Customer case

3 weeks from sketch to manufacturing & assembly documents

November 16, 2022 6 min read

Case details

Country Sweden
Company SSAB
Industry Steel distributors and stockholders

Borlänge, Sweden is home to SSAB’s largest strip rolling facility for making hot-rolled and cold-rolled high strength steels. A by-product of production is iron oxide, that can be collected and recycled internally. The steel mill had worn out the previous container or “tipper” for transporting the iron oxide. The mill operators decided to get a new, improved design for the heavy-duty dumper — one that would deliver better tipping performance and longer service life — yet still be economical.

The previous, worn-out tipper.

Case details

Country Sweden
Company SSAB
Industry Steel distributors and stockholders

The existing forklift truck without the tipper.

Tipper design goals & challenges

In addition to being robust, the new container required tight tolerances to fit the existing forklift truck’s attachments — its side supports, hooklift, and so on. The design needed to enable the maximum tipping angle and otherwise reduce “carry back” of the heavy, wet, iron oxide sludge.

To keep the tipper’s cost low — and to speed its delivery — design for manufacturing was critical. Both the number of parts and welds needed to be minimized, while at the same time optimizing the utilization of the steel plates.

The project’s deliverables were detailed manufacturing and assembly drawings that could be sent out as a comprehensive request for quote (RFQ), as well as technical support during the bidding and manufacturing process.

Product development and engineering of a recycling container

SSAB Product Development and Engineering (PDE) used its own innovation workshop, based on the SSAB ONE lean methodology, to comprehensively gather and structure input and set meaningful goals. This simple workshop helps to cut development times significantly, keeping rework to the minimum (in average, less than 10% of the total project time).

The first concept for the new tipper went through several iterations to fit the tight functional tolerances of the existing forklift truck. The iterations also focused on becoming a leaner design for manufacturability. 

Heavy-duty recycling container, designed for economic durability and manufacturability.

Optimized plate utilization — and a reduced number of parts and welds — sped the assembly of the iron-oxide recycling tipper.

The PDE project engineers selected the steel grades based on performance needs, costs, availability, and nesting requirements. The wear rate for this application is low. The main challenge is protecting the tipper from the iron oxide’s base pH, as well as protecting the forklift interface area. 

To significantly improve the stiffness of the tipper design, especially in the top rails, tight bending radii were used. So, most of the steel used was Strenx® 700 plate and hollow sections. Hardox® 450 wear plate was used in the front wall and as reinforcements in the critical bottom area where the forklifts carry the tipper.

Capturing all design details speeds engineering

PE’s entire functional engineering of the tipper — from sketch to final, fully documented manufacturing and assembly documents — was done in just three weeks. By meeting frequently with all stakeholders, PE efficiently captured all design details. Consequently, there was very little rework, resulting in significant time savings for the steel product’s development and mechanical engineering.

SSAB PE also helped secure steel stock availability for prototyping and gave technical support to the purchasing team during both the tender process and the manufacturing of the container.

The design for manufacturability and the stock plate optimization both led to an economical tipper. And SSAB’s One lean methodology sped the entire project — from kick-off to manufactured prototype — to just six weeks. 

Assembly of tipper in progress

The clean and robust design of the final tipper.

With a higher tipping angle, the SSAB PE design reduces carry back.

A higher functioning design

The all-new container design is proving to be a durable and higher functioning replacement. 

“The greatest difference between the old and new tipper is that now the forklift operator never needs to leave their cab,” says Hans Karlin, SSAB Transport Section Chief. “With the old container, the operator had to get out and go behind the tipper to remove hatch pins with a hammer.”

“Now the operator can stay inside forklift’s cab for the entire dumping operation,” notes Karlin. “This is obviously much safer and faster. Plus, the operator is no longer tracking iron oxide into their cab, since it easily sticks to boots and clothes. So, there’s no extra time spent cleaning the forklift cab.”

Karlin concludes, “Considering its robust yet light design, I personally expect this new tipper to outlive us.”

Optimized flowrates and wear reduction in containers

SSAB PE has developed several recycling containers, for both heavy and light scrap, for SSAB as well as external customers. Our Discrete Element Method (DEM) analysis promises to optimize flowrates and reduce wear in critical areas. 

Accelerate your innovation and product development

SSAB Product Engineering is a global resource for innovation, product development and engineering services. PE services will accelerate your product implementation — from initial concepts to full-scale product. Bring us your product ideas.