Rachaduras?
Rachaduras, Rachaduras, Rachaduras, Rachaduras
Rachaduras
Rachaduras
1) The melt temperature is too high
If the material temperature is too high, the melt will overheat and decompose, forming carbides. In order to avoid the overheat decomposition of the melt, the temperature at the end of the barrel must be strictly controlled for PVC and other heat sensitive thermoplastic materials. When black spots and stripes are found on the surface of the plastic parts, the temperature controller of the barrel should be checked immediately to see if it is out of control, and the temperature of the barrel and die should be reduced appropriately. Contudo, it should be noted that if the material temperature and die temperature are too low, bright streaks will also appear on the surface of plastic parts.
2) Too large gap of material cylinder
If the wear gap between the screw and the barrel is too large, the converging melt will stay in the barrel, resulting in local overheating decomposition of the retained melt and black spots and stripes. A respeito disso, you can first slightly reduce the barrel temperature, observe whether the fault can be eliminated. Problemas comuns no processo de moldagem por injeção de plástico transparente, check the barrel, nozzle and die to see if there is any dead angle and smooth grinding.
After taking the above measures, if the fault is not eliminated, the equipment should be repaired in time, and the gap between screw and barrel should be adjusted.
3) Overheat due to friction between melt and die wall
Se a velocidade de injeção for muito rápida, the injection pressure is too high, and the relative movement speed between the melt and the cavity wall is too high during mold filling, it is easy to cause friction overheating, which will cause the melt to decompose and produce black spots and wrinkles. Portanto, the injection speed and pressure should be reduced appropriately.
4) Poor exhaust of barrel and die
If the cylinder or die is not well vented, the residual gas in the melt will burn due to adiabatic compression, which will cause the melt to overheat and decompose and produce black spots and stripes. Portanto, the injection speed can be reduced appropriately, and the exhaust port structure of the barrel can be improved when the particle size and uniformity of the raw material are suitable.
For the poor exhaust of the mold part, check whether the gate position and exhaust hole position are correct, whether the gate type is suitable, remove the rust inhibitor and other volatile substances adhered in the mold, and reduce the amount of mold release agent. On the premise of no flash, the clamping force can be reduced and the exhaust clearance can be increased. Além disso, check the barrel and thimble for oil leakage.
5) Bulk coking
When the nozzle does not match with the main channel of the mold, the accumulated material will be coking near the gate and injected into the mold cavity with the flowing material, forming black spots and stripes on the surface of the plastic parts. Portanto, the relative position of the nozzle and the main channel of the die should be adjusted in time to make it fit well.
Além disso, if the hot runner of the mold is not well designed or manufactured, the molten material will not flow smoothly in the runner, stay and coke, which will also cause black spots and stripes on the surface of the plastic parts. Portanto, the surface luminosity of hot runner should be increased and the heating temperature of hot runner should be reduced.
6) The raw material does not meet the molding requirements
If the content of volatile matter in raw materials is too high, the drying of water sensitive resin is poor, the amount of recycled materials is too much, the fine powder is too much, the raw materials are not evenly colored, the lubricant type is not selected correctly or used too much, it will lead to black spots and stripes on the surface of plastic parts in varying degrees. A respeito disso, we should take corresponding measures according to different situations and eliminate them separately.
Sobre JasonMould Industrial Company Limited
Jasonmould é um Fabricante de moldes da china de moldes de plástico- molde de injeção, moldes de fundição sob pressão, moldagem por sopro de plástico, moldagem rotacional, médico moldagem por injeção de plástico, dois tiros moldagem por injeção de plástico, inserir moldagem, sobremoldagem, moldagem por injeção de metal, moldagem por micro injeção, moldagem por injeção de pó, moldagem por injeção de cerâmica, moldagem por injeção de líquido, moldagem por injeção husky, molde doméstico, molde de fundição, ferramenta de molde, moldes personalizados, moldes da china, ferramentas de prototipagem rápida, ferramentas de prototipagem de plástico, ferramentas de punção, matriz e ferramentas para peças móveis / celulares, partes automotivas, aspirador de pó, ferramentas recarregáveis, telefones, copiadoras, computadores, alto-falantes multimídia, e muitos outros produtos eletrônicos e eletrodomésticos. E também um fabricante de produtos de plástico, fabricante de moldes China- peças de plástico, tanque de água de plástico, bolas de plástico, recipientes de plástico, fivela de plástico, âncora de plástico, cabide de plástico, colher de plástico, encaixe de tubo de plástico, tombo de plástico, talheres de plástico, copos de plastico, garrafas plásticas, bandeja de plastico, recipiente plástico de cosmético, caixa de plástico, recipiente de plástico para comida, cadeiras de plástico, tampas de plástico, tampa de plástico, tubos de plástico, canos de água de plástico, maçanetas de plástico, tubo de plástico, caixas utilitárias de plástico, prateleiras de plástico e assim por diante.
Contato:
Pessoa: James Yuan
Empresa: JasonMould Industrial Company Limited
Adicionar: LongGang Village,LongXi Town,BoLuo County,Cidade de HuiZhou,Província de Guangdong, China
Tel: 86-752-6682869
E-mail: [email protected]
Local: https://www.jasonmolding.com/custom-injection-molding/
