MATERIAL OPTIONS FOR PLASTIC MANIFOLDS
FACTORS TO CONSIDER WHEN SELECTING RESINS
The material or resin can mean the difference between products that last and those that don't. Engineers have labeled material choice as one of the important design decisions when crafting and creating new products. After choosing either a single-layer manifold, multilayer, or simply 3D printing a prototype, material stands as integral to product success.
Each type of manifold has resins and materials that suit better than others. For single layer plastic manifolds, many more material options exist for selection because of the plastic materials unique qualities and natures. We usually limit bonded plastic manifold options to materials that can take laminating.
A few characteristics to consider regarding material choice:
How will the product be used when it comes to contact with chemicals? Will it interact with typically corrosive or other harsh chemicals?
How high of a temperature will the product have exposure to? In that vein, how low? Does it need to repeatedly handle the sterilization process? Will it be used in cryogenic or other subzero environments?
How limited is the project from a cost perspective? Designers could elect a higher quality resin but would need to consider that this would mean fewer parts.
TENSILE & COMPRESSION STRENGTH
What kind of function will the part need to provide? How strong does it need to be? Does it need the ability to withstand repeated impacts from its environment?
Does the product need window-grade or optics grade clarity? Can the product's purpose stand some opacity, or does it need to be crystal-clear?
REGARDING PLASTIC MATERIAL AVAILABILITY
Please note that for orders with a great quantity, material manufacturer's stock may not be sufficient, and that manufacturer may need extra time to fill an order. This also holds true for those runs that plan to use less common materials and/or blends.
However, plastic manufacturers can source for custom manufacturing runs to test any or all of the following factors:
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COLOR OPTIONS
Plastics can be tinted any PANTONE® color.
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FILLER OPTIONS
Fillers (like glass or carbon fiber) can be added to plastics to make the plastic more robust.
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SOME MATERIAL IN RESIN ONLY
Materials are commonly available in resin only and not stocked.
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CERTIFICATIONS
A product requires special certification like those from the FDA or USP Class VI to ensure quality.
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IMPROVE ASSEMBLY
Custom runs serve to improve manufacturability of difficult part configurations.
To give an idea of what costs would incur on one of these custom runs, we can say one from us ranges between $2500 and $5000. Delivery time is up to 12 weeks.
MORE ABOUT MATERIAL CHOICES FOR SINGLE-LAYER MANIFOLDS
Not all materials have the exact same qualities or capabilities. Some materials exist that we would recommend best used in a single-layer manifold design over bonded, multilayer manifolds and vice versa.
Below, we have listed two different categories of materials based on their clarity (or potential therein) for single-layer manifolds. They tend to have the best qualities and can take the manufacturing process without incident.
CLEAR MATERIALS
- Acrylic
- Polycarbonate
- ULTEM®
- COP/COC
- PVC
- Radel
- Polysulfone
OPAQUE MATERIALS
- Nylon
- PEEK
- PPS
- PET
- PVC
- ABS
- Teflon®
- Noryl
- Polypropylene
- CTFE
- HDPE
- CPVC
- Delrin/Acetal
- UHMW PE
- PVDF
- PBT
MORE ABOUT MATERIAL CHOICES FOR MULTILAYER MANIFOLDS
Some resins have a higher capacity for bonding to create multilayer manifolds. The aforementioned resins work great for other applications that don't need a complex fluidic system. However, these ones listed below mark themselves as best suited for the process.
- Acrylic
- Polycarbonate
- Ultem®
- COP/COC
- PVC
- Radel
- Polysulfone
POTENTIAL MANIFOLD SIZE & THICKNESS BASED ON MATERIAL SELECTION
While most manufacturers can create macro-sized plastic manifolds, there exists some restrictions when it comes to manifold size concerning their max and mins. Single-layer manifolds (SLMs) can amount to larger manifolds but lack some key features that might otherwise influence a designer's decision.
We have those detailed below.
SLM SIZE CAPACITY
FOR MANUFACTURING
40” x 20” max. (100 x 50 cm)
Limitations in the drilling process may decrease this maximum when part requires machining on edge.
BONDED MANIFOLD SIZE CAPACITY
FOR MANUFACTURING
18” x 18” max. (45 x 45 cm - subject to material selection.
12” x 6” (30 x 15 cm) or smaller is recommended when possible; Easier to manufacture at scale, lowering costs.
