Who We Are?

Cojak International Incorporated is a window company established in November 2010. It is primarily engaged in the manufacturing of made-to-order uPVC Windows and Doors. We have been expanding our reach by tapping developers, architects and contractors both locally and globally.

We aim to provide customer with high quality products at very competitive prices. We have employed a team of experienced window technicians who pride themselves in bringing you top quality made-to-order uPVC Windows and Doors.

What Is UPVC?

Unplasticized polyvinyl chloride: very strong plastic used for making window frames and doors.

Unplasticized polyvinyl chloride, more correctly but unusually poly(vinyl chloride), commonly abbreviated PVC, is the third-most widely produced synthetic plastic polymer, after polyethylene and polypropylene.

PVC comes in two basic forms: rigid (sometimes abbreviated as RPVC) and flexible. The rigid form of PVC is used in construction for pipe and in profile applications such as doors and windows. It is also used for bottles, other non-food packaging, and cards (such as bank or membership cards). It can be made softer and more flexible by the addition of plasticizers, the most widely used being phthalates. In this form, it is also used in plumbing, electrical cable insulation, imitation leather, signage, inflatable products, and many applications where it replaces rubber.


Thermal Insulation

The PVC material itself is a poor conductor of heat or cold making it more thermal efficienct resulting to lower electricity bills compared to aluminum windows. This is why we call it as “energy saving eco-friendly products.

Water Tightness

Even smallest amount of water can cause damage to your home. has a high standardized fusion welding and specifically designed stair type structure helps prevent water breakage throughout joint parts.

Wind Load

There is close correlation between wind load and safety because most of the claims and defects root in breakage using of low quality window. Therefore, when choosing window manufacturer, it is strongly recommended to verify the supplier’s technical capability, history and reputation to secure the safety.

Smooth Opening & Closing

PVC material has a unique feature of being self-lubricating. Alignment and coefficiency friction between roller and tracks are the key factor to maintain smoothness.


Sound Insulation

Majority of sound insulation property depends upon glass thickness & type; however the importance of materials cannot be passed over. Thus drawing capability and fabrication quality in fusion welding parts should be well considered.

Fire Resistant

uPVC windows and doors which are based on naturally fire retardant polymer have excellent fire performance qualities since it is self-extinguishing when a flame is removed.

Air Tightness

uPVC windows have a superior air tightness property owing to a low coefficient of permeability comparing to other materials.


Our PVC windows and door are safe and non-toxic.

Anti-Chemical Property (Anti-weather ability)

Special additives were added to prevent aging or discoloration so that the product may be safely used for a longer period of time. In particular, Cojak’s products are highly resistant to ocean wind containing salinity or ozone, coal gas, acid or alkali.