Pharmaceutical packaging aluminum foil and PVC heat seal strength test

The blister packaging of pharmaceuticals is selected from the hard industrial pure aluminum foil as the basic material, which is called the cover material. It is a special equipment for printing and coating aluminum foil, printing text patterns and protective agents on the surface of aluminum foil, on the other side of aluminum foil. Apply adhesive.
The purpose of the coating protector is to prevent the wear of the ink layer of the printed characters, and to prevent the contamination of the drug due to the contact between the outer layer ink and the inner layer adhesive during the coating process and after winding. The adhesive layer is mainly used to ensure the adhesion of the aluminum foil and the PVC plastic hard sheet, and the adhesive strength of the aluminum foil and the PVC after heat sealing is usually measured by the heat seal strength test. The following describes several test equipment and aluminum foil and PVC heat seal strength test methods and analysis of factors affecting the aluminum foil and PVC heat seal strength.
First, the heat seal strength value of aluminum foil and PVC of tensile testing machine is usually made on tensile testing machine. Tensile testing machine is generally composed of main components such as loading mechanism, force measuring mechanism, drawing device, buffer device and force transmission mechanism. According to the different methods and principles of force measurement, it is generally divided into the lever pendulum type, pendulum type and electronic type. Regardless of the type of tensile testing machine, conventional mechanical performance tests such as drawing, compression, bending, shearing, tearing, and peeling can be performed after the replacement of the holder.
1. Lever pendulum type tensile testing machine: The working principle of this machine is: when the sample is subjected to force deformation, the force acting on the upper holder passes through the two-level lever, driving the pendulum to rotate around the fulcrum and lift it up. A lever has two fulcrums. When the specimen is under tension, one point is used as the fulcrum. At two points, it is automatically replaced by 2 points as the fulcrum when pressure is applied, and 1 point is disengaged.
In this way, the pendulum always swings to one side regardless of stretching and retraction. The pendulum rod pushes the horizontal gear and the pointer. The angle of rotation of the pointer is proportional to the force of the sample. The number on the dial is the size of the specimen. The loading method may use a maneuvering and hand-operated device, and the speed adjustment may use a continuously variable transmission. The general testing machine can replace the weights of three kinds of pendulums in three columns. There are also three columns and four kinds of scales on the measuring dial, which respectively represent the measuring range.
2. Pendulum-type tensile testing machine: This type of testing machine uses a certain speed to stretch the sample, so that the pendulum is opened and the size of the pulling force is expressed by the change of the pendulum's lift angle. Its principle of action is: during the test, when the tensile force P of the sample is applied to the sector wheel by the steel band or chain, the moment M1=P·r (r is the radius of the fan-shaped wheel), and it is integrated with the sector wheel. The pendulum tilts at an angle α, thus producing a moment of balance M2. M2=Qlsinα(Q pendulum weight, l pendulum length) Since M1=M2, Pr=Qlsinα, P=(Ql·sinα)/r Because of the radius r, the pendulum length l and pendulum weight Q are constant so Ql /r is also a constant. Let c = Ql/r be P = c · sinα, that is, the pull force P is proportional to the sine of the pendulum tilt angle. According to this relationship, a dial can be established to indicate the size of the pull force.
3. Electronic tensile testing machine: The force applied to the deformation of the sample of the electronic tensile machine is converted into an electrical signal by the resistance strain gauge attached to the elastic element in the force sensor and preamplified to the x-axis of the XY recorder. The small deformation uses a differential transformer as a sensor, and the large deformation utilizes a synchro-synthesizer. After the measurement signal is amplified, it is input to the Y axis of the XY recorder, so that the load deformation curve can be automatically drawn on the recorder.
The differential transformer is mounted on the extensometer and the extensometer is connected to the sample. With the deformation of the specimen, the core of the differential transformer also has a corresponding displacement. After this displacement is converted into an electrical signal lightly, the deformation of the specimen can be recorded on the recorder. The measurement of large deformation is that when the cross beam connecting the lower holder is displaced, the gear box connected with the screw is driven by a certain gear ratio to send the synchro-synthesizer to rotate through the sending autosynthesizer and the XY recorder. The rotary transformer consists of follow-up lines to determine the elongation. The speed of the lower gripper movement is controlled by a complete set of servo systems.
The synchronous motor drives the Synchro machine to rotate at a certain speed through a speed change gear. The receiving selsyn machine is connected with the main unit wheel box. The main gear drives the two high-precision ball screws to rotate, and the cross beam rises and falls accordingly. If the cross beam movement speed does not correspond to that of the sending squaring machine, two self-segment angles are used. The machine has an angular difference. After the signal is amplified, the voltage of the SCR supplied to the AC motor is changed, so that the cross beam can obtain a stable speed. This kind of system makes the beam displacement speed change with the sending autogenerator. Change the gear mesh of the gear box and get different speeds.
4. Automatic tensile testing machine: This testing machine is a fast automatic measurement testing machine. The tester has a conveyor belt with automatic conveying patterns, a metering device, an extension tracking device, a pneumatic ejector device for automatically removing the sample, and an electronic computer. The computer is used to indicate and calculate test results.
The tester can automatically mark the sample with different colors, white or other colors, and measure the thickness of the sample. After the job is completed automatically, the sample is clamped by the pneumatic gripper and sent to the tensile device for tensile test. The machine's stretching speed is 500mm/min or 50mm/min. The machine can be automatically operated for 4-5 hours continuously, and the test results are finally printed out by a computer or saved as punched cards.