top of page
  • Writer's pictureDavide

A Look into Plasma Treatment for Superior Plastic Adhesion

Plasma treatment is a technique used to modify and enhance the surface properties of various materials, including plastics. It employs plasma, the fourth state of matter, to effect physical and chemical changes on the surface without altering the material's internal structure.

Through plasma generation, contaminants are removed, chemical changes begin, and surface energy is increased, resulting in improved performance and functionality of the treated materials.

In this article, we will delve into the method and see why it is crucial for enhancing adhesion, cleanliness, and wettability. Its usefulness means it is indispensable in fields as diverse as plastics printing and medical equipment.

What is Plasma Treatment?

Plasma treatment is a highly effective surface modification technique used to enhance the surface properties of a range of materials, including plastics. It involves the use of plasma — a partially ionized gas to modify, clean, and activate surfaces.

This process facilitates the improvement of adhesion, wettability, and other surface characteristics by changing the chemical and physical properties of the surface without altering the bulk material.


The principle underlying this technology is the interaction between the plasma's reactive nature and the surface of the material undergoing treatment. These reactive ions, electrons, and radicals instigate physical and chemical modifications. The physical changes typically involve the modification of the material's topography, leading to surface changes. This enhanced texture can be instrumental for applications where augmented surface area and improved adhesion are essential.


Chemical changes, on the other hand, are an alteration of the surface that yields improved wettability and bonding capabilities, making plasma treatment a coveted technique in industries ranging from electronics to biomedicine.

The key to plasma treatment lies in its ability to achieve these modifications without compromising the intrinsic properties of the bulk material. Furthermore, plasma treatment abstains from the use of harsh chemicals, presenting an eco-friendly alternative for surface modification. It ensures the safety of operators and end-users.

The parameters of plasma generation can be meticulously controlled to suit the specific needs of a material or application, rendering it a customizable solution for an array of challenges associated with surface properties.

Both types of plasma — atmospheric, or vacuum — have their unique applications and benefits. The choice between them is often dictated by factors including the material type, desired modifications, and application requirements.

Plasma Treatment Used on Plastics to Improve Adhesion

Adhesives, inks, coatings, and other materials often struggle to form a robust bond with the inert and low-energy surfaces of plastics. Plasma treatment has emerged as a high-quality solution.

The treatment of plastics with plasma is instrumental in improving adhesion properties. This is achieved by increasing the surface energy of plastics, leading to enhanced wettability and bonding characteristics.

The process involves exposing the plastic surface to the plasma, which can effectively remove contaminants, introduce functional groups, and increase surface roughness, promoting stronger adhesion.

A refined and optimized surface roughness augments the surface area available for bonding and ensures that adhesives and coatings infiltrate the microscopic valleys on the surface, ensuring a resilient and long-lasting grip.

The Different Applications of Plasma Treatment of Plastics

Plasma cleaning's versatility is showcased in its adaptability to diverse plastics and applications. Every plastic, from polyethylene to the more complex engineering plastics, can be treated with tailored plasma parameters to execute the desired surface characteristics.

1. Increase Surface Wettability

The enhancement of surface wettability stands as one of the significant breakthroughs attributed to the plasma cleaning of plastics. A high-energy, activated surface is a pillar for optimal wettability. This is a prerequisite in applications like coating, painting, and adhesive bonding.

Reactive plasma generated during plasma treatment interacts intensely with plastic surfaces, creating changes that elevate surface energy and promote superior wetting characteristics. Such enhancement is pivotal in sectors like automotive and electronics, where precise, uniform, and durable coatings are essential.

Wettability refers to the ability of a liquid to maintain contact with a solid surface, resulting from the interplay of adhesive and cohesive forces. The degree of wettability is often indicated by the contact angle that a droplet of liquid makes with the solid surface.

2. Improve Printing and Bonding Characteristics

Plasma cleaning has proven vital for augmenting printing and bonding quality on plastics. The technology ensures impeccable cleanliness, eliminating contaminants that often impede the formation of strong bonds.