LAYER THICKNESS
Material vendors sell plastic sheet or plate in fractional sizes. This can lead an engineer to design to those sizes for layer thicknesses. Typically, most manufacturers like us will use the next "size up" material to produce a given thickness. With us, we need 0.125” to 0.2” extra. This is for several reasons.
PRECISION
Successful bonding requires the blank to be precise in both dimensional thickness and flatness.
MATERIAL THICKNESS VARIANCE
Stock materials can vary significantly in thickness across a sheet. For example, Acrylic sheet thickness tolerances are a broad +/- 10% while extremely clear and smooth in stock form but wavy. The diffusion bonding process does not allow stock thickness bonding. Material removal must occur for acrylic.
MACHINING VARIANCES
The machine datum is almost always from the bottom of the part, making Z depths measured from the top of the part vary due to material thickness changes.
POTENTIAL OVERSIZING
Many stock materials have very rough surfaces and/or are warped from the extrusion process. They arrive 0 to +.030” oversized.
POTENTIAL UNDERSIZING
Vendors will sell nominal imperial sizes that turn out to have actual metric measurements and tend to start as undersized (e.g. 1” nominal is actually .944”).
Choosing an economically efficient material thickness is not an exact science as exceptions exist. Like in the above list, purposely oversized material in nominal sheet sizes are available in metric only and varying thickness tolerances. We advise consulting with the specialized plastics manufacturer if any questions should arise in relation to your product.
Design Tip
ABOUT SOURCING YOUR OWN MATERIALS
We highly recommend sourcing materials with the manufacturer and to take advantage of their partnerships with material vendors. Any reputable plastic manufacturer should know the most reliable and best plastic material vendors, saving you precious time in researching and vetting them yourself. If a manufacturer asks you to source your own materials, we strongly encourage you to seek others that already have those established relationships and have thoroughly investigated vendors' product quality. With these relationships, manufacturers have also already negotiated the best prices for the customer, potentially saving that customer thousands more than if they had sought that relationship themselves.
MOST POPULAR PLASTICS FOR BONDED MANIFOLDS
We work with over 30+ varieties of plastic resins and materials. That combined with our decades of experience have granted us the knowledge on which plastics are best suited for bonded manifolds. We have listed some of those below.
Need to know more? Visit our article about the best plastics for bonded manifolds.
ACRYLIC
Acrylic is a great option for making manifolds as it is low cost, clear, scratch resistant, and bonds easily. However, acrylic does not have good chemical, thermal, or mechanical properties making it fragile in comparison to other plastics we make manifolds from. If not handled properly or care taken in assembly, including proper tightening of fasteners, acrylic will stress crack.
POLYCARBONATE
Greater temperature resistance. Good resistance to alcohols for rinse or wash. Slightly tinted gray or purple, good clarity. Not appreciably more expensive than acrylic. Tougher material than acrylic. Not impervious to stress cracking.
ULTEM®
Excellent temperature resistance. Better chemical resistance. Good tensile strength. Strong insulator. More costly. Amber tint. Liquid applications. UltemⓇ is a PEI (Polyetherimide) plastic from SABIC (formerly GE Plastics)
COC/COP
Popular in life sciences. Great clarity & chemical resistance. Low autofluorescence. Low moisture absorption. Scratch resistant. Can be brittle and susceptible to cracking. More cost efficient than UltemⓇ.
ULTEMⓇ VS. COC/COP COMPARISONS
ULTEMⓇ (PEI) and COC/COP (COC = cyclic olefin copolymer, COP = cyclic olefin polymer, both are chemically similar) are materials commonly used in applications with harsh chemicals in life sciences. While they share similar qualities, like low outgassing, they differ on several different fronts. Below are some comparisons between the two.
CHEMICAL RESISTANCES FOR ULTEM & COC/COP
These are very broad categories and as such are meant as a general guide to start the process of finding a solution. True chemical resistance will depend on the specific chemical as well as the concentration and temperature used.
Please note that we have limitations in our understanding of the chemical capabilities of the materials listed below. However, we are more than willing to offer suggestions and provide resources to assist you in the design process. If needed, we can also offer material samples for lifetime or chemical testing in relation to your application.
STRESS SENSITIVITY FOR COC/COP & ULTEM
TEMPERATURE SENSITIVITY FOR COC/COP & ULTEM
ULTEMⓇ costs about twice as much as COC/COP does. However, material costs are never the sole factor when it comes to a manifold construction's total cost. These total costs also depend on the other matters that may not have a significant role in the end total.