Sanding equipment offers smooth solutions.

Sanding equipment rises to the challenge of sanding thinner veneers and more intricate profiles while maintaining productivity.

While appearing at first glance to be a simple operation, feed-through sanding is, in fact, one of the most difficult operations to perfect quick changeover. An improperly setup automatic sander can create costly rejects in a hurry. Yet, once properly set up and calibrated, the high-tolerance capabilities of today's sanding equipment can yield substantial productivity gains and high-quality finishes.

"Sanding equipment is probably the most difficult piece of machinery to operate in the shop," said Fulvio Sussig, marketing director with SGA. "A good, skilled operator can make the difference between rejects and acceptable products. An operator needs to know proper machine setup as well as other outside factors such as material characteristics, thickness variation, temperature and humidity -- especially when sanding thin veneers."

What to look for

Three factors are important when considering a new sander purchase. They include the level of manufacturing or quantity of products sanded, type of finish the manufacturer desires and amount of money budgeted for the purchase.

"Concerning a sander purchase, customers first need to determine if they are a high level manufacturer or a small shop," said Sussig. "Take a look at the number of panels you want to sand in a shift, what type of product you are producing and its finish type, and the money you can afford to spend are all critical areas to explore. Finally, pay attention to such factors as how much material you are planning to remove with the machine, and how accurate and easy it is to recalibrate and setup the machine."

"The sander and pad choice should be based on long term payback, not the next job the shop needs to run," added Doug Armitage, technical sales manager with Force Machinery Co.

Segmented vs. non-segmented sanding pads

Most traditional widebelt sanders offer one of two recognized types of pads which apply pressure to the abrasive belt as it contacts the part to be sanded. Sanding machinery customers should know the difference between machines that offer a segmented or non-segmented sanding pad.

Most segmented pad widebelt machines feature either pneumatic or spring-loaded individual pads which control sanding pressure on a piece. These pads use sensor rollers to sense the shape of the part as it is fed into the machine. The corresponding pad, or segment, is activated with an automatic timer to compensate for speed variation. The segment does not sense shape. The job of the pad is to push the abrasive belt to the surface of the material because the stroke of a well-built segmented pad has a uniform pressure. In turn, the result is a uniform sanded surface.

"One example where segmented pad sanding works well is with chair seat sanding," said Angelo Gangone, marketing manager with SCMI. "Floating pads with a long stroke allow you to through-feed chair seats at up to 300 seats an hour. Segmented platens allow the platens to fill in the areas that require sanding by following the contour of the chair seat."

Non-segmented pads also have their advantages. In addition to often being more affordable than segmented pad sanders, sanders with a non-segmented, or a one-piece, pad offer sanding operations a quality finish if certain guidelines are followed.

"A 24-inch by 24-inch panel can be sanded without any defects if the panel is not more than 0.2 to 0.3mm out of tolerance and does not more than two layers of surface tape, each of which are not more than 0.3mm out of tolerance," Armitage said. "Also, if the tape is not pressed below half the thickness of the veneer and the panel has a 0.5mm tolerance total. Veneer tape is a problem for non-segmented machines to sand because while it is thin, it is still a lot harder than most wood veneers."

Armitage added that rarely in a shop's production are these panel tolerances available on a consistent basis.

White wood finish sanding

Obtaining a smooth finish can be directly affected by the quality of finish sanding equipment. Removal of errant wood fibers and dust particles is necessary before staining and sealing. One alternative is through white wood finish sanding, often referred to as Redder sanding.

The process works with strips of abrasives attached to a sanding head which rotates in a circular motion above the panel or profile, helping it conform to all exposed angles. Imagine numerous horizontally-mounted spinning mop heads rotating in a circular motion and you have the general concept of Redder sanding.

Fladder sanding uses centrifugal force to remove loose fibers and dust particles pressed into the wood from machining or other traditional sanding operations.

"The removal of loose fibers helps a staining operation because the open pores allow stains to better penetrate and give a more uniform finish," said Ben Barama, general manager with Fladder Systems. "Traditional sanding operations sand by pressure and press wood fibers and dust particles into the wood. Fladder sanding uses centrifugal force to shave off excess fibers.

The abrasive strips do not make contact with the feed belt because they are adjusted with 1/8 to 1/16 in. clearance above the feed belt, according to Barama.

Training is crucial

Being able to operate a sander and knowing how to properly identify and correct problems is crucial to producing a smooth finish suitable for staining and seating.

"Operator experience is the most important element in having a productive sanding operation with few defects," said Sussig. "They must know much about material removal and must be proficient in machine set up and calibration. In addition, operators must pay attention to correct sanding grit, correct feed speed and correct bed and roller pressure."

