Does rubber-plastic insulation not require a moisture barrier? ?
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This post was last edited by Laughing in the World of Love and Romance on 2017-8-15 20:11. Is no moisture barrier needed for plastic and rubber insulation? ? Do other insulating materials such as foam glass and polyurethane also require a moisture barrier? Is this statement correct? ? ? Why? ? Closed-cell ratio? ?
Have you all heard this saying? . Let’s discuss it together. . Is rubber and plastic widely used in cold-insulation applications? ? ? ? ? ? ?
No one pays attention to me. . . . . . . . . Can the moderator take a look? . . . . . . .
The last edit to this post was made by realman321 on 2017-8-16 at 16:16. Article 6.1.2 of GB50264 stipulates that: “The thermal insulation structure shall consist of a thermal insulation layer, a moisture-proof layer, and a protective layer.” ”So, my understanding is that all insulation structures should have a moisture barrier to prevent external humidity and water from penetrating into the insulating layer, regardless of the type of insulation material used. However, this provision is not marked in bold, so it does not belong to the category of \"provisions that must be strictly enforced.\" Instead, it uses the word \"should,\" indicating that it is something that should be done under normal circumstances; the interpretation depends on individual judgment. Conservatively speaking, it is better to treat it as a mandatory provision, after all, it originates from mandatory **standards**.
I’ve heard that rubber-plastic materials don’t require a moisture barrier, as they can function as one on their own. . I’m not sure if this statement is correct. . I have seen this practice in person; I’m not sure if it’s reasonable. . . Please give your advice
The function of the moisture barrier is to prevent the insulation material from getting wet, thereby ensuring its insulating properties. Rubber and plastic materials are already waterproof, so there is no need for an additional barrier. There’s no need to focus on precise wording; it’s necessary to consider the function.
My understanding is that the cooling temperature for rubber and plastic materials isn’t very low; it’s usually around -10 degrees. So whether or not a moisture barrier is used makes little difference； Ordinary polyurethane insulation materials are waterproof, and moisture barriers are also installed during on-site construction. My personal understanding.....
Water is a substance with high thermal conductivity, and air can condense into water or ice at low temperatures, which has a serious impact on heat retention; therefore, it must be removed. Insulation layers are generally composed of three tiers, from the inside out as follows: 1. Polyurethane foam layer, used for heat insulation ； 2. Coarse glass cloth, used for moisture prevention ； 3. Alloy aluminum sheet, used for protection.
Rubber-plastic materials do indeed have a high degree of closed porosity; they are impermeable to water and do not absorb it； However, in actual construction, it is not possible to meet the waterproofing requirements ； I have previously worked on the rubber and plastic insulation for liquefied natural gas pipelines, and it is very difficult to ensure the integrity of the seams during the construction process ； At the same time, in low-temperature conditions, the thermal expansion and contraction of rubber and plastic materials can easily damage the joints ； Based on current experience, all low-temperature engineering design solutions, whether they involve polyurethane, foam glass, or rubber plastics, include a moisture-proof layer ； It is recommended to install a moisture barrier
That makes a lot of sense. . It is indeed necessary to install a moisture barrier as required by the standards. . Recently, I’ve seen many projects in the field of fine chemicals where the rubber and plastic materials used for insulation lack a moisture-proof layer; therefore, I’m reaching out to everyone for advice