Speaking of mobile phone shell, we must be very familiar with the selection of mobile phone shell must also be very curious, let us talk about the selection of the phone shell together today.
First, the general requirements of mobile phone case material
High strength, good thermal conductivity, flame retardant, with battery shielding.
Dimensional stability, good appearance and lightweight thin-walled and so on.
Currently used mobile phone shell materials are PC, ABS and PC / ABS.
Second, the characteristics of different materials and selection principles
1, the characteristics of different materials:
PC
High strength, tensile strength of 69MPa, bending strength of 96MPa.
High temperature, long-term use can withstand 130 degrees Celsius temperature environment.
Transparent, non-toxic.
Material color and surface coating as ABS.
PC should be selected high liquidity grade.
Suitable for clamshell machines and cell phones for use in harsh environments.
ABS
Low strength, tensile strength of 43MPa, bending strength of 79MPa.
Not temperature, long-term use temperature shall not exceed 60 degrees Celsius.
Mobility, coloring and surface coating and plating performance are good.
PC / ABS
PC and ABS synthetic materials, taking the first two characteristics, with excellent molding performance, good fluidity, high strength (tensile strength 56MPa, bending strength 86MPa). PC / ABS material is mainly used for straight machine And the general appearance, color demanding and no special requirements for the environment of the clamshell machine.
2, Selection principle:
According to the structure selection
Structural strength is larger, thicker walls, the structure should be the preferred shape of PC / ABS.
When the structure is thinner, less strength, should be selected PC.
According to the appearance of paint color selection:
Bright, multi-color, Xu rigorous requirements, should be the preferred PC / ABS.
The appearance of the electroplating should be selected ABS. Clamshell machines and in harsh environments (such as low temperature, vibration, shock, etc.) should be used to strengthen the PC material PC: PC and PC / ABS materials are Can be used, should be preferred PC / ABS.
Third, the upstart mobile phone case halogen-free flame retardant PC / ABS
With the popularity of candy bar, PC / ABS has naturally become the common choice of cell phone case, but as technology advances, people's voice of safety and environmental protection is on the rise, the material flame retardant performance and environmental friendliness requirements are getting higher and higher At present, halogenated flame retardants such as decabromodiphenyl ether commonly used in the pyrolysis and combustion of materials produce toxic, corrosive gases and large amounts of smoke which pollute the environment and cause secondary pollution. The ROHS The promulgation of the two WEEE directives limits the application of traditional halogen-based flame-retardant PC / ABS alloys in many industries, especially in Europe and the United States in recent years. Therefore, research and development of high efficiency and environment-friendly Halogen flame retardant PC / ABS alloy has gradually become the focus of research in the field of flame retardant.
Halogen-free flame retardants commonly used:
Preparation of flame-retardant engineering plastics commonly used methods are added flame retardant technology and reactive flame retardant technology, for PC / ABS alloy system, most of the current use of additive flame retardant technology at home and abroad are currently used flame retardants are:
Halogen-free flame retardant PC / ABS alloy trends:
With the increasing demand of PC / ABS engineering plastic alloy market and people's increasing emphasis on environmental protection, the development of flame-retardant PC / ABS alloys has gradually become environmentally friendly, high-performance, multi-functional and systematic At present, phosphorus-based flame retardants, silicon-based flame retardants and other halogen-free flame retardants in PC / ABS alloy has broad application prospects.But there are still some shortcomings, such as compatibility with the material is not ideal, In particular, the balance of impact strength, flame retardancy and processability still needs improvement, and some of the flame retardants have high costs. Therefore, how to further improve the flame retardant effect of the flame retardant in order to meet both the requirements of flame retardancy and environmental protection and The comprehensive performance of the alloy, the development of efficient and environmentally friendly flame retardants and functional flame-retardant materials (such as biodegradable materials) are the current research focus and focus.It can be seen that nano-technology, microencapsulation technology, complex coordination technology, surface modification Flame retardant research and development of new technologies such as sexual technology and compatible technology will be continuously developed.