Rubber & Tyre Machinery World

Info on Equipment And Suppliers


6 Comments

Here’s Why TCU Is An Irresistible Ancillary For Your Rubber Machinery And Worth Your Investment.

TCU or Temperature Control Units are ancillary equipment to your rubber machinery that control process temperatures during rubber processing. During rubber processing, you continually seek optimal temperatures for the best product quality.

A TCU achieves temperature control by circulating water or an oil based fluid through the process application (in a closed loop). This results in heating of the application and temperature control of the process.

Temperature control units service a single process at any one time. In rubber industry, water is most popular circulating media.

For example, you have Three-Zone Water TCU’s for your internal mixer where One Zone supplies water to the Rotors, Second Zone to Drilled Sides (or Mixing Chamber) and Third Zone to Discharge Drop Door (and Floating Weight, RE Plates as appropriate to the mixer model). Usage of TCU in an intensive internal mixer is found to improve carbon black dispersion, eliminate first-batch-effect, maintain batch-to-batch consistency of your rubber mix compound, increase productivity, and reduce machine stress (which in turn increases the life of your internal mixer).

Similarly, you have 4 or 5 Zone TCU’s for your Extruders, where each of the zones supply water to screw, forward and rear barrels, die head, feed roll, etc as is required for your rubber extrusion process. Or you may have Two-Zone TCU for open two-roll mixing mills where each zone supplies water to your peripherally drilled or cored rolls. Most Rubber Calenders also have TCU supplying water to the rolls to control the calendering process temperature.

TCU for a 3-Roll Calender

3-Zone TCU for a 3-Roll Vertical Calender – Image from Bainite Machines Website

A properly installed, operated, and maintained TCU system gives you years of reliable operation.

Each TCU is a self-contained system consisting of a centrifugal pump, electric heater, cool/vent solenoid valve, electrical control, including a PID microprocessor controller and thermocouple along with standard safety devices like a mechanical over temperature safety thermostat, a pressure relief valve, motor overload protection, a low pressure cut out switch, etc.

Temperature Control Units come both in portable and robust sizes (depending on the application) with a variety of different control instruments, heater sizes, and cooling vales.

A Compact TCU

Compact TCU – Image from AEC Website

And you are right when you imagine that the portable TCU’s are visually appealing and popular because of their compact size.

At your installation site, you need to provide adequate water (from portable or central chillers or towers) to these TCUs from your plant water supply source. Check your manufacturer’s operations manual to verify the recommended water pressure requirement. This is important because lower than recommended water pressure can cause pump cavitations while excess pressure can damage internal components.

The pump in your TCU is used for rapid circulation of a relatively small amount of water. This in turn ensures close and uniform temperature differences between the delivery and the return lines.

You use temperature control units, when you want to preheat a process to the desired operating temperature. The heater and  cooling valve works together to give fast and accurate response to bring the water up to desired temperature or to change the settings when needed. This controls your circulating water temperature.

Here is an animation, that I found on the website of Sentra Temperature Controllers. It is quite informative and I hope you too like it. (Click on the picture to start animation)

Advantage Make TCU

Upon reaching your desired operating temperature the TCU can continue to add heat or convert into a cooling device by exchanging a small amount of circulated water with cooling water from an external source. Modern TCU have the controls wherein cooling water is precisely metered into the system by the cooling valve.

Most TCU’s in rubber industry for your machinery has temperature control from 30° to 300°F and designed for easy maintenance.

Summarizing, rubber processing under optimal temperature conditions is a must for your final product quality. And the features of TCU makes it irresistible as an efficiency enhancing ancillary equipment, which control process temperatures on your rubber machinery. Thus worth your investment.

Do you agree?


If you liked this article, please do share with your colleagues, customers and friends. And If you would like to be informed of our articles regularly, please register with us for free updates today.


18 Comments

Rubber Mixing Room

Think rubber mixing room, and the image that conjures up in your mind is that of a “black room“!

Factories that have open two roll mill mixing have carbon black particles all over the place, lending credibility and authenticity to “black mixing rooms”. Dust collection system reduces this to a large extent.