Moreover, the introduction of functional groups augments the chemical compatibility between the plastic surface and inks or adhesives. Enhanced chemical bonding at the subatomic level translates into resilient and long-lasting macroscopic bonds. This is vital for applications requiring durability and resistance to environmental stresses.

3. Low Friction Plasma Coatings on Seals and O-Rings

Plasma treatments are also synonymous with the creation of low-friction surfaces, a boon for components like seals and O-rings. The intricate combination of ions and electrons in the plasma modifies the surface topography and chemistry of these components.

This modification results in reduced friction coefficients. Therefore, by reducing the amount of wear and tear, the operational life will be increased. Industries, especially those in the realm of machinery and automotive, benefit immensely, witnessing a reduction in maintenance needs and enhancement in the efficiency of mechanical assemblies.

Plasma Treatment and Printing on Plastics

Printing on plastics has long been a nuanced task, challenged by the inherently low surface energy of plastic substrates that resist the effective adhesion of inks. However, advancements in plasma treatment technology have substantially mitigated these challenges, establishing an optimized canvas for high-quality, durable prints.

Plasma treatment helps ensure that each drop will firmly hold where it is placed during the printing process. A higher surface energy ensures that inks spread uniformly, avoiding issues like beading or poor adhesion. Plasma treatment augments this parameter, ensuring that each print is resilient to wear and environmental stresses.

Plasma treatment ensures that the bond between ink and plastic is immediate and enduring. Prints withstand abrasions, environmental conditions, and chemical exposures, ensuring longevity and consistent performance.

This process also enhances the precision of these prints. Tailored parameters allow for targeted treatment, ensuring intricate designs and texts are printed with impeccable clarity and definition.

Plasma Treatment of Microfluidic Devices

Characterized by their ability to manipulate small volumes of fluids, microfluidic devices are integral in many applications, including medical diagnostics, biological research, and chemical synthesis. The role of surface properties in optimizing fluid flow and ensuring precise control over biochemical reactions is vital in Microfluidic devices.

Microfluidic devices are miniature systems that manipulate small amounts of fluids, typically through channels of micrometer dimensions. These devices are widely used in various fields, including chemistry, biology, and medicine, for applications like precise fluid control, chemical mixing, and biological assays.

Plasma treatment will increase the performance of microfluidic devices. When a device is treated with plasma, the surface undergoes a transformation that optimizes its interaction with fluids. Contaminants, which can impede fluid flow and compromise the accuracy of reactions, are effectively removed, leaving behind a pristine surface.

Elevated surface energy ensures fluids flow seamlessly through microchannels, minimizing issues associated with capillarity and wettability. This ensures that samples and reagents are transported efficiently.

Plasma treatment will also ensure that surfaces are clean and exhibit enhanced biocompatibility. Through this process, entities retain their functionality and integrity. The plasma treatment process is vital for accuracy and assists with the efficiency of microfluidic devices.

Plasma Treatment of Catheters

One of the chief concerns in catheter usage is the adhesion of coatings that are often applied to improve biocompatibility and reduce friction. Plasma treatment ensures that these coatings adhere securely to the catheter surface. It achieves this through the meticulous alteration of surface energy and the introduction of functional groups that foster robust chemical bonds between the coating and catheter material.

Medical procedures often expose catheters to a variety of physical and biochemical stresses. Plasma-treated catheters exhibit enhanced resilience, ensuring their structural integrity and performance remain uncompromised even under demanding conditions.

Sterility is non-negotiable in all medical equipment, and catheters are no exception.

Plasma treatment cleans the catheter surface at a microscopic level and sterilizes it. The reactive species generated during plasma treatment are lethal to a broad spectrum of microbial contaminants, ensuring that catheters are physically clean and microbiologically safe.

