HPL Plywood

HPL sheets ,HPL (High Pressure Laminate) is a decorative high-pressure laminate. HPL is made of layers of Kraft paper impregnated with phenol resins (the core) and decorative melamine impregnated paper (the surface layer), manufactured under high pressure and temperature.

HPL plywood ,from the name ,you can know that the top face and bottom back is HPL sheets laminated .So,how to grade and inspect the HPL Plywood ?The platform are overlaid with HPL (High Pressure Laminate) on one or both sides. On the reverse side balance paper can be applied, prior to make OVERLAY of the plywood to ensure that they are clean and free of surface defects ,Surface defects present on the substrate ,can not accept the telegraphing .

THE HPL PLWOOD IN DIFFERENT COUNTRIES OR MARKETS,THEY HAVE DIFFERENT NAMES ,TO THE USA,they call it   Cabinet Liner panels,, White Cabinet Liner that is “Cold Press Laminated” to either One or Two sides of the panel. These panels are an excellent option for cabinets that would normally require a melamine box, but cannot be made with either IPB or MDF Cores. Other colors are available by special order.

  • 1/4 WHITE CABINET LINER 1 SIDES RAW BACK
  • 1/2 WHITE CABINET LINER 2 SIDES
  • 3/4 WHITE CABINET LINER 1 SIDE RAW BACK
  • 3/4 WHITE CABINET LINER 2 SIDES

Not just the HPL surface ,also the edges of the HPL sheets need to be trimmed well .

Thickness tolerance is also one issue to be considered when inspecting the HPL sheets or the HPL plywood .Expression to indicate a range of thickness values within which a thickness variation is considered proper to the industrial production process and, consequently, acceptable.

Let’s start from the HPL sheets ,HPL (High Pressure Laminate) is a decorative high-pressure laminate. HPL is made of layers of Kraft paper impregnated with phenol resins (the core) and decorative melamine impregnated paper (the surface layer), manufactured under high pressure and temperature.HPL is the direct descendant of the original plastic laminate. It is considered to be one of the most durable decorative surface materials and is available with special performance properties including chemical, fire and wear resistance. Special grades of HPL can be postformed around curved edges by application of heat and restraint. HPL is produced by saturating multiple layers of kraft paper with phenolic resin. A layer of printed décor paper is placed on top of the kraft paper before pressing. The resulting sandwich is fused together under heat and pressure (more than 1,000 PSI).

When making the substrate of the HPL plywood,check with the customers the glue color ,to Israel ,they like red color .To USA and Canada ,they like light color a little yellow .Especially to Israel ,make sure the Glue is real E1 ,or the plywood will be rejected .

The HPL Plywood has two major quality core construction :

1.THe platform are not lamianted the whole piece poplar or birch or hardwood face veneer under the HPL sheets .

2.The Platform are laminated with one piece of poplar face veneer or hardwood face veneer or birch to make sure the HPL sheets have a good surface to be applied with .

The costs of these two core construction decide the final quality and final prices .

HPL overlay is glued with D2, D3 or D4 class glues,4000rmb to 5500rmb per ton always ,very expensive .Before laminating the HPL sheets,the plywood platform should be smoothly sanded ,to make sure the HPL and substrate are bonded glued completely without bubbles .How much glue per layer also need a little thick glue to make sure the HPL sheets will be not failure delaminated .

HPL  Plywood,means ,the inside core is veneer core ,the top fc and bottom bk is HPL sheets .

Furniture industry: kitchen and laboratory furniture components and worktops; furniture for shops.
Transport industry and construction: finishing works of walls and ceiling, surfaces where high wear resistance and appearance are required.

Chinese HPL Plywood is a plywood platform or substrate  plywood overlaid on both sides with an attractive, hard wearing HPL (high pressure laminate). The HPL provides the plywood with a durable, decorative surface and is now available in a selection of modern colours. The strength and stability of the Chinese Poplar and Eucalyptus , combined with the hard wearing HPL surface, allows for a wide range of furniture and joinery applications. Clashing of sheet edges is not required as the fine veneer lay-up provides the  HPL with an attractive edge detail which can be clear finished to emphasise the superior multi-ply edge detail.

