The products we are constantly surrounded by, yet often fail to notice, include rubber profiles. There is hardly a day that goes by without coming into contact with a product or an environment where these profiles are used. Rubber profiles, produced by extrusion, are everyday elements and, as such, are an integral part of the things we use.
Although these are ubiquitous products, we are often unaware of the benefits they bring to our lives and how essential they are in our daily routines. Beyond their primary function, they often provide an additional layer of protection for objects against various environmental degradation factors.
What is Rubber Extrusion?
Rubber extrusion is a manufacturing process that involves the transformation of rubber materials into products with specific shapes designed for particular needs—whether for protection against external elements, sound insulation, vibration control, or impact protection.
The rubber extrusion process “forces” rubber through a die with the desired cross-sectional shape under pressure from an extruder. When heated synthetic or natural rubber passes through the mold, it adopts the required profile and shape, often based on precise customer specifications.
Rubber extrusion allows for customization and provides a wide range of highly durable products that meet specific user needs. Whether in terms of size, shape, length, or resistance levels, profiles can be relatively easily tailored to the required specifications.
Benefits of Rubber Extrusion and Applications
When it comes to rubber extrusion, it’s important to note that the resulting elements are used across almost all industries due to their wide applicability and various benefits they offer to the end user.
Rubber profiles obtained through extrusion are lightweight, flexible, highly durable, and long-lasting. Their greatest advantage lies in their resistance to various impacts, especially external ones, making them suitable for use in the most demanding conditions. Depending on the type of raw material chosen (rubber type), they are durable against exposure to chemicals, high and low temperatures, time, friction, and abrasion.
The applicability of rubber profiles and extruded rubber spans across industries such as the automotive sector, energy, construction, agriculture, logistics and distribution, and many other industrial fields. Regardless of the industry or its size, there is always a place where rubber profiles are needed.
The most visible, common, and familiar use of rubber profiles is in seals for windows and doors, but their utility is far broader, extending from complex machinery to the simplest containers.
Common Types of Rubber Profiles and Materials
The general classification of profiles includes classic rubber profiles and profiles made from foam rubber. The most commonly used raw materials for making profiles include rubbers based on SBR, EPDM, NBR, CR, NR, and VMQ (silicone), chosen based on user specifications and the requirements of the profile. In addition to classification based on composition and resistance to environmental impacts, profiles can also be classified based on hardness and flexibility. Before designing a profile, it is crucial to consider all the requirements the profile must meet during use to choose the most efficient and suitable material for its production.
When it comes to profile design, the following types are worth highlighting:
- U-profile
These profiles are “U-shaped” and have a channel that can hold a metal rod, edge, or other substrates. - J-profile
J-shaped profiles are used to press into place and create a secure sealing connection between two surfaces. They are most commonly used as seals for doors and windows. - C-profile
These profiles are used to protect and cover exposed metal edges, providing sealing, protection against various weather conditions, and vibration damping. - D-profile
D-profiles have a semicircular protrusion and a flat bottom. The protrusion is sealed under compression, while the flat part is attached using an adhesive backing. - P-profile
These profiles have a rounded protrusion and a flat part, resembling the letter “P.” The protrusion ensures sealing under compression, while the flat part attaches to the substrate. - E-profile
These profiles, shaped like the letter “e,” have a typical semicircular protrusion that supports compression, with a flat, narrow section or “tail” that attaches to the substrate. - I-profile
These profiles are shaped like the letter “I,” with a flat body and a flat part on the top and bottom. They can be installed between two surfaces to prevent leakage or used for cushioning or support. - Profiles with multiple grooves and sides
These are typically profiles made to specific customer requirements.
What to Consider When Choosing a Material
Before submitting a request for the creation of a profile, several important factors must be considered.
Choosing the right material (raw material) is crucial, as it determines the profile’s resistance and, consequently, its durability and efficiency. If it’s not possible to independently determine the rubber composition of the profile, it is necessary to specify the media to which the profiles will be exposed (e.g., lubricating oils, acids, alkalis, etc.), as well as environmental influences (e.g., temperature, ozone, etc.). The proper selection of material, or defining the media impacts the profiles will be exposed to, will significantly affect the product’s lifespan.
