Polyimide film

The polyimide film is a new type of high temperature resistant organic polymer film, is from pyromellitic dianhydride (PMDA), and diaminodiphenyl ether (ODA) in the strong solvent dimethylacetamide (DMAC) by polycondensation and salivation film formation, and then by imidization from it is the best performance of the film world class insulating material has excellent mechanical properties, electrical properties, chemical stability, and high radiation resistance, high temperature and low temperature resistance (-269 ℃ to + 400 ° C). 1959 DuPont first synthesis of aromatic polyimide, made of polyimide film (PI film) trial in 1962, began production in 1965, is altered by a KAPTON commodity grades. Polyimide film can be small batch production in the late 1960s, China, is now widely used in aviation, marine, spacecraft, rocket missiles, atomic energy, electrical and electronic industries in various fields.
First, the thin film manufacturing
The production of the polyimide film is basically two-step method, the first step: Synthesis of polyamic acid, the second step: a film formation imidization. Dipping method (or an aluminum foil plastic method) in the film forming method, a casting method, and salivation stretching method. Impregnation method is simple equipment, simple process, but the surface of the film is often sticky aluminum powder, film length is restricted, low production efficiency, this method is not suitable for development; salivation method high precision equipment, film uniformity and good, clean, flat surface, the film length is not restrictions can be continuous production, film various aspects of performance are good, the general requirements of the film can be used to the production of this Act; stretching method to produce the film, performance has improved significantly, but the process complex production under harsh conditions, investment, prices only high-quality film before using this method. Therefore, the site describes the the salivation law.
Salivation method main equipment: stainless steel resin solution tank, drooling mouth, drooling machine, the imidization furnace, winder and hot air system.
Preparation steps:
The polyamic acid solution by a stainless steel solution storage tank via a line after defoaming pressed into the mouth of the tank before the machine head salivation. Uniform running strip to the direction shown, the front of the mouth of the tank solution was salivation blade away, thereby forming a liquid film of uniform thickness, and then dried into the drying Road.
The clean, dry air from the blower into the heater was preheated to a certain temperature into the upper and lower drying Road. The hot air flow direction is opposite to the running direction of the strip, so that the liquid film when the drying temperature is gradually increased, the solvent is gradually volatilized, and to increase the drying effect.
The polyamic acid film on the strip with its run a week, the solvent was evaporated to become a solid film, peeled off from the steel strip under the film by the guide roller toward imidization furnace.
Imidization furnace is generally the form of multi-roller, salivation machine synchronous speed guide roller guide polyamic acid film into the imidization furnace, high temperature imidization, winding winder.
Second, the detection of the film
Polyimide film from -269 ℃ cryogenic to high temperature +400 ° C range still show excellent physical, mechanical, and electrical
Gas properties. After product manufacturing are its tensile strength, elongation at break, power frequency electric strength, surface resistivity, volume
Resistivity, etc. to be tested.
Introduction to testing equipment
YDQC series lightweight high-voltage test transformer
Mainly used to test the electrical strength of polyimide film
: Thickness 0.025mm, 0.04mm, 0.05mm film, the electrical strength: mean ≥ 150Mv / m, the individual values
≥ 100Mv / m
Thickness 0.075mm film, the electrical strength: the average of ≥ 130Mv / m the individual values ​​≥ 80Mv / m
0.1mm film thickness, electrical strength: the average of ≥ 110Mv / m the individual values ​​≥ 70Mv / m
The vertical optimeter for JD3 projection
For the test of the polyimide film thickness tolerances
For example: on the thickness of the film thickness tolerance of 0.025mm tolerance +4, lower tolerance -3
The thickness 0.04mm film thickness tolerances on tolerance +6, lower tolerance -5
Tolerance on the thickness of the the 0.05mm thin film thickness tolerance +7, lower tolerance -6
On the thickness of the film thickness tolerance of 0.075mm tolerance +8, lower tolerance -6
The thickness of the the 0.10mm thin film thickness tolerance on tolerance +10, lower tolerance -7
MZ-4000C micro-controlled electronic universal testing machine
Physical properties of the polyimide film was used for testing in the stretched state, having a speed display, elongation, integrated display
Three display windows with test data, print, and communication functions. The machine adopts the software settings, parameter storage limit Paul
Nursing and other functions.
Force value accuracy: showing the value of -1% to +1% effective bit stretched distance 900mm
Tensile strength: longitudinal ≥ 135Mpa, horizontal ≥ 115Mpa
Elongation at break: vertical, horizontal ≥ 35%