NISSEI PLASTIC INDUSTRIAL

Nissei changes hydraulic two-color/dissimilar material injection molding machine models as part of sales expansion of dedicated machines

November 2004 [News Release]

For the purpose of further increased sales of dedicated machines, Nissei Plastic Industrial Co., Ltd. recently has changed, by upgrading functions, two machine models with a mold clamping force of 120 tons (1190 kN) and 200 tons (1990 kN) of the hydraulic two-color/dissimilar material injection molding machine "DC Series." The company will start receiving orders for the new models from November onward.

The two-color/dissimilar material injection molding machine, using the same resin of different colors or dissimilar resins, is used for the molding of key-tops of personal computers and push-button telephones, tale lumps of automobiles, and various kinds of switches and knobs.
The features of its mechanism are as follows. It is equipped with two injection units and two sets of molds. First, resin is injected from the primary injection unit to fill the primary mold, and mold the primary product. After that, with reverse rotation of a mold, the secondary injection unit to fill and mold a finished product injects dissimilar resin. It can be applied to various uses with different combinations of resins. Also it is able to rationally produce, using only one molding machine, highly value added hybrid products which excel in design and functionality.

The principal purpose of the model change at this time is improvement of the applicability to high-cycle molding and the control properties in the two-color/dissimilar material molding. Its functions have been sharply improved by mounting a new controller "TACT" and reviewing the mechanism. However, its retail price is left unchanged, signifying substantial reduction in price.

Main features of the new controller "TACT" (hydraulic):

(1)	High-speed scanning time of 500 microseconds (1/2,000 second) achieves repeated stable molding.
(2)	The man-machine-interface with a 12.1 inch color liquid crystal screen.
(3)	The tilt mechanism is capable of changing a screen angle to fit with an operator.
(4)	The quick-response/high-resolution touch panel is equipped.
(5)	Various kinds of molding programs are equipped as standard.
(6)	Reinforcement of quality control functions.
(7)	The languages of 6 countries, namely, Chinese, English, Korean, Thai, Japanese and Spanish are equipped as standard.
(8)	The ladder programming function open to users.
(9)	A maximum of 300 molding conditions can be internally memorized.
(10)	A LAN connector and a USB connector are equipped as standard.

Review of the mechanism:
Mold clamping mechanism;

1.	The adoption of a servomotor for a mold reversing system inside the mold clamping mechanism realizes shock-less speed adjustment and high-speed rotation. The reversing time is shortened to a half (0.9 second for DC120 type) of existing machines. It also achieves clean working environment (oil and grease are unnecessary). Moreover, simultaneous operation for "rotation during mold opening" (for ejector operation after rotation) becomes possible, contributing cycle-up of molding.
2.	For preventing abrasion of a turntable, a push-up/pull-in system is adopted, ensuring high precision of the turntable and longer service life of machines and molds.
3.	The adoption of a system to install a quick-feed unit in the outside of a movable platen cylinder achieves the high speed, doubling the mold opening speed of existing machines.
4.	The addition of a mold mounting hole to the top-bottom expands the size of attachable molds. The size is extended 50 mm to the top-bottom for the 120 ton type models and 100 mm for the 200 ton models.
5.	It is of a mold-friendly structure with some artifices including the prevention of inclination of the turntable.

Injection mechanism;

1.	By increasing the number of screw rotations by 25% in comparison with existing machines, plasticizing capacity is improved.
2.	By strengthening the power with loading a 22 kW (18.5 kW up to now) pump motor, injection speed is accelerated (120 tons).

In addition, our company's original two-piston direct pressure clamping system is used for the mold clamping equipment, which has acquired customer's confidence, same as the existing machines.
This system achieves ideal transmission of mold clamping force to the two sets of molds, therefore it is greatly effective in the molding of products with unbalanced projected areas on the primary and secondary sides.

back