THE HPL SHEETS thickness used for plywood are normally 0.5mm,0.6mm,0.8mm present .IF special items,the thickness can be changed .

Somebody called the HPL also fireproof plywood ,but we tested ,most of the HPL plywood is not fireproof if no special production process and no chemical addictives added .So ,don’t missunderstand this .The HPL sheets are widely used for the HPL plywood are from Henan yongwei industry,Changzhou and Linyi local HPL mills,the quality have much difference .

The famous HPL is formica ,famous and good quality .

The HPL has many different colors and finishes ,HPL: Smooth and rough/textured ,also called gloss and matt finish .
HPL color:white, maple grain or other fancy wood grain etcmm,

Thickness are normally 4.8mm, 5mm, 5.2mm, 5.5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 15mm, 16mm, 17mm, 18mm, 20mm, 21mm, 22mm, 25mm, 28mm, 30mm

Most of the HPL plywood shipped to Canada ,Phelipine ,Israel and USA

The following This article was provided by Kent Pitcher of Custom-Pak Adhesives, Inc.

We will describe the gluing of high density plastic laminates (i.e. Formica, Debar, Nevamar, Micarta, Pionite and the like) to plywood, lumber core, and particleboard core ,MDF panels. Such laminations are widely used for table, chest, sink, cabinet and counter tops. 

One of the major problems encountered in bonding high pressure plastic is telegraphing of defects from the underlayment or substrate. This telegraphing is generally accentuated by the high gloss surface on the plastic.

Elimination of telegraphing generally requires either better surface preparations, as with particleboard, or crossbanding with at least one ply of a defect free, close-grained species of veneer, such as poplar or basswood, between the core and plastic. This veneer may be bonded to the core in a separate operation, the assembly sanded and then the plastic face and backing sheets applied.

Sometimes bonding plastic directly to lumber core, particleboard core or rough cross banding will highlight any voids, knots or glue lines present. When bonding the plastic and the veneer to the underlayment in one operation, the pressure required must be carefully controlled for it can cause any open defects, glue lines and/or rough grain in the veneer to telegraph.

Foreign matter in the glue line will also show through the plastic. Straining the glue mix to remove any sawdust, dirt or dried glue before putting it into the spreader is recommended. Also, brushing the plastic with a soft-bristle cleaning brush to remove sanding dust or clinging wood and dirt particles is suggested.

Sanding
The gluing surface of the plastic should be sanded for best adhesion. The manufacture of high density plastic laminates utilizes extremely high pressures and temperatures. This results in two hard glazed surfaces. The non-decorative surface which is bonded requires some sanding to roughen the surface to achieve maximum adhesion. A fine finished sanding should be used, since coarse or rough sanding has a tendency to telegraph.

Warping
To prevent warping, a less expensive backing sheet should be used to balance the construction. The backing sheet must have the same rate of expansion to heat and the same moisture barrier properties as the decorative face. Most manufacturers of decorative face plastic provide a matching backing sheet.

Pressing
Pressures required to bond plastic are relatively low, usually 25 to 50 p.s.i., although occasionally 100 p.s.i. will be reached. As pressure is increased, the tendency to telegraph also increases. Pressing can be done by any of the conventional methods; hot press, cold press, or contact depending on the adhesive system employed.

Hot Pressing
Several hot press urea-formaldehyde resin formulations are used to bond plastic. Because of the expansion differentials between the plastic and most substrate materials, platen temperatures above 190F are not recommended. In addition, higher temperatures may cause blistering of the plastic face sheet due to moisture present.

Improved wetting of the dense plastic surface by urea resins can be accomplished by addition of Craze-Proofing Liquids. Where a craze-resistant bond is required, an internally plasticized urea resin can be used. Phenol-resorcinol resins are rarely used for hot pressing, but if employed in this manner, they will provide a waterproof bond.

Cold Pressing
In cold pressing plastic laminates, urea-formaldehyde, polyvinyl acetate emulsions and urea-polyvinyl acetate mixed adhesives, are regularly employed. Phenol-resorcinol adhesives are utilized, but to a lesser degree. For craze-resistance and improved wetting, either a craze-proofing liquid is added to a conventional urea resin or an internally plasticized resin may be used.

