The selection of the right tubing material is a key factor for a lot of industries, whether it is medical or pharmaceutical, or even food and beverage. The importance of the choice of materials such as Thermoplastic Elastomer (TPE) and silicone can cause a major difference in the output when it comes to the aspects of performance, safety, and the lifespan of the product. Both TPE and silicone display their own unique attribute sets which at the same time indicate the diversity of applications they can be employed in. In order to get the best tubing material for the product, one should have an in-depth knowledge of both materials’ properties, benefits, and downsides.
In this guide, TPE and silicone tubing will be thoroughly compared. Their basic properties will be looked into, their pluses and minuses will be discussed, and their behavior in different situations will be checked. This post will then compare their resistance to chemicals, tolerance of heat, lifespan, and cost-effectiveness. As a result, you will be able to make a difference between them and choose the one that better fits your needs. Consequently, the selected material will improve both efficiency and reliability.
Understanding TPE and Silicone Tubing
What is TPE Tubing?
TPE stands for Thermoplastic Elastomer is a combination of copolymer and physical mix of polymers and it usually represents a combination of plastic and rubber that is able to provide both thermoplastic and elastomeric properties. These elastic materials may be lifted to offer a higher probability of reusing, they will soften and becomes fluid. The hardening process is when the material reaches the specific cooling point. This cooling process is totally reversible and thus the TPE material can be recycled and reprocessed.
One of the reasons TPEs are praised is their adaptability. It is possible to tune their compositions in such a way that they provide a wide spectrum of hardness and other physical properties. The most popular examples of TPEs are styrenic block copolymers (TPS), thermoplastic polyurethanes (TPU), and thermoplastic vulcanizates (TPV). They are frequently used to make flexible and good sealing materials in the tubing industry, as well as for their processing ease.
What is Silicone Tubing?
Polydimethylsiloxane (PDMS), also known as silicone, is a thermoset elastomer. The basic structure of silicon and oxygen atoms alternatively attached together through the silicone chain makes it a very different constituent from the carbon-based residue of most of the organic polymers, e.g., TPEs. In the case of silicone, curing process or vulcanization through the method of chemical cross-linking should be followed during production, which can be started by heat (platinum or peroxide curing). Once cured, silicone gets an inability to be melted and reshaped, so it becomes a thermoset material.
This unique chemical structure makes silicone tubing be remarkably stable throughout a vast temperature range, remarkably flexible even at low temperatures, and incredibly biofriendly. It is identified by being non-reactive and resilient to numerous chemicals, UV rays, and ozone. The mentioned characteristics of silicone are the reason why this material is preferred for high-purity applications found in the medical, pharmaceutical, and food processing industries.
Key Differences Between TPE and Silicone
While both materials are flexible and durable, several key differences define their suitability for various applications:
- Chemical Structure: TPEs are carbon-based polymers, whereas silicone is based on a silicon-oxygen backbone. This fundamental difference affects their thermal stability and chemical resistance.
- Processing: TPE is a thermoplastic that can be melt-processed and recycled. Silicone is a thermoset that undergoes an irreversible chemical curing process.
- Temperature Range: Silicone generally offers a much wider operating temperature range, maintaining its properties from approximately -60°C to 200°C (-76°F to 392°F), with some grades extending even further. TPEs have a more limited range, typically from -30°C to 140°C (-22°F to 284°F).
- Hardness: Both materials are available in a wide range of durometers (hardness levels), but TPE offers greater formulation flexibility, allowing for a broader spectrum of textures and rigidity.
- Cost: The cost of raw materials and processing often makes TPE a more economical option compared to high-purity, medical-grade silicone.
Pros and Cons of TPE Tubing
✓ Advantages of Using TPE Tubing
Cost-Effectiveness:
TPEs are generally less expensive to produce than silicone. Their thermoplastic nature allows for faster processing cycles and the ability to recycle scrap material, which reduces manufacturing waste and lowers overall costs.
Versatility in Formulation:
TPEs can be easily customized. Manufacturers can adjust the formulation to achieve specific properties, such as hardness, color, clarity, and chemical resistance, making them highly adaptable to diverse product requirements.
Good Sealing Properties:
The soft and flexible nature of many TPE grades provides excellent sealing capabilities. This is particularly useful in applications requiring a tight seal against fluids or gases.
Chemical Resistance:
TPEs offer good resistance to a range of chemicals, particularly acids and bases. This makes them suitable for certain fluid transfer applications where exposure to specific chemical agents is expected.
✗ Disadvantages of TPE Tubing
Limited Temperature Range:
TPE’s primary limitation is its narrower operating temperature range compared to silicone. It can become brittle at very low temperatures and may deform or melt at high temperatures, restricting its use in extreme environments.
Lower Purity:
While some medical-grade TPEs exist, they generally contain more extractables and leachables than high-purity, platinum-cured silicone. This can be a concern in sensitive biopharmaceutical or medical applications where product purity is paramount.
Compression Set:
TPEs can have a higher compression set than silicone, meaning they may not return to their original shape as effectively after being compressed for an extended period. This can impact long-term sealing performance.
When to Choose TPE Tubing
TPE tubing is the material of choice when every cost is a crucial factor and the conditions lie within the temperature and chemical resistance levels it withstands. The tubing is good for applications like the moving of general purpose fluids, single-use medical devices, peristaltic pump uses, and consumer products requisitioning a versatile, robust material that is not necessarily high-performing like silicone.
Pros and Cons of Silicone Tubing
✓ Benefits of Silicone Tubing
Exceptional Temperature Resistance:
One of the most remarkable characteristics of silicone is its machinery property that can be effectively sustained across a very substantial range of temperature. It is becoming extremely flexible at low temperatures that other elastomers would be intermittent and also stable at the one that would be detrimental to the TPEs.
