Ce este fulgerul de turnare?
Flash de turnare, cunoscut și sub numele de preaplin, revărsare, cusătură și așa mai departe, apare mai ales în poziția de deschidere și închidere a matriței, cum ar fi interfața matriței, partea de alunecare a cursorului, golul insertului, the hole of the ejector pin and so on. If the flash is not solved in time, it will be further enlarged, resulting in local collapse of the impression die, which may eventually cause permanent damage. The overflow of the insert gap and the top bar hole will also make the product stuck on the mold and affect the demoulding. The flash of the product is shown in the figure
(1) Insufficient clamping force
When the injection pressure is greater than the clamping force, the die parting surface is not well closed, and the overflow flash is easy to occur. În această privință, we should check whether the pressurization is excessive, and check whether the product of plastic projection area and molding pressure exceeds the clamping force of the equipment. The forming pressure is the average pressure in the mold, which is usually calculated as 40MPa. The forming pressure of polyethylene, polipropilenă, polystyrene and ABS is about 30MPa when producing box shaped plastic parts, about 36Mpa when producing deep shaped plastic parts, and about 60MPa when producing small plastic parts with volume less than 10cm3. If the result is that the clamping force is less than the product of the projected area of the plastic part and the molding pressure, it indicates that the clamping force is insufficient or the injection positioning pressure is too high. It is necessary to reduce the injection pressure or the cross-sectional area of the injection port, shorten the holding and pressurization time, reduce the injection stroke, or consider reducing the number of cavities and using the injection machine with large clamping tonnage.
(2) Temperatura materialului este prea mare
The melt viscosity of high temperature melt is small, the flow performance is good, and the molten material can flow into a small gap in the mold to produce overflow flash. Prin urmare, it is necessary to reduce the temperature of barrel, nozzle and mold to shorten the injection cycle.
For low viscosity melt such as polyamide, it is very difficult to solve the flash defect only by changing the molding conditions. În același timp, we should reduce the temperature of the material properly, and try our best to process and repair the die to reduce the die gap.
(3) Defecte de mucegai
Die defect is the main cause of overflow flash. When there are more overflow flash, the die must be checked carefully. The parting surface should be checked again to make the moving die and the fixed die align. The parting surface should be checked to see if it fits closely, and the wear clearance of the sliding parts in the cavity and die core is out of tolerance. Whether there is adhesion or falling foreign matter on the parting surface, whether the templates are parallel, whether there is bending deformation, whether the opening distance of the templates is adjusted to the correct position according to the mold thickness, whether the surface of the guide pin is damaged, whether the pull rod is deformed unevenly, and whether the exhaust slot hole is too large and deep. According to the results of the above step-by-step inspection, the error can be eliminated by machining.
(4) Improper control of process conditions
If the injection speed is too fast, the injection time is too long, the injection pressure is unevenly distributed in the mold cavity, the mold filling rate is not balanced, and the amount of feeding is too much, the excessive use of lubricant will lead to overflow flash, so corresponding measures should be taken according to the specific situation.
It is worth noting that the elimination of overflow flash fault must start from the elimination of mold fault. If the forming conditions or raw material formula are changed due to overflow flash, it often has adverse effects on other aspects and is easy to cause other forming faults.
Despre JasonMould Industrial Company Limited
Jasonmould este un Producător de mucegai din China a matrițelor din plastic- matriță de injecție, matrițe de turnare sub presiune, turnare prin suflare din plastic, turnare prin rotație, medical turnare prin injecție a plasticului, doi împușcați turnare prin injecție a plasticului, turnare cu inserție, supraformare, turnare prin injecție a metalelor, turnare prin injecție micro, turnare prin injecție cu pulbere, turnare prin injecție ceramică, turnare prin injecție de lichid, turnare prin injecție husky, mucegai de uz casnic, mucegai de turnare, unealtă pentru matriță, matrite la comanda, mucegaiuri din china, scule de prototipare rapidă, scule de prototipare din plastic, scule de presare, matriță și scule pentru piese de telefon mobil / mobil, piese auto, aspiratoare, instrumente reîncărcabile, telefoane, copiatoare, calculatoare, difuzoare multimedia, și multe alte produse electronice și electrocasnice. Și, de asemenea, un producător de produse din plastic, producător de mucegai China- componente de plastic, rezervor de apă din plastic, bile de plastic, containere de plastic, cataramă din plastic, ancoră din plastic, cuier din plastic, lingura de plastic, racord de țevi din plastic, cadere din plastic, Veselă din plastic, pahare de plastic, sticle de plastic, tava de plastic, recipient pentru cosmetice din plastic, Cutie de plastic, recipient de plastic pentru alimente, scaune din plastic, capace din plastic, închidere capac plastic, tuburi din plastic, conducte de apă din plastic, butoane din plastic, tuburi din plastic, cutii utilitare din plastic, rafturi din plastic și așa mai departe.
a lua legatura:
Persoană: James Yuan
Companie: JasonMould Industrial Company Limited
Adăuga: Satul LongGang,Orașul LongXi,Județul BoLuo,Orașul HuiZhou,Provincia Guangdong, China
Tel: 86-752-6682869
E-mail: [email protected]
Site: https://www.jasonmolding.com/custom-injection-molding/
