一, The industry background of consumer electronics goods on the precision of injection moulds
1.complicated in structure
Consumer electronics usually have a lot of thin-walled, slender constructions, buckles, brackets, and interfaces. Because the construction is so complicated, moulds need to be very precise, and even a minor mistake might make it hard to put things together or cause a part to fail.
2.High standards for looks
It is necessary for mobile phone cases, tablet back covers, headphone cases, and other parts to have smooth surfaces, no flow markings, no warping, and the same size. The mold's accuracy has a direct impact on the parts' surface quality and dimensional tolerance.
3.Exact functionality
High-precision moulds are needed for internal brackets, buckles, buttons, gears, and other functional parts to make sure they fit tightly during assembly and don't make noise or come free.
二,Specific standards for the accuracy of injection moulds
1. Precision of dimensions
Most of the time, the length, width, height, and hole size of the shell parts need to be accurate to within ± 0.05mm or even more.
Functional parts including buckles, interfaces, and slots must have tolerances of ± 0.02mm to ± 0.05mm.
fthe mould size difference in the SIM card slot of a smartphone shell is more than 0.05mm, it will be hard to take out the card slot or the assembly would fail.
2. Accuracy of Fit
It is very important that pieces work together correctly, including the shell and screen, the button and shell, the module buckle, and so on.
Plug-in mating, sliding mating, and snap fit are all common ways to mate things.
The mould tolerance must be able to keep the assembly gap within 0.05mm.
3. Surface Precision
The surface of the mould cavity directly affects the flatness, texture accuracy, and smoothness of the surface.
To get a high-precision surface, the mould processing must be accurate to within 0.01mm.
三, Important things that affect how accurate injection moulds are
1. How accurate the mould processing is
The ultimate size of the part is directly affected by how accurate the CNC machining is on the mould sections.
Five-axis machining, wire cutting, precision grinding, and mirror polishing are all common ways to make high-precision injection moulds.
The choice of mould steel and heat treatment procedure can also have an effect on how stable the dimensions are.
2. Properties of materials used in injection moulding
varying materials, such ABS, PC, PA, POM, TPE, and others, shrink at varying rates.
When designing a mould, you need to set aside money for high-shrinkage materials.
Before moulding, materials that absorb moisture, like PA, need to be dried. If they aren't, the parts may not fit together properly.
3. Settings for the injection moulding process
The size of the parts is directly affected by the injection pressure, holding duration, mould temperature, and cooling time.
Components with thin walls and extensive channels are more sensitive to process control.
Different materials and architectures need process parameters that are made just for them.
四,Plan for making injection moulds for consumer electronics more accurate
Using high-precision tools for mould processing
Five-axis CNC machining, wire cutting using EDM, and precise grinding
High-precision tools can make sure that the mould cavity is within 0.01–0.02mm.
Choosing the right materials for injection moulding and compensation variables
Change the size of the mould based on how much it shrinks.
Think about how changes in temperature affect size.
Make the design of the mould structure as good as it can be
A good place for the gate to make sure the filling is even
Scientific arrangement of the cooling system to stop warping
The top pin, slider, and plug are all designed to fit perfectly so that the parts are in the right place.
Tight control over the injection moulding process
Standardizing the temperature, pressure, holding duration, and cooling time
Using injection moulding machines with high precision to make things more repeatable
Set up a system for testing moulds with high accuracy
五,A case study on how accurate moulds for consumer electronics are
Case 1: Mould for the shell of a smartphone
The phone case is composed of PC+ABS and has a wall that is only 0.8mm thick.
The accuracy of the cavity is set at 0.01mm, and the overall dimensional tolerance is ± 0.03mm.
Designing the gate for the best performance, making sure the cooling is consistent, and stopping warping
Before each batch of production, use CMM to measure the positions of the critical holes and interfaces. This will make sure that the assembly goes smoothly.
Case 2: Mould for the buckle on a smart watch strap
Small, thin-walled parts manufactured of ABS material that need to be accurate to within ± 0.02mm for the buckle structure
