Silicone liners have been used since the 1980s in the prosthetic industry because 2 component RTV silicones were commonly used in prosthetic facilities for a number of applications thanks to the ease of mixing and to the room temperature cure as well as to the great detail resolution that silicone provided when molded.<\/p>\n
Therefore when the first triple S sockets (silicone suction sockets) were developed by Carlton Fillauer in the 1980\u2019s he simply used, with great success,\u00a0 the 2-component silicones that he already had readily available on his lab bench.<\/p>\n
Ossur, then, developed the first non-custom silicone liner using a matrix reinforcement at the distal end, making a more convenient, off-the-shelf version of the 3S liner, so to speak.<\/p>\n
In many respects silicone seemed, at the time to be the ideal choice for prosthetic liners as it has the following desirable properties:<\/p>\n
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- Easy to clean<\/li>\n
- Repels dirt<\/li>\n
- Does not stain<\/li>\n
- Does not retain bad odors<\/li>\n
- Has a high coefficient of heat transfer (cools the limb better)<\/li>\n
- Can be molded in very thin sections, resulting in very light liners<\/li>\n<\/ul>\n
However, the high coefficient of static friction of silicone caused skin blisters in patients with sensitive skin.<\/p>\n
Therefore approximately 25% of patients could not tolerate long term use of silicone liners.<\/p>\n
The high coefficient of friction per-se would not be a huge problem if the modulus of elasticity of silicone were low enough to allow the skin to move when subjected to shear forces.<\/p>\n
The modulus of silicone though is not low enough for many patients resulting in blistering of the skin.<\/p>\n
Such blisters are prone to be a source of more serious sores especially in patients with poor vascularity.<\/p>\n
Over the years different additives have been developed that are introduced in the silicone rubber formulation which exude from the liners and provide lubricity on the skin.<\/p>\n
And thermoplastic gel liners have been developed having a much lower modulus of elasticity than silicones and some like the EasyGel liners that have a modified surface to eliminate sticking altogether.<\/p>\n
\u00a0ALPS skin friendly silicone liners<\/u><\/em><\/strong><\/p>\n
Prosthetic liners manufacturers tried to solve the above-mentioned issues by including additives to the silicone to reduce the coefficient of static friction; however, the exudate substance can collect dirt, exacerbating the risk of skin issues, and the prosthetic liner may become slippery.<\/p>\n
Alps expertise in processing silicone allowed our engineers to come up with a new manufacturing method which improved the friction characteristics of the silicone prosthetic liner.<\/p>\n
The surface of the prosthetic liner has been modified, to create micro craters that reduce the static friction without any additives, resulting in a completely skin friendly silicone.<\/p>\n
Silicone with the modified surface layer shows a reduction of 80% of the coefficient of static friction, as shown in the graph below.<\/p>\n
![\"\"](\"https:\/\/media.easyliner.eu\/easyliner\/uploads\/2022\/03\/Silicone_EN-1.png\")
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