Polyethylene (PE) foam tape is a type of adhesive tape made with polyethylene foam as its base or carrier. It comes in a variety of thicknesses, colors, and levels of adhesion (‘stickiness’) and can be found everywhere! You will see it used in a wide variety of markets across many industries. Once you recognize polyethylene foam tape, you can’t unsee it because its properties and characteristics are so unique. Have you ever brought a greeting card with something stuck to the front? Had an electrode pad stuck on your skin? Looked through a pane of glass with faux dividers (mutton bars)? Seen a foam gasket inside of an HVAC duct or in a shipping package? Chances are you’ve seen Adhesive Applications’ foam tape in action. In fact, you’ll find our foam tape in 100’s of uses from Automotive to Medical to Aerospace and many, many other specialty bonding, sealing, and damping applications.
Why PE Foam Tape?
These tapes offer superior insulation, cushioning, gap filling, and shock absorption properties compared to other types of adhesive tapes. In this article, we’ll discuss the formats for polyethylene tape, the characteristics of PE foam and foam tape, the range of adhesives for PE tape, how PE foam is manufactured through Adhesive Applications’ affiliate company MHXCo, and the wide range of its applications in various fields.
Features of Polyethylene Foam
Polyethylene foam has properties valuable in a variety of applications:
- Gap filling – because the foam can be made in a range of thicknesses from 1/32” (0.020”) up to 3/16” (0.19”) it can be used for a wide variety of gap filling and sealing applications. MHXCo Foam can also design custom thicknesses for unique applications.
- Water resistant – because polyethylene foam is a closed-cell structure, it repels water and is therefore an effective seal.
- Chemical resistant – the chemical make upmakeup of the material makes it ideal for withstanding exposure to somecertain solvents and chemicals
- Thermal insulation and sound dampening – the cell structure and nature of the foam make it a good solution for applications demanding this type of performance.
- Density Range – MHXCo foams have a density range from 2.5 to 6 pounds, making them a lightweight addition to any application. In addition, MHXCo has developed higher-density foams for specific solutions and can customize for use.
- Appropriate for skin contact – Polyethylene foam can be manufactured for skin contact, which is ideal in medical, transdermal, wearable devices, and personal care applications. MHXCo foams meet the requirements of ISO 10993 and 10993-1 standards.
- Shear and tensile strength – polyethylene foam exhibits excellent shear and tensile performance, making it an ideal solution for specific industrial applications.
- Wide Range of Colors – Typically, polyethylene foam comes in white, gray, black or blue, but at MHXCo, polyethylene foam can be created in almost any color.
MHXCo Polyethylene Foams
MHXCo manufactures a variety of foam formulations used in a variety of industries including ZXET, ZXPE, and ZEVA. Their names refer to the different chemistries used to make the foam that gives them their unique properties:
- ZXET foams offer superior adhesive anchorage and are ideal for tape and other industrial applications where a balance of strength and conformability are desired.
- ZXPE foams offer excellent strength at low densities (therefore lower weight) and provide excellent thermal insulation.
- ZEVA is a very soft and conformable grade ideal for medical and other uses where flexibility and conformability are required
How Foam is Made
There are three steps to making polyethylene foam: extrusion, crosslinking, and expansion:
In extrusion, polymer resin pellets are combined with other materials in a “recipe,” determined by the requirements of the finished product, and extruded out into a sheet. In this form, the foam-to-be is referred to as a “matrix,“ and it looks like a roll of plastic.
The extruded material is then cross-linked. The matrix produced in the extrusion process will go through a high-temperature oven in the expansion process to turn it into a foam. Without an additional process, the matrix would have no internal strength and fall apart when exposed to high stresses or temperatures. Crosslinking prevents that. Crosslinking can be done chemically but that introduces unwanted chemicals into the process and can make the foam less suitable for adhesive tape manufacturing. Instead, MHXCo utilizes ebeam irradiation in which the matrix is irradiated with a million-volt (plus) electron beam. This causes the long chains of polymers (molecules) within the matrix to be bonded or “linked” together. Crosslinking makes materials tougher, less flexible, and resistant to softening when heated. These crosslinks tie all the polymer molecules together.
