DYD’s sandwich panel uses polyurethane foam as core, which is known as the best insulating material to date. The panels are produced through a discontinuous production line. Using a hydraulic multiple bed press, a variety of pre-cut facings (various metal skin, glass wood, plasterboard, etc.) are placed into a jig where the polyurethane components are injected. This method offers flexibility allowing different edge detail and locking mechanisms to be easily incorporated in the design.

        The following is a summary of the difference between polyurethane and polystyrene. It is important to note that Polyurethane was invented to improve the shortcomings of the Expanded polystyrene (EPS).

FEATURE	POLYSTYRENE (EPS)	POLYURETHANE
R-Value	3.5-4.0 per inch	7.0 – 8.0 per inch Twice insulating power!
Fire Resistance	Not a thermal set plastic. Soften and reshapes on heat	Thermal Set Plastic UL rating Class 1
Moisture Resistance	2.0~5.0 permeance rating	1.2~2.5 permeance rating Low moist permeability
Chemical Resistance	Highly reactive to petroleum based chemical product	Resistant to most chemicals
Density	One density of 1 lb.	Can be manufactured in a variety of densities.
Waste	High scrap rate that is non recyclable	Minimum waste on site, recyclable foam on factory.
Manufacture Technique	Uses glue to adhere the foam and the skin	Polyurethane is already the adhesive.

        The table below shows the difference of thickness of walling material needed to reach the insulating capacity of the polyurethane foam.

DESCRIPTION	PANEL THICKNESS MILLIMETER					THERMAL CONDUCTIVITY
Polyurethane	50	75	100	125	150	K = 0.0209 W/m-K
Expanded polystyrene (extruded) plain	86.36	129.6	172.7	215.9	259.1	K = 0.0361 W/m-K
Expanded polystyrene Molded beads	96.65	145.0	193.3	241.6	290.0	K = 0.0404 W/m-K
Expanded polystyrene (extruded), R-12 expanded	65.55	98.33	131.1	163.8	196.7	K = 0.0274 W/m-K
Polystyrene (smooth) Expanded cell	69.38	104.1	138.8	173.4	208.1	K = 0.0290 W/m-K
Expanded Cut Cell polystyrene	83.73	125.6	167.5	209.3	251.2	K = 0.0350 W/m-K
Cork Board	102.9	154.3	205.7	257.2	308.6	K = 0.0430 W/m-K
Concrete Slab	4139	6208	8278	10346	12416	K = 1.7300 W/m-K
Concrete Plaster	172.3	258.4	344.5	430.6	516.8	K = 0.0720 W/m-K