Thermal molding and injection molding equipment are common plastic molding machines in the plastics processing industry. They are widely used in the fields of food packaging, medical supplies, auto parts, electronic product casings, daily products and so on. Because both involve heating and molding plastics, it's easy for many buyers to get confused.
In fact, the two kinds of equipment are very different in processing principle, raw material form, product structure, production efficiency, mold costs, application field, etc. Choosing the right equipment requires a comprehensive assessment based on product size, structural complexity, production and cost requirements.
I. Different Processing Principles
Plastic thermoforming equipment mainly adopts sheet heating molding technology. During production, the softened plastic sheet is softened with a heating system, then pressed against the surface the softened plastic sheet the mold with vacuum, compressed air or mechanical pressure to cool and form the desired product.
The core processes of thermal molding include:
Heating → Sheet softening → molding → cooling → removal → finishing.
Common thermoforming methods include vacuum forming, pressure forming and mechanical forming. For example, plastic cups, food trays and blister boxes are often produced using thermoforming processes.
Injection molding equipment employs a completely different processing method. The injection molder adds granular plastic material to the drum, melts the plastic through heating and screw shearing, and then injects the molten plastic into an enclosed mold at high pressure. After cooling and curing, the product is obtained.
Injection molding process include:
Heat molten plastic granules → grouting → Holding pressure → Cooling → Mold opening and part removal.
Because injection molding is completed under high pressure, plastic parts with complex structure and high dimension accuracy can be made.
II. Different Raw Material Forms
Plastic thermoforming equipment is mainly made of plastic plastic sheets or rolls.
Common materials include:
PET sheets
PP sheet;
PS table
PVC Plates
PLA Environmental Materials
ABS Form
EVOH multilayer composite sheets
These materials are usually extrusion equipment into a plastic sheet of a certain thickness before entering a hot press molding line.
Injection molding equipment is mainly made of plastic granules (resin granules).
Common materials include:
Engineering plastics such as PP, PE, ABS, PC, PA, POM, TPU.
Granular raw materials can be modified to meet the strength, heat resistance and chemical resistance requirements of different products.
III. Different Product Structures and Applications
Plastic thermoforming equipment is more suitable for production:
Large area of thin-walled plastic
Disposable packaging products
Transparent products with high appearance requirements;
Large plastic parts
Typical applications include:
Food packaging industry
For example:
Plastic lunch boxes
Yogurt cups
Drinks cups
Fruit trays
Healthcare
For example:
Medical suction trays
Pharmaceutical packaging boxes
Medical device packaging
Industrial packaging field
For example:
Electronics Insider
Tool Packaging
Auto parts packaging
Injection molding equipment is more suitable for manufacturing:
Complex Structures
High-strength plastic components
Chemicals
Typical products include:
Car interior parts
Mobile phone casings
Electrical casing
Plastic gears
Pipe fittings
Toy parts
IV. INTRODUCTION Big difference in Mold Costs
Mold cost is an important factor in equipment selection.
The structure of Plastic thermoforming molds is relatively simple, usually using aluminum molds, plaster molds or composite mold. Due to the low molding pressure, the mold manufacturing cycle is short and the cost is low.
This makes thermoforming equipment particularly suitable for:
Small-batch production
Product development and testing
Multi-variety production
Injection molds are usually made of steel and need to withstand high pressure, so the structure of injection molds is complex and manufacturing accuracy is high.
Injection molds typically include:
Cavity system
Gating system
Cooling system
Ejection system
As a result, it is more expensive to manufacture but has a longer service life, making it more suitable for large-scale continuous production.
V. Differences in Production Efficiency and automation
Injection molding equipment has a high degree of automation, suitable for long-term, high-speed mass production.
Modern injection molding production lines can generally be connected to:
Automatic feeding systems
Robotic part Processing System
Automatic inspection equipment
Packaging equipment
For hundreds of thousands or even millions of product orders, injection molding has a significant advantage.
In recent years, the level of automation of plastic thermoforming equipment has been increasing, especially the fully automated thermoforming production lines.
Automatic Feeding
Automatic heating
Automatic molding
Automatic Cutting
Automatic stacking
For food packaging and other industries, thermoforming equipment can also achieve high speed continuous production.
VI. INTRODUCTION Differences in Product Precision and Design Freedom
Because of its high pressure injection molding method, injection molding equipment can achieve complex structural design, such as:
Threaded structures
Snap-fit online structure
Reinforced rib designs
Precision assembly structures
Product size stability is high.
Thermoforming equipment is limited by sheet thickness and molding depth, which is more suitable for products with simple structure.
For example, car part shell with complex interiors are usually produced by injection molding, while large transparent packaging box are usually produced by thermopressing.
Abstracts
Although both plastic thermoforming and injection molding equipment are used in plastic products production, their production methods and applications are completely different.
The main advantages of plastic thermoforming equipment are low investment of equipment, low cost of mould, suitable for production of large scale thin-walled packaging products; the advantages of injection molding equipment are high precision, complex structure, suitable for large-scale production of precision plastic parts.
With the development of food packaging, pharmaceutical packaging and environmental protection materials, plastic thermoforming technology is developing in a faster, automated and intelligent direction. At the same time, injection molding technology continues to play an important role in the automotive, electronics and industrial manufacturing sectors.
