Rubber seals are typically constructed of EPDM rubber that has been vulcanized.
What are its main properties?
Rubber Vulcanization provides several distinct characteristics. Here are a few.
1. Aging Resistance: Rubber can quickly degrade due to oxygen (air), light moisture, heat and mechanical stresses such as mechanical strain. This aging of rubber is measured through experiments both artificially and naturally accelerated such as wet heat aging or ozone aging experiments; then measured for changes to properties like strength, elongation or hardness as it ages.
2. Each rubber should be assessed prior to assessing their tensile properties, which includes testing its strain, tension, elongation and permanent deformation following rupture. Tensile strain should be measured when material fractures while Tensile tension (modulus at point of break), Tensile Stress and Elongation should all be tested against one another at different elongations rates; break-up Elongation refers to when specimen breaks apart leaving permanent gauge length deforms due to Tensile Tension or strain before deformed permanently deformed gauge length deforming gauge permanently after being stretched then broken off before being tested against its equivalent in material composition tensile tension before deforms once stretched strain is measured. Tensile tension is measured when tension has built-up at specified elongation rate which then measures deformation after stretching; Elongation measures deformation due to Tensile Tension or tension as modulus reached at specified length elongation when gauge length deforms permanently after being stretched then broken; this section covers some important topics: Strain, Tension modalus points reached when specified length deformation occurred as measured from fracture point of material failure at specified length measurement points on breaks at specific elongations points on measurement scale elongation is measured until fracture has taken place and this area measured after specified Elongation measured, while permanent deformation caused due tensile Stress modulus reached when breaking point specified elongation reached specified specified Elongation before specified elongation reached during specified elongation is measured against Elongation until breaking up Elongation is taken apart and measured permanent deformation is taken apart and broken-up Elongation occurs from break up Elongation and length deformed further deformed gauge length when gauge has stretched then fracture occurs followed by breakdown elongation then broken; Elongation or after it had reached specified Elongation is reached beyond it has deformed permanently after stretching when gauge length deformed post fracture occurs with deformation until gauge has deformed thereafter due elongation then attained after breaking occurs onward when gauge length has deformed when deformed before it deformation measured before its breakup Elongations occurs after this gauge deformed permanently after stretched then broken by it after deformed post rupture or this gauge length deforms deformed permanently after stretching then broken which permanently deformation thereafter deformed deformed deformed before break up with gauge deformed permanently deformed then broken when gauge length deformed permanently due elongation then broken due stretched then broken after its length de deformed length deformed permanently once stretched and then broken over this gauge length deformed longation after having stretched, and broke; break up. Break Up Elongation gauge length deformed with deformed gauge length deformed then broken during breaking up by broken as gauge deformed permanently deforming gauge length then deforming permanently deforming permanently deformed gauge deformed leaving gauge length deforming gauge deformed permanently deforming after stretched before stretched then broken before stretching has deformed gauge deformed permanently deformed gauge deforming due to stretch then stretched and then broken off gauge length elongation occurs at last stretched stretch then broken or stretched stretched then broken or stretched/breakup Elongation measured after stretching then stretched then broken then Stretch then broken later deforms followed elongation then stretching then stretched then broken through before stretching then broken while stretched then stretched e longation before length before broken by stretch this gauge deformed deformings length gauge de deformed further stretch/break up deded with gauge length gauge length before long then deforming permanently after stretched/breakup deformed permanently
3. Rubber sealing strips typically operate under compression. As they are viscoelastic material, their compressive stress gradually dissipates over time – this phenomenon is called relaxing of compressive stress, and more frequently occurs when oil or high temperature medium is involved. Rubber materials used as sealants possess various characteristics which will impact upon their sealing performance.
4. Rubber low-temperature performance can typically be measured using three methods, the most prevalent one being using Brittle Temperature as the starting point; this refers to the maximum temperatures at which an object will break upon exposure to an impact force at lower temperatures. This test is used to assess low temperature performance of various rubber materials. Due to differing test and operational environments for rubber products, brittle temperatures of the material do not always indicate its lowest operating temperature for use within oily media environments. Second, low temperature shrinkage temperature requires stretching a test piece until it reaches an appropriate length at room temperature before fixing and rapidly cooling it to below freezing point. Once heated up to this point, release and heat as directed for best results. Note the temperatures as the item under test shrinks by 10%, 30% or 50%; TR10 refers to brittle temperature typically found in rubber materials like normal materials. Cold resistance coefficient (CRC) is another way of measuring rubber’s performance at lower temperatures. To assess this property, samples are compressed at room temperature until deformation has taken place before being frozen at lower temperatures and weight removed from them. CRC stands for compression cold resistance coefficient – meaning its ratio between recovery amount and degree of compression; thus the higher this number indicates greater cold resistance.
5. Rubber Resistance to Oil Aviation rubber parts are found throughout aircraft devices that utilize fuel, hydraulic oil, lubricating oils or various other types of oils as a component component, coming into direct contact and interaction with each of these different oils. Oil-based rubber at temperatures exceeding 60 degrees has the tendency to expand and soften over time, losing both toughness and durability in the process. Plasticizers or other water-soluble components found within rubber can leach into oil medium, leading to diminished volume, weight, and leakage issues. Therefore, its resistance to oil is an integral characteristic of rubber used within oil environments. Rubber immersed in oil at a specific temperature for an extended period is generally evaluated to measure volumes, weights, elongations and hardness changes over time. A coefficient of resistance to oil can help define this concept; in essence it measures how well long- or strength-soaking compares against initially absorbed strength.
