Storage tanks and containers
Hollow bodies with application-specific shape, openings and connection points. Define the contents, installation, support, access and required verification before settling the wall and fitting details.
Product Development & Manufacturing
Custom Rotational Molding
Develop hollow plastic products around the way your customers use them.
We help distributors improve existing products, customize for local applications and develop new hollow plastic products. Product structure, PE material, tooling, rotational molding and related PU foam filling are considered together.
Hollow products with a purpose
Start with what the product holds, protects, carries or supports. The useful design includes the body, openings, hardware and the way the product is handled, cleaned, stored and shipped.
Handling bins and tubs
Products for material handling, storage and transport. Review usable space, loading, lifting, drainage, cleaning, stacking and the hardware needed by the operating routine.
Insulated boxes and transport products
Inner and outer shells can be developed with PU foam filling as part of a double-wall construction. Lid fit, wall space, filling access, closures and the intended thermal requirement belong in the same brief.
Covers and equipment shells
Hollow covers, guards and shaped bodies for equipment. Mounting points, access, clearances, parting lines and the surrounding assembly define the practical geometry.
These are product directions for project review. Choose an existing product reference or share a new application so the appropriate structure and production route can be discussed.
Choose the right starting point
Use an existing product direction
Begin with a relevant tank, bin, box or shell, then identify the dimensions, hardware, appearance or packing that your market needs.
Improve an existing product
Bring the sample and the customer problem. Lid fit, handling, drainage, cleaning, stacking and transport space can be considered alongside the molded body.
Develop a new hollow product
Establish the application, usable dimensions, loading, environment and expected quantity before deciding the mold scope.
PE material and product geometry work together
PE and HDPE material options are reviewed against the product and its service conditions. The resin grade, powder condition, color and molding behavior influence the structure that can be produced.
A material name alone does not define the finished product's performance. Consider impact, loading, temperature, cleaning, exposure and the required life of the product when setting the brief.
| Design topic | What to define |
|---|---|
| Body and walls | Product envelope, usable volume, wall direction, stiffening features and loaded condition. |
| Openings and connections | Access, fitting locations, drains, lids, inserts and the parts that connect to the body. |
| Handling | Handles, lifting method, grip areas and the path through the customer's operation. |
| Cleaning and service | Accessible surfaces, corners, drainage and the expected cleaning routine. |
| Storage and shipping | Stacking, nesting, protective packing and the space used during transport. |
Requirements involving contact with food, outdoor exposure, chemicals or thermal performance need a defined material reference and application-specific verification. They should be established in the product brief.
Design the mold around the complete product
The mold defines the hollow product geometry and how it is released. Product shape, parting arrangement, openings, draft, inserts and access are considered before the tool is finalized.
The design should allow the material to distribute through the intended geometry and the product to be cooled and removed without unnecessary distortion or damage. Deep details, local thickness changes and difficult release areas need particular attention.
Develop the mold together with lids, handles, latches, seals and fittings when those parts affect the body. This makes sample review more useful than assessing the shell in isolation.
How rotational molding creates the hollow body
The production route connects a measured powder charge with a heated, rotating mold, controlled cooling and demolding.
Charge and close
The material quantity is prepared for the product and loaded into the mold. The mold is closed and made ready for the cycle.
Heat and rotate
Rotation about two axes moves the material through the heated mold. As it heats and fuses, it forms the product wall along the internal surface.
Cool while rotating
Cooling develops the shape and allows the product to solidify. Cooling conditions and support affect the final shape and its release.
Demold and finish
Open the mold, remove the product and prepare the required openings, edges and assembly details. Check the resulting body against the product reference.
The three-arm carousel illustration explains how heating, cooling and loading or unloading can be arranged around the process. It is a principle illustration, not a machine specification.
Inside the rotomolding workshop
Our rotomolding route connects the prepared material charge with heating, rotation, cooling and the finishing needed by the product.