High Purity and Biocompatibility:
Silicone that has been cured by platinum is the most remarkable since it has hardly any elements that can be extracted and the resulting absence of leaching makes it biocompatible and non-toxic to a very high degree. This grade of silicone conforms to the most rigorous standards set by governmental and medical institutions (such as USP Class VI and FDA) and is hence very suitable for medical, pharmaceutical, and food-grade uses.
Excellent Flexibility and Low Compression Set:
Silicone is extremely flexible and has a small percentage of compression set, which indicates that it rebounds sharply even after compression. This assures that sealing performance would remain reliable and consistent over a long time particularly in peristaltic pumps and in sealing gaskets.
Resistance to UV and Ozone:
The chemical bond between silicon and oxygen, also referred to as the silicon-oxygen backbone, is very strong and not easily affected by environmental issues such as UV light and ozone, hence guaranteeing no cracks and a long service life in applications that are open-air and exposed to the elements.
✗ Drawbacks of Silicone Tubing
Higher Cost:
The raw materials and curing process for silicone are more expensive than for TPE, resulting in a higher cost per foot of tubing. This can be a prohibitive factor for cost-sensitive applications.
Lower Tear Strength and Abrasion Resistance:
Compared to some TPE grades (like TPU), silicone has lower tear strength and abrasion resistance. It can be susceptible to tearing if nicked or cut, which requires careful handling during installation and use.
Limited Resistance to Certain Chemicals:
While silicone resists many chemicals, it is not compatible with concentrated acids, solvents, and certain oils. Exposure to these substances can cause the material to swell and degrade.
When to Use Silicone Tubing
People always go for silicone tubing when the utmost purity, compatibility with living tissues, and functioning in very high or low temperatures are a must. It is primarily used in pharmaceutical manufacturing and medical instrument production (e.g., catheters and drain tubes), as well as in food and beverage processing and wherever very strict regulatory measures have to be obeyed. Besides this, the biocompatible nature of the material makes it an unrivalled choice in the medical field for assisted delivery and drainage lines.
Durability and Performance Comparison
Durability of TPE vs. Silicone Tubing
There are various means by which the toughness of a material can be quantified, such as tensile and tear strength, as well as abrasion resistance. For example, in terms of thermal toughness, silicone is the material of choice; however, some TPE types, especially the thermoplastic polyurethanes (TPU), have higher tensile strength and are more abrasion-resistant. For this reason, TPE grades show less wear and have better durability in high-abrasion applications. Silicone, on the other hand, continues to be a more suitable material for extensive exposure conditions as it shows stronger resistance against environmental aging caused by UV and ozone.
Performance Under Stress and Temperature
Silicone is the best material for high-temperature applications. It can operate comfortably in an environment in which TPE would melt. Thus, for purposes requiring sterilization through autoclaving or gamma radiation, the silicone is the better choice because it hardly changes through those methods. While TPE can be sterilized, it may have limits when it comes to the number of cycles it can take.
In terms of mechanical stress, silicone’s low compression set makes it superior for long-term sealing applications. For dynamic applications like peristaltic pumps, both materials can perform well, but platinum-cured silicone often provides a longer pump life due to its excellent flex fatigue resistance.
Long-Term Use and Maintenance
TPE as well as Silicone are both materials of low maintenance. Cleaning is a breeze with the hydrophobic surface of Silicone which also discourages the growth of biological material. TPE can be cleaned easily as well, but the continuous heat or chemical exposure might threaten its long-term performance to a greater extent. So in case one is looking at using and sterilizing it multiple times, silicone would be the more reliable and less expensive option in the long run.
Choosing the Right Tubing for Your Application
Factors to Consider When Choosing Tubing
- Temperature Range: What are the minimum and maximum temperatures the tubing will be exposed to?
- Chemical Compatibility: What substances will the tubing come into contact with?
- Regulatory Requirements: Does the application require compliance with standards like FDA, USP Class VI, or ISO 10993?
- Mechanical Stress: Will the tubing be subjected to abrasion, high pressure, or repeated flexing?
- Cost Constraints: What is the budget for the project?
- Lifespan and Reusability: Is the tubing for single-use or long-term, repeated use?
Applications Best Suited for TPE Tubing
- Single-Use Medical Devices: Syringe plunger tips, IV bags, and disposable fluid transfer sets.
- Food and Beverage Dispensing: General-purpose tubing where high temperatures and aggressive cleaning agents are not used.
- Consumer Goods: Grips, seals, and flexible parts in various household products.
- Industrial Fluid Transfer: For non-aggressive chemicals within a moderate temperature range.
Applications Best Suited for Silicone Tubing
- Biopharmaceutical Processing: Fluid transfer, peristaltic pump tubing, and cell culture applications.
- Medical Devices: Catheters, respiratory tubing, implants, and wound drains.
- Food and Beverage Processing: High-temperature fluid transfer, dairy processing, and applications requiring FDA compliance.
- Aerospace and Automotive: Seals, gaskets, and hoses exposed to extreme temperatures.
Reference Sources
- Introduction to polymers: View as single page | OpenLearn
This source provides foundational knowledge about polymers, including silicone rubber, which is relevant to understanding material properties. - Latest Model Pharmaceutical Tubing Plug Single-use
This discusses the use of TPE and silicone tubing in pharmaceutical applications, highlighting their compatibility and assembly. - Shear strength and artificial aging
This academic paper explores material properties like bonding shear strength, which can be relevant when comparing TPE and silicone tubing. - Find more info now.
