Cracking of rubber-plastic insulation layers is a common quality problem in air conditioning, chilled water, and refrigerant piping systems. This issue not only affects appearance but also compromises anti-condensation and insulation performance, and in severe cases, can lead to localized corrosion and increased energy consumption. The following is a systematic analysis of the main causes of cracking in rubber-plastic insulation layers from the perspectives of materials, design, construction, and the operating environment.

First, stress-induced construction is a core cause of cracking. When installing rubber-plastic insulation pipes or boards, if the material is stretched, forcibly aligned, or compressed to achieve a perfect fit, the initial stress is "locked" within the insulation layer. During system operation, temperature changes cause normal thermal expansion and contraction of the material, and these initial stresses gradually concentrate at joints or corners, eventually leading to cracking or joint breakage.

Second, improper joint treatment is also a common contributing factor. Uneven joint cuts, loose seams, or uneven adhesive application can make the joints weak points in the structure. When rubber and plastic materials experience slight shrinkage or vibration during operation, the joints are most prone to failure first, leading to cracks that propagate along the seam direction.

Third, improper selection or use of adhesives directly affects the integrity of the rubber and plastic insulation layer. If the adhesive is incompatible with the rubber and plastic material, or if its temperature and aging resistance are insufficient, the bonding strength will decrease after a period of use, causing the joints to gradually loosen and crack under external force or temperature differences.

Fourth, environmental factors causing material aging cannot be ignored. Long-term exposure to ultraviolet radiation, high temperatures, or ozone will cause rubber and plastic materials to age, harden, and lose elasticity. When the material's flexibility decreases, its ability to adapt to deformation weakens, and even normal thermal expansion and contraction can trigger cracks, especially in outdoor and high-temperature areas such as computer rooms.

Fifth, mechanical compression and external forces are also important factors leading to cracking. In areas such as supports, clamps, and wall sleeves, if the rubber and plastic insulation layer is compressed for a long time, the local thickness decreases, and the material is under high stress, making it prone to cracking at edges or areas of concentrated stress.

Sixth, improper selection or insufficient thickness can amplify the risk of cracking. An excessively thin rubber-plastic insulation layer has limited buffering capacity under temperature changes and vibration conditions, making it more prone to cracking due to stress concentration. Simultaneously, products with unstable density and quality, and uneven internal material structure, will also reduce overall crack resistance.

Seventh, unsuitable construction environment conditions can also create hidden dangers. Construction in low-temperature, high-humidity environments makes it difficult for adhesives to fully cure. While the joints may appear strong initially, they are prone to gradual cracking after operation.

In summary, cracking of rubber-plastic insulation layers is often not caused by a single factor, but rather the result of multiple problems. Among these, stress-induced construction, inadequate joint treatment, and material aging are the most significant causes. By selecting appropriate materials, standardizing cutting and bonding processes, avoiding tensile installation, and strengthening protective measures, the probability of cracking in rubber-plastic insulation layers can be effectively reduced, ensuring the long-term stable operation of the system.