For general remote controller enclosure, there will be top cabinet, bottom cabinet,
battery door, lens, and rubber keypad. Additional parts are light guide,
inlay, keycap etc.
Thermoplastic is the common polymer used for product enclosure and injection
machine is production machine used for thermoplastic fabrication.
Cabinets and Battery door
a) Plastic Material
? ABS is the popular used thermoplastic material which gives comparative mechanical
strength, cosmetic appearance and coloration.
? HIPS is a bit cheaper but only be benefit from large volume production as
weight-to-strength ratio is less than ABS.
? If high gloss surface is required, different material such as MABS can be considered,
but it needs production technique with adequate injection machine
and injection conditions.
? If thinner material thickness is required to provide good strength, PC+ABS
material can be considered but it almost triples the price of general ABS.
? The ABS brands come from Korea (such as LG) or Taiwan (such as Chi Mei)
can provide comparative price and reliable quality when compare to common
brand (Such as BASF, DOW, Toray). There is also China local brand material
available when cost is major factor than cosmetic and quality.
? There is also engineering plastic that applied on specific design requirement,
such as the SABIC NORYL N1250 used on BW7530 battery module.
b) Regrind material
? For cost saving and environmental consideration, plastic material can be mixed
with regrind material from 10-20% depends on the cosmetic and mechanical
requirement.
? Regrind material includes ground flash, runners, sprue gating and non-contaminated
rejected parts during molding process.
? After reground, only black plastic color available.
Tooling Cavity arrangement Consideration
? For achieving lower unit price, large volume output with unified part characteristic,
one single part will be made into multiple cavities in a tooling, such
as the lens or battery door.
? For small volume product, different parts will be put in same tooling provided
they are using same material, such as top cabinet put together with bottom
cabinet in a tooling. It is also called family tooling.
Two-shot molding
? Two-shot molding means use 2 different materials to form one individual part
during plastic fabrication, or sometimes fabricate 2 different colors of same
material.
? It gives 2 difference material properties on one part that serve difference purpose,
such as a rubberized shell over an ABS body for shock absorption.
? It saves post process for binding two parts together and gives better strength.
Decoration
a) Surface finish
? Normal product comes with textured surface. If no preference, the normal
EDM (Electrical Discharge Machining) texture will be used.
? If texture etching surface is required, the texture standard can be referred to
“Yick Sang” which is popular used in HK. US general refer to MoldTech standard
but less popular in HK.
? When product surface required high gloss finish, following areas need considered
together to give best result.
? Material selection, general is MABS and PC.
? Part design to avoid molding defect.
? tooling material and design
? Injection machine with assist setup to avoid human interaction.
? Injection process precise control in temperature and pressure.
? it need adding protective sheet to cover the gloss surface in packing to avoid
chance of scratch and fingerprint.
b) Engraving
? Plastic engraving on product surface, such as logo, is normal in emboss condition.
? Deboss engraving is possible but more complicate in tooling fabrication process
and higher tooling cost. Also deboss engraving has limitation in size and
shape.
c) Spray Paint
? Casing can be sprayed with required color or for decoration or protective purpose.
? It can apply on plastic or metal parts.
? Sometimes use spraying to cover the imperfection of plastic casing.
? Usually spraying carryout in a ventilation room with water curtain booth facility.
c) Electroplating
? It can apply on plastic or metal parts.
? Plastic part can be electroplated to have Chrome or Nickel outlook and other
colors are also possible.
? It can provide protection from erosion on the plastic part.
? The plastic part should be designed in a simple geometry for application of
electro-plating.
e) Printing
? If the print area is relative flat, silk screen printing is used as operation is simple.
? If the print area is uneven, pad printing (tampo printing) will give better printing
result.
? If the printed legends need higher durability, a clear printing can be applied
over the original legends.
f) Hot stamping
? Hot stamping is making the desired graphic pattern on an embossed die and
then hot press the pattern through a color foil onto the product.
g) Heat transfer printing
transfer printing is making the desired graphic pattern on a PET film and
then use heat to transfer the graphic onto the product.
? The graphic can be complicate and multi-colored, but it needs very large MOQ
for the graphic film foil.
IR Lens
? Plastic PC material is used for IR transmission due to its clarity, gloss and
strength properties.
? The lens is always colored in dark purple or dark red transparent for IR ray
transmit through while blocking the other visible light as possible.
? Surface finish is glossy for minimize the IR ray diffraction
? Mixing with regrind plastic material is not possible as it will affect the transparent.
? It needs a separate tooling as the material PC is generally different from casing
material ABS. If cost is a concern, IR lens can be omitted and just put the
IR diode extruded from the casing.
Decorative Lens and Light guide
? PMMA (Acrylic) can be used for decorative lens purpose as lower mechanical
strength is accepted.
? It is commonly fabricated in clear transparent while decoration printing on
the reverse side.
? It is cheaper than PC.
? It is also used for LED light guide due to its clarity property.
? Mixing with regrind material is not possible as it will affect the transparent.
Plastic cosmetic defect
? Weld line around keyholes can be minimized by using higher injection temperature
but it induces higher unit price.
? Color contamination on light color part need compromise with customer on
acceptable standard.
? Gloss surface minor defect can be easily observed and need compromise with
customer on acceptable standard.
? Color or texture variation on user visible surface may need injection condition
control to minimize.
? Flash on the parting line will need post process for touch up after injection
process.
Plastic Sheet Inlay
? Inlay is used for cosmetic purpose or cover non-use key holes on casing for
different remote version.
? PC sheet is most popular use inlay material, and supply in different thickness
at gloss or texture surface.
? Inlay can also be used for lens purpose for protection on LCD display.
? Color printing is on the inlay reverse side to avoid abrasion but also possible
print at front side if required.
? Metal die tooling is required.
? Metallic printing effect is possible but at higher cost
? Generally use Japan Nitto brand adhesive tape while use 3M in some application
but at a bit higher unit cost.
Metal plate or Cover
? Aluminum sheet is commonly used as it gives metal shinny look and cold hand
touch.
? Aluminum Cover is formed with metal tooling for geometrical shape and then
adhered onto a plastic frame for better support.
? It needs undergo anodizing process for corrosion and wear resistance, which
provides better adhesion for cosmetic painting and apply glues than using
bare metal plate.
? Sand blasting process can add small dotted texture on plate surface, or add
hairline finish by brushing process.
? Cosmetic limit sample is required since the cosmetic may vary slightly from
lot to lot.
? Other than Al plate use as decorative purpose, Al material can be used as
remote enclosure by extrusion process.
Counter weight
? When it requires a balanced feel product or a solid-weighted product when
user holding in hand, then need design the product center of gravity close
to its center of the geometrical shape by adding metal weight at calculated
position.
? The weight is commonly formed by stacking layers of metal plates of same
thickness.