Monitoring & Controlling Temperature Efficiently In Plastic Industry

Since the 90’s, Dpstar has helped define and grow a unique technology market, providing testing and troubleshooting capabilities that have grown to mission critical status in manufacturing and service industries. From industrial electronic installation, maintenance and service, to precision measurement and quality control, Dpstar tools help keep businesses and industries up and running.  

Success in manufacturing is the ability to ensure a standardized level of quality – repeatedly and consistently. When businesses invest in equipment, the goal is always to improve performance, throughput and product quality. Dpstar helps to eliminate the costs attributed to manual errors so you can continuously verify your process and produce products that meet the gold standard. Faulty stock or equipment malfunctions can lead to significant losses that compromise your entire production line but, with accurate temperature measurement, you can quickly validate the quality and meet your output quotas. This helps to maintain a better reputation with your customers and ensures that your brand remains consistent. 

Major Applications 

Accurate ongoing temperature measurement is crucial to any plastic industry process where temperature is a factor. The following are examples of different types of process lines and how our noncontact infrared sensors can increase productivity and product quality. 

Blown Film Extrusion

In a blown film extrusion process, film is extruded as a continuous tube, then air cooled, collapsed, and wound onto rolls as bags, or slit into single layer widths. Accurate temperature monitoring coupled with the ability to adjust heating and cooling helps maintain the plastic’s tensile integrity and thickness. Raytek point sensors can take spot measurements at the die and the collapsing frame, and MP150 linescanners can take temperature profiles between the frost line and collapsing frame. 

Benefits

• Early detection of die bolt problems 
• Elimination of gauge bands 
• Real-time monitoring of air ring efficiency 
• More consistent lay-flat width 
• Better run ability and less breaks 
• Reduced scrap rate 

Cast Film Extrusion 

In the cast film extrusion process, the melt is extruded through a wide die as a thin web and is cooled on a polished metal casting roll. Raytek point sensors help control temperatures so that proper thickness and finish uniformity are maintained. An MP150 linescanner mounted after the die can give early detection of die bolt heater problems or plugged dies. 

Benefits

• Early detection of die bolt heater problems and/or plugged die 
• Greater film thickness uniformity 
• Enhanced surface finish uniformity 
• Improved final film shape stability 
• Less breaks and machine downtime 
• Increased productivity 

Sheet Extrusion 

The illustration is an example of a typical sheet extrusion process. Note that material thickness determine the type of sensor and the type of optical resolution needed for optimum noncontact temperature measurement. Installing an MP150 linescanner before the three-roll finisher allows the operator to monitor the sheet temperature and adjust the die heater and/or the roll cooling, so product quality is consistent. A linescanner mounted before the pull rolls helps safeguard against tears and irregularities. 

Benefits

• Sheet temperature profile feedback for more effective chill roll control 
• Melt temperature profile for die bolt heater control 
• Increased sheet thickness uniformity 
• Uniform cooling prevents curl and twist 
• Faster grade changes and reduced scrap 
• Increased productivity 

Biaxially-oriented Film Extrusion 

In a biaxially-oriented film extrusion process, MP150 linescanners can be mounted at the die to monitor the die bolt heater and take a melt temperature profile, and at the heat set. Thermalert sensors can be mounted at the cast roll unit for chill roll control and at the pre heater and cooling units, for heating and cooling control. A sensor mounted after the cooling unit helps determine if the product is cool enough for finishing. 

Benefits

• Real-time feedback for rapid zone temperature adjustments 
• Greater thickness and tensile strength uniformity 
• Early detection of die problems 
• Less breaks and downtime 
• Reduced scrap rate 

Extrusion Coating 

A molten web from a die is applied to paper, film, or foil in an extrusion coating process. The distance between the die and the pressure and chill rolls is usually 75 to 125 mm (3 to 5 inches). The resin temperature at this location must be very hot for the melt to adhere to the substrate. The narrow and often difficult to access measurement area is not a problem when using Raytek sensors. The operator can monitor and adjust the die heater and the chill roll temperatures either manually or automatically. For adhesion to smooth surfaces, such as aluminum foil, other processes include heating the substrate, increasing melt temperatures and adding chemical primers. Point sensors mounted after a pre heater can monitor exit temperature and automatically adjust heating elements. Another MP150 linescanner mounted after the chill roll or after the edge trimmer can help detect tears or irregularities before the product is cut or rolled. 

Benefits

• Early detection of die bolt heater or cooler problems 
• Enhanced surface finish uniformity 
• Better run ability and roll building 
• Less breaks and machine downtime 
• Reduced scrap rate 
• Increased productivity 

Laminating and Embossing

The illustration shows where sensors can be located so the laminating and embossing process runs smoothly and efficiently, producing a quality product. MP150 linescanners can be mounted at the preheat and curving ovens. At these points, the linescanner can monitor cross-web temperatures and help in the control of adjustments to heating elements. At the cooling tunnel, the linescanner can monitor cooling efficiency. At the windup roll, the linescanner checks for tears or breaks in the material. 

Benefits

• Early detection of die bolt heater or cooler problems 
• Help in heating and cooling control 
• Less breaks and machine downtime 
• Reduced scrap rate 
• Increased productivity 

Thermoforming 

The illustration shows an example of sensor locations for a thermoforming process. If laminating is part of the process, a Raytek infrared sensor can ensure proper temperatures for laminating a multi-layer product for subsequent forming. An MP150 linescanner or Raytek point sensors positioned between the heater and the forming machine, or mounted as an integral part of the heater, can help monitor the material’s temperature distribution at its proper level prior to entering the thermoformer. 

Benefits

• Improved quality and part uniformity 
• Early detection of heater and cooler problems 
• Better run ability of thermoformer 
• Energy savings 
• Reduced scrap rate 
• Increased productivity 

Advice tailored to your needs

With our comprehensive experience in the plastic industry, we can deliver top-quality engineered solutions for every stage of your plastic manufacturing.

Dpstar Group
No 35, Jalan OP ½, Pusat Perdagangan One Puchong,
Off Jalan Puchong, 47160 Puchong,
Selangor Darul Ehsan, Malaysia.
Email: [email protected]