Reduction of surface friction is a critical attribute, especially for catheters that are inserted into blood vessels or other sensitive tissues. Plasma treatment can tailor the surface properties to achieve a low friction coefficient. This ensures ease of insertion and removal, minimizing patient discomfort and reducing the risk of tissue damage.

More Fields That Use Plasma Treatment on Plastics

Plasma treatment finds applications across a broad array of industries due to its efficacy in enhancing surface properties, adhesion, and cleanliness. Here are some fields that significantly benefit from this technology:

Construction Industry

In construction, materials are subject to stringent durability, safety, and performance criteria. Plastics are often preferred for their versatility, strength, and resistance to environmental elements. However, their surface properties sometimes require enhancement to meet the operational demands of the construction environment.

Plasma treatment in the construction industry is employed to improve the surface characteristics of plastic materials. For instance, plastic pipes, panels, and fixtures can be treated to enhance their adhesion properties.

Biotechnology and Laboratory Equipment

Plasma treatment is vital for cleaning, sterilizing, and modifying the surface properties of plastic labware, promoting improved sample handling and analysis. Plastic materials are frequently employed, given their versatility, durability, and cost-effectiveness. However, their inherent surface properties can sometimes be limiting, especially in applications requiring enhanced cleanliness, biocompatibility, and specific surface functionalities.

Plasma treatment addresses these challenges head-on, offering tailored solutions to optimize the performance of plastic labware and equipment. When it comes to cleanliness and sterilization, plasma’s reactive species effectively remove organic and inorganic contaminants from the surfaces. This guarantees the physical cleanliness and sterilization of labware like plastic containers, pipettes, Petri dishes, and other equipment used in delicate biological and chemical experiments.

Consumer Goods

In the consumer goods industry, plasma treatment is instrumental in ensuring that decorative elements, labels, and coatings adhere securely to the plastic parts of consumer goods. It achieves this by increasing the surface energy of plastics, promoting better wettability and adhesion.

Plasma treatment can also enhance the functional properties of plastic components. For example, plasma can be used to improve the water-resistance or hydrophilic properties in items that come into contact with liquids, depending on the specific requirements.

Textile Industry

Plasma treatment has carved a niche in the textile industry, especially concerning synthetic fibers and fabrics. Natural fibers have inherent properties that facilitate dyeing and finishing processes. However, synthetic textiles, often made from various plastics, can be challenging to dye and finish due to their low surface energy.

Plasma treatment modifies the surface properties of synthetic textiles, enhancing their dyeability and the adhesion of finishes. It introduces functional groups onto the fiber surfaces, promoting the binding of dyes and finishes, resulting in vibrant, long-lasting colors and textures.

Packaging Industry

The packaging industry is another area where plasma treatment is profoundly impactful. Plastic packaging needs to be printable and bondable to ensure product information, branding, and labels are securely affixed and visually appealing.

Plasma treatment cleans and activates the surface of plastic packaging materials, ensuring enhanced adhesion for inks, labels, and adhesives. It increases the surface energy, promotes wettability, and ensures that prints and labels are durable and resistant to handling and environmental conditions.

Final Thoughts

Plasma treatment is revolutionizing the modification and enhancement of material surfaces, including plastics, and is particularly instrumental in medical, industrial, and research settings. It optimizes surface adhesion, wettability, and cleanliness, ensuring robust and durable bonds for inks, coatings, and adhesives.

In the context of microfluidic devices, plasma treatment ensures optimal fluid flow and precision in biochemical interactions. It enhances biocompatibility, sterility, and performance when applied to catheters, ensuring patient safety and procedural efficacy. This versatile technology offers tailored solutions, ensuring materials meet stringent operational, safety, and environmental standards across diverse applications.

At SCI Automation, we’re not just service providers but partners in your journey, committed to delivering excellence that translates into enhanced material performance, product quality, and operational efficiency. Trust in our expertise is trust in a legacy of innovation, quality, and unparalleled customer service. Contact us today and let's see how we can meet your plasma cleaning needs.

bottom of page