Custom Polycarbonate (PC) Injection Molding
Polycarbonate is chosen when clarity and impact have to coexist: a lens that will not shatter, a cover that stays clear, a housing that survives a drop. The material is unforgiving about moisture and stress, so the result depends on drying discipline and gate design rather than on the machine.
Free Consultation24h
Rapid Quote
100 pcs
Molding MOQ
up to 90 percent
Light Transmission
to 130 degree C
Heat Deflection
Materials
| Grade | Properties | Typical Applications |
|---|---|---|
| Optical PC | High light transmission up to about 90 percent with low haze and good impact, the grade for clear parts that must stay transparent. Sensitive to drying and mould release, so process control decides the result. | Lenses, light guides, transparent covers, sight glasses, display windows |
| Food Contact PC | Transparent and impact resistant, selected from grades approved for the relevant food contact regulation. We supply the resin maker documentation for the grade used and keep lot traceability. | Appliance components, transparent containers, water contact parts, food equipment housings |
| Flame Retardant PC (UL 94 V-0) | Listed to UL 94 V-0 at a defined wall thickness, available halogen free or brominated, giving ignition resistance for enclosures around live conductors. | Electrical enclosures, lighting bodies, connector surrounds, control housings |
| Glass Filled PC (10 to 30 percent) | Meaningfully stiffer and more dimensionally stable at temperature, with anisotropic shrinkage that must be modelled. More weld lines and more abrasion on the tool than unfilled. | Structural brackets, load bearing frames, automotive parts, housings replacing diecast in low load cases |
| Medical Grade PC | Transparent and capable of common sterilisation methods, selected per the biocompatibility requirement of the device. We keep resin documentation and lot traceability for the grade used. | Diagnostic equipment housings, clear device components, laboratory ware |
| UV Stabilised PC | Additives slowing the yellowing and property loss that polycarbonate suffers under prolonged ultraviolet exposure, used outdoors or near a window. | Exterior enclosures, lighting covers and trim near glazing |
Process Parameters
| Parameter | Standard Range |
|---|---|
| Drying Requirement | 110 to 120 degree C for 3 to 4 hours, target moisture below 0.02 percent |
| Melt Temperature Window | 280 to 320 degree C, above which degradation begins to show |
| Mould Temperature | 80 to 120 degree C, higher for gloss and larger cosmetic parts |
| Injection Pressure | 800 to 1,500 bar depending on flow length and wall |
| Recommended Wall Thickness | 1.5 to 3.5 mm uniform to reduce stress cracking |
| Mould Shrinkage | 0.5 to 0.7 percent depending on grade and flow direction |
| Clamp Force Requirement | 2 to 5 tonnes per square centimetre of projected area |
| Cycle Time | 30 to 70 seconds per part depending on wall and size |
| Part Tolerance | plus or minus 0.05 mm standard, tighter by agreement |
| Maximum Moulded Part Size | up to 800 x 600 x 400 mm |
Surface Finishes
SPI Polish (A-1)
Optical-grade polished cavity giving high clarity straight from the tool. Requires steel tooling, excellent venting and controlled drying, because any defect shows through clear PC.
Texture (VDI 3400)
Matte or satin anti-glare surface for parts where clarity is not wanted and fingerprints or flow lines must be hidden.
Hard-coat Painting
A clear or tinted coating adding scratch and ultraviolet resistance, used on exposed clear parts such as covers and visors that will be handled.
UV Printing
Logos and markings printed on clear parts with flexible inks, popular for branded transparent products where pad printing would obscure the surface.
Vapour Polish
A solvent vapour smooths the surface of clear parts for improved clarity and a sealed finish, used on lenses and medical components.
Chrome Effect and Metallisation
Vacuum metallisation over a lacquer base gives a metallic appearance without electroplating, used on premium cosmetic and lighting trim.
