For any questions about our services you can call us at: +86 17833674102(Whatsapp)

LML Metal Products Ltd.No. D309, Yunchuang E Valley, No. 3 Huanshi West Road, Tangxia Town, Dongguan City, Guangdong,China
(86) 17833674102dlynn9527@gmail.com

All injection Molding Plastics

Over 20 different kinds of surface finishes for you.Make your part more corrosion resistant and aesthetical.
Home / All injection molding plastics

Injection Molding Materials

Performance and Application Comparison
ImageMaterialKey GradesKey PropertiesTypical ApplicationsProcessability
PPPolypropylene (PP)Homopolymer, Copolymer, Glass-filledDensity: 0.89–0.91 g/cm³; Chemical resistance; Microwave-safeFood containers, automotive parts, medical packagingMelt temp: 200–300°C; Shrinkage: 1.5–2.5%
PEPolyethylene (PE)HDPE, LDPE, UHMWPEHDPE rigidity: 0.94–0.97 g/cm³; LDPE flexibility: 0.91–0.93 g/cm³Bottle caps, pipes, plastic bags, tubesMelt temp: 180–280°C; Shrinkage: 2.0–4.0%
PSPolystyrene (PS)GPPS, HIPS, EPS≥90% light transmittance; Rigid but brittleDisposable cutlery, CD cases, instrument housingsMelt temp: 180–280°C; Shrinkage: 0.4–0.7%
ABSABSStandard, Flame-retardant, High-impactImpact strength: 20–40 kJ/m²; Glossy surface; Moderate weather resistanceElectronics housings, LEGO bricks, automotive interiorsMelt temp: 210–250°C; Shrinkage: 0.5–0.7%
NylonPolyamide (Nylon)PA6, PA66, PA11, Glass-filledTensile strength: 80 MPa; Self-lubricating; HygroscopicGears, bearings, sports equipmentPre-drying required (80–120°C); Melt temp: 260–290°C
PCPolycarbonate (PC)Standard, Optical, Flame-retardantImpact resistance: >60 kJ/m²; 90% transparency; HDT 130–140°CBulletproof glass, helmets, medical devicesMelt temp: 280–320°C; Prone to stress cracking
POMPOMHomopolymer, Copolymer, PTFE-lubricatedFlex modulus: 2.5–3.5 GPa; Low friction (μ=0.15–0.25)Precision gears, bearings, zipper teethMelt temp: 190–210°C; Mold temp: 80–120°C
PMMAPMMACast, Extruded, Impact-modified92% light transmittance; UV-resistant; High surface hardnessLenses, signage lightboxes, automotive taillightsMelt temp: 240–260°C; Scratch-prone

Technical Notes:

Material Selection Guide

  • Chemical Resistance: PP/PE resist acids/alkalis (e.g., detergent containers) [6](@ref)
  • High-Temperature: PEEK/PPS replace metals in >200°C environments (e.g., engine parts)
  • Optical Needs: Use PC for impact-resistant transparency, PMMA for max. clarity

Processing Criticals

  • Drying: PA/PC require 4–6 hours at 80–120°C (moisture ≤0.025%) to prevent bubbles
  • Mold Temp: High-crystallinity materials (e.g., POM) need 80–120°C for dimensional accuracy

Sustainability & Compliance

  • ♻️Recycling: PP/PE/PET mechanically recyclable (15–30% property loss) [5](@ref)
  • ⚠️Hazard Alert: POM releases formaldehyde in acids—requires controlled disposal

LML's portfolio of Metals

Secondary operation will improve aestheic or prevent injuries from sharp corner of the products.