The expansion process is the final step in foam manufacturing. Referred to as the “the magic moment at MHXCo, this is when the extruded roll is fed into the oven and expands or foams into a lighter wider roll of foam with controlled thickness and density. As the material leaves the oven, it is checked for quality, rolled, and bagged.
| A Note About Stearates When manufacturing foam for a pressure-sensitive adhesive (PSA) application, it is important to consider stearate-free foam. Adhesive Application’s sister company, MHXCo, produces polyethylene foam in rolls that are stearate-free. Some foam manufacturers use zinc stearate in their processes as a lubricant and a release agent. Lubricant enables the product to flow through production equipment easier and a release agent minimizes the foam from sticking to the manufacturing equipment. Stearate can reduce the performance of adhesives that are used in customers’ foam applications such as tape. For this reason, MHXCo does NOT use zinc stearate in any of its products. |
Making Polyethylene Foam a Tape: Adhesives for Polyethylene Foam
There is nothing inherently sticky about polyethylene foam. It’s often combined with an acrylic or rubber-based adhesive. To create polyethylene foam tape, large rolls of foam are coated with adhesive in a roll-to-roll process. MHXCo’s sister company, Adhesive Applications, coats foam rolls as wide as 63 inches with a variety of adhesive formulations and thicknesses for different applications.
Characteristics of Polyethylene Foam Tape: The Foam
Closed-cell polyethylene foam is made of polyolefin resin. Polyolefin is a type of synthetic plastic prepared by the polymerization of olefins. In polymerization, small molecules, called monomers, chemically combine to produce a very large molecule called a polymer. Usually, at least 100 monomer molecules combine to make a polymer that has certain desirable physical properties, such as elasticity, or high tensile strength.
Olefins are hydrocarbons (compounds containing hydrogen [H] and carbon [C]) whose molecules contain a pair of carbon atoms linked together by a double bond of their orbiting electrons. Olefin’s advantages are its strength, colorfastness, and resistance to staining, mildew, abrasion, and sunlight.
Polyethylene Foam Tape Product Structure
Polyethylene foam tape can be single or double-coated. In a single-coated product, the adhesive is coated onto only one side of the roll and a liner is applied so that the tape does not stick to itself. In a double-coated product, adhesive is coated onto both sides of the foam and a release liner is applied to one or both sides of the foam.
Rubber versus Acrylic Adhesive for Polyethylene Foam
Polyethylene foam is typically coated with a rubber or acrylic adhesive. Rubber adhesives are based on natural or synthetic rubbers and are made with resins, oils, and other ingredients. Because rubber exhibits high “tack” it sticks almost instantly in the right conditions.
Rubber is also economical but is not the best choice for high or low temperatures or applications where the tape will be exposed to solvents, such as in some automotive uses.
Acrylic adhesives are made with acrylic polymers that stand up well in temperature extremes and age well over time and are generally more transparent. Depending on the formulation they can also have higher strength, and be modified for removability.
Logs vs Rolls vs Die Cut vs Spools: the Forms of Polyethylene Foam Tape
Polyethylene foam tape is an excellent material for a variety of converting processes. It can be purchased on large rolls right off a coater; cut down to smaller specified roll lengths and widths; spooled for easy application in a variety of lengths and widths; or die cut with specifically sized and shaped pieces. The form will be dictated by the end use applications and the application process.
Applications for Polyethylene Foam Tape: Why It Can’t Be Unseen
PE foam tape has a range of uses across various industries, such as aerospace and automotive engineering, product development, electronics manufacturing, construction projects, research laboratories, medical field devices, and more. You can find PE foam in a lifesaving EKG pad; dampening the shake and rattle of a headliner inside a car, or as an attachment for a greeting card that raises the profile of a novelty.
In the aerospace and automotive industry, polyethylene foam tapes are used to provide thermal insulation between components such as engines and tanks. They are also used in automotive engineering for sound-dampening purposes such as reducing road noise inside the cabin or engine noise outside the vehicle bodywork.
Look inside the box of a new electronic device. In freight and packaging, PE foam tapes are widely used by product developers for cushioning fragile items during shipping or storage which helps prevent damage due to shock or vibration while also providing additional protection against dust or moisture infiltration.
Lastly, they are widely used in research laboratories where they are used on delicate equipment that needs to remain vibration-free during operation or storage due to their superior shock-absorbing properties.
A Note About Sustainability
MHXCo ensures that little to none of the scrap generated by the manufacture of polyethylene foam goes into a landfill. Much of the matrix that has not been crosslinked is reused for specific applications. And offcuts from the rolls of polyethylene foam are used to make playground flooring.
In conclusion, polyethylene foam tape is a versatile material with many potential uses across multiple industries including aerospace engineering, automotive engineering, product development, and research laboratories among others. Its unique combination of thermal insulation properties along with superior shear strength makes it an ideal choice for many applications where cushioning or protection from vibrations is required. As technology advances so do the use of polyethylene foam and its applications.With its wide range of uses across different fields; understanding how polyethylene foam tape works can help engineers choose the right material for their projects—and prevent costly mistakes down the line. For help with polyethylene foam, reach out to MHXCo at info@MHXCo.com or (518) 843-8400. Or for polyethylene foam tape, reach out to Adhesive Applications at info@adhesiveapps.com or call (413) 527-7120.