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.
Quality control of raw materials
Most of the commercially produced glass is a multi-component cooling melt with sodium, calcium and silicon as the main body, the main raw materials used include: quartz sand, feldspar, calcite, soda ash, etc. Auxiliary raw materials include: Sodium sulfate, toner, 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, and the purity and particle size of raw materials will have an impact on the production process and product quality of glass.
In order to ensure the incoming quality of raw materials, corresponding directives have been established to make guidelines for the inspection of raw materials, which need to be strictly observed.
Sampling of raw materials
(1) Bulk raw materials: take at least two points at the same depth in each direction according to different directions of top, middle, bottom, left and right.
(2) Bagged raw materials: take a certain number of bags of raw materials according to the number of incoming goods, sample at a certain interval, and insert the sampling brazier into the bag at least 10cm or more.
(3) Each batch of raw materials sampling quantity is about 4 kg, and each sample is given a unique number according to the batch number.
Sample pretreatment
(1) The retrieved samples will be dried in the oven, and the samples will be allocated to the required amount by the sample splitter, part of which will be used for retention, part of which will be used for particle size analysis, and part of which will be used for compositional analysis.
(2) After grinding and dissolving, the sample is prepared into a test solution for composition analysis (sample solution preparation for AAS analysis).
Particle size analysis
A set of 10 sieves of different sizes from 3.2mm to 0.071mm, can be used for particle size analysis according to the requirements of different raw materials.
Chemical composition analysis
In order to ensure the accuracy of the chemical composition analysis, we use the atomic absorption spectrometer, and the analysis method is based on the recommended method for chemical analysis of soda-lime-silica glass and raw materials in the European glass industry.
Product Quality Control
In order to ensure the quality of the produced glass bottles can meet the customer’s requirements, the monitoring items include: glass composition, glass density, glass bubbles, glass color, and glass bottle post-processing products.
01 Glass composition
The glass chemical composition is controlled within the set requirements of the glass formula composition, which is the basic requirement to ensure the quality of glass bottles.
02 Glass Density
The change of glass density directly reflects whether the chemical composition of glass is stable or not. Use SAINT-GOBAIN OBERLAND’s glass density automatic tester to monitor the change of glass density every day to ensure the stability of glass composition.
(Automatic glass density tester)
03 Glass bubbles
The number of glass bubbles directly reflects the good or bad of glass melting state. The selected MSC&SGCC’s seedlab3 bubble tester automatically takes pictures, counts the bubbles of glass﹥100μm, and gets the number of glass bubbles accurately and quickly, and adjusts the furnace combustion parameters by monitoring the daily changes of the number of glass bubbles.
(Bubble detector)
04 Glass color
Quantify the glass color in order to effectively monitor the glass color and achieve the purpose of keeping the glass color stable. Using the SPECORD200 UV/Visible spectrophotometer from Jena, Germany, the glass is tested daily for transmission from 330 to 1100nm, and the test data is converted into color LAB values to express the glass color in numbers.
(UV/Visible spectrophotometer)
05 Glass bottle post-processing products
(1) Adhesion test for glass bottle varnished, silk-screened and hot-stamped products
In order to monitor the adhesion of glass bottle lacquered, silk-screened and hot-stamped products, a 100-gram test can be performed.
(2) Soaking test for glass bottle lacquered products
In order to monitor the adhesion of glass bottle lacquered products after immersion, immersion test can be conducted.
(3) Glass bottle spraying product yellowing resistance test
In order to monitor the degree of aging yellowing resistance of glass bottle spraying, sunlight resistance test can be conducted.