Short-Wave Infrared Heating: Delivering Instant Thermal Energy for High-Efficiency Flexible Forming Processes

Shortwave infrared lamp can be designed with powerful density, its peak wavelength is 1.0-1.4μm, it is particularly suited for fast response heating processes as shortwave infrared penetrates more deeply into materials with full-efficiency within seconds.

Halogen short-wave infrared heating lamp has the following advantages:

1. Fast response time, the heating temperature can rise and fall quickly

2. By combining with the reflection module, IR lamps can work in a small area by concentrating light or parallel irradiation

3. The lamp does not touch the heated object and can be used in a clean environment and no harmful

4. The working lamp is not disturbed by the atmosphere and external environment and can be used in a vacuum oven.

5. Inside of filaments can be designed and heat up to 2600°C, so the objects can be heated up to 1000°C or higher, depending on the material and size being heated.

Short Wave Infrared Heating: Injecting Instant Thermal Energy into Flexible Forming Processes

Flexible forming processes shape plastic materials by applying force and thermal energy, and are widely used in the manufacture of plastic and rubber products through blow molding, injection molding, compression molding, and hot press molding. A common core step across these processes-heating plastic pellets or prepregs to a molten or softened state—relies on efficient and precise electric heating technologies. Driven by this need, shortwave infrared quartz heating lamps have become a highly favored heating solution in flexible forming, thanks to their unique instant heating and instant cooling performance.

Working Principle of Short Wave Infrared Quartz Heating lamps

The core structure of a short wave infrared quartz heating lamp consists of a high purity tungsten alloy heating wire sealed inside a quartz glass tube. When energized, the heating wire rapidly rises to over 2000 °C, generating intense short wave infrared radiation with a peak wavelength of approximately 0.9–1.4 μm. Quartz glass has excellent transmittance for short wave infrared, allowing the radiant energy to pass through the tube wall with almost no loss and directly irradiate the surface of the material to be heated, penetrating deep into its interior. This radiative heating method is fundamentally different from traditional convection or conduction heating—heat travels at the speed of light, acts directly at the molecular level, and excites atomic vibrations within the material to generate heat, without needing to heat the surrounding air or the mold as an intermediate medium.

Instant Response, Deep Penetration, Precise Temperature Control

The most prominent advantage of short wave infrared heating is its extremely fast heating rate. The heating lamp can reach over 90 % of its rated power output within 1–2 seconds after being switched on, and cools down to ambient temperature within a few seconds after power off. This very low thermal inertia enables a “heat on demand” approach—energy is supplied only at the exact moment the material needs it, avoiding energy waste and overheating risks from continuous heating.

Secondly, short wave infrared offers stronger penetration. Unlike far infrared, which mainly heats the surface, short wave radiation can penetrate several millimeters or even deeper into plastics, rubbers, and other materials, achieving a “volumetric heating” effect. This means the temperature gradient between the interior and exterior of the material is small, resulting in more uniform melting, effectively preventing product defects caused by surface overheating while the interior remains unmelted.

Moreover, short wave infrared heating boasts extremely high energy conversion efficiency. The conversion rate from electrical energy to infrared radiation can exceed 90 %, and the radiant energy is delivered directly to the material without heating an intermediate medium. When combined with efficient reflectors and thermal insulation designs, it can significantly reduce workshop ambient temperature rise, saving electricity and improving working conditions.

Infrared Heating Applications in Various Flexible Forming Processes

  In blow molding, plastic pellets must be rapidly melted into a melt within the barrel, which is then blown into shape by air pressure. Short wave infrared heating lamps can directly radiate the outer wall of the barrel, bringing the material temperature to the set value within seconds. With fast cooling response, precise zone temperature control is achieved, which is particularly suitable for the rapid heating of PET preforms.

Injection molding involves injecting molten plastic into a mold cavity. The heating sections of the injection molding machine barrel can adopt short wave infrared auxiliary heating, significantly reducing preheating time while improving melt uniformity. For thin walled, precision injection molded parts, the instant response capability of short wave infrared can compensate for heat losses during the injection process in real time, ensuring stable melt temperature and improving part dimensional accuracy.

Compression molding is used for producing rubber seals and other rubber products, requiring the thermoplastic rubber to be heated and pressurized for curing in a mold. Short wave infrared can simultaneously and rapidly preheat the mold and the rubber blank, greatly shortening the vulcanization cycle and boosting production efficiency.

Hot press molding is applied to fiber reinforced plastics, where prepregs need to be cured under high temperature and high pressure. A short wave infrared preheating system can quickly bring the prepreg to the forming temperature before pressing, reducing the waiting time inside the press, while ensuring thorough resin melting and good fiber impregnation, thus enabling stable production of high strength, lightweight parts.

The essence of flexible forming processes is to apply heat and force to materials to achieve deformation, and the efficiency of the heating step directly determines the overall energy consumption, production cycle, and product quality. With its unique advantages of instant heating, instant cooling, deep penetration, and precise controllability, the short wave infrared quartz heating lamp is injecting a powerful “thermal pulse” into various flexible forming processes—blow molding, injection molding, compression molding, and hot press molding—driving the plastics and rubber processing industry toward greater efficiency and energy conservation.