On the industrial two-way stretching machine, synchronous two-way stretching method is longitudinal and transverse stretching on an accelerated expansion machine, this step of the two direction stretching directional film has two advantages:
First,It can be used to make plastic films that cannot be produced using step by step stretching techniques. This is because the above thin film is easy to crystallize, and stretching can promote crystallization. During the two-way gradual stretching, the thin film has been rapidly improved, and it is difficult to stretch horizontally again. Therefore, polymers with fast crystallization speed, high crystallization and easy crystallization are not suitable for gradual two-way stretching process, but only for synchronous two-way stretching process.
Second,Ultrathin films can be produced, reduce cost, improve transparency, and synchronous biaxial orientation method can produce 0.5~1.55mm thick films.
Biaxialy oriented film equipment mainly has the following main types:
1. Expansion and expansion chain type
The clamp of this stretching machine, mounted on a gratuitous circulation chain, runs through a transmission system composed of a motor, reducer, and sprocket to operate on a particular guide rail. The distance between the fixtures depends on the width of the restricted track between the two rows of chain axes in the front and rear of the chain, and changes with the width of the restricted track. amplitude hot is adjusted to adjust. When the chain leaves the entrance sprocket, the spacing between the fixtures changes from maximum to minimum. In the whole preheating care, the limit guide rail between the chain shafts reaches the maximum width, the chain is completely folded, the fixtures are together with each other, because the bearing diameter on the chain pin shaft is larger than the width of the fixture, the extrusion pressure between the fixtures passes. After entering the tensile area, the width of the limit guide rail gradually decreases, the resistance between the front and rear chain axles gradually decreases, under the pull of the outlet guide the chain, the distance between the splints gradually increases, the chain is gradually straightened until the return to the maximum value of the clamps.
2. screw drive type
This type of primary stretching machine, the clamp is mainly operated by the pitch-changing screw, sprocket, or attached ring conveyor drive. The area clamps are essentially equidistant except that the pitch of the screw in the tensile area is increasing and the outer clamps at the tensile machine entrance is decreasing. This transmission mode gives the clamp a large driving force and a reliable operation. ESSO Research was patented in 1965. In 1972, KAMPF provided two types of BOPET film stretching machines to the ORWO plant. The biggest drawback of this device is that it is difficult to change the longitudinal tensile multiple and needs to replace the drive screws. However, due to its large transmission power, the production speed can be accelerated, so it can be used to produce plastic films.
3. roller set-transverse stretching combination of guide rail
This type of primary stretching machine, longitudinal stretching is using the speed difference of the roll group at the inlet and exit of the stretching machine, horizontal
Direction stretching is a forced expansion to use the limiter or to use the non-rigid connection clamp
4. linear type magnetoelectric transmission type
Composition of linear magneto-electric transmission type clamp, guide rail and control system. The fixture is fitted with multiple rolling bearings resting firmly on the guide rail with flexible movement along the rails, each with a protruding portion forming a moving sheet similar to a linear motor. The entire guide rail is equipped with a short-core stator coil. When the stator coil is charged with three-phase AC, when the electromagnetic wave and a magnet on the fixture act, the independent fixture moves synchronously with the electromagnetic wave on the guide rail.
In the laboratory, in order to quickly obtain the film two-way stretching test results, you can choose to use a small film two-way stretching test machine (aka film pulling machine / handkerchief machine).
Guangzhou POTOP thin film Biaxialy oriented film simulator can realize step-by-step stretching and synchronous stretching, and select the appropriate stretching mode according to the material crystallization properties. The film two-way tensile test machine can make the thick film sample with square thickness of 80,115 and 140, conduct the film tensile test within suitable temperature and time for physical and chemical testing analysis, and redetermine various additives and formulations according to the sample film properties. Then applied to the production line, you can greatly reduce the trial production cost. Any crystalline type and non-crystalline polymer that can be used for two-way stretching, made into thick sheets, can be subjected to static stretching on a thin-film two-way stretching experimental machine, such as PET,PA,PP,PS,PLA,PETG, etc.
Guangzhou POTOP provides flexible customized services. Users can choose appropriate models according to the film tensile ratio and tensile temperature, among which the stress and strain test, film infrared temperature measurement, annealing function, and cooling function can be selected according to their needs.
