Bi-injection unit is different from general injection molding machine mainly in the injection element and movable mold plate design. Generally, Bi-injection has two independent injection elements, but only one with general injection unit. The deployment of two injection element has various type different from designs of one to another manufacture, such as horizontal parallel, horizontal Y uni-direction, horizontal L type, Vertical L and vertical Y, even in horizontal parallel contra-direction arrangement for two plats clamping structure. As to movable mold plate design, it has to have rotating mechanism. Frequently seen designs include rotary table or rotary axis mechanism to provide 180 deg. Reciprocal rotating function to allow cycling alternate motion. Still other special Bi-injection units do not need rotary table or rotary axis mechanism, but for the mold to provide the alternate or horizontal rotation.

Interval injection and sandwich injection are almost same general injection molding unit, and the only difference is the interval injection and sandwich injection unit both has two set injection elements injecting material into molds from common nozzle, and the difference between interval injection and sandwich injection is in the design of compound nozzle.

GAIM is injecting nitrogen into mold cavity during injection molding process and using the nitrogen to perform pressure holding , making hollow products to reduce weight and prevent retraction sinking, and cut down pressure required. It is also call Nitrogen Hallow Injection Molding or Lowe Pressure Hollow Injection Molding. But it is different from Blow Molding.

GAIM is basically including the following 4 steps:
1. Injecting fixed quantity of material into mold.
2. Injection nitrogen to hollowing product to reduce weight and assist the fluidity of material.
3. Nitrogen pressure holding: As the material is cooling and retracting, the nitrogen will undergo secondary penetration and prevent the product from sinking or spring-back.
4. Release of high pressure nitrogen: releasing nitrogen in the mold cavity.

1. For bulky / thick products
a. Saving material, reduce weight by 20~50%.
b. Shortening molding cycle（reducing cooling time）to 20%.
c. Reduction of mold cost.
d. Saving in post-processing.
2. For flat products
a. Increase in design varieties.
b. Appearance improvement and better electroplating effects.
c. Eliminating thick rib sinking of products.
d. Realizing low pressure molding and reducing clamping force.
e. Less residual stress in product and reduce the distortion and deformation.
f. Increase the structural rigidity of products.
g. Reduce number of parts.

It needs 98% purity nitrogen or higher, because nitrogen is easily available, low prices and will not react with the material. The oxygen in high air may mix and combust with molten resin, so the later is rather not suitable.

It needs 98% purity nitrogen or higher, because nitrogen is easily available, low prices and will not react with the material. The oxygen in high air may mix and combust with molten resin, so the later is rather not suitable.

The following equipment are required to apply GAIM techniques.
1. Injection molding machine.
2. Gas Assisted Injection equipment.
3. Nitrogen Generator or Nitrogen Cylinder.
4. Air Compressor.
5. Necessary molding peripherals.

Techniques involved with GAIM include mold design, product design, gas pin location design and analysis, gas assisting device techniques, injection molding techniques, solution for defective molded product and mold flow analysis.

Not necessary, GAIM system of Fu Chun Shin can match with other brands of injection molding machine.

In addition to providing GAIM equipment, we also provide training on GAIM techniques, mold flow CAE analysis, product structure design, practice instruction and turn-key technical services packaged with injection molding machine.

1. 5 stagers gas pressure and velocity control (suitable for any GAIM mold.)
2. Single unit dual independent loops, expandable to 4 loops.
3. Close loop pressure control.
4. Max. output gas pressure 340 bar.
5. Controller adapts touch-screen.
6. Dynamic graphic molding pressure curve monitoring.
7.50 set mold title management and memory function.
8.Low pressure air 2 stage high efficiency pressure boosting
9.0.1% proportion valve accuracy、pressure sensing accuracy 1% 、pressure gauge accuracy 3%.
10. Compact size, light weight, easily movable.

They are identical in appearance and the difference is that GA-25 is a GAIM system containing booster, and GA-25C is a GAIM controller without booster. It depends on equipment in customer’s plant to select. GA-25 is suitable for whole plant low pressure piping, while GA-25C is suitable for whole plant high pressure piping.

Home appliance: TV、Air-Conditioner、Refrigerator、Dehumidifier.
Vehicle: Arms、Steering wheel、dashboard、pedal、bumper、window/door frame、mirror frame.
Computer: computer monitor shell、computer monitor bottom、NB shell、communication product.
Office equipment: chair arm、chair back、chair leg、desk leg、handle、table- top.
House ware: clothe rack、knife handle、racket、showerhead、faucet、bath tub handle、 computerized toilet basin seat.

1. Entering from nozzle:
Benefit
a.  Can readily use with modification to existing mold
b.  Runner is in hollow shape, reduce the quantity of resin
c.  Product free of needle trace
Short
a. All air path must be connected
b. Air paths must be symmetric and balanced
c. Cannot be used in hot runner system
d. Nozzle of machine must be replaced at high cost.
2. Entering through mold:
Benefit
a. Can enter through multi-point, and the air paths need not be totally connected
b. Gas and resin can be injected in at same time
c. Hot runner design mold permitted
d. Can be used in asymmetric mold cavity molding
Shorts
a. Need to develop and design new mold
b. Leaving needle trace on the product