Heating, rotation and cooling are connected variables. A thicker local feature or a change to the powder charge can influence the way the body forms. Process development therefore follows the actual product and trial observations.
PU foam filling for double-wall products
For suitable products, the molded inner and outer shells form a space that can be filled with PU foam. This is a related operation after shell molding, with its own fixture, material preparation, filling and curing considerations.
The product discussion includes the shell spacing, filling access, venting, lid and closure arrangement, target use and required verification. Foam filling should be developed together with the structure it supports.
The reference process uses located shells in temperature-conditioned fixtures, metered component delivery and top injection across a multi-station arrangement. The fixture holds the shell geometry while the foam develops and cures.
Locate the shells → Meter and fill → Allow curing → Release and check
The review looks at filling completeness, voids, consistency, the shell-to-foam interface and the finished shape. Any insulation target is agreed with a defined test method; it is not inferred from the presence of foam.
Add the details that make the body usable
Openings, trims and hardware turn the molded shell into the product the customer handles. Define these requirements early enough to include them in design and sampling.
- Lids and closures: opening direction, fit, latch location and the intended closing action.
- Handles and movement: grip, lifting access and any hardware required for handling.
- Drains and fittings: positions, connections, access and how the contents are removed.
- Inserts and attachment points: mating components, location and the expected installation method.
- Stacking and nesting: contact surfaces, stability, usable access and transport arrangement.
- Identification and appearance: color, logo areas and the visible surfaces to confirm.
The proposal should state which trimming, fittings, assembly and packing operations are included.
Quality review connects molding with product use
Define the important dimensions and checks with the reference sample, drawing and application. Inspection should reflect how the product will be assembled, loaded, closed or handled.
| Product feature | Examples of review points |
|---|---|
| Molded body | Wall distribution, surface condition, pinholes, shape and distortion. |
| Openings and fit | Location of openings, lid interface, fittings and hardware alignment. |
| Demolded surfaces | Release condition, edge treatment and visible damage. |
| Foam-filled structure | Filling completeness, voids, consistency, interface and finished geometry. |
| Complete product | Closure, handling, agreed functional checks and packing. |
Share any loading, leakage, insulation or environmental requirement with its acceptance criteria. The trial and verification plan can then be agreed for the actual product.
Plan handling and shipping before tooling
A container can be straightforward to mold yet inconvenient to carry or expensive to ship. Usable space, external envelope, stacking contact and nesting direction should therefore be part of early development.
Discuss whether lids and accessories travel fitted or separately, how the product sits on the pallet, what surfaces need protection and how the customer will unpack it. Confirm these details with the product and packing reference.
From the market requirement to a confirmed product
Share the application
Send a reference image, existing product or sketch, intended use, rough dimensions, loading and service conditions.
Develop the structure
Work through material, wall geometry, mold direction, hardware and any foam-filled construction.
Review samples
Check body shape, fit, operation, appearance and the agreed functional requirements.
Confirm production and supply
Record the product reference, inspection criteria, included operations, packing and delivery requirements.
Questions before starting
Can we use an existing product as the starting point?
Yes. Start with the closest product direction and explain the changes your market needs. Existing tooling suitability still needs to be checked against that requirement.
Does every hollow product need PU foam filling?
No. Foam filling is considered for a defined product requirement. The shell, use and verification plan determine whether it belongs in the construction.
Can lids, handles and fittings be included?
Share the complete product and required hardware. The design and proposal can define the corresponding molded interfaces, assembly and delivery scope.
How are size and wall thickness decided?
They depend on the geometry, loading, material, mold and molding route. Send the application and drawing for a specific review.
Can you guarantee an insulation duration from the material alone?
No. Thermal performance depends on the complete construction and test conditions. The target and verification method should be agreed for the product.
Connect with our other manufacturing processes
Let’s review your hollow plastic product
Send the application, drawing or reference product, target dimensions, loading, material requirements, hardware, expected quantity and packing needs. Include thermal requirements if foam filling is being considered.