applications for UHMW/PE are many and varied. Among the places you’ll find UHMW/PE in use is:

Food Service Cabinets

Because UHMW/PE is corrosion resistant, easy to clean and durable, it makes an ideal liner for food service cabinets.

Marine Industry

The high molecular weight of UHMW/PE makes it moisture resistant. It’s also enormously strong, hard and abrasion resistant. As a result, it’s the ideal plastic for dock construction and for dock fenders that keep ships from damaging wooden docks.

Construction Equipment

UHMW/PE has a low coefficient of friction and significant impact strength. This makes it the perfect thermoplastic to keep boom trucks and cranes from slipping on unstable surfaces. Its ability to withstand temperatures of more than 200 degrees, make UHMW/PE ideal for even the hottest construction sites as the pads will not slip or fail.

Conveyor Systems

UHMW/PE works beautiful on conveyor systems where the thermoplastic serves not only as a buffer against steel parts with considerable drag but also provides extended belt life. In conveyor systems involving bottles for food and beverages, the thermoplastic protects the bottles from breaking or being damaged.


UHMW/PE has long been used as a biomaterial for hip, knee and spine implants. Its use in all kinds of surgical orthopaedic parts continues to grow.

UHMW/PE Fibers

This flexible thermoplastic can be extruded into fibers that have number applications. That includes personnel armor, vehicle armor, cut-resistant gloves, bow strings, climbing equipment, fishing lines, parachutes, high-performance sails, skis, snowboards, guitar picks and kite lines.

Everyday Products

It’s hard to go through a day without using or coming into contact with a product with UIHMW/PE as a component. That includes guide rails in car washes, snow blower scraper blades, commercial refrigerators, walkway handrails at airports, forklifts and waterway gates. The list of uses for extruded UHMW/PE is endless.

What to look for when buying extruded UHMW/PE for your parts

If you’re searching for the very best UHMW/PE for your parts you want to find an experienced manufacturer expert in extruding the plastic to your exact specifications. You’ll also want a company that can build any part shape or size and who can take on complicated, customized projects, if required. There’s a short list of qualified experts in the field of UHMW/PE extrusion, so to find the right one for you should not be difficult.

All You Need to Know About Conveyor Guide Rails

Not all conveyor guide rails are equal.  Yet sometimes in the big picture of securing all the components required for an efficient and effective conveyor system to move your products, conveyor guide rails are overlooked.

So let’s take a look at what makes a solid conveyor guide rail and the differences between a good one and one that is not as effective.

Conveyor guide rail components 

Conveyor guide rails are part plastic and part metal or stainless steel. The metal used can be aluminum. There are different types and grades of plastic. You’ll want to focus on conveyor guide rails made with Ultra-High Molecular Weight Polyethylene, known as UHMW/PE.

For instance, if your plant environment is above 185F the guide rail

can break down if you are using the wrong plastic, so you’ll want a high temperature resistant UHMW/PE. Anti-static UHMW/PE helps safeguard against static discharges and dust accumulation. If color is an issue, any color UHMW/PE can be extruded although white is the most common.

The process

It’s important to know the process in which the conveyor guide rails are made. Generally, raw plastic goes through an extrusion process in which it is shaped and then crimped into the metal or stainless steel. The top part of the conveyor guide rail is plastic, and the bottom is metal.  If UHMW/PE is slipped over aluminum it does not need to be crimped.

The key is making sure there is no gap between the plastic and the metal. A gap can be trouble because the open space can become contaminated with dirt and bacteria, which can cause contamination in food applications.  

Standard or custom?

Some companies only make standard conveyor guide rails, which are built to fit more standard conveyor operating systems. However, there are more complex and unique systems that require a custom-made conveyor guide rail or plastic shape. The companies that build standard systems as well as produce custom ones are usually an excellent choice as it will give you more options when looking for the right conveyor guide rail system for your system.

How flexible is the guide rail? 

Flexibility can be a significant component of any conveyor guide rail you purchase. If your conveyor system bends you want to be sure the plastic component of the conveyor guide rail system stays inside of the stainless steel or aluminum, keeping your products on track.

This can mean custom-made guide rail systems, as opposed to a standard one. Again, not all companies are equipped to manufacture custom conveyor guide rails.

 One stop shopping?

As discussed earlier, not all conveyor guide rail manufacturers handle all of the part processing in house.  It’s usually a good idea to do business with conveyor guide rail manufacturers who do all their own tooling and handle the building of the part from start to finish.

The bottom line?

 The most important thing to look for you are buying a conveyor guide rail is a system that will keep your products moving along the conveyor seamlessly without any chance of damage to your products or stopping the line because of a breakdown. And you want a system you know is built well with the best components – as in built to last.