modern console table,entry table console,travertine table,stone table Kumusi (Dongguan) Furniture Co., Ltd. , https://www.kcoffeetable.com
First, the pharmaceutical aluminum foil printing principle and its material performance standards
1. How Foil Printing Works
Aluminum foil printing is carried out on a special aluminum foil printing and coating machine. The principle is that the printed surface or the pattern is printed on the concave surface of the printing roller. Therefore, it is also called gravure printing. It is the printing roller through the external processing into a printed version of the text, graphic part of the roller on the copper surface is etched into the ink hole or pit, non-graphic part is the roller copper surface itself, printing plate The roller rotates in the ink tank, and each ink hole is filled with thin ink. When the roller rotates to rotate out of the surface ink tank, the excess ink on the upper surface is the squeegee installed on the surface of the plate cylinder. When the printing roller rotates and contacts the aluminum foil, the elastic roller presses the aluminum foil to the printing plate roller so that the ink in the ink hole is transferred to the surface of the aluminum foil, and the printing work of the aluminum foil is completed. The main raw materials used are pharmaceutical aluminum foils, aluminum foil inks and solvent materials, and aluminum foil coating binders. The following is a brief introduction.
2. The properties of medicinal aluminum foils and their physical and mechanical strength tests.
Medicinal aluminum foil is made of electrolytic aluminum with a purity of 99% or more. It is non-toxic and odorless, has excellent electrical conductivity and shading properties, and has extremely high moisture resistance, gas barrier and taste protection. Aluminum foil has a highly dense metal crystal structure, it can completely block any gas, water vapor and light, so it can protect the most effective drugs, in modern packaging almost all opaque or high barrier composites are used to block aluminum foil Layers, especially pharmaceutical packaging, have requirements for the physical and mechanical properties of aluminum foils with a burst strength of more than 90 Kpa, a tensile strength of 98 Mpa and a thickness of 0.02 mm. The surface is clean, smooth, no wrinkles, no indentations, no damage, no films. For fluorescent substances, pinholes with a diameter greater than 0.3 mm do not exceed 1 per cubic meter, and the wet surface tension is not less than 32.
(1) Determination of aluminum foil rupture strength: Use a burst strength meter to take 3 specimens of 40 mm x 40 mm in the finished product of the aluminum foil, place the specimen one by one in the crevice of the instrument, and turn on the oil pump, depending on the indicated numerical rupture strength on the pressure gauge, not less than 90 kPa.
(2) Pinhole test: Use a wooden box of 800mm x 600mm x 300mm or an appropriate volume. Install a 30W fluorescent lamp in the wooden box. Put a glass plate on the wooden box and leave a 400mm x 250mm space to check the pinhole of the aluminum foil. . Ten samples of length 400 mm and width 250 mm were taken from the finished product of the aluminum foil and placed one by one on a pinhole inspection table, and the pinholes were checked in the dark place to see if they met the standards.
(3) Determination of aluminum foil fluorescent substances using an ultraviolet analyzer with wavelengths of 24 nm and 365 nm. In the finished product of aluminum foil, 5 pieces of 100 mm×100 mm lines were taken, and the fluorescence was not observed in the above wavelengths. (4) Determination of tensile strength of aluminum foil is performed on an automatic tensile testing machine. Samples of aluminum foil of a certain size are taken. The samples are clamped on the upper and lower clamps of the testing machine, the tensile testing machine is started, and the test data is recorded against the standard. Does it meet the standard requirements.
3. Properties and detection methods of ink and filler materials for aluminum foil
(1) Composition of ink for aluminum foil: It is mainly composed of pigment, filler material, synthetic resin and solvent.
(2) The quality standard of ink for aluminum foil: Color: Approximate to the standard color sample (scratch visual inspection), coloring power: 95% to 110% compared with the standard sample. Fineness: ≤ 25 microns. Viscosity: 25 s to 27 s with a No. 4 coating cup at 25°C.
(3) Ink solvent performance: refers to the solvent used in the printing and coating process. Its main representatives are: aromatic hydrocarbons of xylene [C6H4(OH3)2] are fractionated coal tar light oil fraction or catalytic weight The entire light gasoline is fractionated or disproportionated by toluene. It is a colorless, transparent, volatile liquid with aromatic odor, toxic, and insoluble in water. Ketone solvent is represented by acetone (CH3COCH3) is a colorless volatile and flammable liquid, melting point -94.6 °C, boiling point 56.5 °C, a flash point of -20 °C, relatively lively chemical properties, explosive limit of 2.55% to 12.8% (volume) . Ester solvent ethyl acetate (CH3COOC2H5), also known as ethyl acetate, a colorless flammable liquid with fruit aroma, is acetic acid and ethanol in the presence of sulfuric acid in the distillation and obtained, melting point -83.6 °C, boiling point 77.1 °C , easy to fire, slightly soluble in water, the explosion limit of 7.5% to 11.2%.