Shop floor experience is important to operators, but an intensive training program from the manufacturer is critical in helping operators troubleshoot problems; which may arise.

"No matter what flexibility you have within a machine, it will never work without properly training the operator," said Scott Grissom, technical sales and service member, Costa & Grissom Machinery Co. Inc. "Classroom training, as well as hands-on experience, are important. The most important thing to sanding any material is first knowing what to look for and second, knowing how to make the machine perform."

Available equipment

The following is a review of some feed-through sanding equipment available to the woodworking industry. For more information, circle the corresponding numbers on the Reader's Service Card. For a more comprehensive overview of sanding equipment market, consult the 1994 Red Book Annual Buyer's Specification Guide.

Widebelt sanders

The Tagliabue TAG Series widebelt sanding machines from Servatek feature modular construction design with up to five sanding heads. These models can be used for finish sanding of veneer, high gloss polyester, UV varnish and solid wood materials. The TAG Series feature a patented electronic 40-section pad for part thickness variations, microprocessor controls for ease of setup and changeover linked with electric caliper for board thickness variations.

The Buetfering Q Series VEGA electronic abrasive machining centers from Force Machinery Co. feature a new patented system of CPS electronic segmented pad controls. Computer controlled, the Vega Series is available with a cross belt and with a choice of two or three heads.

Boere/Danckaert widebelt sanders from Danckaert Woodworking Machinery Co. feature Lamellas material support sections located directly under the downward material pressure elements and sanding elements. This results in the capability to automatically compensate for variations in thickness from one piece of material to another, or within the material itself.

The Model Pro-3000 37-in. widebelt sander from Woodmaster Tools Inc. features single- and three-phase motors with infrared tracking, motor load meter, metal disc brake and variable feed speed.

Costa & Grissom, offers the Model 80 line of sanders that reportedly eliminate hand sanding. The sander can also be equipped with a new computer system known as the Sanding Manager, an IBM-compatible industrial grade PC which uses MS DOS and Windows 3.1 The screen displays the machine's configuration and all machine functions are mouse-activated. The P.C. also features automatic trouble-shooting, electrical and electronic schematics and a bar code reader system for faster machine setup.

The Halsty widebelt sander features a 37-in. by 75-in. abrasive belt, 8 1/2-in. working height, combination head with nine-position platen and four-speed conveyer belt.

Precision Manufacturing offers a widebelt sander with features that include: a quick change sanding belt with no loose parts, electronic photo eye tracking system with emergency shutdown if the belt misses the tracks, and an easy-to-read material thickness scale. Other features include a variable speed conveyor, main control panel that is accessible from the front or the rear of the machine, 37-in. by 75-in. abrasive belt size and a combination head with adjustable platen.

SCMI's Sandya WIN widebelt sander is designed so that even the smallest shop can install it. It is a compact, low-energy consuming sander, the company says. Its sanding unit combines a grooved-steel roller and pad to perform both stock removal and finish sanding. It has a working width of 630mm, maximum machining thickness of 3mm to 160mm, sawdust extraction and other features.

Available from SGA (Stefani Group America) Inc., Stemac's Star series of calibrating and sanding machines have height-adjustable working tables and can be equipped with one or more sanding belts. The machines can be fitted with several configurations for full calibrating and veneer/lacquer requirements.

The Haney Corp. has added a new single-head drum sander to its line of Pro-Sand sanders. The sanders are available in 38-in. and 50-in. widths and feature an angled head. The angled head simulates the abrasive belt tracking of a widebelt for longer abrasive life and good finish, according to the company.

The Heesemann FGA 8 finishing sander available from Stiles Machinery Inc., is a widebelt sanding system that features the patented CSD electronic pressure beam control system. The system reads variations in panel thickness and automatically adjusts individual pressure elements to achieve the best possible finish.

The Series 500 knife planer/sander from Abrasive Engineering & Mfg. features a unique spiral cutterhead in the first station. The unit can be used for furniture, cabinetry and millwork production requiring dimensioning and sanding of edge-glued lumber, banded particle-board and corestock materials.

The full digitized automatic sander set-up from Cemco uses existing program logic control-based positioning controls in conjunction with Magnostrictive signaling tO guarantee accuracies to 0.001 in., according to the company. Designed for use with medium-duty and production series widebelt sanders, benefits of the system include immunity to dust, operation off machine power and no friction device which means the device will never wear out, the company says.

Tekna Machinery offers the DMC Topsand Series of sanders. It features two cross belts and 48 sectional pads. Other features include the optional Histogram, which graphically keeps track of the number of belts used and the belt life. It also performs diagnostics and provides full-control of feed speeds, belt pressures, belt speeds, and belt timing.

