Multi-Color-Rotary Axis

Most of two-color handles are made by rotary axis plastic injection moulds.

Rotary axis process or rotary core process means that the two-color plastic injection mould won't rotate by injection machine, however, the cores of mold will be rotated by injection machine or cylinder of injection mould.   When the injection part will be made the second color, the controller of injection machine will deliver signal of core pulling system to rotate the 1st core of mould to second position of core, then make the second color injection.

Why the two-color handles are made by rotary cores plastic injection moulds instead of rotary moulds? 

If the second color of two-color plastic products is on the surface of first color, it is generally made by rotary moulds process.  If the second color is covered both side of two-color plastic products, it shall be made by rotary cores plastic injection mould, such as tooth brush handles, screw driver handles, knife handles, razor handle and so on.

The advantage of rotary core two-color plastic injection mould is easy to make insert for some plastic parts which is required for inserting steel parts, such as screw driver, knife and so on.  Meanwhile, it is easier to get high-end quality of over moulding than making injection two times separately.

Of course, the mould design and structure are more complicate than single color mould.  The machinery of cores shall be very precise in order to avoid destroy during making the second injection.  The cylinder of rotary cores shall be high quality and durable to ensure the mould performance and quality.  Meanwhile, full hot runner for each cavity is considered for better quality of surface on two-color plastic products.  Generally speaking, the plentiful experience on fabricating mould design and two-color plastic injection moulds are very important to get good quality of two-color plastic products.