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Beverage plastic cap production industry, Plastic cap injection moulding or continuous compression moulding China?
- Dec 12, 2018 -

     Beverage plastic cap production industry, Plastic cap injection moulding or continuous compression moulding China?

1. Beverage packaging industry market current situation:

In recent year, water and beverage industry remain speedy growth. According to the report of Chinese Beverage Industry 2011,the output of soft drink in China this year was 11,762.32 Ton, which increased by 22% year on year. Sales volume reached more than 6Billion USD, with 32.06% year-on-year growth.

This drives the enormous market and developing prospect of beverage packaging industry. In the cost of water and beverage cost, package play an important role. Thus, how to improve the quality of bottled water and beverage package, and reduce the cost, are highly regarded by each beverage manufacturer.

In bottled water and beverage package, PET bottle play an absolutely part. China is at the rapid developing stage of PET beverage package, it has become the significant manufacturing base. At present, PET bottle account for 57.4% of Soft Drink package, the demand will still remain fast expansion. Likewise, there is also a huge demand of plastic bottle cap, annual demand reaches more than several billion pieces. 

2. Typical plastic closure structure profile:

Plastic closure volume is not big though, construction is very complex. Inner seal, thread, knurl, link bridge and tamper evident and other structure have strict criteria,such as sealing performance, drop performance, heat resistance, open torque, band break and capping performance,etc.


In order to prevent fake products, and ensure evil damage, plastic bottle caps in the market are using TE(Tamper Evident) structure.


For example, the following picture is typical purified water anti-theft plastic closure. HDPE material, cap weight is about 2.0g. From the structure, we can see there is a seal ring and inner thread, between the cap body and Tamper Evident band, there are some small link bridge, diameter is about 0.7mm,they will be broken once cap open. 

Plastic closure production technology introduction:

Plastic bottle closure production looks simple but actually requires high professional technology. In the field of plastic bottle closure, there are mainly two technologies: Injection moulding and Continuous compression moulding.

3. Injection processing:

Injection moulding products normally uses rubber and plastic injection. The simple process of injection is: Resins go through hopper and get to heating extruder, then get molten after heating. Under the pressure of extruder and piston of plastic closure injection machine, resin enter and fill in the plastic cap injection mould through nozzle, after cooling ,molding and demolding,then get the final plastic injection closure. 

Due to capacity demand in plastic closure injection moulding machine production, generally adopting multi-cavity mould, (24~96 capacities). In a production cycle, mould open and close once. Plastic resin enter through the hopper, and plasticize in the extruder, then inject into hot runner system, and distribute into each cavity unit.


Injection molding can product all kinds of plastic cap products, including universal beverage bottle caps, sport cap and flip-top cap. For common beverage Anti-theft beverage cap, injection is able to realize one-step moulding, don’t need the additional cap slitting procedure.


Since the high-efficiency requirement in plastic closure production, plastic closure mould is extraordinarily complicated. Generally speaking, the whole plastic cap injection mould price will exceed the plastic closure injection moulding machine. In order to achieve shorter production cycle, plastic cap mould has rigid requirement on cap mould cooling.

4. Compression moudling processing:

Continuous compression moulding, also named cap compression moulding, the technology is more simple: Through resin extrusion and plasticization system, quantitive pellet is dropped into the plastic cap mould cavity, then realize the the process by clamping, after cooling, demoulding, finally finish cap production. Cap compression Molding machine is already a well-known and popular technology worldwide in plastic bottle caps production application. 

5.Developing direction:


From the view of energy and material consumption, environmental protection, plastic cap compression moulding is the mainstream in the market and becoming the tendency in beverage field. With its unique advantages, plastic cap compression moulding take up more than 60% market share in Chinese water and beverage at present. In Coca Cola, Pepsi Cola, more than 80% caps use compression moulding China. The national famous bottled water and beverage brand- Wahaha and C'estbon, 100% caps are continuous compression moulding.