Q&A with a Schaefer Packaging Expert: Molded Foam Material and Application
In this edition of Q&A with a Schaefer Packaging Expert, we speak with Darcy Nettleton, National Canadian Sales Manager of Packaging Systems, about Molded Foam material and how it is used in packaging systems.
Darcy is a veteran of the packaging industry and has vast experience specifically in molded foam applications. Previous experience in packaging includes sales management at The Woodbridge Group, where Nettleton managed all particle foam packaging programs, primarily for the automotive and pharmaceutical markets.
Table of Contents
What are the main materials used in returnable molded foam applications and what are the benefits of each?
- Expanded polypropylene (EPP)
- Mold ability, light weight, good heat, oil, and insulating properties, excellent shape memory, ability to take multiple impacts
Expanded polyethylene (EPE)- Similar characteristics to EPP but with a very soft and smooth surface which lends itself well to packaging parts with sensitive finishes that require non-abrasive contact
- Expanded polystyrene / polyethylene (EPS/EPE Hybrid branded as ARCEL® from NOVA Chemicals)
- Cost effective, higher compression strength foam, ideal for tote inserts, dunnage bars, and cold chain coolers
How different industries use molded foam in their supply chain?
- Automotive, Energy management – bumper cores, sun visors, tool kits, floor spacers, headrests, consoles, seat systems – various returnable packaging (totes/tote and bulk bin inserts/ dunnage bars/ rack dunnage)
- Electronics – PS/PE – flat screen TVs, (EPS primarily)
- Consumer Goods – sporting helmet liners, (bicycle, football) (EPP)
- Pharma – EPP & PS/PE – returnable cold chain cooler shipments
- Military – missile launcher components and end caps, helmet liners (EPE/EPP)
- Marine – watercraft components (EPE/EPP), dock cushions, buoys (EPP)
- HVAC – water tank covers, boiler surrounds, dryer muffler, valve covers (EPP)
Would foam materials ever be compounded / mixed for certain applications?
- EPS/EPE Hybrid foam materials were developed as a more robust option to traditional foam packaging. It allows for a reduction of overall package size and weight. Printers traditionally use EPS end caps, using EPS/EPE Hybrid foam materials can reduce the cap size because of the improved protective properties. This reduces the corrugated box size, increasing more parts per pallet resulting in cost savings through the supply chain.
What would you highlight as the greatest immediate advantages of molded foam for protective packaging?
- Ability to capture and support complex part geometry’s
- Recycling ability
- Integrated dunnage & tote – 1 substrate
- Ergonomic and light weight
- Ability to withstand multiple impacts
- Custom footprints
- Thermal properties
- ESD & FR options
- “A” surface friendly
- Color options
- Good chemical resistance
- Increased QPC
- Water resistant
- No sharp edges
What factors determine if molded foam is the right fit for the project?
- Part geometry, sensitivity, project volume, budget
Comparing molded foams to traditional dunnage materials, when is it a better option and where does it come up short?
- When the design requires a large amount of fabricated substrates and labor, higher volumes, ergonomic constraints
- Volume usually drives the molded foam decision – there are design limitations as well that have to be considered- part size, weight, material, temperature etc
What are the advantages and applications as an ESD protective material looking forward as electric vehicles emerge?
- Immediate applications include dunnage packaging for battery casings and other electronic components.
- Long term possibilities increase as vehicles get more sensitive electrical components. There will be more demand for sophisticated packaging designs and ESD materials.
Is molded foam a good material to be used in automation systems (pushing & pulling product through a system and on conveyors)?
- Yes, we have supplied molded trays that are robotically loaded with various parts coming out of an injection molding machines as well as various other assemblies.
- For basic loading and unloading scenarios, we design to very specific tolerances of foam thickness, density, and surface profiles (see chart).
| Dimensions | Tolerance / Density | ||||
| Linear / Thickness Foam Dimensions | 16 to 24 g/l | 25 to 30 g/l | 31 to 50 g/l | 51 to 80 g/l | 81 g/l + |
| 0 to 5mm | ± 0.75 | ± 0.5 | ± 0.5 | ± 0.5 | ± 0.5 |
| 6 to 15 | ± 1.25 | ± 1.0 | ± 1.0 | ± 1.0 | ± 1.0 |
| 16 to 25 | ± 1.75 | ± 1.5 | ± 1.5 | ± 1.0 | ± 1.0 |
| 26 to 50 | ± 2.25 | ± 2.0 | ± 1.5 | ± 1.5 | ± 1.5 |
| 51 to 100 | ± 2.5 | ± 2.0 | ± 2.0 | ± 1.5 | ± 1.5 |
| 101 to 250 | ± 3.0 | ± 2.5 | ± 2.5 | ± 2.0 | ± 2.0 |
| 251 to 500 | ± 4.0 | ± 3.5 | ± 0.75 | ± 3.0 | ± 2.5 |
| 501 to 1000 | ± 6.0 | ± 5.0 | ± 0.75 | ± 4.0 | ± 3.5 |
| > 1000 | ± 1.25% | ± 1.1% | ± 1.0% | ± 0.75% | ± 0.5% |
| Surface Profiles (GD&T) | 7.0 | 6.0 | 5.0 | 4.0 | 3.0 |
| Hole / Slot Dimensions (MMC) | 16 to 24 g/l | 25 to 30 g/l | 31 to 50 g/l | 51 to 80 g/l | 81 g/l + |
| 5 to 10 | ± 1.25 | ± 1.0 | ± 0.5 | ± 0.5 | ± 0.5 |
| 11 to 25 | ± 1.25 | ± 1.0 | ± 1.0 | ± 1.0 | ± 1.0 |
| 26 to 50 | ± 2.0 | ± 1.5 | ± 1.0 | ± 1.0 | ± 1.0 |
What are the temperature ranges where molded foam is most effective?
- Temperature allowance is approximately -30°C to +80°C (-22°F to +176°F)
- A design consideration is what temperature is the foam is exposed to for prolonged periods. With lower temperatures it becomes stiff as with higher temps the material becomes softer and more pliable, this can effect compression creep.
How does impact resistance and energy absorption relate to part protection?
- This can be the main criteria for selecting molded foam, you consider the foam thickness, bead grade and density, these all contribute to the optimal packaging performance.
- When deciding what direction you look at product fragility (G’s), the material handling environment, determine the cushion curve that will absorb shock/load, design limitations, and then prototype to test.
- In short if the packaging will be taking multiple impacts you will design with EPP and EPE due to their resiliency.