It is often desirable to utilize an adhesive with a high wet tack or quick set. In such instances, a polyvinyl acetate emulsion adhesive is recommended. Where both the tack and setting speed of a polyvinyl and the water resistance and economics of a urea are desired, a blend mixture of the two adhesives can be used.

Casein adhesives can be used where plant temperatures are below 65F, but utilization is somewhat limited because high moisture introduced into the glue line that may cause telegraphing through the plastic surface.

Contact Bonding
Both solvent and water based contact adhesives are utilized to bond plastic laminates. The general directions for using these systems is to apply the adhesive to surfaces to be glued by applicator, roller, spreading or spraying, and allowing to dry. The surfaces are then mated and pressure applied sufficient to bring the surfaces into intimate contact with each other. This is accomplished with nip rolls, and air or hydraulic presses. Contact cements are extensively used to bond plastic edge banding.

Note: Best results are obtained when the gluing surface of the laminate has been sanded. Both adhesive and stock should have a temperature of at least 70F when bonding high pressure laminates.

Trouble Shooting
The following is a description of the troubles often encountered in high pressure plastic laminating and some possible causes:

Telegraphing – Improper underlayment or too low a grade. Laminating pressure too high. Unsanded or rough sanded underlayment or plastic. Foreign matter in glue line or on face of plastic. Laminating directly to core stock (lumber or particle- board) without x-banding.

Loose corners or edges – Core material not sanded evenly. Non-uniform pressure due to poorly aligned platens or nip rolls. Plastic not thoroughly sanded. Too low a laminating pressure Improper loading in press.

Blisters under plastic face – Core material not sanded evenly. Plastic not thoroughly sanded. Air entrapped (contact adhesive). Too low a laminating pressure. Excessive assembly time. Insufficient glue spread.

Warping – Improper backing sheet. Core material not balanced. Too high a gluing temperature (hot pressing).

Adhesive on plastic faces – Too thin an adhesive mix. Too heavy an adhesive spread. Improper stacking in press.

Slippage – Improper stacking in press. Too heavy an adhesive spread. Too thin an adhesive mix. Improper and uneven pressure.Carelessness – spots on decorative surface must be washed off with water while soft. Wax decorative surface to prevent sticking.

High Pressure Laminated Panels (HPL)

Decorative surfaces are not only beautiful but they are also purposeful.  High Pressure Laminates (HPL) are one of the most durable decorative surfaces.  When its time to give your design a new dimension, High Pressure Laminates offer the flexibility and character you need.  some of the premier companies in North America and Europe such as Greelam, Wilsonart, Formica, Pionite, Nevamar, Arborite and Decotone to offer what you want.

THE FEATURES & BENEFITS

HPL- High Pressure Laminate – is composed of a resin impregnated kraft paper, a decorative paper and a clear melamine overlay.  These sheets are bonded at high pressures and temperatures.   The sheets are bonded to substrates such as MDF (medium density fiberboard) or particle board.

Uses:  Horizontal and vertical applications.

There are multiple grades of HPL that include chemical resistant, wear resistant for high demand applications, and even fire rated laminates.  You can also add some shine to your next project.  shiny silver, mirror, brushed, and patterned metallic laminates. These products are available as either a solid or perforated product. Metallic laminates are often found in the cosmetics or related areas of mass merchandise, discount and drug stores. It can be applied to hardboard, HDF & MDF.   The metallic laminates can be applied to ¾” MDF to produce unique slatwall for store perimeters, vendor shops and garage and workshop conversions.

TECHNICAL SPECIFICATIONS
Thicknesses:
1/4″ – 1-1/4″
Std. Sheet Sizes:
4′ & 5′ widths
8′ & 10′ lengths (cut to size available)

LAMINATE GRADES
Standard
Post Forming
Vertical
Liner
Backer

SUBSTRATES USED
Pine Particleboard
Fir Particleboard
MDF
Plywood with MDF Face & Back
Plywood with MDF Face & Back: FSC® Certified & NAUF Resin

MARKETS FOUND
Retail Industry
Hospitality
Kitchen & Bath
RTA Furniture
Product Display