Membrane panel is widely used in product design. It's mostly made of film screen printing and rear adhesive past, it can be used for product display, control and beautification, greatly reducing the cost of product keys, windows, and has a high aesthetic and sealing. The process is widely used in instruments, equipment, electronics, home appliances, machinery and other fields.
The substrate is the material of the membrane panel, mostly used substrate has PVC, PC, PET three kinds, in addition PMMA is also commonly used in the production of panels.
Features of the panel substrate:
Impact resistance, high tensile strength. Heat resistance, cold resistance and aging resistance. Resistance to weak acids and bases. The light transmittance is 78%. The temperature resistance range is -30 ~ 90 °C.
The most extensive range of applications, to meet the majority of membrane switch panel requirements.
Good strength and toughness, wear resistance, excellent tensile strength. No alkali resistance. High temperature resistance, anti-aging. The light transmittance is 89%. The temperature resistance range is -10 ~ 120 °C.
Suitable for high environmental requirements or products have digital displays.
Light transmittance is the best of the three materials. Brittle, soluble in organic solvents, not flame retardant. Wear resistance is not good, easy to scratch, easy brittle. Light transmittance 92%, temperature range is 10 ~ 60 °C.
Suitable for higher transparent windows, the flat products. Sheet thickness of 3 mm can be produced.
Strength and toughness: PET > Acrylic > PC
Softness: PC > PET > Acrylic
Light transmittance: acrylic > PET > PC
Wear Resistance: PET (Matte) > PC (Atte)
The mostly used membrane panel is 3M467MP, 3M9472LSE, 3M9448A double-sided adhesive, which is a non-woven substrate double-sided tape, long-term resistance to 90 °C high temperature. Gum good and bad, durability, temperature resistance, waterproof performance vary greatly, membrane panel process requirements should be marked with glue.
About 3M adhesive, the common 3M double sided adhesive is mainly non-substrate double-sided adhesive, non-woven (cotton paper) substrate double-faced adhesive, transparent PET substrate double-face adhesive, foam substrates double-faced glue, etc., there are the difference thickness choice of each series adhesive, the special insulating adhesive like conductive adhesive and so on.
The foam substrate double-sided adhesive stickiness is better, there are shockproof, shading and other effects, if the choice of foam substrate double sided adhesive, should pay attention to the thickness of the choice.
The adhesive design need to pay attention to set aside a certain size of shrinkage in the window, through hole, etc., to avoid overflow, shrinkage is not too large, will affect the paste performance and flatness, we suggest the adhesive width more than 3.0mm.
Membrane panels are usually screen printed. Screen printing refers to the use of screen as a base, made with graphic screen printing. The use of screen printing plate graphics and text part of the mesh through ink, non-graphics part of mesh can't through ink printing principle. The characteristics of screen printing determines that it is difficult to do gradient colors, transparent gradient wrapped monochrome and the gradient between difference colors.
There are two most important links in screen printing:
1) Screen production
The design engineer don't design the screen printing plate, but the engineer need design that be sure all the solid colors separate, because every each color need the unique silk screen printing plate. The number of screens required for a color pattern is the amount of colors it uses. Screen parameters are mesh, the number of mesh per unit area, commonly used mesh is 300 mesh, this parameter will be adjusted according to ink and pattern area.
2) Ink Toning
Color matching is the most critical link in screen printing, we design the pattern of color without a direct corresponding color value of ink, which requires the printer do the ink mixing color matching. Because of the computer, mobile phone and other screen display problems as well as the requirements of surface texture, toning needs intermediate to do reference, the most effective is use the customer color swatch. Without the customer sample for match, the secondly ideal is use the Pantone color card to do the color of the intermediate, manufacturers in accordance with the color card color to adjust the colors.
The printing ink also has the difference color standard, the different brands of ink itself performance is also very different, such as permeability, adhesion, most printing defects can be solved by changing ink.
In addition to the basic ink toning, ink can also play a lot of other roles, such as lighting key parts, you can use uniform ink to astigmatism, in order to make light soft, wider viewing angle. The principle of uniform ink is very simple, is to add uniform powder in the transparent ink so that light through the scattering, The core of the two indicators are light transmittance and uniformity, which are two contradictory indicators, the better the light uniformity is, the lower the transmittance, the darker the light.
The membrane panel has beautiful appearance, clear handwriting, bright color and good sealing. It has the characteristics of waterproof, anti-deformation, anti-pollution, anti-high temperature, strong viscosity, friction resistance, sensitive touch control and high identification. It widely used in medical equipment, CNC machine tools, electronic scales, refrigerators, microwave ovens, fans, washing machines, rice cookers, water heaters, range hoods and other industrial and household electrical products.