Rotational Molding

Rotational Molding

Rotational molding has also become rotomoulding. It is a kind of manufacturing process that is very versatile and suitable for various industries. It can be customized to produce hollow plastic molding products of various shapes and sizes. No matter the batch is large or small, the volume is large or small, roto molding services Both can achieve multi-functional manufacturing functions. Professional rotomolding mold engineers will have great design freedom, because this is a plastic molding process that does not limit any shape and size, similar to casting technology.

Common rotomolding products include: water storage tanks, oil storage tanks, large buckets, kayaks, fitness equipment, trash cans, mobile toilets, traffic barriers, cartoon dolls, septic tanks, etc.

Mulan MFG has been focusing on helping customers develop, design and manufacture a series of customized rotational molding parts, with rich experience and expertise. In 2014, we established a large rotomolding factory and established an advanced manufacturing system with 6 large-scale rotational molding parts. The automated rotational molding equipment has a maximum rotation capacity of more than 10 feet. We actively respond to all complex rotational molding projects at any time, constantly challenge opportunities and raise technical barriers.

Our Rotomolding Capabilities

Rotomolding products & mold design: We provide customers with professional rotomolding design technical support services, mainly focusing on the design of rotomolding molds. We use our rich experience to reduce quality risks in the design and ensure the high quality of products as you expect , And reduce the cost of mold modification due to design errors.

● In-house Mold Manufacturing: 

We have a powerful rotational molding mold manufacturing center, three 5-meter-long CNC machining centers, which can accurately engrave the details of the mold. Usually we will use high-quality aluminum alloy or cast aluminum to make rotomolding molds. High-quality mold manufacturing ensures that you can receive the highest quality products in the shortest time and have economic benefits.

And we can add custom textures, logos, batch numbers and other copywriting on the surface of the mold.

 

● Rotomolding Manufacturing:

We have 6 large-scale automated CNC rotational molding equipment, 7*24 hours for production tasks, to ensure that all products can be delivered to customers on time, and our production plan is not limited by the number, at least one piece can start our production plan.

 

● Secondary Processing:

In order to better customize the rotomolding parts according to the customer's design, we will perform secondary processing on the finished product to ensure the realization of the functional application of the product. like:

In-mold inlay: Fix metal fasteners or other metal parts in the mold, used for fastener assembly between products, metal reinforcement ribs and other functions.

● Inject A Foaming Agent:

Applied to rotomolding products that need to float, carry, or sound insulation.

Industry Application
Food & Medical
Military & Aerospace
Automobile Industry
Energy & Industry

Rotomolding Process

The process of rotational molding is much simpler than the manufacturing process that relies on pressure molding, but in fact it requires very rich experience and technical knowledge. While the material cannot be controlled by high pressure, the environmental temperature, environmental humidity, mold type, material specification, material Factors such as pretreatment quality will directly affect the final quality of rotomolding products.

 

● Put the powdered plastic into the hollow mold.

● Close the mold and rotate along the two axes.

● Heating the mold during the rotation process to melt the powder material.

● After all the materials are melted, cool the mold.

● After the product has solidified, open the mold and take out the product.

Advantages Of Rotomolding

● Low Mold Cost:

Rotomolding molds are usually made of cast aluminum or steel plates without the aid of high pressure, so the mold process is relatively simple, the cost is low, and small batch production has economic advantages and is suitable for early investment in product development.

● Complex Shape: 

Rotomolding relies on the material to adhere to the inner wall of the mold, which has very low restrictions on the shape of the product. It can be achieved smoothly through reasonable design of the mold details. And you can easily create functions such as reinforced ribs, custom textures, and in-mold inlays.

● Uniform Wall Thickness: 

Rotational molding can achieve very uniform wall thickness, and the corners will be thickened, which greatly enhances the strength and integrity of the product. Unlike blow molding, the corners will be pulled thin by pressure and cracked. , Affect the intensity.

● Flexibility:

low cost, low restriction, and short production cycle, which means that rotomolding has unique flexibility and is suitable for small batch production.

 

Disadvantages Of Rotational Molding

Like any plastic molding process, rotational molding has its disadvantages:

 

● Long Production Cycle: 

With a frequency of 6 rotations per minute, it takes 100 minutes to complete the rotomolding process of a part.

● Material Restriction: 

Usually rotomoulding uses fine powdered plastic, which must have high thermal stability, and PE is widely used as raw material.

● Raw Material Cost: 

In accordance with the thermal stability requirements of the material for rotational molding, the cost of additives is increased, which is slightly higher than that of normal materials.

● Low Repeatability: 

In the production of small batches of products, we will choose low-cost soft metals, such as cast aluminum, thin plates, etc. But after producing more than 2,000 pieces, the mold must be repaired or replaced.

● High labor Costs: 

Rotomolding has not yet achieved mechanization and automation, and requires higher labor costs than similar plastic molding processes.

 

In the same production of plastic molded products with a hollow structure, factors such as part weight, porosity, mold cost, cycle time and other factors will directly determine the unit price of the product. Blow molding is more economical than rotational molding.

If you want to know more information, please click here-Extrusion Blow Molding Process .

Case Studies

More than 1,000 parts cases, learn about us.

our service can always exceed customer expectations and deliver cost-effective parts.

What Is Rotational Molding?

Rotational molding has also become rotomoulding. Rotational molding is a method in which thermoplastic plastics are rotated to form hollow plastic parts.

The plastic raw material powder is added to the mold, and the mold is continuously rotated along two axes while heating. Under the action of gravity and thermal energy, the material presents a hollow plastic part with uniform wall thickness and complex structure.

What Is Rotational Molding Used For?

With the continuous improvement of rotational molding technology, more and more rotational molding products are used in various industries, including:

Containers: water barrels, water storage tanks, oil storage barrels, chemical barrels, etc.

Auto parts: car fuel tanks, seats, armrests, luggage racks, etc.

Outdoor products: slides, outdoor fitness equipment, dolls, park sculptures, etc.

Other fields: toys, models, handicrafts, trash cans, public toilets, equipment enclosures, kayaks, etc.

How Do You Do Rotational Molding?

●  Add mold release agent: it is convenient for the ejection of the product and does not stick to the mold.

●  Install inserts or other accessories: increase local strength, threads or special details.

●  Loading: Put in the calculated weight of the material.

●  Closing the mold: to ensure that the closed mold is sealed to prevent leakage.

●  Rotation and heating: Rotate the mold along the horizontal and vertical axes, and heat the material to evenly distribute the material in the cavity of the mold.

●  Cooling and shaping: After the material is cooled, take out the product. The cooling process takes some time.

●  Cleaning the mold: remove the residual materials and debris in the mold to prepare for the next rotomolding cycle.

What Are Rotational Molds Made Of?

●  High-quality aluminum alloy profiles

●  Precision casting aluminum alloy

●  High-quality die steel

●  High quality cold rolled steel sheet

Can Abs Be Rotational Moulded?

No, rotomolding requires the use of thermoplastics as raw materials.

We have gone through many ABS rotational molding experiments and have not been successful so far.