(4) Solvent detection method: The water content of the solvent should not exceed 0.2%, and its purity should not be lower than 99%. Control method: gas-phase spectrometer with nitrogen as carrier and thermal conductivity cell detector. A set of solvent peaks with different concentrations, peak heights and concentrations were used to obtain the working curve, and then the corresponding peak height was sampled for each batch of solvent under the same conditions to obtain the concentration. Specific detection methods: Gas chromatograph, gasification chamber temperature 250°C, detection chamber temperature 200°C, column chamber temperature 150°C with polymer porous beads as column packing. An analytically pure reagent that chemically purifies the solvent is distilled. The purified solvent and water were used to prepare a standard solvent with water content of 0.02%, 0.05%, 0.1%, 0.15%, and 0.2%. The injection volume of 0.1 ml was sampled. Under a certain bridge current and attenuation, the response peak of water was obtained, and the peak height of water was plotted against the concentration to obtain the working curve. Samples were taken from each batch of raw materials and the same sample was injected under the same conditions. Peak heights were used to compare the corresponding concentrations with the standards in the working curve. Every time the start-up test must work curve, regardless of whether the same conditions as before, the same preparation of pure concentration of 100%, 99.8%, 99.5%, 99.2%, 99% of the concentration, the injection is 0.1 ml into the test dilution The peak height of the agent is plotted against the peak height and the working curve is obtained. The peak height is then sampled and the corresponding concentration is obtained based on the working curve.
4. Aluminum foil adhesive properties and testing
The currently used adhesive is a two-component polyurethane adhesive because the main agent is composed of a substance containing many active hydrogens, such as a hydroxylamino group, and the curing agent is a compound having a polyisocyanate composition, and an isocyanate group in the curing agent. When contacted with the active hydrogen in the main agent molecule, an addition reaction is automatically performed to generate a carbamate structure, so that the main agent and the curing agent combine to increase the molecular weight, and even generate a three-dimensional conformation with a branched chain structure. Cross-linked products, with high temperature resistance, high adhesion characteristics. The isocyanate group (-NCO) in the curing agent is an active reactive group. Besides being reactive with the active hydrogen in the main agent molecule, it can also react with the active hydrogen in the surface material of the adherent material to form a chemical bond. This allows the adhesive molecules to bridge the aluminum foil PVC material at the same time, resulting in stronger adhesion.
The main indicators of adhesive testing:
(1) Determination method of solid content: Take 5 g of binder in a beaker and dry the beaker in an oven at 110°C for 2 hours and then weigh again: Solid content = dry film weight / 5 g × 100%.
(2) Measurement of adhesive viscosity: The viscosity at 25°C was measured with a rotational viscometer. The method is: under the conditions of 25 °C, the sample glue thermostat 0.5 hours or more, according to the viscosity of the provided adhesive, using a viscometer to check the comparison.
(3) Acidity According to GB/T/458-83 with a glass motor pH meter, it can also be used to detect the pH value of precision test paper.
Second, the main quality problems and analysis of medicinal aluminum foil printing
1. Pharmaceutical aluminum foil printing appearance quality requirements
(1) The printed surface of aluminum foil is correct in hue, bright in color, bright in color, bright in ink and smooth in edges.
(2) Printing fastness: The adhesive ink is not decolorized with transparent tape.
(3) The pattern text and lines are clear, complete and indestructible.
(4) Rich layers of printing textures and clear outlets.
(5) The appearance of the printing is clean and tidy, no obvious dirty knife wire.
(6) The same color density deviation and the same batch color difference index meet the requirements after the final managerial inspection.
2. Foil printed text or figure incomplete
Cause Analysis:
(1) The ink dries too quickly, resulting in a dry print.
(2) Excessive wind and heat affect the concave surface of the printing roller.
(3) plate etching line, ink adhesion.
(4) The squeegee is too far away from the print point on the printing roller.
(5) The speed is too slow.
3. Aluminum foil printed surface colored lines (lines)
Cause Analysis:
(1) The squeegee blade has hard particles close to the roller and debris must be removed. If you encounter a fixed line must be sharpened or tool change can be.
(2) If the lines are fixed, the hard spots in the rollers are embedded in the rollers and must be removed by parking.
(3) When the new roll was started to use, it was found that the fixed line mark was generally caused by the chrome plating of the printing roller and the rough surface was not sanded or repaired, resulting in pinholes.
(4) The resin and pigment in the ink are not ground, it will also cause line marks, which must be removed by wire mesh filter.
(5) Squeegee angle and position, hardness must be adjusted properly.
·Editor Li Yonglin·
The blister packs of pharmaceuticals began to rise in Europe in the 1930s. In the 1990s, the blister packs in China developed rapidly. Not only can they produce monochrome “PTP†pharmaceutical aluminum foil coating equipment, but also mass production of color and gold series.†"PTP" products, the main material of aluminum foil and aluminum foil ink, adhesives can meet the needs of domestic production. As a manufacturer of pharmaceutical "PTP" packaging materials, the selection of high-quality raw materials is a prerequisite for the production of customer-satisfactory products. Therefore, based on the performance of homemade "PTP" materials and printing materials, this article describes its quality standards and testing methods. The reason why these materials are used in the gravure coating process is analyzed to analyze the cause.
December 25, 2023