PVC pipe manufacturers introduced that the molecular chain structure determines the physical and mechanical properties of PVC. Under natural conditions, PVC polymer presents an amorphous molecular structure, and the molecular chains are arranged randomly in the direction. However, under certain temperature, pressure and speed conditions, when the material is biaxially stretched, the molecular chains of the PVC polymer are arranged along the stretching direction to form a layered structure. In the production process of PVC pipes, only a certain degree of axial stretching at high temperatures, little improvement in the performance of PVC.
Under the premise of the aforementioned axial stretching, the PVC-O pipe is subjected to a biaxial stretching process at a low temperature, so that the PVC molecular chain is further stretched in the axial direction, and it is important to stretch in the diameter direction. The molecular chain structure of PVC is completely changed, and the molecular arrangement in the tube wall is transformed from the original random arrangement to a layered structure. This layered structure enables the pipe to withstand the brittle failure originating from the micro cracks of the material body or the scratches on the pipe wall surface, thereby avoiding the phenomenon of rapid cracking.
Steps for bonding PVC pipes and fittings for water supply: Before bonding PVC pipes and fittings, use a dry cloth to wipe the socket side and the outside of the socket. When there is oil on the surface, wipe it with acetone. The pipe section should be flat, vertical to the pipe axis and chamfered. Before bonding, draw the insertion mark and perform trial insertion. The trial insertion depth can only be inserted to 1/3 to 1/2 of the original depth. When the gap is too large, it is strictly forbidden to use the bonding method.
When applying the adhesive, you should apply the inside of the socket first, and then the outside of the socket. When applying the socket, apply a proper amount evenly from the inside to the outside along the axial direction. Do not miss or overspread (200g/m2). After the adhesive is applied, it is advisable to align the axis and push once continuously to the marking line within 20s, rotate the pipe or fittings ≤90º, and keep the applied external force unchanged within 1 minute to maintain the straightness of the interface And the location is correct.
After the bonding is completed, wipe off the excess adhesive in time, and do not apply force or force loading during the curing time. The bonding joint shall not be constructed in rain or water, and shall not be operated below 5°C. Connection procedure: preparation→cleaning the working surface→test insertion→brushing adhesive→bonding→maintenance.