Design for Manufacturing (DFM)
- Dry the polycarbonate properly and verify it before running, because hydrolysis turns PC into molecular fragments and causes silver streaking and brittle parts
- Keep wall thickness uniform between 1.5 and 3.5 mm; thick sections hold heat, increase cycle time and raise stress cracking risk
- Use 1 to 2 degree draft; polished moulds need slightly more for clean release without scuffing the gloss
- Avoid sharp corners and specify a minimum 0.5 mm radius, because polycarbonate does not tolerate stress concentration and cracks begin at corners
- Place gates away from cosmetic and high stress areas; PC flow lines and gate vestige show on clear surfaces and weaken loaded features
- Check every chemical the part will meet in service, including cleaning agents and adhesives, because environmental stress cracking is the characteristic field failure
- Consider stress relief annealing where the part is loaded and exposed to chemicals, since it is cheap relative to a field failure
- Keep petroleum solvent mould release sprays away, as they are a stress cracking agent on polycarbonate
- Specify UV stabilised grades on anything near a window, since standard grades yellow over a few years of exposure
- Upload STEP, IGES or DXF and receive a free material and DFM review within 24 hours covering wall, gate, draft and chemical exposure
Tooling & Capacity
| Type | Lead Time | Suitable For |
|---|---|---|
| Aluminium Soft Tooling | 2 to 3 weeks | 25 to 1,000 pieces, pilot runs and design validation. Gloss and optical surfaces need steel, so soft tooling is for matte functional parts |
| Production Steel Tooling | 4 to 6 weeks | Annual volumes above roughly 10,000 pieces and any cosmetic or optical cavity |
| Polished Steel Tooling | 4 to 6 weeks | Gloss and optical grade parts where the cavity finish defines the part finish |
| Multi-Cavity Tooling | 5 to 7 weeks | Higher volume programmes where cycle time governs and balanced fill is needed |
Quality Assurance
- Incoming polycarbonate is moisture checked before processing and logged, since this one control prevents most PC defects
- Melt temperature is checked at the nozzle, since a machine setting is not the real temperature the polycarbonate reaches
- A first article inspection and dimensional report precede the balance of the polycarbonate run
- Visual checks for silver streaking, splay and burning are made on every setup change of polycarbonate
- Impact behaviour is checked on samples from the actual polycarbonate lot where a drop test applies
- Colour is checked and logged against the reference, with delta E reported for each lot
- Weld line strength is reviewed at design and reported at trial rather than found in service
- Polycarbonate lot traceability is retained per run, and the supplier certificate is filed against it
- Polycarbonate lots ship with a dimensional report, material certificate and Certificate of Origin
- SGS, Bureau Veritas or TUV third-party inspection is arranged on request for polycarbonate parts
Applications
- LED lenses and optical light guides
- Safety helmets, visors and protective shields
- Transparent appliance covers and windows
- Electronic device housings and bezels
- Diagnostic and laboratory equipment components
- Automotive lighting and interior parts
- Water contact and food equipment parts, grades selected per regulation
- Outdoor and lighting covers near glazing
- Premium cosmetic and structural transparent parts
Why Choose FHY Precision
Grade chosen from clarity, impact and temperature rather than from whatever is cheapest per kilogram
We treat drying, shear limits and residence time as process controls, removing the defects most shops misread as bad material
Stress cracking is assessed at design, including the chemicals the polycarbonate part will meet in real use
Free polycarbonate material and DFM review within 24 hours, including two candidate grades where the best option is not obvious
From 25 pieces in aluminium tooling, pilots precede any production steel commitment
Welding, painting and marking are quoted alongside the moulding, making the finished polycarbonate part one purchase order
Resin lot traceability is retained, and third-party SGS, Bureau Veritas or TUV inspection is available on request
PC parts moulded in China at factory-direct pricing with no trading layer
FAQ
1. What is the difference between polycarbonate and acrylic (PMMA)?
PMMA is clearer and harder but brittle and cracks on impact. Polycarbonate is slightly less optically pure but survives drops and impacts that shatter acrylic, and it tolerates higher temperature. If the part is handled, dropped or load bearing, PC is usually right; if it is a static display window where maximum clarity wins, PMMA may be. We compare both against your impact and temperature targets at review.
2. Why does PC have to be dried before moulding?
Because polycarbonate reacts chemically with water at processing temperature. The reaction splits the polymer chains, and the visible results are silver streaking on the surface, bubbles and a part that is brittle even though the geometry is right. Drying at 110 to 120 degree C for 3 to 4 hours down to below 0.02 percent moisture prevents this completely, which is why it is a process control rather than an option.