When an internal Banbury mixer or Intermix mixers with semi/automatic carbon feeding, filler feeding, oil dosing and effective dust collection systems are deployed, they present a safer and cleaner environment. Maintenance is easier and mixing rooms need not be “black” any longer.

A representative image of a mixing room is as below.

ThyssenKrupp Mixing Room Image

ThyssenKrupp Mixing Room Image from the web

Depending on the technology and layout adopted, the set-up could vary. And if you are curious to visualize how the complete system works, here is a video of a rubber mixing line.

Automated Mixing Line From Bainite Machines

Automated Mixing Line From Bainite Machines

Newer and most state-of-the-art rubber mixing and compounding factories invest in automated rubber mixing rooms to reduce reliance on labour, increase efficiency and production.


If you liked this article, please do not forget to share with your colleagues and friends. And If you would like to be informed of our articles regularly, please register with us for free updates today.


11 Comments

Peripherally Drilled Rolls or Centrally Cored Rolls?

Do you use centrally cored rolls or peripherally drilled rolls in your two-roll mixing mills? Or a combination of both?

Roll selection for a mixing mill is of decisive importance for the quality of many high-tech products manufactured by the rubber industry. Open two-roll mills in rubber processing are recommended when quick cooling for the batch being mixed is sought, say for example in final mix compounds.

Generally, these rolls are made of Chilled Cast Iron (CI) through a process of vertical casting. Chilled CI has greater resistance to deflection and uniform heat transfer characteristics. Depending on the presence or absence of alloy, the hardness of the outer working (chill) zone could be in the range of 460-650 HV with a thickness 12-20 mm.

Basis the application, manufacturers take extreme care on the properties of the rolls that include breaking strength from journals and core material, thermal conductivity, surface quality and wear resistance of the roll, overall machining and surface quality.

As these rolls operate at high speeds, precise concentricity with proper balancing of rolls is a prerequisite for efficient utilization of material and energy. The surface quality of the rolls is crucial for the products to be produced. The smoother and more precise the rolls, better the product.

Viscous deformation of the rubber compounds occurs between the rolls of mills during mixing and mastication. This generates heat that needs to be removed through effective cooling. Hence, water circulation passages for cooling are an essential feature of the roll design in rubber mills. These passages allow a pre-defined circulation of the cooling agent (mainly water) and ensure that the temperature can be kept within a prescribed tolerance over the entire face length of the rolls.

Two designs are normally available – centrally cored rolls and peripherally drilled rolls. Peripherally drilled rolls are possible for diameter greater than 150mm (or 6 inches). The cross-section of a centrally cored roll is easy to visualize. But, ever wondered how the insides of a peripherally drilled roll looks like?

Well here is with a sectional view with water flow.

Peripherally Drilled Roll

The water entering into the roll is cooler (blue colour) and as the heat transfer occurs, the water temperature rises gradually (red colour at exit).

The efficiency of heat transfer is relatively higher in the case of peripherally drilled rolls than in centrally cored rolls due to close proximity of the water channels to the roll surface. In peripherally drilled rolls, the passages for heat exchange are provided approximately 25mm under the roll surface and can vary nominally between manufacturers. Reputed roll manufacturers like Walzen Irle, Leonhard Breitenbach and Karl Buch, in their decades of existence, have built their own standards. Roll manufacturers are also available in China, Taiwan and India for various sizes.

The manufacturing processes and costs involved in producing a peripherally drilled rolls is relatively high, hence they are priced higher than cored rolls. Your choice of peripherally drilled or cored rolls depends on the quality of rubber processing required in mixing mills and the marketability of your rubber products for a price that profitably covers your investment.

Any state-of-the-art Calender in rubber processing also use peripherally drilled rolls for its stated advantages.


If you liked this article, please do not forget to share with your colleagues and friends. And If you would like to be informed of our articles regularly, please register with us for free updates today.


5 Comments

Why Hydraulic Ram in an Internal Mixer?

In internal mixers, hydraulic ram assembly is an apt replacement (over pneumatic ram) because they improve rubber compounding quality.

