Plastic bottles are mainly made of polyethylene or polypropylene and other materials with the addition of various organic solvents. Plastic bottles are widely used polyester (PET), polyethylene (PE), polypropylene (PP) as materials, after adding corresponding organic solvents, after heating at high temperature, through plastic molds through blow molding, extrusion blowing, or injection molding plastic containers.
It is mainly used for liquid or solid disposable plastic packaging containers such as beverages, food, pickles, honey, dried fruits, edible oils, agricultural and veterinary drugs, etc. Plastic bottles have the characteristics of being unbreakable, low cost, high transparency, and food-grade materials.
At that time, the world economy was undergoing changes, and the domestic industrial structure was also in a constant upgrading stage. In the process of industrial upgrading at that time, some low-value-added enterprises encountered various operational difficulties and encountered unprecedented challenges and faced various difficulties. Today, we will talk about the plastic bottle enterprises in the transformation storm.
Regarding plastic bottles, there were all kinds of problems at that time. Let's analyze it carefully. First of all, plastic bottles are labor-intensive work, and labor costs are constantly rising. For plastic bottle companies, labor costs have become a huge pressure. Secondly, the prices of raw materials continue to rise. Due to the rise in various costs in the market, the raw materials have risen significantly, which has created another layer of pressure on plastic bottle companies. Third, with the European debt crisis and the weakening of the world economy, the foreign trade orders for plastic bottles have gradually declined, and many foreign trade enterprises have turned to the domestic market, which has brought more pressure to the domestic plastic bottle market, which is already fiercely competitive. The war is getting more and more fierce, and the profits of enterprises are getting lower and lower.
Regarding plastic bottle manufacturers, under various pressures at that time, they should take the road of industrial upgrading, take the road of innovation in the field of plastic packaging, and try their best to increase the added value of plastic bottles. From the design of plastic bottles, production and sales of all aspects of continuous improvement.
Plastic bottles are made of polyester (PET), polyethylene (PE), and polypropylene (PP), after adding the corresponding organic solvent, after heating at high temperature, through plastic molds through blow molding, extrusion blowing, or injection molding plastic containers. Plastic bottles have the characteristics of being unbreakable, low cost, high transparency, and food-grade materials.
Pay special attention when using plastic products, do not touch vinegar, detergents, etc., avoid direct sunlight, high temperature, etc., to avoid chemical reactions. In addition, when you buy plastic tableware, you should choose plastic products with PE (polyethylene) or PP (polypropylene) markings on the product, few decorative pictures, colorless, odorless, and smooth surface.
There are many methods for producing polyethylene, and the common one is to polymerize ethylene at a high temperature of 200 to 300°C and a pressure of 1000 to 2000 atmospheres. In polyethylene, no other substances are doped. The polyethylene obtained in this way has low density, soft texture, and high stability with respect to sunlight, air, moisture and chemical reagents, so there is no need to add stabilizers and plasticizers, and stabilizers and plasticizers are mostly Poisonous or highly toxic.
The plastic bottle bento is easy to carry, not afraid of falling, has the characteristics of acid and alkali resistance, produces bento, and is also conducive to recycling.
(1) When planning a kneading plastic bottle, if the material is high-density polyethylene or polypropylene, the cross-section of the plastic bottle should be rectangular or oval. For low-density polyethylene or other flexible plastic bottles, its cross-section should be The cross section is preferably circular. This facilitates the extrusion of the contents from the plastic bottle. The plastic parts used in cooperation with the plastic bottle mouth are mainly bottle caps and sealers. The planning of the plastic bottle finish should focus on how to make the plastic bottle finish better cooperate with the cap and sealer. The bottom of the plastic bottle is the thin part of the mechanical function of the plastic bottle. Therefore, the bottom of the plastic bottle is generally designed to be inwardly concave; the corners of the plastic bottle and the inner concave are made of larger arcs. In order to facilitate the accumulation of plastic bottles and increase the stacking stability of plastic bottles, the bottom of the plastic bottle should be designed with an inner groove.
(2) When selecting labels on the surface of plastic bottles, the label surface should be flat. A "sash" can be planned on the surface of the plastic bottle, so that the label is accurately positioned and does not move. In blow molding, the first contact part of the parison inflation is always the part that hardens first. Therefore, the wall thickness of this part is also larger. The edge and corner parts are the parts where the parison is finally contacted by inflation, and the wall thickness of this part is relatively small. Therefore, the edges and corners of the plastic bottle should be designed with rounded corners. By changing the surface shape of the plastic bottle, for example, the middle of the plastic bottle is relatively thinner, and adding circumferential grooves or ribs on the surface of the plastic bottle can improve the rigidity and bending resistance of the plastic bottle. Longitudinal grooves or stiffeners can eliminate deflection, sagging or deformation of plastic bottles under long-term loads.
(3) The printing surface of the plastic bottle is the part where consumers' attention converges. The printing surface should be flat and continuous; if the plastic bottle contains structures such as handles, grooves, reinforcing ribs, etc., care should be taken not to cause inconvenience to the printing operation when planning. The oval-shaped plastic bottle has higher rigidity, but the manufacturing cost of the mold is higher. Therefore, in order to ensure the rigidity of the plastic bottle, in addition to selecting materials with high rigidity, the rigidity and load-resistant strength of the plastic bottle should be enhanced through the shape planning of the plastic bottle.
(4) Because most plastics are notch sensitive, cracks and cracks are likely to occur in plastic bottles at sharp corners, the root of the mouth thread, neck and other parts, so these parts should be designed with rounded corners. Regarding the transfer point of the rectangular plastic bottle, it needs to support most of the load of the plastic bottle, so the wall thickness at this point is partially increased, which is also conducive to improving the rigidity and load-resistant strength of the plastic bottle.