Another important criterion is defining the design (cross-section) of the profile to ensure that its adaptation to the substrate is as effective as possible. Each profile, with its geometry and design, should be maximally suited to the needs and purpose. If the design is well-defined, the profile will fit perfectly on the surfaces it adheres to, increasing performance and efficiency.
It’s important to also consider the required tolerances concerning the profile’s dimensions when placing an order. The tolerances for rubber profiles are defined according to the ISO 3302-1 standard in classes E1, E2, and E3.
Some of the factors to consider when selecting rubber and designing a profile include:
- Material hardness (ShA) and density
- Temperature resistance
- Abrasion resistance
- Ozone and UV radiation resistance
- Resistance to oils, fuels, and gases
- Acid resistance
- Flexibility
All these factors will define the final product and its properties. Therefore, it is crucial to define all these aspects before proceeding with production to allow for sample testing and ensure the highest possible quality and performance of the product.
A Product That Will Never Be Forgotten
Recommended Product Lifespan
First and foremost, it’s important to distinguish between “shelf life” and “service life” of rubber products. “Shelf life” refers to the period of storage during which the product retains its usability properties, while “service life” refers to the time during which the product can be functionally utilized. The recommended shelf life is generally related to the type of elastomer (rubber) the profile is made from, assuming proper storage conditions are maintained.
Storage
Over time, all rubber products may undergo changes in their physical properties and become unusable due to excessive hardening, softening, cracking, the formation of fissures, or other surface degradations. These changes can be the result of one or more factors, such as exposure to oxygen, ozone, light, heat, moisture, water, oils, and solvents. The harmful effects of these factors can be minimized or eliminated with appropriate storage conditions.
Temperature
The recommended storage temperature for rubber products is between 2°C and 25°C, although, ideally, temperatures should be below 15°C. High temperatures accelerate the aging and degradation of rubber. The effects of low temperatures are less harmful to the rubber itself, but in such cases, rubber elements can become harder and lose some functionality. It is recommended that temperatures not fall below 2°C. The relative humidity of the air in the storage area should be between 40% and 70%. Very humid or dry environments should be avoided. If necessary, the storage area should be ventilated, and condensation should not be allowed to form.
Light
Rubber profiles should be protected from strong light sources, such as sunlight or intense artificial light with high UV radiation.
Oxygen and Ozone Exposure
Where possible, rubber products should be protected from oxygen (O2) and ozone (O3). Ozone is especially harmful because it causes the breakdown of polymer chains by breaking carbon bonds into smaller chains. Therefore, rubber profiles should be stored away from ozone-generating equipment, such as electric motors, fluorescent lighting, and high-voltage devices.
Oils, Solvents, Corrosive Liquids, or Vapors
Exposure or contact with certain oils, solvents, and corrosive liquids and vapors can significantly negatively affect most elastomers (rubber), accelerating the degradation of the product.
Regardless of the recommended shelf life, we believe it is beneficial to thoroughly inspect rubber profiles before discarding them, and the decision to dispose of them should primarily be based on whether they can still be used for their original purpose.
Conclusion
Rubber profiles are certainly not products that will fade into oblivion. While the raw materials may evolve over time due to innovations, the need for these products will remain. Wherever we turn, rubber profiles are a part of our daily lives. Though they may seem like trivial parts of a product or machine, they are anything but that. They ensure the proper functioning of products at maximum performance levels, providing safety and resistance. As industries and innovations progress, we will likely see an increasing demand for custom profiles tailored to specific industries and applications. For example, the electric vehicle industry is already seeking such profiles. Special materials and profile designs are becoming the new standard. Thanks to this demand, the rubber manufacturing and extrusion industry can achieve a greater balance between durability, quality, design, and functionality. vozila to već sada traži. Posebni materijali i dizajn profila postaju novi standard. Zahvaljujući takvoj potražnji i sama industrija proizvodnje i ekstruzije gume može postići veći balans između trajnosti, kvalitete, dizajna i funkcionalnosti.