In pneumatic rams, pressure may vary while the hydraulic version ensures constant, reproducible ram pressure. When you cut compressed air, operating costs reduce because you remove the central compressed air requirement in your plant. You also remove the maintenance issues associated with these air systems in the process. This leads to energy savings in your operations.

A constant pressure from hydraulically actuated rams eliminates variations in ram pressure caused by varying compressed air-supply to the mixers’ pneumatic cylinders. Hence, these are more efficient than air compressors for application of sustained batch-mixing pressure. This in turn, provides consistent mixing process conditions that enhances product uniformity – all of which leads to improved mix quality.

The hydraulic rams can be fine controlled with the hydraulic power. The result is shorter mixing cycles, higher productivity and improved batch-to-batch consistency. Further, the hydraulic ram reduces the noise level within the vicinity of the mixer. So, apart from improving the work environment they use less energy and are quieter in operation.

Representative Image of A Rebuild Internal Mixer

Representative Image of A Rebuild Internal Mixer

In intermeshing type of mixers, cooling water passed through ram provides extra cooling. This control feature is critical when processing heat-sensitive compounds.

Please remember, this is a technology upgrade. Hence, when you choose your tangential and intermeshing mixer, you need to ask for this option. Else, you may continue to receive manufacturer’s standard pneumatic ram only.

Existing pneumatic ram on your internal mixers can be converted to hydraulic ram. Internal mixer manufacturers like HF Mixing Group, Kobelco, Bainite Machines, etc can guide you with energy-saving data for your mixer and offer conversion at an optimized investment.

Let us know if you found this post useful to shortlist energy-efficient features for your next internal mixer purchase.


If you liked this article, please do not forget to share with your colleagues and friends. And If you would like to be informed of our articles regularly, please register with us for free updates today.


1 Comment

Rubber Sheet Feeder

Internal Mixers and Mixing Mills are familiar rubber compounding machineries for short production runs. This is because of their broad range of shear capabilities and acceptance of all feed forms. Yet, rubber goods producers and tire manufacturers are familiar with their demerits viz. varying power demand, batch-to-batch quality variation and labor intensive operations.

Can you improve the experience and performance expectation? Yes, through the introduction of Sheet Feeders with Rotary Cutter.

Image Courtesy: Bainite Machines Pvt Ltd

Image Courtesy: Bainite Machines Pvt Ltd

Sheet feeders are designed for quick installation onto your existing layout. It could be either mounted to your Mixing Mill frame or put up in front of the weighing conveyor in a Mixer feed line. This means that space constraint never becomes an issue for you to extract more out of your existing mixing operations. And since only one operator can control the mill (or mixer) and sheet feeder, the operation does not increase your labor cost.

Sheet feeder’s with hugger belts replaces the conventional manual loading of rubber sheet on to the mill. This machine enhances your worker’s safety, and makes the loading operation safe. And because it facilitates continuous positive feed of the rubber sheets into the mill (or mixer), the operation feels ‘automatic’.

The rotary cutter on the sheet feeder cuts the fed rubber sheets into uniform rectangular pieces. This results in better dispersion of the rubber sheets in the mixing mill (or mixer for final batch).

The internal mixer rotors performs reactive, dispersive and distributive mixing of uniformly cut rubber sheets faster and better than a long sheet fed into the mixing chamber. The result you experience is a homogenized rubber mix, independent of the operator efficiency or any weight variations in the batch. The quicker mixing of the cut pieces shortens the mix cycle; thereby increasing the productivity of your internal mixer or mixing mill.

Summarizing, Sheet Feeders, is a simple machine which when installed to feed the mixing mill line or batch mixers, increases efficiency, reduces manual intervention and improves consistency of mix. This is also known as Mill Feeder, Rubber Feeder or Stock Loader with disc cutter.

Prodicon, Bainite Machines and few Chinese manufacturers offer them in the world market with customized specifications. Pelmar offers used-machinery of this category.

Please do let us know of your observations and notes on this allied machinery increasing efficiency into your existing rubber mixing line.


If you liked this article, please do not forget to share with your colleagues and friends. And If you would like to be informed of our articles regularly, please register with us for free updates today.