Linden Machines offers the new generation of Sandingmaster widebelt sanders. The Lindotronic features an electronic segmented platen and a compact, segmented crossbelt. Other available models include 53-in. and 42-in. twin head and triple head models.

The Model 352-2MPIC milling planer from Timesavers Inc. is equipped with a unique multi-cutterhead feature in the first station for heavy stock removal, followed by a sanding head in the second station for final grit finish and tolerance. The A.D.D. (automatic dimensioning device) is used to properly adjust the opening or thickness setting of the unit on the outfeed of the machine.

Profile/edge sanders

The series HN throughfeed profile sander from U.S. Concepts is designed for sanding and buffing of various mouldings with combination sanding and buffing wheels, and sanding belts up to eight units. Sanding units can be equipped with a variable speed controller and automatic indexing for wheel position in relation to its wear.

The LASM LS-INR profile sander from Atlantic Machinery Co. has one variable speed station with 45-degree tilt for sanding or shaping applications and one sanding belt station with 135-degree tilt. It also has automatic feed with variable speed and reverse feed features. The machine is available in several versions with up to four stations.

The P.A.O. Macc automatic profile sander from Tech Mark Inc. is equipped with a unique material transport system which controls the alignment of the moulding, special 100mm wide drive belts to ensure uniform speeds, solid bed plate under material for positive pressure for the sanding head and easy-to-adjust guides.

The Model 320 Shape and Sand System from Unique Machine & Tool Co. shapes cabinet and furniture parts and then sands the parts with its feed-through system. Variable speed controls and multiple stations allow for finish sanding to be completed to exact requirements. In addition, the machine is capable of sanding arches and shapes.

The DMP-1W profile sander from Derda Inc. can be used in various configurations and can sand straight mouldings, curved frames or shaped doors. The abrasive wheel holder assembly can be freely moved backwards and forwards, as well as up and down. The machine is reported to be able to sand any type of wood, particleboard or veneered surface, whether varnished or not.

The Reckmann Favorit-M profile sander allows for sanding of production runs, according to E & R Supply. Features include two sanding heads and dust extraction system. Sanding material only needs changing after 500 to 800 meters, the company says.

Designed to eliminate hand sanding, Turbosand, available from the Voorwood Co., has a die-cast profile shape that reportedly is accurate when sanding to within 0.001 in. Spaced slots in the head create a turbine effect that blow the abrasive clean and prevent loading and burning. Grits are available from 80 to 200 and aluminum oxide and custom profiles can be produced.

Delle Vedove USA offers profile and edge sanding machines that can sand a wide variety of pieces and can be equipped with various belts, abrasive wheels and special wheels for handling intricate shapes.

The Model 225 profile contour sander from Crouch Machinery features: a 2-hp Baldor DC drive motor, variable speed adjustment, 4-in. vertical wheel adjustment, fabricated steel base, maple table and 1-in. spindle diameter.

The LTC 4 profile sander from Makor USA Inc. features 40-200 fpm feed speeds, and can sand veneer, plywood, particleboard and other materials. It features four sanding heads.

The Heesemann UKP Series universal edge and profile sander from European Woodworking Machinery Co. offers from 1 to 10 sanding heads, 20 and 40 fpm feed speeds, and features optional motorized adjustment of the three axes of sanding units and CNC controls.

Sanders from Whirlwind Inc. feature Baldor motors, precision ground platens and tables, and platens which oscillate with the belt for longer belt life.

Other sanders

Fladder Systems says the Fladder 300/Gyro sanding system offers the following benefits: uniform stain penetration for smoother sealer or primer coat application and minimum grain raising. The machine is available in 52-in. and 39-in. widths.

A line of 16-, 22-, commercial duty 25-and 37-in. drum sanders from Performax Products Inc. offer ultra-wide sanding and abrasive planing. The company says it will guarantee to precisely dimension stock to within 0.001-in. uniform thickness.

The Model 14 oscillating spindle sander from Powermatic is reported to provide a smooth, scratch-free finish. Features include: a 1/2-hp, 115-volt motor, removable safety key switch, cast-iron tilting table, integral dust collection shroud aria brass and steel gears.

Progress Machine Co. offers the P-203 pneumatic drum and brush sander with spindle lock, wrench and brass nuts. It is designed for curved or fiat work which involves a radius on corners, such as chairs, top rails and more. It is ideal, according to the company, when used with pneumatic drum or brush head, for profile sanding and flat work.

RBIndustries offers a 38-in. drum sander for small- and medium-shops. The single drum sander reportedly gives users control over sanding projects.