Four Reasons for Insufficient Filling of Injection Molding Products

  1. Improper feed adjustment, lack of material.


Inappropriate feeding metering or abnormal operation of the feeding control system, abnormal injection cycle caused by injection molding machine or mold or operating conditions, small back pressure of pre-plastics or small particle density in the barrel may result in material shortage, for large particles, large voids and crystalline plastics such as polyethylene, polypropylene, nylon For example, ABS and high viscosity plastics such as dragon should be adjusted to a higher volume.


When the barrel end stock is too much, the screw will consume additional injection pressure to compress and push the excess stock in the barrel, which greatly reduces the effective injection pressure of the plastic into the mold cavity and makes the product difficult to fill.


  1. Injection pressure is too low, injection time is short, plunger or screw back too early.


Molten plastics have higher viscosity and poor fluidity at lower working temperature, and should be injected at higher pressure and speed. For example, when making ABS color parts, the high temperature resistance of the colorant limits the heating temperature of the barrel, which is compensated by higher injection pressure and longer injection time than usual.


  1. Slow injection speed


Injection rate is very important for some products with complex shape, large thickness variation, long process, and viscous plastics such as toughened ABS. When high pressure can not be used to fill the product, high-speed injection should be considered to overcome the defect of unsatisfactory injection.


  1. Material temperature is too low.


The low temperature at the front end of the barrel prevents the melt entering the cavity from flowing prematurely due to the cooling effect of the mold, which prevents the filling of the distal end of the barrel. The upper melt enters the cavity at low pressure and low speed.


If the nozzle temperature is low, it may be that the nozzle loses heat when it contacts the cold mold for a long time, or if the heating ring of the nozzle is not heated enough or the material temperature is not good enough, it may block the feeding channel of the mold; if the mold does not have a cold material well, the nozzle is self-locking nozzle and the feeding procedure is adopted, the nozzle can keep the necessary. Temperature; when the nozzle is too cold when starting, it can sometimes be heated by a flame gun to accelerate the temperature rise of the nozzle.


JasonMould Industrial Company Limited, established in 2010, is a leading injection moulding manufacturer in China. JasonMould specializes in plastic mould production for household appliances, medical equipments, electronic equipments, safety equipments as well as monitoring system.

The company has over 15000 square metres factory. With plastic injection tooling divisions possessing different machinery and expertise, JasonMould offers tools from small and precise mobile phone parts to as big as automotive parts. Our tools are mainly exported to U.S.A., Europe, Japan and UK. JasonMould’s diversification strategy and full service has won compliment from customers all over the world.

Our mission is to provide our customers high quality moulding products and services. We aim to exceed our customers’ expectations of pricing, quality and on-time delivery. To achieve our mission, JasonMould:

  • Commits to continually improve employee skills and efficiency,
  • Provides our employees a clean and safe working environment,
  • Upgrades machine technology and support equipment through a strict maintenance program, and
  • Maintains customers’ tooling to its highest peak of performance

For more about custom manufacturer of plastic molding products,please visit

Inquiry Contact:

Contact person: James Yuan

Company name: JasonMould Industrial Company Limited

Address: LongGang Village,LongXi Town,BoLuo County,HuiZhou City,GuangDong Province, China

Telephone: 86-752-6682869

Email: [email protected]


Share this post