The acrylic bottles we often see nowadays are composed of an oval container and a piston. It comes from the force of the spring, which uses the contraction force to prevent air from entering the bottle, and then uses the atmospheric pressure to make the piston move forward. However, we must be aware that the contractile force between the piston and the bottle wall should not be too large; otherwise, it will be very difficult for us to move forward. Of course, if you can move forward with special power, normal use will also be affected. If a leakage occurs, the requirements for the manufacturer will be very high.
It can be said that the launch of acrylic bottles has brought us great convenience, especially for the women's cosmetics industry. It can effectively ensure the quality of the product and keep it fresh. However, due to the complex structure of vacuum, its price is relatively high.
At present, we are not using many acrylic bottles. It is believed that with the expansion of consumer demand, more progress will be made in meeting the needs of different grades of skin care products. Through the above introduction, we believe that you have gained a good understanding of acrylic bottles and their functions. We believe that it will be applied more widely in the future.
Acrylic bottle processing technology
1. Casting molding
Casting molding is used to form shapes such as acrylic plates and rods, that is, to form shapes through bulk polymerization. The products after casting need to undergo post-treatment. The post-treatment conditions are to hold at 60℃ for 2 hours and at 120℃ for 2 hours.
2. Injection molding
The particles produced by suspension polymerization are used for injection molding, which is carried out on a common plunger or screw injection molding machine. Injection molded products also need to undergo post-treatment to relieve internal stress. The processing is carried out in a hot air circulation drying furnace at 70-80℃. The processing time is usually about 4 hours depending on the thickness of the product.
3. Extrusion molding
Polymethyl methacrylate can also be extruded to prepare PMMA plates, rods, pipes, sheets, etc., which contain particles produced by suspension polymerization. However, due to the small molecular weight of the polymer, the profiles prepared in this way, especially the plates, have lower mechanical properties, heat resistance and solvent resistance compared with the profiles formed by casting. This has the advantage of high production efficiency, especially for pipes and other molds that use the casting method. Difficult-to-manufacture profiles. Extrusion can be carried out using single-stage or double-stage vented extruders, and the screw length-to-diameter ratio is usually 20-25. Table 2 shows the typical process conditions of extrusion molding.
4. Thermoforming
Thermoforming is the process of manufacturing acrylic sheets or plates into products of various sizes and shapes. The billet cut to the required size is clamped onto the mold frame, heated to soften it, and then pressed close to the mold surface to obtain the same shape as the mold surface. After cooling and molding, the edges are trimmed to obtain the product. Pressurization can be carried out by vacuum drawing or direct pressurization with a profile punch. The thermoforming temperature can be referred to the recommended temperature range in Table 3. When using rapid vacuum low-stretch forming products, it is better to use temperatures close to the lower limit. When forming deep drawing products with complex shapes, it is advisable to use temperatures close to the upper limit. Generally, it is better to use at room temperature.