3. What causes cracking in PC parts after they are in service?
Typically environmental stress cracking in polycarbonate, which needs three things together: moulded in stress, load, and a chemical environment that attacks polycarbonate. Common culprits are certain cleaning agents, some adhesives and petroleum based sprays. Reducing any one of the three prevents it, and we look at all of them at review rather than waiting for failures.
4. Do you supply UL 94 V-0 rated material?
Yes, we mould flame retardant grades listed to UL 94 V-0 at a defined wall thickness, and we supply the resin maker documentation for the grade used. To be precise about what that covers, the listing belongs to the resin grade rather than to our factory, so what we provide is the correct grade and its supporting paperwork.
5. Should I use glass filled PC?
Reserve glass filled PC for when stiffness governs the design. Glass roughly doubles stiffness at 20 percent content and improves dimensional stability at temperature, but it costs more, it abrades tooling, it produces more weld lines and it warps anisotropically. If the part fails on deflection it is the right answer, and if it fails on anything else it usually is not.
6. Can you mould optically clear PC parts?
Yes, with discipline. Optical PC in a polished steel tool, controlled drying and excellent venting gives clarity straight from the tool. Any contamination, release agent or moisture shows through, so we run clear parts as a clean process with verified material and protect the surface with hard-coat where it will be handled.
7. Can PC be used for medical device parts?
Yes, for transparent housings and components using medical grade PC selected per the device requirement. We keep the resin maker documentation and lot traceability for the grade used. The biocompatibility approval belongs to the resin grade, so we provide the correct grade and its supporting paperwork and the process controls that keep the part clean.
8. How does PC compare with ABS for a housing?
PC is clearer, tougher at low temperature and more heat resistant, but more expensive and more sensitive to stress and chemicals. ABS is cheaper and easier to finish cosmetically. Where the housing is dropped, near heat or transparent, PC wins; where it is a painted interior shell, ABS is often the better economy. ABS PC blends sit between the two.
9. Do you offer stress relief annealing?
Yes, annealing is worth specifying for polycarbonate parts that carry load while exposed to chemicals. A controlled thermal cycle relaxes the moulded in stress that would otherwise combine with service load to cause cracking. It is a small addition to the process cost and it removes a failure mode rather than reducing it.
10. What wall thickness should I design for PC?
1.5 to 3.5 mm for most structural applications, held uniform. Thicker is not stronger in any useful sense here, it mostly adds cycle time and increases the chance of sink and voids. Where extra stiffness is needed, ribs and gussets do the job at lower cost than wall thickness does.
11. What tolerances can I hold on PC parts?
Plus or minus 0.05 mm is standard on critical features, tighter by agreement. The practical limit is shrinkage and stress, not the machine, so we review which dimensions are critical at DFM stage and we anneal loaded parts where needed. Gloss and optical parts are measured after the surface is verified defect free.
12. How long does PC tooling take?
Aluminium soft tooling takes 2 to 3 weeks and suits matte pilot parts. Production and polished steel tooling takes 4 to 6 weeks. Multi-cavity tools for higher volume take 5 to 7 weeks. Trial moulding and first article approval add about a week before release.
13. What is your minimum order quantity for PC parts?
Standard moulding MOQ is 100 pieces. For pilot runs we machine aluminium soft tooling and produce from 25 pieces. Optical and gloss parts need steel tooling, so the pilot route there is matte validation first, then a polished production cavity once the geometry is fixed.
14. Can PC parts be used in food contact?
Yes, using food contact approved PC grades selected per the relevant regulation. We supply the resin maker documentation for the grade used and keep lot traceability. The food contact approval belongs to the resin grade rather than to our factory, so what we provide is the correct grade and its supporting paperwork plus clean process controls.
15. Can you mould PC automotive lighting parts?
Yes. PC is the standard for lenses and lighting bodies because of clarity and heat resistance. We select UV stabilised grades for exterior light, control drying and gate location to avoid flow marks on the optic, and verify dimensional stability at temperature. We model warp on any glass filled version used for a structural bezel.
16. Do you arrange third-party inspection for PC parts?
Yes. We arrange SGS, Bureau Veritas or TUV at any point you specify, including incoming resin verification, dimensional checks and coating verification. Where your part carries a flame rating or food contact requirement, inspecting against the resin maker documentation is often what your end customer actually needs.