Knurling

After knurling, it can increase the sense of beauty of the part and make it easy to handle. It is often used for the outer surface processing of casing, hinge wrench and other parts

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Chamfering

After knurling, it can increase the sense of beauty of the part and make it easy to handle. It is often used for the outer surface processing of casing, hinge wrench and other parts

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Grinding

After knurling, it can increase the sense of beauty of the part and make it easy to handle. It is often used for the outer surface processing of casing, hinge wrench and other parts

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Heat Treatment

After knurling, it can increase the sense of beauty of the part and make it easy to handle. It is often used for the outer surface processing of casing, hinge wrench and other parts

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welding

After knurling, it can increase the sense of beauty of the part and make it easy to handle. It is often used for the outer surface processing of casing, hinge wrench and other parts

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riveting

After knurling, it can increase the sense of beauty of the part and make it easy to handle. It is often used for the outer surface processing of casing, hinge wrench and other parts

learn more

Cosmetic Finishes

Surface finishes can have either a functional or aesthetic intent. Finishes that cater to both aspects are classified as cosmetic finishes and are frequently employed for enhancing the appearance of different parts. The fabrication of these parts demands additional measures to minimize defects such as tool-induced marks and scratches.

Functional

There is no necessary to have aesthetic look.Machining veins will be seen

  • Smooth machining
  • Passivation
  • TYPE III andozied
  • Glossing
  • Brushing
  • Black oxide
  • Mechanical Polishing
  • Etching
  • Degreasing
  • Electroplating
  • Electrophoresis deposition

Matte

slogan:Removes surface streaks and defects, make surface matt and rough

  • Blasting
  • Acid pickling
  • Passivation
  • Parkerising

Functional

There is no necessary to have aesthetic look.Machining veins will be seen

  • Chemical or electrochemical polishing
  • Blasting+Anodizing
  • Glossing+Brushing
  • Glossing+Polish
  • Powder coating

Wide Array of Materials We Offer

Call on RapidDirect’s staff to recommend the right materials from our rich selection of metal and plastic materials with different colors, infill, and hardness. Every material we utilize comes from reputable suppliers and is thoroughly inspected to ensure they can be matched to various manufacturing styles, from plastic injection molding to sheet metal fabrication.

Competitive Prices

You are guaranteed 30% lower costs and competitive prices to help you settle your material and start your project.

Reliable supply chain

Apart from self-owned factory, we have thousands of suppliers to maintain a stable supply of materials.

Superior Quality

Each of our material bears certified material certification to guarantee excellent quality for your parts.

Professional Support

Creative engineers and technicians are happy to help and recommend the suitable material for you.

Gallery of Surface Finishing Parts Made by LML

The metal part can serve as functional or aesthetic purpose,and the way of usage will decide on the type of surface finish.

Defining an A and a B side

We can generate instant machining quotes for 50+ metals and plastics.

Surface finishing often leaves aesthetic defects on yourparts, such as hang marks for anodizing. Defining an Aand a B-side in your design will ensure that the most important areas of your part remain free of defects

In this image you can see how you can define an A-side and a B-side in your technical drawina:

A side: Indicates the most aesthetically importantsurface, typically the visible side of your product.

B side: Indicates the side that is not aesthetically important, typically the side hidden from visibility after assembly

For the primary surface (A-side) of your part, we guaranteedefect-free production. In contrast, secondary surfaces (B-side)may be machined with hanging marks and other minor defects. Bside surfaces, like the rest of your part, will be free of scratches.stains and blemishes.

Manufacturing Vetted Network of Our Services

We look forward to delivering high-quality products and professional services to meet your expectations and requirements.

Consistency requirements

Each part must be visually consistent across the same batch.meaning:

  • Same grit must be used across parts for sanding orbrushing
  • Brush marks must be in the same direction*
  • Color must be consistent to the same pantone when parts are placed next to each other
  • Gloss units must be consistent across the batch

* Manual brushing marks will be as unidirectional aspossible. Please note that for rounded geometries, brushingmarks may not be entirely unidirectional.*

Visual inspection conditions

The surface quality of every part must meet the followingconditions:

  • Distance: 50cm +10cm (19,7 in + 3,9 in) with a 10/10 vision(or corrected)
  • Incidence angle: Approximately 45 in all directions
  • Lighting conditions: 500-1000 Lux, color 3300-5300 Kelvin(neutral white)

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The metal part can serve as functional or aesthetic purpose,and the way of usage will decide on the type of surface finish.

FAQs

LML takes the stress out of manufacturing by guaranteeing the quality and consistency of every part. Each order is dimensionally and visually inspected by our in-house quality control team to make sure it meets the LML Standard. If you’re not satisfied with your order, we’ll remake your parts as fast as possible, free of charge, or refund you - whichever you prefer.
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