Jälkikovetuslahoja

Jälkikovetuslahoja is a Finnish term that translates to "post-curing defects" or "secondary curing defects" in English. It refers to imperfections that appear in materials after they have undergone an initial curing process. These defects are not present immediately after the primary hardening phase but develop over time due to various factors.

These defects can manifest in several ways. One common type is cracking, which can occur due to internal stresses within the material that are released or exacerbated by changes in temperature, humidity, or mechanical loading. Another form of jälkikovetuslahoja is delamination, where layers within a composite material separate. This can be caused by poor bonding between layers or by moisture absorption that leads to swelling and separation. Surface imperfections, such as blistering or peeling, can also be considered post-curing defects.

The causes of jälkikovetuslahoja are diverse. In polymers and resins, residual stresses from the initial polymerization process can lead to cracking if not properly managed. Thermal expansion and contraction cycles can induce stress, especially if the material has a low thermal conductivity or is subjected to rapid temperature changes. Moisture ingress is a significant factor, as water can penetrate the material and cause swelling, hydrolysis, or promote chemical degradation, leading to embrittlement and cracking. Improper storage conditions, such as exposure to direct sunlight or extreme temperatures, can also contribute to the development of these defects. Environmental factors, including exposure to chemicals or UV radiation, can also degrade the material over time, leading to secondary issues.