Facebook
Twitter
LinkedIn

Detailed introduction to the process of automatic hollow blow molding machine

Blow molding
is also called hollow blow molding, a rapidly developing plastic processing method. The tubular plastic parison obtained by extrusion or injection molding of the thermoplastic resin is placed in a split mold while it is hot (or heated to a softened state). After the mold is closed, compressed air is injected into the parison to blow the plastic parison It expands and clings to the inner wall of the mold, and after cooling and demolding, various hollow products are obtained. The manufacturing process of blown film is very similar in principle to blow molding of hollow products, but it does not use a mold. From the perspective of plastic processing technology classification, the molding process of blown film is usually included in the extrusion. The blow molding process was used to produce low-density polyethylene vials during the Second World War. In the late 1950s, with the birth of high-density polyethylene and the development of blow molding machines, blow molding technology was widely used. The volume of the hollow container can reach thousands of liters, and some production has adopted computer control. Plastics suitable for blow molding include polyethylene, polyvinyl chloride, polypropylene, polyester, etc. The resulting hollow containers are widely used as industrial packaging containers.
According to the parison production method, blow molding can be divided into extrusion blow molding and injection blow molding, and the newly developed multi-layer blow molding and stretch blow molding.

Plastic mold common sense-extrusion blow molding
Extrusion blow molding is a method of manufacturing hollow thermoplastic parts. Popular blow molding objects include bottles, barrels, cans, boxes, and all containers for packaging food, beverages, cosmetics, medicines and daily necessities. Large blow-molded containers are commonly used for packaging of chemical products, lubricants and bulk materials. Other blow-molded products include balls, bellows and toys. For the automotive industry, fuel tanks, car shock absorbers, seat backs, center brackets, armrests and headrest coverings are all blow molded. For machinery and furniture manufacturing, blow-molded parts include shells, door frames, racks, clay pots, or boxes with an open face.
polymer
The most common raw material for blow-molded plastics is high-density polyethylene, and most milk is usually made of this polymer. Other polyolefins are also often processed by blow molding. Depending on the application, styrene polymers, polyvinyl chloride, polyester, polyurethane, polycarbonate and other thermoplastics can also be used for blow molding.
Recently, engineering plastics have been widely accepted in the automotive industry. Material selection is based on mechanical strength, weather resistance, electrical properties, optical properties and other properties.
process
3/4 of blow molded products are manufactured by extrusion blow molding. The extrusion process is to force the material through a hole or die to make a product.
The extrusion blow molding process consists of 5 steps:

1. Plastic preform (extrusion of the hollow plastic tube);

2. Close the flap mold on the preform, clamp the mold and cut off the preform;

3. To the mold cavity Cold wall inflation type training, adjust the opening and maintain a certain pressure during cooling,

4.open the mold, write down the blown parts;

5. Trim the flash to get the finished product.

Extrusion
“Polymer blending” is defined as a process in which polymers or polymer systems are upgraded through melt blending. The mixing process ranges from the addition of a single additive to the treatment of multiple additives, polymer alloys and reactive mixing. It is estimated that one-third of polymer production in the United States has to be mixed. The compounding ingredients can be customized according to the performance requirements of the final application. Mixed products have hybrid properties, such as high gloss and excellent impact strength, or precision moldability and good stiffness.
The compounded polymer is usually pelletized for further processing. However, the industry is increasingly interested in combining compounding with the next steps, such as profile extrusion, to avoid reheating the polymer.
mix
People use various types of melt mixing equipment, from roll mills and batch mixers to single-screw and twin-screw extruders. Continuous compounding (extruder) is the most commonly used equipment because it can provide products of consistent quality and reduce operating costs. There are two types of mixing: Distributed mixed materials can be evenly distributed without using high shear stress in the remarried ingredients. This type of mixed liquid is called extensible mixing or laminar mixing.
Dispersive mixing, also known as intensive mixing, in which high shear stress is applied to break up the agglomerated solids. For example, when the additive mass is broken, the actual particle size becomes smaller.
Mixing operations often require two types of mixing in one process.

Blister
is a kind of plastic processing technology. The main principle is to heat the flat plastic hard sheet to soften it, then use vacuum to absorb it on the surface of the mold, and cool it to form. It is widely used in plastic packaging, lighting, advertising, decoration and other industries.
blister packaging: the general term used to produce plastic products using blister technology and package the products with corresponding equipment.
Blister packaging products include: blister, tray, blister box, synonyms are: vacuum cover, blister, etc.
The main advantages of blister packaging are that it saves raw and auxiliary materials, is light in weight, convenient to transport, has good sealing performance, and meets the requirements of environmentally friendly green packaging; it can package any special-shaped products without additional cushioning materials for packing; the packaged products are transparent and visible, Beautiful appearance, easy to sell, and suitable for mechanized and automated packaging, convenient for modern management, saving manpower, and improving efficiency
blister packaging equipment mainly includes: blister forming machine, punching machine, sealing machine, high frequency machine, folding machine.
The packaging products formed by encapsulation can be divided into: plug-in card, blister card, double blister, half blister, double-fold blister, tri-fold blister, etc.

Contact us

small_c_popup.png

Let's have a chat

Leave your information, our sales will contact ASAP!