What is Vacuum Molding?

A company that develops itself into a global one based on continued research and introduction of new technology

After heating thermoplastic material close to the softening point, contact it to the mold and depressurize at the lower part of the mold at the same time. Then, the air in the space between the sheet and the mold is let out of there, and a vacuum is created, so the one that has the same shape of the mold is made. (The industrialization began in Japan in 1955)

Comparison between the advantage and disadvantage of vacuum molding and injection molding
Category Vacuum molding Injection molding


  • Low cost for molding
  • Satisfactory productivity
  • Thin molding is possible
  • Suitable for small quantity batch production(mobile and etc.)
  • Easy to modify designs and the cost for it is low
  • Various types of applicable materials
  • Precise management of measurement is possible and the thicknesses of product are equal
  • Molding as the form of resin
  • Suitable for mass production of a few selected items(automobile and etc.)


  • Management of precise measurement and thickness are not easy(angled parts at the bottom are vulnerable)
  • Pre-manufacturing of sheet is necessary
  • Scrap generated(about 20%)
  • High cost for molding
  • Thin molding is not easy

ESD Tray

Electrostatic discharge + Optimized for the prevention of infection by alien substances(dust and etc.)

Electrostatic discharge +This is the tray optimized for the prevention of infection by alien substances(dust and etc.), and SUNGGOK's ESD tray is categorized into the following three according to the surface resistivity (Ω) in accordance with the US Military Standard.

Category Surface resistivity(Ω/cm) Electrification Application field

Anti-static tray

1010 ≤ Rs ≤ 1011 Ω/Sq

Attenuate immediately after charging with electricity


Static Dissipative tray

106 ≤Rs ≤ 109 Ω/Sq

Barely charge with electricity

Anti-static / Prevent power storage

Conductive tray

Rs ≤ 10z5 Ω/Sq

No charge with electricity at all

Electromagnetic shield

Main products
  • Tray for transporting small-sized module(mobile, tablet and etc.)
  • Tray for transporting medium and large-sized module(monitor, TV and etc.)
  • Tray for mobile cell process
  • Mobile component tray
  • Automobile battery tray
Comparison of raw material property according to ESD function realization method
Method Realization method Surface resistance Advantage Disadvantage

Surfactant surface coating

Spray surfactant on the sheet or the tray and dry it

1010 ~ 1011

  • Low cost
  • Simple process
  • ESD effect is inadequate
  • Migration generated
  • Durablity ↓
  • Low recyclability

Carbon Blending

Add the blended electrical conductive carbon compound to the raw material, produce sheet and mold it using tray

103 ~ 109

  • Low cost
  • Successful ESD effect
  • ESD durability ↑
  • Black dust generated
  • Limit in embodying colors

IDP added

Blend BlendIDP(Conducting polymer) and add it to the raw material, produce sheet and mold it using tray

105 ~ 109

  • Equal ESD effect
  • ESD durablity ↑
  • The highest cost
  • Dust can be generated

IDP surface coating

Coat the surface of the raw material sheet with transparent IDP(conductive high polymer) using the roll coating method

105 ~ 109

  • No migration
  • No dust
  • Relatively high cost
  • ESD durabiliy ↓

Slide core

Due to the automation of client company lines, tray rotation additive manufacturing is changing to top-set one. To solve the existing countergradient stopper problem that this top-set way has and improve the functions, a patent for a groundbreaking mold–mounted movement module is filed and it is being applied to trays in various forms.
(Patent application No. : 10-2017-0035525)

Rotation type

Slide type

Size of slide core product
Type Name of model Nominal measurement Note


Core A-1


Core A-2

Core A-3


Core B-1


Core B-2


Core C-1


Core C-2


Core D-1


Core D-2

Core D-3


Core E-1

Core E-2

Introduction of process

Tighter management in each process is performed to provide products of the best quality and ultimate operation capability from material warehousing to shipment.

Step 1 : Prepare materials

Import inspection after storing raw materials → Import inspection completed → Load in the storage

Instrumentation device for import inspection

Digital color-difference meter

Surface resistivity meter(Probe Type)

Surface resistivity meter


XRF measuring instrument

Step 2 : Vacuum molding process

Material loading

Insert sheet




Mold contact vacuum

Cooling Unloading

Refrigerate mold and blow down products


Trimming products

Step 3 : Cleanse and shipping

1. Deburring

2. Laser marking

3. Air cleanse

4. Final inspection

5. Completed product packing

6. Shipment