The quality control of cosmetic glass bottles is divided into two parts, one is the quality control of raw materials, and the other is the quality control of products.
The quality control of raw materials
Most of the glass produced on the market is a multi-component cooling melt with soda-lime silicon as the main body. The main raw materials used include: quartz sand, feldspar, calcite, soda ash, etc.; auxiliary raw materials include: Yuanming powder, carbon powder, Selenium powder, oxygen cobalt, etc. Many of these raw materials are natural minerals and rocks. The quality of raw materials determines the quality of glass products. The purity and particle size of raw materials will affect the production process and product quality of glass.
In order to ensure the quality of incoming raw materials, corresponding instructions have been formulated to guide the inspection of raw materials, which must be strictly followed.
01 Raw material sampling
(1) Bulk raw materials: according to different orientations of the upper, middle, lower, left, and right, at least two points are taken at the same depth in each orientation;
(2) Raw materials in bags: extract a certain number of bags of raw materials according to the purchased quantity, and there must be a certain interval when sampling, and insert the sampling bit into the bag for at least 10cm or more;
(3) The sampling quantity of each batch of raw materials is about 4 kg, and each sample is given a unique number according to the regulations of the batch number;
02 Sample pretreatment
(1) The retrieved samples are dried in an oven, and the samples are distributed to the required amount of inspection by a sample divider, part of which is used for sample retention, part for particle size analysis, and part for component analysis;
(2) After the sample for component analysis is ground and dissolved, it is prepared into a test solution for component analysis (preparation of sample solution for AAS analysis);
03 Particle size analysis
A set of 10 analytical sieves with different specifications ranging from the largest 3.2mm to the smallest 0.071mm, and different analytical sieves are selected for particle size analysis according to different raw material requirements;
04 Chemical composition analysis
In order to ensure the accuracy of chemical composition analysis, the testing instrument selected a novAA350 atomic absorption spectrometer from Jena, Germany. The analysis method refers to the recommended method for the chemical analysis of soda-lime-silica glass and raw materials in the European glass industry. The inspection items include Al₂O₃, Fe₂O₃, CaO, MgO, Na₂O, K₂O, Li₂O, and SiO₂ (QC-LAB-006B atomic absorption spectrometer).
The quality control of products.
In order to ensure that the quality of the produced glass bottles can meet the requirements of customers, the monitoring items include: glass composition, glass density, glass bubbles, glass color, and glass bottle post-processing products.
01 Glass composition
Controlling the chemical composition of glass within the set requirements of glass formula composition is the basic requirement to ensure the quality of glass bottles. The analysis of glass composition will be carried out twice a week, using atomic absorption spectrometer to measure: Al₂O₃, Fe₂O₃, CaO, MgO , Na₂O, K₂O, Li₂O, and SiO₂.
02 Glass density
The change of glass density directly reflects whether the chemical composition of glass is stable or not. The automatic glass density tester of SAINT-GOBAIN OBERLAND is used to monitor the change of glass density every day to ensure the stability of glass composition.
03 Glass bubbles
The number of glass bubbles directly reflects the quality of the melting state of the glass. The selected seedlab3 bubble detector of MSC&SGCC can automatically take pictures and count the bubbles > 100 μm in the glass, and obtain the number of glass bubbles accurately and quickly. Furnace combustion parameters are adjusted.
04 Glass color
Only by quantifying the color of the glass can we effectively monitor the color of the glass and achieve the purpose of maintaining the stability of the glass color. Using a SPECORD200 UV/Vis spectrophotometer from Jena, Germany, the glass was tested at 330-1100 nm in transmission every day, the detection data was converted into a color LAB value, and the glass color was expressed numerically.
05 Glass bottle post-processing products
(1) Adhesion test of glass bottle varnishing, silk-screening and bronzing products
In order to monitor the adhesion of varnished, silk-screened, and hot-stamped products on glass bottles, a 100-grid test can be performed.
(2) Immersion test of glass bottle varnished products
To monitor the adhesion of glass-coated products after immersion, a immersion test can be performed.
(3) Yellowing resistance test of glass bottle spray products
In order to monitor the degree of anti-aging and yellowing of glass bottle spraying, a light fastness test can be carried out.