Table Mould(FURNITUREMOULD) cracking is a common defect in plastic products, and the main reason is due to stress deformation. There are mainly residual stress, external stress and stress deformation caused by external environment. What should I do after cracking? 1. Cracks caused by residual stress The residual stress is mainly caused by the following three conditions, i.e. excess filling, ejection from mould and metal inlay. As a crack generated under the condition of excess filling, the prevention and control methods can be mainly started from the following aspects: (1) Since the pressure loss of the sprue is the smallest, if cracks are mainly generated near the sprue, the multi-point distribution of point gates, side gates and shank gates can be considered instead. (2) On the premise of ensuring that the resin does not decompose or deteriorate, appropriately increasing the resin temperature can reduce the melt viscosity and improve the fluidity, and at the same time can reduce the injection pressure to reduce the stress. (3) In general, stress is easy to occur when the mould temperature is low, and the temperature should be appropriately increased. However, when the injection speed is higher, even if the mould temperature is lower, the generation of stress can be reduced. 2. Cracking Caused by External Stress The external stress here is mainly caused by stress concentration due to unreasonable design, especially at sharp corners. 3. Cracking Caused by External Environment Chemicals, water degradation caused by moisture absorption, and excessive use of recycled materials will degrade physical properties and produce cracks. 4. How to deal with the cracked table mould (1) Annealing treatment. After the parts are moulded, they are heated for a period of time. The heating equipment can be a hot air blower, a stoneware furnace or constant temperature water. The annealing temperature can be the drying temperature of the raw materials, and the annealing time depends on the cracking degree. (2) Soaking in normal temperature tap water. After the moulded parts are taken out of the mould, they are put into a water pan for soaking and cooling, and the bigger the cracking degree is, the longer the soaking time is, and the longest time is more than 24 hours. The length of soaking time depends on the cracking degree of the parts. This is the most practical prevention method often used in most factories, but this method also has certain limitations, such as easy to damage products, so be careful when handling, or the products need to be sufficiently dried for post-treatment, such as pad printing, spraying, electroplating, etc. If you are interested in our products, you can click Air Cooler Mould to learn more information.
