5 Sets Of Classic Injection Mold Design Case Analysis

Here are 5 sets of classic injection mold design case. It involves three-plate molds, sliders, inclined tops and other mold mechanisms. Each set of molds has plastic part analysis and mold opening and closing videos.

This mold produces two plastic parts in one shot, and the number of mold cavities is 1+1. The picture below shows the part of the plastic parts.

Plastic Part2 has several undercuts. Need to set the slider structure. However, due to the problem of the parting surface, the slider can only be set in the fixed mold. The wedge is installed on the fixed plate, and the slider is disengaged or reset during the mold opening and closing process. The slider is limited by the ball catch. The mold structure is a three-plate mold. The external double-strand parting mechanism is adopted. The gate type is point gate.

The characteristic of the three-plate mold is that when the mold is opened, the cold slag of the gate has been separated from the product. The structure is to add a sliding plate to the fix mold for the gate material to detachment. The commonly used three plate mold has three parts: the first time is between the stripping plate and the fix mold; the second time is between the stripping plate and the upper fixed plate; the third time is between the Movable mold and the fix mold.

The mobile phone case is made of TPU. There is an upside down buckle around the product, but the buckle is not deep. The production cannot be automated, and the products need to be picked up manually. The appearance requirements of mobile phone protective cases are strict. The gate cannot be set on the surface of the product, but should be set at the camera hole. The feeding method is from small runner to large runner, and the gate type is side gate.

This mold produces two products in one shot. The mold structure is 3 sliders and 1 lifter. The analysis of plastic parts is as follows:

The blue part has a through hole and no undercuts. So set two horizontal sliders according to the arrangement direction. In the process of opening and closing the mold, the slider is driven by the angle pin column to pull the core and reset. The pink part has a hole on the side. Core pulling are realized by the slider. This slider is also driven by the angle pin on the fixed die. There is also an undercut on the back of the pink part. The undercut is located in the concave part of the plastic part, which cannot be solved by the slider, only set the lifter. The lifter is ejected together with the push plate and the product, and will gradually move away from the product undercut due to structural limitations.

The parts are shown below. The pink parts are iron inserts and the green parts are plastic.

Before injection molding, place the iron part in the mold and close the mold. There are corresponding inserts in the mold for fixing the iron parts. The plastic part cannot be directly ejector due to the 3 buckles on the circumference. Therefore, three lifters are set, also can be used the slider mechanism. This lifter is different from the mechanism in the first subsection. It is a ejector type , without a lifter seat, and takes up little space. The feeding method is the large runner side gate. Considering the way of feeding glue, the nozzle is eccentric.

This part has 4 undercuts. The first part of the undercut can be solved by the lifter. The second part is solved with a slider, but the slope is larger and the angle needs to be converted. This mold is one shot with two outputs, and the gate type is submarine gate.